text: /*
   * Copyright (c) 2014 Apple Inc. All rights reserved.
   *
   * @APPLE_LICENSE_HEADER_START@
   *
   * This file contains Original Code and/or Modifications of Original Code
   * as defined in and that are subject to the Apple Public Source License
   * Version 2.0 (the 'License'). You may not use this file except in
   * compliance with the License. Please obtain a copy of the License at
   * http://www.opensource.apple.com/apsl/ and read it before using this
   * file.
   *
   * The Original Code and all software distributed under the License are
   * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
   * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
   * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
   * Please see the License for the specific language governing rights and
   * limitations under the License.
   *
   * @APPLE_LICENSE_HEADER_END@
   */
  
  /*	CFRunLoop.c
   Copyright (c) 1998-2014, Apple Inc. All rights reserved.
   Responsibility: Tony Parker
   */
  
  #include <CoreFoundation/CFRunLoop.h>
  #include <CoreFoundation/CFSet.h>
  #include <CoreFoundation/CFBag.h>
  #include <CoreFoundation/CFNumber.h>
  #include <CoreFoundation/CFPreferences.h>
  #include "CFInternal.h"
  #include <math.h>
  #include <stdio.h>
  #include <limits.h>
  #include <pthread.h>
  #include <dispatch/dispatch.h>
  
  
  #if DEPLOYMENT_TARGET_WINDOWS
  #include <typeinfo.h>
  #endif
  #include <checkint.h>
  
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
  #include <sys/param.h>
  #include <dispatch/private.h>
  #include <CoreFoundation/CFUserNotification.h>
  #include <mach/mach.h>
  #include <mach/clock_types.h>
  #include <mach/clock.h>
  #include <unistd.h>
  #include <dlfcn.h>
  #include <pthread/private.h>
  #include <os/voucher_private.h>
  extern mach_port_t _dispatch_get_main_queue_port_4CF(void);
  extern void _dispatch_main_queue_callback_4CF(mach_msg_header_t *msg);
  #elif DEPLOYMENT_TARGET_WINDOWS
  #include <process.h>
  DISPATCH_EXPORT HANDLE _dispatch_get_main_queue_handle_4CF(void);
  DISPATCH_EXPORT void _dispatch_main_queue_callback_4CF(void);
  
  #define MACH_PORT_NULL 0
  #define mach_port_name_t HANDLE
  #define mach_port_t HANDLE
  #define _dispatch_get_main_queue_port_4CF _dispatch_get_main_queue_handle_4CF
  #define _dispatch_main_queue_callback_4CF(x) _dispatch_main_queue_callback_4CF()
  
  #define AbsoluteTime LARGE_INTEGER 
  
  #endif
  
  #if DEPLOYMENT_TARGET_WINDOWS || DEPLOYMENT_TARGET_IPHONESIMULATOR
  CF_EXPORT pthread_t _CF_pthread_main_thread_np(void);
  #define pthread_main_thread_np() _CF_pthread_main_thread_np()
  #endif
  
  #include <Block.h>
  #include <Block_private.h>
  
  #if DEPLOYMENT_TARGET_MACOSX
  #define USE_DISPATCH_SOURCE_FOR_TIMERS 1
  #define USE_MK_TIMER_TOO 1
  #else
  #define USE_DISPATCH_SOURCE_FOR_TIMERS 0
  #define USE_MK_TIMER_TOO 1
  #endif
  
  
  static int _LogCFRunLoop = 0;
  static void _runLoopTimerWithBlockContext(CFRunLoopTimerRef timer, void *opaqueBlock);
  
  // for conservative arithmetic safety, such that (TIMER_DATE_LIMIT + TIMER_INTERVAL_LIMIT + kCFAbsoluteTimeIntervalSince1970) * 10^9 < 2^63
  #define TIMER_DATE_LIMIT	4039289856.0
  #define TIMER_INTERVAL_LIMIT	504911232.0
  
  #define HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY 0
  
  #define CRASH(string, errcode) do { char msg[256]; snprintf(msg, 256, string, errcode); CRSetCrashLogMessage(msg); HALT; } while (0)
  
  #if DEPLOYMENT_TARGET_WINDOWS
  
  static pthread_t kNilPthreadT = { nil, nil };
  #define pthreadPointer(a) a.p
  typedef	int kern_return_t;
  #define KERN_SUCCESS 0
  
  #else
  
  static pthread_t kNilPthreadT = (pthread_t)0;
  #define pthreadPointer(a) a
  #define lockCount(a) a
  #endif
  
  #pragma mark -
  
  #define CF_RUN_LOOP_PROBES 0
  
  #if CF_RUN_LOOP_PROBES
  #include "CFRunLoopProbes.h"
  #else
  #define	CFRUNLOOP_NEXT_TIMER_ARMED(arg0) do { } while (0)
  #define	CFRUNLOOP_NEXT_TIMER_ARMED_ENABLED() (0)
  #define	CFRUNLOOP_POLL() do { } while (0)
  #define	CFRUNLOOP_POLL_ENABLED() (0)
  #define	CFRUNLOOP_SLEEP() do { } while (0)
  #define	CFRUNLOOP_SLEEP_ENABLED() (0)
  #define	CFRUNLOOP_SOURCE_FIRED(arg0, arg1, arg2) do { } while (0)
  #define	CFRUNLOOP_SOURCE_FIRED_ENABLED() (0)
  #define	CFRUNLOOP_TIMER_CREATED(arg0, arg1, arg2, arg3, arg4, arg5, arg6) do { } while (0)
  #define	CFRUNLOOP_TIMER_CREATED_ENABLED() (0)
  #define	CFRUNLOOP_TIMER_FIRED(arg0, arg1, arg2, arg3, arg4) do { } while (0)
  #define	CFRUNLOOP_TIMER_FIRED_ENABLED() (0)
  #define	CFRUNLOOP_TIMER_RESCHEDULED(arg0, arg1, arg2, arg3, arg4, arg5) do { } while (0)
  #define	CFRUNLOOP_TIMER_RESCHEDULED_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP(arg0) do { } while (0)
  #define	CFRUNLOOP_WAKEUP_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_DISPATCH() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_DISPATCH_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_NOTHING() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_NOTHING_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_SOURCE() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_SOURCE_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_TIMEOUT() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_TIMEOUT_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_TIMER() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_TIMER_ENABLED() (0)
  #define	CFRUNLOOP_WAKEUP_FOR_WAKEUP() do { } while (0)
  #define	CFRUNLOOP_WAKEUP_FOR_WAKEUP_ENABLED() (0)
  #endif
  
  // In order to reuse most of the code across Mach and Windows v1 RunLoopSources, we define a
  // simple abstraction layer spanning Mach ports and Windows HANDLES
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
  
  CF_PRIVATE uint32_t __CFGetProcessPortCount(void) {
      ipc_info_space_t info;
      ipc_info_name_array_t table = 0;
      mach_msg_type_number_t tableCount = 0;
      ipc_info_tree_name_array_t tree = 0;
      mach_msg_type_number_t treeCount = 0;
      
      kern_return_t ret = mach_port_space_info(mach_task_self(), &info, &table, &tableCount, &tree, &treeCount);
      if (ret != KERN_SUCCESS) {
          return (uint32_t)0;
      }
      if (table != NULL) {
          ret = vm_deallocate(mach_task_self(), (vm_address_t)table, tableCount * sizeof(*table));
      }
      if (tree != NULL) {
          ret = vm_deallocate(mach_task_self(), (vm_address_t)tree, treeCount * sizeof(*tree));
      }
      return (uint32_t)tableCount;
  }
  
  CF_PRIVATE CFArrayRef __CFStopAllThreads(void) {
      CFMutableArrayRef suspended_list = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, NULL);
      mach_port_t my_task = mach_task_self();
      mach_port_t my_thread = mach_thread_self();
      thread_act_array_t thr_list = 0;
      mach_msg_type_number_t thr_cnt = 0;
      
      // really, should loop doing the stopping until no more threads get added to the list N times in a row
      kern_return_t ret = task_threads(my_task, &thr_list, &thr_cnt);
      if (ret == KERN_SUCCESS) {
          for (CFIndex idx = 0; idx < thr_cnt; idx++) {
              thread_act_t thread = thr_list[idx];
              if (thread == my_thread) continue;
              if (CFArrayContainsValue(suspended_list, CFRangeMake(0, CFArrayGetCount(suspended_list)), (const void *)(uintptr_t)thread)) continue;
              ret = thread_suspend(thread);
              if (ret == KERN_SUCCESS) {
                  CFArrayAppendValue(suspended_list, (const void *)(uintptr_t)thread);
              } else {
                  mach_port_deallocate(my_task, thread);
              }
          }
          vm_deallocate(my_task, (vm_address_t)thr_list, sizeof(thread_t) * thr_cnt);
      }
      mach_port_deallocate(my_task, my_thread);
      return suspended_list;
  }
  
  CF_PRIVATE void __CFRestartAllThreads(CFArrayRef threads) {
      for (CFIndex idx = 0; idx < CFArrayGetCount(threads); idx++) {
          thread_act_t thread = (thread_act_t)(uintptr_t)CFArrayGetValueAtIndex(threads, idx);
          kern_return_t ret = thread_resume(thread);
          if (ret != KERN_SUCCESS) CRASH("*** Failure from thread_resume (%d) ***", ret);
          mach_port_deallocate(mach_task_self(), thread);
      }
  }
  
  static uint32_t __CF_last_warned_port_count = 0;
  
  static void foo() __attribute__((unused));
  static void foo() {
      uint32_t pcnt = __CFGetProcessPortCount();
      if (__CF_last_warned_port_count + 1000 < pcnt) {
          CFArrayRef threads = __CFStopAllThreads();
          
          
          // do stuff here
          CFOptionFlags responseFlags = 0;
          SInt32 result = CFUserNotificationDisplayAlert(0.0, kCFUserNotificationCautionAlertLevel, NULL, NULL, NULL, CFSTR("High Mach Port Usage"), CFSTR("This application is using a lot of Mach ports."), CFSTR("Default"), CFSTR("Altern"), CFSTR("Other b"), &responseFlags);
          if (0 != result) {
              CFLog(3, CFSTR("ERROR"));
          } else {
              switch (responseFlags) {
                  case kCFUserNotificationDefaultResponse: CFLog(3, CFSTR("DefaultR")); break;
                  case kCFUserNotificationAlternateResponse: CFLog(3, CFSTR("AltR")); break;
                  case kCFUserNotificationOtherResponse: CFLog(3, CFSTR("OtherR")); break;
                  case kCFUserNotificationCancelResponse: CFLog(3, CFSTR("CancelR")); break;
              }
          }
          
          
          __CFRestartAllThreads(threads);
          CFRelease(threads);
          __CF_last_warned_port_count = pcnt;
      }
  }
  
  
  typedef mach_port_t __CFPort;
  #define CFPORT_NULL MACH_PORT_NULL
  typedef mach_port_t __CFPortSet;
  
  static void __THE_SYSTEM_HAS_NO_PORTS_AVAILABLE__(kern_return_t ret) __attribute__((noinline));
  static void __THE_SYSTEM_HAS_NO_PORTS_AVAILABLE__(kern_return_t ret) { HALT; };
  
  static __CFPort __CFPortAllocate(void) {
      __CFPort result = CFPORT_NULL;
      kern_return_t ret = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_RECEIVE, &result);
      if (KERN_SUCCESS != ret) {
          char msg[256];
          snprintf(msg, 256, "*** The system has no mach ports available. You may be able to diagnose which application(s) are using ports by using 'top' or Activity Monitor. (%d) ***", ret);
          CRSetCrashLogMessage(msg);
          __THE_SYSTEM_HAS_NO_PORTS_AVAILABLE__(ret);
          return CFPORT_NULL;
      }
      
      ret = mach_port_insert_right(mach_task_self(), result, result, MACH_MSG_TYPE_MAKE_SEND);
      if (KERN_SUCCESS != ret) CRASH("*** Unable to set send right on mach port. (%d) ***", ret);
      
      
      mach_port_limits_t limits;
      limits.mpl_qlimit = 1;
      ret = mach_port_set_attributes(mach_task_self(), result, MACH_PORT_LIMITS_INFO, (mach_port_info_t)&limits, MACH_PORT_LIMITS_INFO_COUNT);
      if (KERN_SUCCESS != ret) CRASH("*** Unable to set attributes on mach port. (%d) ***", ret);
      
      return result;
  }
  
  CF_INLINE void __CFPortFree(__CFPort port) {
      mach_port_destroy(mach_task_self(), port);
  }
  
  static void __THE_SYSTEM_HAS_NO_PORT_SETS_AVAILABLE__(kern_return_t ret) __attribute__((noinline));
  static void __THE_SYSTEM_HAS_NO_PORT_SETS_AVAILABLE__(kern_return_t ret) { HALT; };
  
  CF_INLINE __CFPortSet __CFPortSetAllocate(void) {
      __CFPortSet result;
      kern_return_t ret = mach_port_allocate(mach_task_self(), MACH_PORT_RIGHT_PORT_SET, &result);
      if (KERN_SUCCESS != ret) { __THE_SYSTEM_HAS_NO_PORT_SETS_AVAILABLE__(ret); }
      return (KERN_SUCCESS == ret) ? result : CFPORT_NULL;
  }
  
  CF_INLINE kern_return_t __CFPortSetInsert(__CFPort port, __CFPortSet portSet) {
      if (MACH_PORT_NULL == port) {
          return -1;
      }
      return mach_port_insert_member(mach_task_self(), port, portSet);
  }
  
  CF_INLINE kern_return_t __CFPortSetRemove(__CFPort port, __CFPortSet portSet) {
      if (MACH_PORT_NULL == port) {
          return -1;
      }
      return mach_port_extract_member(mach_task_self(), port, portSet);
  }
  
  CF_INLINE void __CFPortSetFree(__CFPortSet portSet) {
      kern_return_t ret;
      mach_port_name_array_t array;
      mach_msg_type_number_t idx, number;
      
      ret = mach_port_get_set_status(mach_task_self(), portSet, &array, &number);
      if (KERN_SUCCESS == ret) {
          for (idx = 0; idx < number; idx++) {
              mach_port_extract_member(mach_task_self(), array[idx], portSet);
          }
          vm_deallocate(mach_task_self(), (vm_address_t)array, number * sizeof(mach_port_name_t));
      }
      mach_port_destroy(mach_task_self(), portSet);
  }
  
  #elif DEPLOYMENT_TARGET_WINDOWS
  
  typedef HANDLE __CFPort;
  #define CFPORT_NULL NULL
  
  // A simple dynamic array of HANDLEs, which grows to a high-water mark
  typedef struct ___CFPortSet {
      uint16_t	used;
      uint16_t	size;
      HANDLE	*handles;
      CFLock_t lock;		// insert and remove must be thread safe, like the Mach calls
  } *__CFPortSet;
  
  CF_INLINE __CFPort __CFPortAllocate(void) {
      return CreateEventA(NULL, true, false, NULL);
  }
  
  CF_INLINE void __CFPortFree(__CFPort port) {
      CloseHandle(port);
  }
  
  static __CFPortSet __CFPortSetAllocate(void) {
      __CFPortSet result = (__CFPortSet)CFAllocatorAllocate(kCFAllocatorSystemDefault, sizeof(struct ___CFPortSet), 0);
      result->used = 0;
      result->size = 4;
      result->handles = (HANDLE *)CFAllocatorAllocate(kCFAllocatorSystemDefault, result->size * sizeof(HANDLE), 0);
      CF_SPINLOCK_INIT_FOR_STRUCTS(result->lock);
      return result;
  }
  
  static void __CFPortSetFree(__CFPortSet portSet) {
      CFAllocatorDeallocate(kCFAllocatorSystemDefault, portSet->handles);
      CFAllocatorDeallocate(kCFAllocatorSystemDefault, portSet);
  }
  
  // Returns portBuf if ports fit in that space, else returns another ptr that must be freed
  static __CFPort *__CFPortSetGetPorts(__CFPortSet portSet, __CFPort *portBuf, uint32_t bufSize, uint32_t *portsUsed) {
      __CFLock(&(portSet->lock));
      __CFPort *result = portBuf;
      if (bufSize < portSet->used)
          result = (__CFPort *)CFAllocatorAllocate(kCFAllocatorSystemDefault, portSet->used * sizeof(HANDLE), 0);
      if (portSet->used > 1) {
          // rotate the ports to vaguely simulate round-robin behaviour
          uint16_t lastPort = portSet->used - 1;
          HANDLE swapHandle = portSet->handles[0];
          memmove(portSet->handles, &portSet->handles[1], lastPort * sizeof(HANDLE));
          portSet->handles[lastPort] = swapHandle;
      }
      memmove(result, portSet->handles, portSet->used * sizeof(HANDLE));
      *portsUsed = portSet->used;
      __CFUnlock(&(portSet->lock));
      return result;
  }
  
  static kern_return_t __CFPortSetInsert(__CFPort port, __CFPortSet portSet) {
      if (NULL == port) {
          return -1;
      }
      __CFLock(&(portSet->lock));
      if (portSet->used >= portSet->size) {
          portSet->size += 4;
          portSet->handles = (HANDLE *)CFAllocatorReallocate(kCFAllocatorSystemDefault, portSet->handles, portSet->size * sizeof(HANDLE), 0);
      }
      if (portSet->used >= MAXIMUM_WAIT_OBJECTS) {
          CFLog(kCFLogLevelWarning, CFSTR("*** More than MAXIMUM_WAIT_OBJECTS (%d) ports add to a port set.  The last ones will be ignored."), MAXIMUM_WAIT_OBJECTS);
      }
      portSet->handles[portSet->used++] = port;
      __CFUnlock(&(portSet->lock));
      return KERN_SUCCESS;
  }
  
  static kern_return_t __CFPortSetRemove(__CFPort port, __CFPortSet portSet) {
      int i, j;
      if (NULL == port) {
          return -1;
      }
      __CFLock(&(portSet->lock));
      for (i = 0; i < portSet->used; i++) {
          if (portSet->handles[i] == port) {
              for (j = i+1; j < portSet->used; j++) {
                  portSet->handles[j-1] = portSet->handles[j];
              }
              portSet->used--;
              __CFUnlock(&(portSet->lock));
              return true;
          }
      }
      __CFUnlock(&(portSet->lock));
      return KERN_SUCCESS;
  }
  
  #endif
  
  #if !defined(__MACTYPES__) && !defined(_OS_OSTYPES_H)
  #if defined(__BIG_ENDIAN__)
  typedef	struct UnsignedWide {
      UInt32		hi;
      UInt32		lo;
  } UnsignedWide;
  #elif defined(__LITTLE_ENDIAN__)
  typedef	struct UnsignedWide {
      UInt32		lo;
      UInt32		hi;
  } UnsignedWide;
  #endif
  typedef UnsignedWide		AbsoluteTime;
  #endif
  
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
  
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
  #endif
  #if USE_MK_TIMER_TOO
  extern mach_port_name_t mk_timer_create(void);
  extern kern_return_t mk_timer_destroy(mach_port_name_t name);
  extern kern_return_t mk_timer_arm(mach_port_name_t name, AbsoluteTime expire_time);
  extern kern_return_t mk_timer_cancel(mach_port_name_t name, AbsoluteTime *result_time);
  
  CF_INLINE AbsoluteTime __CFUInt64ToAbsoluteTime(uint64_t x) {
      AbsoluteTime a;
      a.hi = x >> 32;
      a.lo = x & (uint64_t)0xFFFFFFFF;
      return a;
  }
  #endif
  
  static uint32_t __CFSendTrivialMachMessage(mach_port_t port, uint32_t msg_id, CFOptionFlags options, uint32_t timeout) {
      kern_return_t result;
      mach_msg_header_t header;
      header.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_COPY_SEND, 0);
      header.msgh_size = sizeof(mach_msg_header_t);
      header.msgh_remote_port = port;
      header.msgh_local_port = MACH_PORT_NULL;
      header.msgh_id = msg_id;
      result = mach_msg(&header, MACH_SEND_MSG|options, header.msgh_size, 0, MACH_PORT_NULL, timeout, MACH_PORT_NULL);
      if (result == MACH_SEND_TIMED_OUT) mach_msg_destroy(&header);
      return result;
  }
  #elif DEPLOYMENT_TARGET_WINDOWS
  
  static HANDLE mk_timer_create(void) {
      return CreateWaitableTimer(NULL, FALSE, NULL);
  }
  
  static kern_return_t mk_timer_destroy(HANDLE name) {
      BOOL res = CloseHandle(name);
      if (!res) {
          DWORD err = GetLastError();
          CFLog(kCFLogLevelError, CFSTR("CFRunLoop: Unable to destroy timer: %d"), err);
      }
      return (int)res;
  }
  
  static kern_return_t mk_timer_arm(HANDLE name, LARGE_INTEGER expire_time) {
      BOOL res = SetWaitableTimer(name, &expire_time, 0, NULL, NULL, FALSE);
      if (!res) {
          DWORD err = GetLastError();
          CFLog(kCFLogLevelError, CFSTR("CFRunLoop: Unable to set timer: %d"), err);
      }
      return (int)res;
  }
  
  static kern_return_t mk_timer_cancel(HANDLE name, LARGE_INTEGER *result_time) {
      BOOL res = CancelWaitableTimer(name);
      if (!res) {
          DWORD err = GetLastError();
          CFLog(kCFLogLevelError, CFSTR("CFRunLoop: Unable to cancel timer: %d"), err);
      }
      return (int)res;
  }
  
  // The name of this function is a lie on Windows. The return value matches the argument of the fake mk_timer functions above. Note that the Windows timers expect to be given "system time". We have to do some calculations to get the right value, which is a FILETIME-like value.
  CF_INLINE LARGE_INTEGER __CFUInt64ToAbsoluteTime(uint64_t desiredFireTime) {
      LARGE_INTEGER result;
      // There is a race we know about here, (timer fire time calculated -> thread suspended -> timer armed == late timer fire), but we don't have a way to avoid it at this time, since the only way to specify an absolute value to the timer is to calculate the relative time first. Fixing that would probably require not using the TSR for timers on Windows.
      uint64_t now = mach_absolute_time();
      if (now > desiredFireTime) {
          result.QuadPart = 0;
      } else {
          uint64_t timeDiff = desiredFireTime - now;
          CFTimeInterval amountOfTimeToWait = __CFTSRToTimeInterval(timeDiff);
          // Result is in 100 ns (10**-7 sec) units to be consistent with a FILETIME.
          // CFTimeInterval is in seconds.
          result.QuadPart = -(amountOfTimeToWait * 10000000);
      }
      return result;
  }
  
  #endif
  
  #pragma mark -
  #pragma mark Modes
  
  /* unlock a run loop and modes before doing callouts/sleeping */
  /* never try to take the run loop lock with a mode locked */
  /* be very careful of common subexpression elimination and compacting code, particular across locks and unlocks! */
  /* run loop mode structures should never be deallocated, even if they become empty */
  
  static CFTypeID __kCFRunLoopModeTypeID = _kCFRuntimeNotATypeID;
  static CFTypeID __kCFRunLoopTypeID = _kCFRuntimeNotATypeID;
  static CFTypeID __kCFRunLoopSourceTypeID = _kCFRuntimeNotATypeID;
  static CFTypeID __kCFRunLoopObserverTypeID = _kCFRuntimeNotATypeID;
  static CFTypeID __kCFRunLoopTimerTypeID = _kCFRuntimeNotATypeID;
  
  typedef struct __CFRunLoopMode *CFRunLoopModeRef;
  
  struct __CFRunLoopMode {
      CFRuntimeBase _base;
      pthread_mutex_t _lock;	/* must have the run loop locked before locking this */
      CFStringRef _name;
      Boolean _stopped;
      char _padding[3];
      CFMutableSetRef _sources0;
      CFMutableSetRef _sources1;
      CFMutableArrayRef _observers;
      CFMutableArrayRef _timers;
      CFMutableDictionaryRef _portToV1SourceMap;
      __CFPortSet _portSet;
      CFIndex _observerMask;
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
      dispatch_source_t _timerSource;
      dispatch_queue_t _queue;
      Boolean _timerFired; // set to true by the source when a timer has fired
      Boolean _dispatchTimerArmed;
  #endif
  #if USE_MK_TIMER_TOO
      mach_port_t _timerPort;
      Boolean _mkTimerArmed;
  #endif
  #if DEPLOYMENT_TARGET_WINDOWS
      DWORD _msgQMask;
      void (*_msgPump)(void);
  #endif
      uint64_t _timerSoftDeadline; /* TSR */
      uint64_t _timerHardDeadline; /* TSR */
  };
  
  CF_INLINE void __CFRunLoopModeLock(CFRunLoopModeRef rlm) {
      pthread_mutex_lock(&(rlm->_lock));
      //CFLog(6, CFSTR("__CFRunLoopModeLock locked %p"), rlm);
  }
  
  CF_INLINE void __CFRunLoopModeUnlock(CFRunLoopModeRef rlm) {
      //CFLog(6, CFSTR("__CFRunLoopModeLock unlocking %p"), rlm);
      pthread_mutex_unlock(&(rlm->_lock));
  }
  
  static Boolean __CFRunLoopModeEqual(CFTypeRef cf1, CFTypeRef cf2) {
      CFRunLoopModeRef rlm1 = (CFRunLoopModeRef)cf1;
      CFRunLoopModeRef rlm2 = (CFRunLoopModeRef)cf2;
      return CFEqual(rlm1->_name, rlm2->_name);
  }
  
  static CFHashCode __CFRunLoopModeHash(CFTypeRef cf) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)cf;
      return CFHash(rlm->_name);
  }
  
  static CFStringRef __CFRunLoopModeCopyDescription(CFTypeRef cf) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)cf;
      CFMutableStringRef result;
      result = CFStringCreateMutable(kCFAllocatorSystemDefault, 0);
      CFStringAppendFormat(result, NULL, CFSTR("<CFRunLoopMode %p [%p]>{name = %@, "), rlm, CFGetAllocator(rlm), rlm->_name);
      CFStringAppendFormat(result, NULL, CFSTR("port set = 0x%x, "), rlm->_portSet);
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
      CFStringAppendFormat(result, NULL, CFSTR("queue = %p, "), rlm->_queue);
      CFStringAppendFormat(result, NULL, CFSTR("source = %p (%s), "), rlm->_timerSource, rlm->_timerFired ? "fired" : "not fired");
  #endif
  #if USE_MK_TIMER_TOO
      CFStringAppendFormat(result, NULL, CFSTR("timer port = 0x%x, "), rlm->_timerPort);
  #endif
  #if DEPLOYMENT_TARGET_WINDOWS
      CFStringAppendFormat(result, NULL, CFSTR("MSGQ mask = %p, "), rlm->_msgQMask);
  #endif
      CFStringAppendFormat(result, NULL, CFSTR("\n\tsources0 = %@,\n\tsources1 = %@,\n\tobservers = %@,\n\ttimers = %@,\n\tcurrently %0.09g (%lld) / soft deadline in: %0.09g sec (@ %lld) / hard deadline in: %0.09g sec (@ %lld)\n},\n"), rlm->_sources0, rlm->_sources1, rlm->_observers, rlm->_timers, CFAbsoluteTimeGetCurrent(), mach_absolute_time(), __CFTSRToTimeInterval(rlm->_timerSoftDeadline - mach_absolute_time()), rlm->_timerSoftDeadline, __CFTSRToTimeInterval(rlm->_timerHardDeadline - mach_absolute_time()), rlm->_timerHardDeadline);
      return result;
  }
  
  static void __CFRunLoopModeDeallocate(CFTypeRef cf) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)cf;
      if (NULL != rlm->_sources0) CFRelease(rlm->_sources0);
      if (NULL != rlm->_sources1) CFRelease(rlm->_sources1);
      if (NULL != rlm->_observers) CFRelease(rlm->_observers);
      if (NULL != rlm->_timers) CFRelease(rlm->_timers);
      if (NULL != rlm->_portToV1SourceMap) CFRelease(rlm->_portToV1SourceMap);
      CFRelease(rlm->_name);
      __CFPortSetFree(rlm->_portSet);
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
      if (rlm->_timerSource) {
          dispatch_source_cancel(rlm->_timerSource);
          dispatch_release(rlm->_timerSource);
      }
      if (rlm->_queue) {
          dispatch_release(rlm->_queue);
      }
  #endif
  #if USE_MK_TIMER_TOO
      if (MACH_PORT_NULL != rlm->_timerPort) mk_timer_destroy(rlm->_timerPort);
  #endif
      pthread_mutex_destroy(&rlm->_lock);
      memset((char *)cf + sizeof(CFRuntimeBase), 0x7C, sizeof(struct __CFRunLoopMode) - sizeof(CFRuntimeBase));
  }
  
  #pragma mark -
  #pragma mark Run Loops
  
  struct _block_item {
      struct _block_item *_next;
      CFTypeRef _mode;	// CFString or CFSet
      void (^_block)(void);
  };
  
  typedef struct _per_run_data {
      uint32_t a;
      uint32_t b;
      uint32_t stopped;
      uint32_t ignoreWakeUps;
  } _per_run_data;
  
  struct __CFRunLoop {
      CFRuntimeBase _base;
      pthread_mutex_t _lock;			/* locked for accessing mode list */
      __CFPort _wakeUpPort;			// used for CFRunLoopWakeUp
      Boolean _unused;
      volatile _per_run_data *_perRunData;              // reset for runs of the run loop
      pthread_t _pthread;
      uint32_t _winthread;
      CFMutableSetRef _commonModes;
      CFMutableSetRef _commonModeItems;
      CFRunLoopModeRef _currentMode;
      CFMutableSetRef _modes;
      struct _block_item *_blocks_head;
      struct _block_item *_blocks_tail;
      CFAbsoluteTime _runTime;
      CFAbsoluteTime _sleepTime;
      CFTypeRef _counterpart;
  };
  
  /* Bit 0 of the base reserved bits is used for stopped state */
  /* Bit 1 of the base reserved bits is used for sleeping state */
  /* Bit 2 of the base reserved bits is used for deallocating state */
  
  CF_INLINE volatile _per_run_data *__CFRunLoopPushPerRunData(CFRunLoopRef rl) {
      volatile _per_run_data *previous = rl->_perRunData;
      rl->_perRunData = (volatile _per_run_data *)CFAllocatorAllocate(kCFAllocatorSystemDefault, sizeof(_per_run_data), 0);
      rl->_perRunData->a = 0x4346524C;
      rl->_perRunData->b = 0x4346524C; // 'CFRL'
      rl->_perRunData->stopped = 0x00000000;
      rl->_perRunData->ignoreWakeUps = 0x00000000;
      return previous;
  }
  
  CF_INLINE void __CFRunLoopPopPerRunData(CFRunLoopRef rl, volatile _per_run_data *previous) {
      if (rl->_perRunData) CFAllocatorDeallocate(kCFAllocatorSystemDefault, (void *)rl->_perRunData);
      rl->_perRunData = previous;
  }
  
  CF_INLINE Boolean __CFRunLoopIsStopped(CFRunLoopRef rl) {
      return (rl->_perRunData->stopped) ? true : false;
  }
  
  CF_INLINE void __CFRunLoopSetStopped(CFRunLoopRef rl) {
      rl->_perRunData->stopped = 0x53544F50;	// 'STOP'
  }
  
  CF_INLINE void __CFRunLoopUnsetStopped(CFRunLoopRef rl) {
      rl->_perRunData->stopped = 0x0;
  }
  
  CF_INLINE Boolean __CFRunLoopIsIgnoringWakeUps(CFRunLoopRef rl) {
      return (rl->_perRunData->ignoreWakeUps) ? true : false;
  }
  
  CF_INLINE void __CFRunLoopSetIgnoreWakeUps(CFRunLoopRef rl) {
      rl->_perRunData->ignoreWakeUps = 0x57414B45; // 'WAKE'
  }
  
  CF_INLINE void __CFRunLoopUnsetIgnoreWakeUps(CFRunLoopRef rl) {
      rl->_perRunData->ignoreWakeUps = 0x0;
  }
  
  CF_INLINE Boolean __CFRunLoopIsSleeping(CFRunLoopRef rl) {
      return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)rl)->_cfinfo[CF_INFO_BITS], 1, 1);
  }
  
  CF_INLINE void __CFRunLoopSetSleeping(CFRunLoopRef rl) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rl)->_cfinfo[CF_INFO_BITS], 1, 1, 1);
  }
  
  CF_INLINE void __CFRunLoopUnsetSleeping(CFRunLoopRef rl) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rl)->_cfinfo[CF_INFO_BITS], 1, 1, 0);
  }
  
  CF_INLINE Boolean __CFRunLoopIsDeallocating(CFRunLoopRef rl) {
      return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)rl)->_cfinfo[CF_INFO_BITS], 2, 2);
  }
  
  CF_INLINE void __CFRunLoopSetDeallocating(CFRunLoopRef rl) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rl)->_cfinfo[CF_INFO_BITS], 2, 2, 1);
  }
  
  CF_INLINE void __CFRunLoopLock(CFRunLoopRef rl) {
      pthread_mutex_lock(&(((CFRunLoopRef)rl)->_lock));
      //    CFLog(6, CFSTR("__CFRunLoopLock locked %p"), rl);
  }
  
  CF_INLINE void __CFRunLoopUnlock(CFRunLoopRef rl) {
      //    CFLog(6, CFSTR("__CFRunLoopLock unlocking %p"), rl);
      pthread_mutex_unlock(&(((CFRunLoopRef)rl)->_lock));
  }
  
  static CFStringRef __CFRunLoopCopyDescription(CFTypeRef cf) {
      CFRunLoopRef rl = (CFRunLoopRef)cf;
      CFMutableStringRef result;
      result = CFStringCreateMutable(kCFAllocatorSystemDefault, 0);
  #if DEPLOYMENT_TARGET_WINDOWS
      CFStringAppendFormat(result, NULL, CFSTR("<CFRunLoop %p [%p]>{wakeup port = 0x%x, stopped = %s, ignoreWakeUps = %s, \ncurrent mode = %@,\n"), cf, CFGetAllocator(cf), rl->_wakeUpPort, __CFRunLoopIsStopped(rl) ? "true" : "false", __CFRunLoopIsIgnoringWakeUps(rl) ? "true" : "false", rl->_currentMode ? rl->_currentMode->_name : CFSTR("(none)"));
  #else
      CFStringAppendFormat(result, NULL, CFSTR("<CFRunLoop %p [%p]>{wakeup port = 0x%x, stopped = %s, ignoreWakeUps = %s, \ncurrent mode = %@,\n"), cf, CFGetAllocator(cf), rl->_wakeUpPort, __CFRunLoopIsStopped(rl) ? "true" : "false", __CFRunLoopIsIgnoringWakeUps(rl) ? "true" : "false", rl->_currentMode ? rl->_currentMode->_name : CFSTR("(none)"));
  #endif
      CFStringAppendFormat(result, NULL, CFSTR("common modes = %@,\ncommon mode items = %@,\nmodes = %@}\n"), rl->_commonModes, rl->_commonModeItems, rl->_modes);
      return result;
  }
  
  CF_PRIVATE void __CFRunLoopDump() { // __private_extern__ to keep the compiler from discarding it
      CFShow(CFCopyDescription(CFRunLoopGetCurrent()));
  }
  
  CF_INLINE void __CFRunLoopLockInit(pthread_mutex_t *lock) {
      pthread_mutexattr_t mattr;
      pthread_mutexattr_init(&mattr);
      pthread_mutexattr_settype(&mattr, PTHREAD_MUTEX_RECURSIVE);
      int32_t mret = pthread_mutex_init(lock, &mattr);
      pthread_mutexattr_destroy(&mattr);
      if (0 != mret) {
      }
  }
  
  /* call with rl locked, returns mode locked */
  static CFRunLoopModeRef __CFRunLoopFindMode(CFRunLoopRef rl, CFStringRef modeName, Boolean create) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      struct __CFRunLoopMode srlm;
      memset(&srlm, 0, sizeof(srlm));
      _CFRuntimeSetInstanceTypeIDAndIsa(&srlm, __kCFRunLoopModeTypeID);
      srlm._name = modeName;
      rlm = (CFRunLoopModeRef)CFSetGetValue(rl->_modes, &srlm);
      if (NULL != rlm) {
          __CFRunLoopModeLock(rlm);
          return rlm;
      }
      if (!create) {
          return NULL;
      }
      rlm = (CFRunLoopModeRef)_CFRuntimeCreateInstance(kCFAllocatorSystemDefault, __kCFRunLoopModeTypeID, sizeof(struct __CFRunLoopMode) - sizeof(CFRuntimeBase), NULL);
      if (NULL == rlm) {
          return NULL;
      }
      __CFRunLoopLockInit(&rlm->_lock);
      rlm->_name = CFStringCreateCopy(kCFAllocatorSystemDefault, modeName);
      rlm->_stopped = false;
      rlm->_portToV1SourceMap = NULL;
      rlm->_sources0 = NULL;
      rlm->_sources1 = NULL;
      rlm->_observers = NULL;
      rlm->_timers = NULL;
      rlm->_observerMask = 0;
      rlm->_portSet = __CFPortSetAllocate();
      rlm->_timerSoftDeadline = UINT64_MAX;
      rlm->_timerHardDeadline = UINT64_MAX;
      
      kern_return_t ret = KERN_SUCCESS;
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
      rlm->_timerFired = false;
      rlm->_queue = _dispatch_runloop_root_queue_create_4CF("Run Loop Mode Queue", 0);
      mach_port_t queuePort = _dispatch_runloop_root_queue_get_port_4CF(rlm->_queue);
      if (queuePort == MACH_PORT_NULL) CRASH("*** Unable to create run loop mode queue port. (%d) ***", -1);
      rlm->_timerSource = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, rlm->_queue);
      
      __block Boolean *timerFiredPointer = &(rlm->_timerFired);
      dispatch_source_set_event_handler(rlm->_timerSource, ^{
          *timerFiredPointer = true;
      });
      
      // Set timer to far out there. The unique leeway makes this timer easy to spot in debug output.
      _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 321);
      dispatch_resume(rlm->_timerSource);
      
      ret = __CFPortSetInsert(queuePort, rlm->_portSet);
      if (KERN_SUCCESS != ret) CRASH("*** Unable to insert timer port into port set. (%d) ***", ret);
      
  #endif
  #if USE_MK_TIMER_TOO
      rlm->_timerPort = mk_timer_create();
      ret = __CFPortSetInsert(rlm->_timerPort, rlm->_portSet);
      if (KERN_SUCCESS != ret) CRASH("*** Unable to insert timer port into port set. (%d) ***", ret);
  #endif
      
      ret = __CFPortSetInsert(rl->_wakeUpPort, rlm->_portSet);
      if (KERN_SUCCESS != ret) CRASH("*** Unable to insert wake up port into port set. (%d) ***", ret);
      
  #if DEPLOYMENT_TARGET_WINDOWS
      rlm->_msgQMask = 0;
      rlm->_msgPump = NULL;
  #endif
      CFSetAddValue(rl->_modes, rlm);
      CFRelease(rlm);
      __CFRunLoopModeLock(rlm);	/* return mode locked */
      return rlm;
  }
  
  
  // expects rl and rlm locked
  static Boolean __CFRunLoopModeIsEmpty(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFRunLoopModeRef previousMode) {
      CHECK_FOR_FORK();
      if (NULL == rlm) return true;
  #if DEPLOYMENT_TARGET_WINDOWS
      if (0 != rlm->_msgQMask) return false;
  #endif
      Boolean libdispatchQSafe = pthread_main_np() && ((HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && NULL == previousMode) || (!HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && 0 == _CFGetTSD(__CFTSDKeyIsInGCDMainQ)));
      if (libdispatchQSafe && (CFRunLoopGetMain() == rl) && CFSetContainsValue(rl->_commonModes, rlm->_name)) return false; // represents the libdispatch main queue
      if (NULL != rlm->_sources0 && 0 < CFSetGetCount(rlm->_sources0)) return false;
      if (NULL != rlm->_sources1 && 0 < CFSetGetCount(rlm->_sources1)) return false;
      if (NULL != rlm->_timers && 0 < CFArrayGetCount(rlm->_timers)) return false;
      struct _block_item *item = rl->_blocks_head;
      while (item) {
          struct _block_item *curr = item;
          item = item->_next;
          Boolean doit = false;
          if (CFStringGetTypeID() == CFGetTypeID(curr->_mode)) {
              doit = CFEqual(curr->_mode, rlm->_name) || (CFEqual(curr->_mode, kCFRunLoopCommonModes) && CFSetContainsValue(rl->_commonModes, rlm->_name));
          } else {
              doit = CFSetContainsValue((CFSetRef)curr->_mode, rlm->_name) || (CFSetContainsValue((CFSetRef)curr->_mode, kCFRunLoopCommonModes) && CFSetContainsValue(rl->_commonModes, rlm->_name));
          }
          if (doit) return false;
      }
      return true;
  }
  
  #if DEPLOYMENT_TARGET_WINDOWS
  
  uint32_t _CFRunLoopGetWindowsMessageQueueMask(CFRunLoopRef rl, CFStringRef modeName) {
      if (modeName == kCFRunLoopCommonModes) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopGetWindowsMessageQueueMask: kCFRunLoopCommonModes unsupported"));
          HALT;
      }
      DWORD result = 0;
      __CFRunLoopLock(rl);
      CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
      if (rlm) {
          result = rlm->_msgQMask;
          __CFRunLoopModeUnlock(rlm);
      }
      __CFRunLoopUnlock(rl);
      return (uint32_t)result;
  }
  
  void _CFRunLoopSetWindowsMessageQueueMask(CFRunLoopRef rl, uint32_t mask, CFStringRef modeName) {
      if (modeName == kCFRunLoopCommonModes) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopSetWindowsMessageQueueMask: kCFRunLoopCommonModes unsupported"));
          HALT;
      }
      __CFRunLoopLock(rl);
      CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true);
      rlm->_msgQMask = (DWORD)mask;
      __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
  }
  
  uint32_t _CFRunLoopGetWindowsThreadID(CFRunLoopRef rl) {
      return rl->_winthread;
  }
  
  CFWindowsMessageQueueHandler _CFRunLoopGetWindowsMessageQueueHandler(CFRunLoopRef rl, CFStringRef modeName) {
      if (modeName == kCFRunLoopCommonModes) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopGetWindowsMessageQueueMask: kCFRunLoopCommonModes unsupported"));
          HALT;
      }
      if (rl != CFRunLoopGetCurrent()) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopGetWindowsMessageQueueHandler: run loop parameter must be the current run loop"));
          HALT;
      }
      void (*result)(void) = NULL;
      __CFRunLoopLock(rl);
      CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
      if (rlm) {
          result = rlm->_msgPump;
          __CFRunLoopModeUnlock(rlm);
      }
      __CFRunLoopUnlock(rl);
      return result;
  }
  
  void _CFRunLoopSetWindowsMessageQueueHandler(CFRunLoopRef rl, CFStringRef modeName, CFWindowsMessageQueueHandler func) {
      if (modeName == kCFRunLoopCommonModes) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopGetWindowsMessageQueueMask: kCFRunLoopCommonModes unsupported"));
          HALT;
      }
      if (rl != CFRunLoopGetCurrent()) {
          CFLog(kCFLogLevelError, CFSTR("_CFRunLoopGetWindowsMessageQueueHandler: run loop parameter must be the current run loop"));
          HALT;
      }
      __CFRunLoopLock(rl);
      CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true);
      rlm->_msgPump = func;
      __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
  }
  
  #endif
  
  #pragma mark -
  #pragma mark Sources
  
  /* Bit 3 in the base reserved bits is used for invalid state in run loop objects */
  
  CF_INLINE Boolean __CFIsValid(const void *cf) {
      return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)cf)->_cfinfo[CF_INFO_BITS], 3, 3);
  }
  
  CF_INLINE void __CFSetValid(void *cf) {
      __CFBitfieldSetValue(((CFRuntimeBase *)cf)->_cfinfo[CF_INFO_BITS], 3, 3, 1);
  }
  
  CF_INLINE void __CFUnsetValid(void *cf) {
      __CFBitfieldSetValue(((CFRuntimeBase *)cf)->_cfinfo[CF_INFO_BITS], 3, 3, 0);
  }
  
  struct __CFRunLoopSource {
      CFRuntimeBase _base;
      uint32_t _bits;
      pthread_mutex_t _lock;
      CFIndex _order;			/* immutable */
      CFMutableBagRef _runLoops;
      union {
          CFRunLoopSourceContext version0;	/* immutable, except invalidation */
          CFRunLoopSourceContext1 version1;	/* immutable, except invalidation */
      } _context;
  };
  
  /* Bit 1 of the base reserved bits is used for signalled state */
  
  CF_INLINE Boolean __CFRunLoopSourceIsSignaled(CFRunLoopSourceRef rls) {
      return (Boolean)__CFBitfieldGetValue(rls->_bits, 1, 1);
  }
  
  CF_INLINE void __CFRunLoopSourceSetSignaled(CFRunLoopSourceRef rls) {
      __CFBitfieldSetValue(rls->_bits, 1, 1, 1);
  }
  
  CF_INLINE void __CFRunLoopSourceUnsetSignaled(CFRunLoopSourceRef rls) {
      __CFBitfieldSetValue(rls->_bits, 1, 1, 0);
  }
  
  CF_INLINE void __CFRunLoopSourceLock(CFRunLoopSourceRef rls) {
      pthread_mutex_lock(&(rls->_lock));
      //    CFLog(6, CFSTR("__CFRunLoopSourceLock locked %p"), rls);
  }
  
  CF_INLINE void __CFRunLoopSourceUnlock(CFRunLoopSourceRef rls) {
      //    CFLog(6, CFSTR("__CFRunLoopSourceLock unlocking %p"), rls);
      pthread_mutex_unlock(&(rls->_lock));
  }
  
  #pragma mark Observers
  
  struct __CFRunLoopObserver {
      CFRuntimeBase _base;
      pthread_mutex_t _lock;
      CFRunLoopRef _runLoop;
      CFIndex _rlCount;
      CFOptionFlags _activities;		/* immutable */
      CFIndex _order;			/* immutable */
      CFRunLoopObserverCallBack _callout;	/* immutable */
      CFRunLoopObserverContext _context;	/* immutable, except invalidation */
  };
  
  /* Bit 0 of the base reserved bits is used for firing state */
  /* Bit 1 of the base reserved bits is used for repeats state */
  
  CF_INLINE Boolean __CFRunLoopObserverIsFiring(CFRunLoopObserverRef rlo) {
      return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 0, 0);
  }
  
  CF_INLINE void __CFRunLoopObserverSetFiring(CFRunLoopObserverRef rlo) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 0, 0, 1);
  }
  
  CF_INLINE void __CFRunLoopObserverUnsetFiring(CFRunLoopObserverRef rlo) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 0, 0, 0);
  }
  
  CF_INLINE Boolean __CFRunLoopObserverRepeats(CFRunLoopObserverRef rlo) {
      return (Boolean)__CFBitfieldGetValue(((const CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 1, 1);
  }
  
  CF_INLINE void __CFRunLoopObserverSetRepeats(CFRunLoopObserverRef rlo) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 1, 1, 1);
  }
  
  CF_INLINE void __CFRunLoopObserverUnsetRepeats(CFRunLoopObserverRef rlo) {
      __CFBitfieldSetValue(((CFRuntimeBase *)rlo)->_cfinfo[CF_INFO_BITS], 1, 1, 0);
  }
  
  CF_INLINE void __CFRunLoopObserverLock(CFRunLoopObserverRef rlo) {
      pthread_mutex_lock(&(rlo->_lock));
      //    CFLog(6, CFSTR("__CFRunLoopObserverLock locked %p"), rlo);
  }
  
  CF_INLINE void __CFRunLoopObserverUnlock(CFRunLoopObserverRef rlo) {
      //    CFLog(6, CFSTR("__CFRunLoopObserverLock unlocking %p"), rlo);
      pthread_mutex_unlock(&(rlo->_lock));
  }
  
  static void __CFRunLoopObserverSchedule(CFRunLoopObserverRef rlo, CFRunLoopRef rl, CFRunLoopModeRef rlm) {
      __CFRunLoopObserverLock(rlo);
      if (0 == rlo->_rlCount) {
          rlo->_runLoop = rl;
      }
      rlo->_rlCount++;
      __CFRunLoopObserverUnlock(rlo);
  }
  
  static void __CFRunLoopObserverCancel(CFRunLoopObserverRef rlo, CFRunLoopRef rl, CFRunLoopModeRef rlm) {
      __CFRunLoopObserverLock(rlo);
      rlo->_rlCount--;
      if (0 == rlo->_rlCount) {
          rlo->_runLoop = NULL;
      }
      __CFRunLoopObserverUnlock(rlo);
  }
  
  #pragma mark Timers
  
  struct __CFRunLoopTimer {
      CFRuntimeBase _base;
      uint16_t _bits;
      pthread_mutex_t _lock;
      CFRunLoopRef _runLoop;
      CFMutableSetRef _rlModes;
      CFAbsoluteTime _nextFireDate;
      CFTimeInterval _interval;		/* immutable */
      CFTimeInterval _tolerance;          /* mutable */
      uint64_t _fireTSR;			/* TSR units */
      CFIndex _order;			/* immutable */
      CFRunLoopTimerCallBack _callout;	/* immutable */
      CFRunLoopTimerContext _context;	/* immutable, except invalidation */
  };
  
  /* Bit 0 of the base reserved bits is used for firing state */
  /* Bit 1 of the base reserved bits is used for fired-during-callout state */
  /* Bit 2 of the base reserved bits is used for waking state */
  
  CF_INLINE Boolean __CFRunLoopTimerIsFiring(CFRunLoopTimerRef rlt) {
      return (Boolean)__CFBitfieldGetValue(rlt->_bits, 0, 0);
  }
  
  CF_INLINE void __CFRunLoopTimerSetFiring(CFRunLoopTimerRef rlt) {
      __CFBitfieldSetValue(rlt->_bits, 0, 0, 1);
  }
  
  CF_INLINE void __CFRunLoopTimerUnsetFiring(CFRunLoopTimerRef rlt) {
      __CFBitfieldSetValue(rlt->_bits, 0, 0, 0);
  }
  
  CF_INLINE Boolean __CFRunLoopTimerIsDeallocating(CFRunLoopTimerRef rlt) {
      return (Boolean)__CFBitfieldGetValue(rlt->_bits, 2, 2);
  }
  
  CF_INLINE void __CFRunLoopTimerSetDeallocating(CFRunLoopTimerRef rlt) {
      __CFBitfieldSetValue(rlt->_bits, 2, 2, 1);
  }
  
  CF_INLINE void __CFRunLoopTimerLock(CFRunLoopTimerRef rlt) {
      pthread_mutex_lock(&(rlt->_lock));
      //    CFLog(6, CFSTR("__CFRunLoopTimerLock locked %p"), rlt);
  }
  
  CF_INLINE void __CFRunLoopTimerUnlock(CFRunLoopTimerRef rlt) {
      //    CFLog(6, CFSTR("__CFRunLoopTimerLock unlocking %p"), rlt);
      pthread_mutex_unlock(&(rlt->_lock));
  }
  
  static CFLock_t __CFRLTFireTSRLock = CFLockInit;
  
  CF_INLINE void __CFRunLoopTimerFireTSRLock(void) {
      __CFLock(&__CFRLTFireTSRLock);
  }
  
  CF_INLINE void __CFRunLoopTimerFireTSRUnlock(void) {
      __CFUnlock(&__CFRLTFireTSRLock);
  }
  
  #pragma mark -
  
  /* CFRunLoop */
  
  CONST_STRING_DECL(kCFRunLoopDefaultMode, "kCFRunLoopDefaultMode")
  CONST_STRING_DECL(kCFRunLoopCommonModes, "kCFRunLoopCommonModes")
  
  // call with rl and rlm locked
  static CFRunLoopSourceRef __CFRunLoopModeFindSourceForMachPort(CFRunLoopRef rl, CFRunLoopModeRef rlm, __CFPort port) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      CFRunLoopSourceRef found = rlm->_portToV1SourceMap ? (CFRunLoopSourceRef)CFDictionaryGetValue(rlm->_portToV1SourceMap, (const void *)(uintptr_t)port) : NULL;
      return found;
  }
  
  // Remove backreferences the mode's sources have to the rl (context);
  // the primary purpose of rls->_runLoops is so that Invalidation can remove
  // the source from the run loops it is in, but during deallocation of a
  // run loop, we already know that the sources are going to be punted
  // from it, so invalidation of sources does not need to remove from a
  // deallocating run loop.
  static void __CFRunLoopCleanseSources(const void *value, void *context) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)context;
      CFIndex idx, cnt;
      const void **list, *buffer[256];
      if (NULL == rlm->_sources0 && NULL == rlm->_sources1) return;
      
      cnt = (rlm->_sources0 ? CFSetGetCount(rlm->_sources0) : 0) + (rlm->_sources1 ? CFSetGetCount(rlm->_sources1) : 0);
      list = (const void **)((cnt <= 256) ? buffer : CFAllocatorAllocate(kCFAllocatorSystemDefault, cnt * sizeof(void *), 0));
      if (rlm->_sources0) CFSetGetValues(rlm->_sources0, list);
      if (rlm->_sources1) CFSetGetValues(rlm->_sources1, list + (rlm->_sources0 ? CFSetGetCount(rlm->_sources0) : 0));
      for (idx = 0; idx < cnt; idx++) {
          CFRunLoopSourceRef rls = (CFRunLoopSourceRef)list[idx];
          __CFRunLoopSourceLock(rls);
          if (NULL != rls->_runLoops) {
              CFBagRemoveValue(rls->_runLoops, rl);
          }
          __CFRunLoopSourceUnlock(rls);
      }
      if (list != buffer) CFAllocatorDeallocate(kCFAllocatorSystemDefault, list);
  }
  
  static void __CFRunLoopDeallocateSources(const void *value, void *context) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)context;
      CFIndex idx, cnt;
      const void **list, *buffer[256];
      if (NULL == rlm->_sources0 && NULL == rlm->_sources1) return;
      
      cnt = (rlm->_sources0 ? CFSetGetCount(rlm->_sources0) : 0) + (rlm->_sources1 ? CFSetGetCount(rlm->_sources1) : 0);
      list = (const void **)((cnt <= 256) ? buffer : CFAllocatorAllocate(kCFAllocatorSystemDefault, cnt * sizeof(void *), 0));
      if (rlm->_sources0) CFSetGetValues(rlm->_sources0, list);
      if (rlm->_sources1) CFSetGetValues(rlm->_sources1, list + (rlm->_sources0 ? CFSetGetCount(rlm->_sources0) : 0));
      for (idx = 0; idx < cnt; idx++) {
          CFRetain(list[idx]);
      }
      if (rlm->_sources0) CFSetRemoveAllValues(rlm->_sources0);
      if (rlm->_sources1) CFSetRemoveAllValues(rlm->_sources1);
      for (idx = 0; idx < cnt; idx++) {
          CFRunLoopSourceRef rls = (CFRunLoopSourceRef)list[idx];
          __CFRunLoopSourceLock(rls);
          if (NULL != rls->_runLoops) {
              CFBagRemoveValue(rls->_runLoops, rl);
          }
          __CFRunLoopSourceUnlock(rls);
          if (0 == rls->_context.version0.version) {
              if (NULL != rls->_context.version0.cancel) {
                  rls->_context.version0.cancel(rls->_context.version0.info, rl, rlm->_name);	/* CALLOUT */
              }
          } else if (1 == rls->_context.version0.version) {
              __CFPort port = rls->_context.version1.getPort(rls->_context.version1.info);	/* CALLOUT */
              if (CFPORT_NULL != port) {
                  __CFPortSetRemove(port, rlm->_portSet);
              }
          }
          CFRelease(rls);
      }
      if (list != buffer) CFAllocatorDeallocate(kCFAllocatorSystemDefault, list);
  }
  
  static void __CFRunLoopDeallocateObservers(const void *value, void *context) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)context;
      CFIndex idx, cnt;
      const void **list, *buffer[256];
      if (NULL == rlm->_observers) return;
      cnt = CFArrayGetCount(rlm->_observers);
      list = (const void **)((cnt <= 256) ? buffer : CFAllocatorAllocate(kCFAllocatorSystemDefault, cnt * sizeof(void *), 0));
      CFArrayGetValues(rlm->_observers, CFRangeMake(0, cnt), list);
      for (idx = 0; idx < cnt; idx++) {
          CFRetain(list[idx]);
      }
      CFArrayRemoveAllValues(rlm->_observers);
      for (idx = 0; idx < cnt; idx++) {
          __CFRunLoopObserverCancel((CFRunLoopObserverRef)list[idx], rl, rlm);
          CFRelease(list[idx]);
      }
      if (list != buffer) CFAllocatorDeallocate(kCFAllocatorSystemDefault, list);
  }
  
  static void __CFRunLoopDeallocateTimers(const void *value, void *context) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)value;
      if (NULL == rlm->_timers) return;
      void (^deallocateTimers)(CFMutableArrayRef timers) = ^(CFMutableArrayRef timers) {
          CFIndex idx, cnt;
          const void **list, *buffer[256];
          cnt = CFArrayGetCount(timers);
          list = (const void **)((cnt <= 256) ? buffer : CFAllocatorAllocate(kCFAllocatorSystemDefault, cnt * sizeof(void *), 0));
          CFArrayGetValues(timers, CFRangeMake(0, CFArrayGetCount(timers)), list);
          for (idx = 0; idx < cnt; idx++) {
              CFRetain(list[idx]);
          }
          CFArrayRemoveAllValues(timers);
          for (idx = 0; idx < cnt; idx++) {
              CFRunLoopTimerRef rlt = (CFRunLoopTimerRef)list[idx];
              __CFRunLoopTimerLock(rlt);
              // if the run loop is deallocating, and since a timer can only be in one
              // run loop, we're going to be removing the timer from all modes, so be
              // a little heavy-handed and direct
              CFSetRemoveAllValues(rlt->_rlModes);
              rlt->_runLoop = NULL;
              __CFRunLoopTimerUnlock(rlt);
              CFRelease(list[idx]);
          }
          if (list != buffer) CFAllocatorDeallocate(kCFAllocatorSystemDefault, list);
      };
      
      if (rlm->_timers && CFArrayGetCount(rlm->_timers)) deallocateTimers(rlm->_timers);
  }
  
  CF_EXPORT CFRunLoopRef _CFRunLoopGet0b(pthread_t t);
  
  static void __CFRunLoopDeallocate(CFTypeRef cf) {
      CFRunLoopRef rl = (CFRunLoopRef)cf;
      
      if (_CFRunLoopGet0b(pthread_main_thread_np()) == cf) HALT;
      
      /* We try to keep the run loop in a valid state as long as possible,
       since sources may have non-retained references to the run loop.
       Another reason is that we don't want to lock the run loop for
       callback reasons, if we can get away without that.  We start by
       eliminating the sources, since they are the most likely to call
       back into the run loop during their "cancellation". Common mode
       items will be removed from the mode indirectly by the following
       three lines. */
      __CFRunLoopSetDeallocating(rl);
      if (NULL != rl->_modes) {
          CFSetApplyFunction(rl->_modes, (__CFRunLoopCleanseSources), rl); // remove references to rl
          CFSetApplyFunction(rl->_modes, (__CFRunLoopDeallocateSources), rl);
          CFSetApplyFunction(rl->_modes, (__CFRunLoopDeallocateObservers), rl);
          CFSetApplyFunction(rl->_modes, (__CFRunLoopDeallocateTimers), rl);
      }
      __CFRunLoopLock(rl);
      struct _block_item *item = rl->_blocks_head;
      while (item) {
          struct _block_item *curr = item;
          item = item->_next;
          CFRelease(curr->_mode);
          Block_release(curr->_block);
          free(curr);
      }
      if (NULL != rl->_commonModeItems) {
          CFRelease(rl->_commonModeItems);
      }
      if (NULL != rl->_commonModes) {
          CFRelease(rl->_commonModes);
      }
      if (NULL != rl->_modes) {
          CFRelease(rl->_modes);
      }
      __CFPortFree(rl->_wakeUpPort);
      rl->_wakeUpPort = CFPORT_NULL;
      __CFRunLoopPopPerRunData(rl, NULL);
      __CFRunLoopUnlock(rl);
      pthread_mutex_destroy(&rl->_lock);
      memset((char *)cf + sizeof(CFRuntimeBase), 0x8C, sizeof(struct __CFRunLoop) - sizeof(CFRuntimeBase));
  }
  
  static const CFRuntimeClass __CFRunLoopModeClass = {
      0,
      "CFRunLoopMode",
      NULL,      // init
      NULL,      // copy
      __CFRunLoopModeDeallocate,
      __CFRunLoopModeEqual,
      __CFRunLoopModeHash,
      NULL,      //
      __CFRunLoopModeCopyDescription
  };
  
  static const CFRuntimeClass __CFRunLoopClass = {
      0,
      "CFRunLoop",
      NULL,      // init
      NULL,      // copy
      __CFRunLoopDeallocate,
      NULL,
      NULL,
      NULL,      //
      __CFRunLoopCopyDescription
  };
  
  CF_PRIVATE void __CFFinalizeRunLoop(uintptr_t data);
  
  CFTypeID CFRunLoopGetTypeID(void) {
      static dispatch_once_t initOnce;
      dispatch_once(&initOnce, ^{ __kCFRunLoopTypeID = _CFRuntimeRegisterClass(&__CFRunLoopClass); __kCFRunLoopModeTypeID = _CFRuntimeRegisterClass(&__CFRunLoopModeClass); });
      return __kCFRunLoopTypeID;
  }
  
  static CFRunLoopRef __CFRunLoopCreate(pthread_t t) {
      CFRunLoopRef loop = NULL;
      CFRunLoopModeRef rlm;
      uint32_t size = sizeof(struct __CFRunLoop) - sizeof(CFRuntimeBase);
      loop = (CFRunLoopRef)_CFRuntimeCreateInstance(kCFAllocatorSystemDefault, CFRunLoopGetTypeID(), size, NULL);
      if (NULL == loop) {
          return NULL;
      }
      (void)__CFRunLoopPushPerRunData(loop);
      __CFRunLoopLockInit(&loop->_lock);
      loop->_wakeUpPort = __CFPortAllocate();
      if (CFPORT_NULL == loop->_wakeUpPort) HALT;
      __CFRunLoopSetIgnoreWakeUps(loop);
      loop->_commonModes = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
      CFSetAddValue(loop->_commonModes, kCFRunLoopDefaultMode);
      loop->_commonModeItems = NULL;
      loop->_currentMode = NULL;
      loop->_modes = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
      loop->_blocks_head = NULL;
      loop->_blocks_tail = NULL;
      loop->_counterpart = NULL;
      loop->_pthread = t;
  #if DEPLOYMENT_TARGET_WINDOWS
      loop->_winthread = GetCurrentThreadId();
  #else
      loop->_winthread = 0;
  #endif
      rlm = __CFRunLoopFindMode(loop, kCFRunLoopDefaultMode, true);
      if (NULL != rlm) __CFRunLoopModeUnlock(rlm);
      return loop;
  }
  
  static CFMutableDictionaryRef __CFRunLoops = NULL;
  static CFLock_t loopsLock = CFLockInit;
  
  // should only be called by Foundation
  // t==0 is a synonym for "main thread" that always works
  CF_EXPORT CFRunLoopRef _CFRunLoopGet0(pthread_t t) {
      // 如果参数为空，那么就默认是主线程
      if (pthread_equal(t, kNilPthreadT)) {
          t = pthread_main_thread_np();
      }
      
      __CFLock(&loopsLock);
      
      // static CFMutableDictionaryRef __CFRunLoops = NULL;
      // 存放Runloop对象的字典
      // 先判断这个Runloop字典存在不，不存在就创建一个，并加主线程Runloop加进入
      if (!__CFRunLoops) {
          __CFUnlock(&loopsLock);
          
          CFMutableDictionaryRef dict = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, NULL, &kCFTypeDictionaryValueCallBacks);
          CFRunLoopRef mainLoop = __CFRunLoopCreate(pthread_main_thread_np());
          CFDictionarySetValue(dict, pthreadPointer(pthread_main_thread_np()), mainLoop);
          
          if (!OSAtomicCompareAndSwapPtrBarrier(NULL, dict, (void * volatile *)&__CFRunLoops)) {
              CFRelease(dict);
          }
          
          CFRelease(mainLoop);
          
          __CFLock(&loopsLock);
      }
      
      // 根据线程去这个字段取Runloop
      CFRunLoopRef loop = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(t));
      
      __CFUnlock(&loopsLock);
      
      // 如果不存在，就创建一个Runloop，并加到字典中
      if (!loop) {
          CFRunLoopRef newLoop = __CFRunLoopCreate(t);
          __CFLock(&loopsLock);
          loop = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(t));
          if (!loop) {
              CFDictionarySetValue(__CFRunLoops, pthreadPointer(t), newLoop);
              loop = newLoop;
          }
          // don't release run loops inside the loopsLock, because CFRunLoopDeallocate may end up taking it
          __CFUnlock(&loopsLock);
          CFRelease(newLoop);
      }
      if (pthread_equal(t, pthread_self())) {
          _CFSetTSD(__CFTSDKeyRunLoop, (void *)loop, NULL);
          if (0 == _CFGetTSD(__CFTSDKeyRunLoopCntr)) {
              _CFSetTSD(__CFTSDKeyRunLoopCntr, (void *)(PTHREAD_DESTRUCTOR_ITERATIONS-1), (void (*)(void *))__CFFinalizeRunLoop);
          }
      }
      return loop;
  }
  
  // should only be called by Foundation
  CFRunLoopRef _CFRunLoopGet0b(pthread_t t) {
      if (pthread_equal(t, kNilPthreadT)) {
          t = pthread_main_thread_np();
      }
      __CFLock(&loopsLock);
      CFRunLoopRef loop = NULL;
      if (__CFRunLoops) {
          loop = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(t));
      }
      __CFUnlock(&loopsLock);
      return loop;
  }
  
  static void __CFRunLoopRemoveAllSources(CFRunLoopRef rl, CFStringRef modeName);
  
  // Called for each thread as it exits
  CF_PRIVATE void __CFFinalizeRunLoop(uintptr_t data) {
      CFRunLoopRef rl = NULL;
      if (data <= 1) {
          __CFLock(&loopsLock);
          if (__CFRunLoops) {
              rl = (CFRunLoopRef)CFDictionaryGetValue(__CFRunLoops, pthreadPointer(pthread_self()));
              if (rl) CFRetain(rl);
              CFDictionaryRemoveValue(__CFRunLoops, pthreadPointer(pthread_self()));
          }
          __CFUnlock(&loopsLock);
      } else {
          _CFSetTSD(__CFTSDKeyRunLoopCntr, (void *)(data - 1), (void (*)(void *))__CFFinalizeRunLoop);
      }
      if (rl && CFRunLoopGetMain() != rl) { // protect against cooperative threads
          if (NULL != rl->_counterpart) {
              CFRelease(rl->_counterpart);
              rl->_counterpart = NULL;
          }
          // purge all sources before deallocation
          CFArrayRef array = CFRunLoopCopyAllModes(rl);
          for (CFIndex idx = CFArrayGetCount(array); idx--;) {
              CFStringRef modeName = (CFStringRef)CFArrayGetValueAtIndex(array, idx);
              __CFRunLoopRemoveAllSources(rl, modeName);
          }
          __CFRunLoopRemoveAllSources(rl, kCFRunLoopCommonModes);
          CFRelease(array);
      }
      if (rl) CFRelease(rl);
  }
  
  pthread_t _CFRunLoopGet1(CFRunLoopRef rl) {
      return rl->_pthread;
  }
  
  // should only be called by Foundation
  CF_EXPORT CFTypeRef _CFRunLoopGet2(CFRunLoopRef rl) {
      CFTypeRef ret = NULL;
      __CFLock(&loopsLock);
      ret = rl->_counterpart;
      __CFUnlock(&loopsLock);
      return ret;
  }
  
  // should only be called by Foundation
  CF_EXPORT CFTypeRef _CFRunLoopGet2b(CFRunLoopRef rl) {
      return rl->_counterpart;
  }
  
  #if DEPLOYMENT_TARGET_MACOSX
  void _CFRunLoopSetCurrent(CFRunLoopRef rl) {
      if (pthread_main_np()) return;
      CFRunLoopRef currentLoop = CFRunLoopGetCurrent();
      if (rl != currentLoop) {
          CFRetain(currentLoop); // avoid a deallocation of the currentLoop inside the lock
          __CFLock(&loopsLock);
          if (rl) {
              CFDictionarySetValue(__CFRunLoops, pthreadPointer(pthread_self()), rl);
          } else {
              CFDictionaryRemoveValue(__CFRunLoops, pthreadPointer(pthread_self()));
          }
          __CFUnlock(&loopsLock);
          CFRelease(currentLoop);
          _CFSetTSD(__CFTSDKeyRunLoop, NULL, NULL);
          _CFSetTSD(__CFTSDKeyRunLoopCntr, 0, (void (*)(void *))__CFFinalizeRunLoop);
      }
  }
  #endif
  
  CFRunLoopRef CFRunLoopGetMain(void) {
      CHECK_FOR_FORK();
      static CFRunLoopRef __main = NULL; // no retain needed
      if (!__main) __main = _CFRunLoopGet0(pthread_main_thread_np()); // no CAS needed
      return __main;
  }
  
  CFRunLoopRef CFRunLoopGetCurrent(void) {
      CHECK_FOR_FORK();
      CFRunLoopRef rl = (CFRunLoopRef)_CFGetTSD(__CFTSDKeyRunLoop);
      if (rl) return rl;
      return _CFRunLoopGet0(pthread_self());
  }
  
  CFStringRef CFRunLoopCopyCurrentMode(CFRunLoopRef rl) {
      CHECK_FOR_FORK();
      CFStringRef result = NULL;
      __CFRunLoopLock(rl);
      if (NULL != rl->_currentMode) {
          result = (CFStringRef)CFRetain(rl->_currentMode->_name);
      }
      __CFRunLoopUnlock(rl);
      return result;
  }
  
  static void __CFRunLoopGetModeName(const void *value, void *context) {
      CFRunLoopModeRef rlm = (CFRunLoopModeRef)value;
      CFMutableArrayRef array = (CFMutableArrayRef)context;
      CFArrayAppendValue(array, rlm->_name);
  }
  
  CFArrayRef CFRunLoopCopyAllModes(CFRunLoopRef rl) {
      CHECK_FOR_FORK();
      CFMutableArrayRef array;
      __CFRunLoopLock(rl);
      array = CFArrayCreateMutable(kCFAllocatorSystemDefault, CFSetGetCount(rl->_modes), &kCFTypeArrayCallBacks);
      CFSetApplyFunction(rl->_modes, (__CFRunLoopGetModeName), array);
      __CFRunLoopUnlock(rl);
      return array;
  }
  
  static void __CFRunLoopAddItemsToCommonMode(const void *value, void *ctx) {
      CFTypeRef item = (CFTypeRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)(((CFTypeRef *)ctx)[0]);
      CFStringRef modeName = (CFStringRef)(((CFTypeRef *)ctx)[1]);
      if (CFGetTypeID(item) == CFRunLoopSourceGetTypeID()) {
          CFRunLoopAddSource(rl, (CFRunLoopSourceRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopObserverGetTypeID()) {
          CFRunLoopAddObserver(rl, (CFRunLoopObserverRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopTimerGetTypeID()) {
          CFRunLoopAddTimer(rl, (CFRunLoopTimerRef)item, modeName);
      }
  }
  
  static void __CFRunLoopAddItemToCommonModes(const void *value, void *ctx) {
      CFStringRef modeName = (CFStringRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)(((CFTypeRef *)ctx)[0]);
      CFTypeRef item = (CFTypeRef)(((CFTypeRef *)ctx)[1]);
      if (CFGetTypeID(item) == CFRunLoopSourceGetTypeID()) {
          CFRunLoopAddSource(rl, (CFRunLoopSourceRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopObserverGetTypeID()) {
          CFRunLoopAddObserver(rl, (CFRunLoopObserverRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopTimerGetTypeID()) {
          CFRunLoopAddTimer(rl, (CFRunLoopTimerRef)item, modeName);
      }
  }
  
  static void __CFRunLoopRemoveItemFromCommonModes(const void *value, void *ctx) {
      CFStringRef modeName = (CFStringRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)(((CFTypeRef *)ctx)[0]);
      CFTypeRef item = (CFTypeRef)(((CFTypeRef *)ctx)[1]);
      if (CFGetTypeID(item) == CFRunLoopSourceGetTypeID()) {
          CFRunLoopRemoveSource(rl, (CFRunLoopSourceRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopObserverGetTypeID()) {
          CFRunLoopRemoveObserver(rl, (CFRunLoopObserverRef)item, modeName);
      } else if (CFGetTypeID(item) == CFRunLoopTimerGetTypeID()) {
          CFRunLoopRemoveTimer(rl, (CFRunLoopTimerRef)item, modeName);
      }
  }
  
  CF_EXPORT Boolean _CFRunLoop01(CFRunLoopRef rl, CFStringRef modeName) {
      __CFRunLoopLock(rl);
      Boolean present = CFSetContainsValue(rl->_commonModes, modeName);
      __CFRunLoopUnlock(rl);
      return present;
  }
  
  void CFRunLoopAddCommonMode(CFRunLoopRef rl, CFStringRef modeName) {
      CHECK_FOR_FORK();
      if (__CFRunLoopIsDeallocating(rl)) return;
      __CFRunLoopLock(rl);
      if (!CFSetContainsValue(rl->_commonModes, modeName)) {
          CFSetRef set = rl->_commonModeItems ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModeItems) : NULL;
          CFSetAddValue(rl->_commonModes, modeName);
          if (NULL != set) {
              CFTypeRef context[2] = {rl, modeName};
              /* add all common-modes items to new mode */
              CFSetApplyFunction(set, (__CFRunLoopAddItemsToCommonMode), (void *)context);
              CFRelease(set);
          }
      } else {
      }
      __CFRunLoopUnlock(rl);
  }
  
  
  static void __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__(void *msg) {
      _dispatch_main_queue_callback_4CF(msg);
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__(CFRunLoopObserverCallBack func, CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *info) {
      if (func) {
          func(observer, activity, info);
      }
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__(CFRunLoopTimerCallBack func, CFRunLoopTimerRef timer, void *info) {
      if (func) {
          func(timer, info);
      }
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__(void (^block)(void)) {
      if (block) {
          block();
      }
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  static Boolean __CFRunLoopDoBlocks(CFRunLoopRef rl, CFRunLoopModeRef rlm) { // Call with rl and rlm locked
      if (!rl->_blocks_head) return false;
      if (!rlm || !rlm->_name) return false;
      Boolean did = false;
      struct _block_item *head = rl->_blocks_head;
      struct _block_item *tail = rl->_blocks_tail;
      rl->_blocks_head = NULL;
      rl->_blocks_tail = NULL;
      CFSetRef commonModes = rl->_commonModes;
      CFStringRef curMode = rlm->_name;
      __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
      struct _block_item *prev = NULL;
      struct _block_item *item = head;
      while (item) {
          struct _block_item *curr = item;
          item = item->_next;
          Boolean doit = false;
          if (CFStringGetTypeID() == CFGetTypeID(curr->_mode)) {
              doit = CFEqual(curr->_mode, curMode) || (CFEqual(curr->_mode, kCFRunLoopCommonModes) && CFSetContainsValue(commonModes, curMode));
          } else {
              doit = CFSetContainsValue((CFSetRef)curr->_mode, curMode) || (CFSetContainsValue((CFSetRef)curr->_mode, kCFRunLoopCommonModes) && CFSetContainsValue(commonModes, curMode));
          }
          if (!doit) prev = curr;
          if (doit) {
              if (prev) prev->_next = item;
              if (curr == head) head = item;
              if (curr == tail) tail = prev;
              void (^block)(void) = curr->_block;
              CFRelease(curr->_mode);
              free(curr);
              if (doit) {
                  __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__(block);
                  did = true;
              }
              Block_release(block); // do this before relocking to prevent deadlocks where some yahoo wants to run the run loop reentrantly from their dealloc
          }
      }
      __CFRunLoopLock(rl);
      __CFRunLoopModeLock(rlm);
      if (head) {
          tail->_next = rl->_blocks_head;
          rl->_blocks_head = head;
          if (!rl->_blocks_tail) rl->_blocks_tail = tail;
      }
      return did;
  }
  
  /* rl is locked, rlm is locked on entrance and exit */
  static void __CFRunLoopDoObservers() __attribute__((noinline));
  static void __CFRunLoopDoObservers(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFRunLoopActivity activity) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      
      CFIndex cnt = rlm->_observers ? CFArrayGetCount(rlm->_observers) : 0;
      if (cnt < 1) return;
      
      /* Fire the observers */
      STACK_BUFFER_DECL(CFRunLoopObserverRef, buffer, (cnt <= 1024) ? cnt : 1);
      CFRunLoopObserverRef *collectedObservers = (cnt <= 1024) ? buffer : (CFRunLoopObserverRef *)malloc(cnt * sizeof(CFRunLoopObserverRef));
      CFIndex obs_cnt = 0;
      for (CFIndex idx = 0; idx < cnt; idx++) {
          CFRunLoopObserverRef rlo = (CFRunLoopObserverRef)CFArrayGetValueAtIndex(rlm->_observers, idx);
          if (0 != (rlo->_activities & activity) && __CFIsValid(rlo) && !__CFRunLoopObserverIsFiring(rlo)) {
              collectedObservers[obs_cnt++] = (CFRunLoopObserverRef)CFRetain(rlo);
          }
      }
      __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
      for (CFIndex idx = 0; idx < obs_cnt; idx++) {
          CFRunLoopObserverRef rlo = collectedObservers[idx];
          __CFRunLoopObserverLock(rlo);
          if (__CFIsValid(rlo)) {
              Boolean doInvalidate = !__CFRunLoopObserverRepeats(rlo);
              __CFRunLoopObserverSetFiring(rlo);
              __CFRunLoopObserverUnlock(rlo);
              __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__(rlo->_callout, rlo, activity, rlo->_context.info);
              if (doInvalidate) {
                  CFRunLoopObserverInvalidate(rlo);
              }
              __CFRunLoopObserverUnsetFiring(rlo);
          } else {
              __CFRunLoopObserverUnlock(rlo);
          }
          CFRelease(rlo);
      }
      __CFRunLoopLock(rl);
      __CFRunLoopModeLock(rlm);
      
      if (collectedObservers != buffer) free(collectedObservers);
  }
  
  static CFComparisonResult __CFRunLoopSourceComparator(const void *val1, const void *val2, void *context) {
      CFRunLoopSourceRef o1 = (CFRunLoopSourceRef)val1;
      CFRunLoopSourceRef o2 = (CFRunLoopSourceRef)val2;
      if (o1->_order < o2->_order) return kCFCompareLessThan;
      if (o2->_order < o1->_order) return kCFCompareGreaterThan;
      return kCFCompareEqualTo;
  }
  
  static void __CFRunLoopCollectSources0(const void *value, void *context) {
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)value;
      CFTypeRef *sources = (CFTypeRef *)context;
      if (0 == rls->_context.version0.version && __CFIsValid(rls) && __CFRunLoopSourceIsSignaled(rls)) {
          if (NULL == *sources) {
              *sources = CFRetain(rls);
          } else if (CFGetTypeID(*sources) == CFRunLoopSourceGetTypeID()) {
              CFTypeRef oldrls = *sources;
              *sources = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeArrayCallBacks);
              CFArrayAppendValue((CFMutableArrayRef)*sources, oldrls);
              CFArrayAppendValue((CFMutableArrayRef)*sources, rls);
              CFRelease(oldrls);
          } else {
              CFArrayAppendValue((CFMutableArrayRef)*sources, rls);
          }
      }
  }
  
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__(void (*perform)(void *), void *info) {
      if (perform) {
          perform(info);
      }
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__() __attribute__((noinline));
  static void __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__(
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
                                                                         void *(*perform)(void *msg, CFIndex size, CFAllocatorRef allocator, void *info),
                                                                         mach_msg_header_t *msg, CFIndex size, mach_msg_header_t **reply,
  #else
                                                                         void (*perform)(void *),
  #endif
                                                                         void *info) {
      if (perform) {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          *reply = perform(msg, size, kCFAllocatorSystemDefault, info);
  #else
          perform(info);
  #endif
      }
      asm __volatile__(""); // thwart tail-call optimization
  }
  
  /* rl is locked, rlm is locked on entrance and exit */
  static Boolean __CFRunLoopDoSources0(CFRunLoopRef rl, CFRunLoopModeRef rlm, Boolean stopAfterHandle) __attribute__((noinline));
  static Boolean __CFRunLoopDoSources0(CFRunLoopRef rl, CFRunLoopModeRef rlm, Boolean stopAfterHandle) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      CFTypeRef sources = NULL;
      Boolean sourceHandled = false;
      
      /* Fire the version 0 sources */
      if (NULL != rlm->_sources0 && 0 < CFSetGetCount(rlm->_sources0)) {
          CFSetApplyFunction(rlm->_sources0, (__CFRunLoopCollectSources0), &sources);
      }
      if (NULL != sources) {
          __CFRunLoopModeUnlock(rlm);
          __CFRunLoopUnlock(rl);
          // sources is either a single (retained) CFRunLoopSourceRef or an array of (retained) CFRunLoopSourceRef
          if (CFGetTypeID(sources) == CFRunLoopSourceGetTypeID()) {
              CFRunLoopSourceRef rls = (CFRunLoopSourceRef)sources;
              __CFRunLoopSourceLock(rls);
              if (__CFRunLoopSourceIsSignaled(rls)) {
                  __CFRunLoopSourceUnsetSignaled(rls);
                  if (__CFIsValid(rls)) {
                      __CFRunLoopSourceUnlock(rls);
                      __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__(rls->_context.version0.perform, rls->_context.version0.info);
                      CHECK_FOR_FORK();
                      sourceHandled = true;
                  } else {
                      __CFRunLoopSourceUnlock(rls);
                  }
              } else {
                  __CFRunLoopSourceUnlock(rls);
              }
          } else {
              CFIndex cnt = CFArrayGetCount((CFArrayRef)sources);
              CFArraySortValues((CFMutableArrayRef)sources, CFRangeMake(0, cnt), (__CFRunLoopSourceComparator), NULL);
              for (CFIndex idx = 0; idx < cnt; idx++) {
                  CFRunLoopSourceRef rls = (CFRunLoopSourceRef)CFArrayGetValueAtIndex((CFArrayRef)sources, idx);
                  __CFRunLoopSourceLock(rls);
                  if (__CFRunLoopSourceIsSignaled(rls)) {
                      __CFRunLoopSourceUnsetSignaled(rls);
                      if (__CFIsValid(rls)) {
                          __CFRunLoopSourceUnlock(rls);
                          __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__(rls->_context.version0.perform, rls->_context.version0.info);
                          CHECK_FOR_FORK();
                          sourceHandled = true;
                      } else {
                          __CFRunLoopSourceUnlock(rls);
                      }
                  } else {
                      __CFRunLoopSourceUnlock(rls);
                  }
                  if (stopAfterHandle && sourceHandled) {
                      break;
                  }
              }
          }
          CFRelease(sources);
          __CFRunLoopLock(rl);
          __CFRunLoopModeLock(rlm);
      }
      return sourceHandled;
  }
  
  CF_INLINE void __CFRunLoopDebugInfoForRunLoopSource(CFRunLoopSourceRef rls) {
  }
  
  // msg, size and reply are unused on Windows
  static Boolean __CFRunLoopDoSource1() __attribute__((noinline));
  static Boolean __CFRunLoopDoSource1(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFRunLoopSourceRef rls
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
                                      , mach_msg_header_t *msg, CFIndex size, mach_msg_header_t **reply
  #endif
  ) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      Boolean sourceHandled = false;
      
      /* Fire a version 1 source */
      CFRetain(rls);
      __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
      __CFRunLoopSourceLock(rls);
      if (__CFIsValid(rls)) {
          __CFRunLoopSourceUnsetSignaled(rls);
          __CFRunLoopSourceUnlock(rls);
          __CFRunLoopDebugInfoForRunLoopSource(rls);
          __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__(rls->_context.version1.perform,
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
                                                                     msg, size, reply,
  #endif
                                                                     rls->_context.version1.info);
          CHECK_FOR_FORK();
          sourceHandled = true;
      } else {
          if (_LogCFRunLoop) { CFLog(kCFLogLevelDebug, CFSTR("%p (%s) __CFRunLoopDoSource1 rls %p is invalid"), CFRunLoopGetCurrent(), *_CFGetProgname(), rls); }
          __CFRunLoopSourceUnlock(rls);
      }
      CFRelease(rls);
      __CFRunLoopLock(rl);
      __CFRunLoopModeLock(rlm);
      return sourceHandled;
  }
  
  static CFIndex __CFRunLoopInsertionIndexInTimerArray(CFArrayRef array, CFRunLoopTimerRef rlt) __attribute__((noinline));
  static CFIndex __CFRunLoopInsertionIndexInTimerArray(CFArrayRef array, CFRunLoopTimerRef rlt) {
      CFIndex cnt = CFArrayGetCount(array);
      if (cnt <= 0) {
          return 0;
      }
      if (256 < cnt) {
          CFRunLoopTimerRef item = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(array, cnt - 1);
          if (item->_fireTSR <= rlt->_fireTSR) {
              return cnt;
          }
          item = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(array, 0);
          if (rlt->_fireTSR < item->_fireTSR) {
              return 0;
          }
      }
      
      CFIndex add = (1 << flsl(cnt)) * 2;
      CFIndex idx = 0;
      Boolean lastTestLEQ;
      do {
          add = add / 2;
          lastTestLEQ = false;
          CFIndex testIdx = idx + add;
          if (testIdx < cnt) {
              CFRunLoopTimerRef item = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(array, testIdx);
              if (item->_fireTSR <= rlt->_fireTSR) {
                  idx = testIdx;
                  lastTestLEQ = true;
              }
          }
      } while (0 < add);
      
      return lastTestLEQ ? idx + 1 : idx;
  }
  
  static void __CFArmNextTimerInMode(CFRunLoopModeRef rlm, CFRunLoopRef rl) {    
      uint64_t nextHardDeadline = UINT64_MAX;
      uint64_t nextSoftDeadline = UINT64_MAX;
      
      if (rlm->_timers) {
          // Look at the list of timers. We will calculate two TSR values; the next soft and next hard deadline.
          // The next soft deadline is the first time we can fire any timer. This is the fire date of the first timer in our sorted list of timers.
          // The next hard deadline is the last time at which we can fire the timer before we've moved out of the allowable tolerance of the timers in our list.
          for (CFIndex idx = 0, cnt = CFArrayGetCount(rlm->_timers); idx < cnt; idx++) {
              CFRunLoopTimerRef t = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(rlm->_timers , idx);
              // discount timers currently firing
              if (__CFRunLoopTimerIsFiring(t)) continue;
              
              int32_t err = CHECKINT_NO_ERROR;
              uint64_t oneTimerSoftDeadline = t->_fireTSR;
              uint64_t oneTimerHardDeadline = check_uint64_add(t->_fireTSR, __CFTimeIntervalToTSR(t->_tolerance), &err);
              if (err != CHECKINT_NO_ERROR) oneTimerHardDeadline = UINT64_MAX;
              
              // We can stop searching if the soft deadline for this timer exceeds the current hard deadline. Otherwise, later timers with lower tolerance could still have earlier hard deadlines.
              if (oneTimerSoftDeadline > nextHardDeadline) {
                  break;
              }
              
              if (oneTimerSoftDeadline < nextSoftDeadline) {
                  nextSoftDeadline = oneTimerSoftDeadline;
              }
              
              if (oneTimerHardDeadline < nextHardDeadline) {
                  nextHardDeadline = oneTimerHardDeadline;
              }
          }
          
          if (nextSoftDeadline < UINT64_MAX && (nextHardDeadline != rlm->_timerHardDeadline || nextSoftDeadline != rlm->_timerSoftDeadline)) {
              if (CFRUNLOOP_NEXT_TIMER_ARMED_ENABLED()) {
                  CFRUNLOOP_NEXT_TIMER_ARMED((unsigned long)(nextSoftDeadline - mach_absolute_time()));
              }
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
              // We're going to hand off the range of allowable timer fire date to dispatch and let it fire when appropriate for the system.
              uint64_t leeway = __CFTSRToNanoseconds(nextHardDeadline - nextSoftDeadline);
              dispatch_time_t deadline = __CFTSRToDispatchTime(nextSoftDeadline);
  #if USE_MK_TIMER_TOO
              if (leeway > 0) {
                  // Only use the dispatch timer if we have any leeway
                  // <rdar://problem/14447675>
                  
                  // Cancel the mk timer
                  if (rlm->_mkTimerArmed && rlm->_timerPort) {
                      AbsoluteTime dummy;
                      mk_timer_cancel(rlm->_timerPort, &dummy);
                      rlm->_mkTimerArmed = false;
                  }
                  
                  // Arm the dispatch timer
                  _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, deadline, DISPATCH_TIME_FOREVER, leeway);
                  rlm->_dispatchTimerArmed = true;
              } else {
                  // Cancel the dispatch timer
                  if (rlm->_dispatchTimerArmed) {
                      // Cancel the dispatch timer
                      _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 888);
                      rlm->_dispatchTimerArmed = false;
                  }
                  
                  // Arm the mk timer
                  if (rlm->_timerPort) {
                      mk_timer_arm(rlm->_timerPort, __CFUInt64ToAbsoluteTime(nextSoftDeadline));
                      rlm->_mkTimerArmed = true;
                  }
              }
  #else
              _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, deadline, DISPATCH_TIME_FOREVER, leeway);
  #endif
  #else
              if (rlm->_timerPort) {
                  mk_timer_arm(rlm->_timerPort, __CFUInt64ToAbsoluteTime(nextSoftDeadline));
              }
  #endif
          } else if (nextSoftDeadline == UINT64_MAX) {
              // Disarm the timers - there is no timer scheduled
              
              if (rlm->_mkTimerArmed && rlm->_timerPort) {
                  AbsoluteTime dummy;
                  mk_timer_cancel(rlm->_timerPort, &dummy);
                  rlm->_mkTimerArmed = false;
              }
              
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
              if (rlm->_dispatchTimerArmed) {
                  _dispatch_source_set_runloop_timer_4CF(rlm->_timerSource, DISPATCH_TIME_FOREVER, DISPATCH_TIME_FOREVER, 333);
                  rlm->_dispatchTimerArmed = false;
              }
  #endif
          }
      }
      rlm->_timerHardDeadline = nextHardDeadline;
      rlm->_timerSoftDeadline = nextSoftDeadline;
  }
  
  // call with rlm and its run loop locked, and the TSRLock locked; rlt not locked; returns with same state
  static void __CFRepositionTimerInMode(CFRunLoopModeRef rlm, CFRunLoopTimerRef rlt, Boolean isInArray) __attribute__((noinline));
  static void __CFRepositionTimerInMode(CFRunLoopModeRef rlm, CFRunLoopTimerRef rlt, Boolean isInArray) {
      if (!rlt) return;
      
      CFMutableArrayRef timerArray = rlm->_timers;
      if (!timerArray) return;
      Boolean found = false;
      
      // If we know in advance that the timer is not in the array (just being added now) then we can skip this search
      if (isInArray) {
          CFIndex idx = CFArrayGetFirstIndexOfValue(timerArray, CFRangeMake(0, CFArrayGetCount(timerArray)), rlt);
          if (kCFNotFound != idx) {
              CFRetain(rlt);
              CFArrayRemoveValueAtIndex(timerArray, idx);
              found = true;
          }
      }
      if (!found && isInArray) return;
      CFIndex newIdx = __CFRunLoopInsertionIndexInTimerArray(timerArray, rlt);
      CFArrayInsertValueAtIndex(timerArray, newIdx, rlt);
      __CFArmNextTimerInMode(rlm, rlt->_runLoop);
      if (isInArray) CFRelease(rlt);
  }
  
  
  // mode and rl are locked on entry and exit
  static Boolean __CFRunLoopDoTimer(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFRunLoopTimerRef rlt) {	/* DOES CALLOUT */
      Boolean timerHandled = false;
      uint64_t oldFireTSR = 0;
      
      /* Fire a timer */
      CFRetain(rlt);
      __CFRunLoopTimerLock(rlt);
      
      if (__CFIsValid(rlt) && rlt->_fireTSR <= mach_absolute_time() && !__CFRunLoopTimerIsFiring(rlt) && rlt->_runLoop == rl) {
          void *context_info = NULL;
          void (*context_release)(const void *) = NULL;
          if (rlt->_context.retain) {
              context_info = (void *)rlt->_context.retain(rlt->_context.info);
              context_release = rlt->_context.release;
          } else {
              context_info = rlt->_context.info;
          }
          Boolean doInvalidate = (0.0 == rlt->_interval);
          __CFRunLoopTimerSetFiring(rlt);
          // Just in case the next timer has exactly the same deadlines as this one, we reset these values so that the arm next timer code can correctly find the next timer in the list and arm the underlying timer.
          rlm->_timerSoftDeadline = UINT64_MAX;
          rlm->_timerHardDeadline = UINT64_MAX;
          __CFRunLoopTimerUnlock(rlt);
          __CFRunLoopTimerFireTSRLock();
          oldFireTSR = rlt->_fireTSR;
          __CFRunLoopTimerFireTSRUnlock();
          
          __CFArmNextTimerInMode(rlm, rl);
          
          __CFRunLoopModeUnlock(rlm);
          __CFRunLoopUnlock(rl);
          __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__(rlt->_callout, rlt, context_info);
          CHECK_FOR_FORK();
          if (doInvalidate) {
              CFRunLoopTimerInvalidate(rlt);      /* DOES CALLOUT */
          }
          if (context_release) {
              context_release(context_info);
          }
          __CFRunLoopLock(rl);
          __CFRunLoopModeLock(rlm);
          __CFRunLoopTimerLock(rlt);
          timerHandled = true;
          __CFRunLoopTimerUnsetFiring(rlt);
      }
      if (__CFIsValid(rlt) && timerHandled) {
          /* This is just a little bit tricky: we want to support calling
           * CFRunLoopTimerSetNextFireDate() from within the callout and
           * honor that new time here if it is a later date, otherwise
           * it is completely ignored. */
          if (oldFireTSR < rlt->_fireTSR) {
              /* Next fire TSR was set, and set to a date after the previous
               * fire date, so we honor it. */
              __CFRunLoopTimerUnlock(rlt);
              // The timer was adjusted and repositioned, during the
              // callout, but if it was still the min timer, it was
              // skipped because it was firing.  Need to redo the
              // min timer calculation in case rlt should now be that
              // timer instead of whatever was chosen.
              __CFArmNextTimerInMode(rlm, rl);
          } else {
              uint64_t nextFireTSR = 0LL;
              uint64_t intervalTSR = 0LL;
              if (rlt->_interval <= 0.0) {
              } else if (TIMER_INTERVAL_LIMIT < rlt->_interval) {
                  intervalTSR = __CFTimeIntervalToTSR(TIMER_INTERVAL_LIMIT);
              } else {
                  intervalTSR = __CFTimeIntervalToTSR(rlt->_interval);
              }
              if (LLONG_MAX - intervalTSR <= oldFireTSR) {
                  nextFireTSR = LLONG_MAX;
              } else {
                  if (intervalTSR == 0) {
                      // 15304159: Make sure we don't accidentally loop forever here
                      CRSetCrashLogMessage("A CFRunLoopTimer with an interval of 0 is set to repeat");
                      HALT;
                  }
                  uint64_t currentTSR = mach_absolute_time();
                  nextFireTSR = oldFireTSR;
                  while (nextFireTSR <= currentTSR) {
                      nextFireTSR += intervalTSR;
                  }
              }
              CFRunLoopRef rlt_rl = rlt->_runLoop;
              if (rlt_rl) {
                  CFRetain(rlt_rl);
                  CFIndex cnt = CFSetGetCount(rlt->_rlModes);
                  STACK_BUFFER_DECL(CFTypeRef, modes, cnt);
                  CFSetGetValues(rlt->_rlModes, (const void **)modes);
                  // To avoid A->B, B->A lock ordering issues when coming up
                  // towards the run loop from a source, the timer has to be
                  // unlocked, which means we have to protect from object
                  // invalidation, although that's somewhat expensive.
                  for (CFIndex idx = 0; idx < cnt; idx++) {
                      CFRetain(modes[idx]);
                  }
                  __CFRunLoopTimerUnlock(rlt);
                  for (CFIndex idx = 0; idx < cnt; idx++) {
                      CFStringRef name = (CFStringRef)modes[idx];
                      modes[idx] = (CFTypeRef)__CFRunLoopFindMode(rlt_rl, name, false);
                      CFRelease(name);
                  }
                  __CFRunLoopTimerFireTSRLock();
                  rlt->_fireTSR = nextFireTSR;
                  rlt->_nextFireDate = CFAbsoluteTimeGetCurrent() + __CFTimeIntervalUntilTSR(nextFireTSR);
                  for (CFIndex idx = 0; idx < cnt; idx++) {
                      CFRunLoopModeRef rlm = (CFRunLoopModeRef)modes[idx];
                      if (rlm) {
                          __CFRepositionTimerInMode(rlm, rlt, true);
                      }
                  }
                  __CFRunLoopTimerFireTSRUnlock();
                  for (CFIndex idx = 0; idx < cnt; idx++) {
                      __CFRunLoopModeUnlock((CFRunLoopModeRef)modes[idx]);
                  }
                  CFRelease(rlt_rl);
              } else {
                  __CFRunLoopTimerUnlock(rlt);
                  __CFRunLoopTimerFireTSRLock();
                  rlt->_fireTSR = nextFireTSR;
                  rlt->_nextFireDate = CFAbsoluteTimeGetCurrent() + __CFTimeIntervalUntilTSR(nextFireTSR);
                  __CFRunLoopTimerFireTSRUnlock();
              }
          }
      } else {
          __CFRunLoopTimerUnlock(rlt);
      }
      CFRelease(rlt);
      return timerHandled;
  }
  
  
  // rl and rlm are locked on entry and exit
  static Boolean __CFRunLoopDoTimers(CFRunLoopRef rl, CFRunLoopModeRef rlm, uint64_t limitTSR) {	/* DOES CALLOUT */
      Boolean timerHandled = false;
      CFMutableArrayRef timers = NULL;
      for (CFIndex idx = 0, cnt = rlm->_timers ? CFArrayGetCount(rlm->_timers) : 0; idx < cnt; idx++) {
          CFRunLoopTimerRef rlt = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(rlm->_timers, idx);
          
          if (__CFIsValid(rlt) && !__CFRunLoopTimerIsFiring(rlt)) {
              if (rlt->_fireTSR <= limitTSR) {
                  if (!timers) timers = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeArrayCallBacks);
                  CFArrayAppendValue(timers, rlt);
              }
          }
      }
      
      for (CFIndex idx = 0, cnt = timers ? CFArrayGetCount(timers) : 0; idx < cnt; idx++) {
          CFRunLoopTimerRef rlt = (CFRunLoopTimerRef)CFArrayGetValueAtIndex(timers, idx);
          Boolean did = __CFRunLoopDoTimer(rl, rlm, rlt);
          timerHandled = timerHandled || did;
      }
      if (timers) CFRelease(timers);
      return timerHandled;
  }
  
  
  CF_EXPORT Boolean _CFRunLoopFinished(CFRunLoopRef rl, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      Boolean result = false;
      __CFRunLoopLock(rl);
      rlm = __CFRunLoopFindMode(rl, modeName, false);
      if (NULL == rlm || __CFRunLoopModeIsEmpty(rl, rlm, NULL)) {
          result = true;
      }
      if (rlm) __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
      return result;
  }
  
  static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInterval seconds, Boolean stopAfterHandle, CFRunLoopModeRef previousMode) __attribute__((noinline));
  
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
  
  #define TIMEOUT_INFINITY (~(mach_msg_timeout_t)0)
  
  static Boolean __CFRunLoopServiceMachPort(mach_port_name_t port, mach_msg_header_t **buffer, size_t buffer_size, mach_port_t *livePort, mach_msg_timeout_t timeout, voucher_mach_msg_state_t *voucherState, voucher_t *voucherCopy) {
      Boolean originalBuffer = true;
      kern_return_t ret = KERN_SUCCESS;
      for (;;) {		/* In that sleep of death what nightmares may come ... */
          mach_msg_header_t *msg = (mach_msg_header_t *)*buffer;
          msg->msgh_bits = 0;
          msg->msgh_local_port = port;
          msg->msgh_remote_port = MACH_PORT_NULL;
          msg->msgh_size = buffer_size;
          msg->msgh_id = 0;
          if (TIMEOUT_INFINITY == timeout) { CFRUNLOOP_SLEEP(); } else { CFRUNLOOP_POLL(); }
          ret = mach_msg(msg, MACH_RCV_MSG|(voucherState ? MACH_RCV_VOUCHER : 0)|MACH_RCV_LARGE|((TIMEOUT_INFINITY != timeout) ? MACH_RCV_TIMEOUT : 0)|MACH_RCV_TRAILER_TYPE(MACH_MSG_TRAILER_FORMAT_0)|MACH_RCV_TRAILER_ELEMENTS(MACH_RCV_TRAILER_AV), 0, msg->msgh_size, port, timeout, MACH_PORT_NULL);
          
          // Take care of all voucher-related work right after mach_msg.
          // If we don't release the previous voucher we're going to leak it.
          voucher_mach_msg_revert(*voucherState);
          
          // Someone will be responsible for calling voucher_mach_msg_revert. This call makes the received voucher the current one.
          *voucherState = voucher_mach_msg_adopt(msg);
          
          if (voucherCopy) {
              if (*voucherState != VOUCHER_MACH_MSG_STATE_UNCHANGED) {
                  // Caller requested a copy of the voucher at this point. By doing this right next to mach_msg we make sure that no voucher has been set in between the return of mach_msg and the use of the voucher copy.
                  // CFMachPortBoost uses the voucher to drop importance explicitly. However, we want to make sure we only drop importance for a new voucher (not unchanged), so we only set the TSD when the voucher is not state_unchanged.
                  *voucherCopy = voucher_copy();
              } else {
                  *voucherCopy = NULL;
              }
          }
          
          CFRUNLOOP_WAKEUP(ret);
          if (MACH_MSG_SUCCESS == ret) {
              *livePort = msg ? msg->msgh_local_port : MACH_PORT_NULL;
              return true;
          }
          if (MACH_RCV_TIMED_OUT == ret) {
              if (!originalBuffer) free(msg);
              *buffer = NULL;
              *livePort = MACH_PORT_NULL;
              return false;
          }
          if (MACH_RCV_TOO_LARGE != ret) break;
          buffer_size = round_msg(msg->msgh_size + MAX_TRAILER_SIZE);
          if (originalBuffer) *buffer = NULL;
          originalBuffer = false;
          *buffer = realloc(*buffer, buffer_size);
      }
      HALT;
      return false;
  }
  
  #elif DEPLOYMENT_TARGET_WINDOWS
  
  #define TIMEOUT_INFINITY INFINITE
  
  // pass in either a portSet or onePort
  static Boolean __CFRunLoopWaitForMultipleObjects(__CFPortSet portSet, HANDLE *onePort, DWORD timeout, DWORD mask, HANDLE *livePort, Boolean *msgReceived) {
      DWORD waitResult = WAIT_TIMEOUT;
      HANDLE handleBuf[MAXIMUM_WAIT_OBJECTS];
      HANDLE *handles = NULL;
      uint32_t handleCount = 0;
      Boolean freeHandles = false;
      Boolean result = false;
      
      if (portSet) {
          // copy out the handles to be safe from other threads at work
          handles = __CFPortSetGetPorts(portSet, handleBuf, MAXIMUM_WAIT_OBJECTS, &handleCount);
          freeHandles = (handles != handleBuf);
      } else {
          handles = onePort;
          handleCount = 1;
          freeHandles = FALSE;
      }
      
      // The run loop mode and loop are already in proper unlocked state from caller
      waitResult = MsgWaitForMultipleObjectsEx(__CFMin(handleCount, MAXIMUM_WAIT_OBJECTS), handles, timeout, mask, MWMO_INPUTAVAILABLE);
      
      CFAssert2(waitResult != WAIT_FAILED, __kCFLogAssertion, "%s(): error %d from MsgWaitForMultipleObjects", __PRETTY_FUNCTION__, GetLastError());
      
      if (waitResult == WAIT_TIMEOUT) {
          // do nothing, just return to caller
          result = false;
      } else if (waitResult >= WAIT_OBJECT_0 && waitResult < WAIT_OBJECT_0+handleCount) {
          // a handle was signaled
          if (livePort) *livePort = handles[waitResult-WAIT_OBJECT_0];
          result = true;
      } else if (waitResult == WAIT_OBJECT_0+handleCount) {
          // windows message received
          if (msgReceived) *msgReceived = true;
          result = true;
      } else if (waitResult >= WAIT_ABANDONED_0 && waitResult < WAIT_ABANDONED_0+handleCount) {
          // an "abandoned mutex object"
          if (livePort) *livePort = handles[waitResult-WAIT_ABANDONED_0];
          result = true;
      } else {
          CFAssert2(waitResult == WAIT_FAILED, __kCFLogAssertion, "%s(): unexpected result from MsgWaitForMultipleObjects: %d", __PRETTY_FUNCTION__, waitResult);
          result = false;
      }
      
      if (freeHandles) {
          CFAllocatorDeallocate(kCFAllocatorSystemDefault, handles);
      }
      
      return result;
  }
  
  #endif
  
  struct __timeout_context {
      dispatch_source_t ds;
      CFRunLoopRef rl;
      uint64_t termTSR;
  };
  
  static void __CFRunLoopTimeoutCancel(void *arg) {
      struct __timeout_context *context = (struct __timeout_context *)arg;
      CFRelease(context->rl);
      dispatch_release(context->ds);
      free(context);
  }
  
  static void __CFRunLoopTimeout(void *arg) {
      struct __timeout_context *context = (struct __timeout_context *)arg;
      context->termTSR = 0ULL;
      CFRUNLOOP_WAKEUP_FOR_TIMEOUT();
      CFRunLoopWakeUp(context->rl);
      // The interval is DISPATCH_TIME_FOREVER, so this won't fire again
  }
  
  /* rl, rlm are locked on entrance and exit */
  static int32_t __CFRunLoopRun(CFRunLoopRef rl, CFRunLoopModeRef rlm, CFTimeInterval seconds, Boolean stopAfterHandle, CFRunLoopModeRef previousMode) {
      uint64_t startTSR = mach_absolute_time();
      
      if (__CFRunLoopIsStopped(rl)) {
          __CFRunLoopUnsetStopped(rl);
          return kCFRunLoopRunStopped;
      } else if (rlm->_stopped) {
          rlm->_stopped = false;
          return kCFRunLoopRunStopped;
      }
      
      // 获取主线程消息端口，用于 main queue 事件的派发
      mach_port_name_t dispatchPort = MACH_PORT_NULL;
      Boolean libdispatchQSafe = pthread_main_np() && ((HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && NULL == previousMode) || (!HANDLE_DISPATCH_ON_BASE_INVOCATION_ONLY && 0 == _CFGetTSD(__CFTSDKeyIsInGCDMainQ)));
      if (libdispatchQSafe && (CFRunLoopGetMain() == rl) && CFSetContainsValue(rl->_commonModes, rlm->_name)) dispatchPort = _dispatch_get_main_queue_port_4CF();
      
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
      // 初始化GCD timer
      mach_port_name_t modeQueuePort = MACH_PORT_NULL;
      if (rlm->_queue) {
          modeQueuePort = _dispatch_runloop_root_queue_get_port_4CF(rlm->_queue);
          if (!modeQueuePort) {
              CRASH("Unable to get port for run loop mode queue (%d)", -1);
          }
      }
  #endif
      
      // 设置超时时间
      dispatch_source_t timeout_timer = NULL;
      struct __timeout_context *timeout_context = (struct __timeout_context *)malloc(sizeof(*timeout_context));
      if (seconds <= 0.0) { // instant timeout
          seconds = 0.0;
          timeout_context->termTSR = 0ULL;
      } else if (seconds <= TIMER_INTERVAL_LIMIT) {
          dispatch_queue_t queue = pthread_main_np() ? __CFDispatchQueueGetGenericMatchingMain() : __CFDispatchQueueGetGenericBackground();
          timeout_timer = dispatch_source_create(DISPATCH_SOURCE_TYPE_TIMER, 0, 0, queue);
          dispatch_retain(timeout_timer);
          timeout_context->ds = timeout_timer;
          timeout_context->rl = (CFRunLoopRef)CFRetain(rl);
          timeout_context->termTSR = startTSR + __CFTimeIntervalToTSR(seconds);
          dispatch_set_context(timeout_timer, timeout_context); // source gets ownership of context
          dispatch_source_set_event_handler_f(timeout_timer, __CFRunLoopTimeout);
          dispatch_source_set_cancel_handler_f(timeout_timer, __CFRunLoopTimeoutCancel);
          uint64_t ns_at = (uint64_t)((__CFTSRToTimeInterval(startTSR) + seconds) * 1000000000ULL);
          dispatch_source_set_timer(timeout_timer, dispatch_time(1, ns_at), DISPATCH_TIME_FOREVER, 1000ULL);
          dispatch_resume(timeout_timer);
      } else { // infinite timeout
          seconds = 9999999999.0;
          timeout_context->termTSR = UINT64_MAX;
      }
      
      Boolean didDispatchPortLastTime = true;
      int32_t retVal = 0;
      do {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          voucher_mach_msg_state_t voucherState = VOUCHER_MACH_MSG_STATE_UNCHANGED;
          voucher_t voucherCopy = NULL;
  #endif
          uint8_t msg_buffer[3 * 1024];
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          mach_msg_header_t *msg = NULL;
          mach_port_t livePort = MACH_PORT_NULL;
  #elif DEPLOYMENT_TARGET_WINDOWS
          HANDLE livePort = NULL;
          Boolean windowsMessageReceived = false;
  #endif
          __CFPortSet waitSet = rlm->_portSet;
          
          __CFRunLoopUnsetIgnoreWakeUps(rl);
          
          if (rlm->_observerMask & kCFRunLoopBeforeTimers) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopBeforeTimers);
          if (rlm->_observerMask & kCFRunLoopBeforeSources) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopBeforeSources);
          
          __CFRunLoopDoBlocks(rl, rlm);
          
          Boolean sourceHandledThisLoop = __CFRunLoopDoSources0(rl, rlm, stopAfterHandle);
          if (sourceHandledThisLoop) {
              __CFRunLoopDoBlocks(rl, rlm);
          }
          
          Boolean poll = sourceHandledThisLoop || (0ULL == timeout_context->termTSR);
          
          if (MACH_PORT_NULL != dispatchPort && !didDispatchPortLastTime) {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
              msg = (mach_msg_header_t *)msg_buffer;
              if (__CFRunLoopServiceMachPort(dispatchPort, &msg, sizeof(msg_buffer), &livePort, 0, &voucherState, NULL)) {
                  goto handle_msg;
              }
  #elif DEPLOYMENT_TARGET_WINDOWS
              if (__CFRunLoopWaitForMultipleObjects(NULL, &dispatchPort, 0, 0, &livePort, NULL)) {
                  goto handle_msg;
              }
  #endif
          }
          
          didDispatchPortLastTime = false;
          
          if (!poll && (rlm->_observerMask & kCFRunLoopBeforeWaiting)) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopBeforeWaiting);
          __CFRunLoopSetSleeping(rl);
          // do not do any user callouts after this point (after notifying of sleeping)
          
          // Must push the local-to-this-activation ports in on every loop
          // iteration, as this mode could be run re-entrantly and we don't
          // want these ports to get serviced.
          
          __CFPortSetInsert(dispatchPort, waitSet);
          
          __CFRunLoopModeUnlock(rlm);
          __CFRunLoopUnlock(rl);
          
          CFAbsoluteTime sleepStart = poll ? 0.0 : CFAbsoluteTimeGetCurrent();
          
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
          do {
              if (kCFUseCollectableAllocator) {
                  // objc_clear_stack(0);
                  // <rdar://problem/16393959>
                  memset(msg_buffer, 0, sizeof(msg_buffer));
              }
              msg = (mach_msg_header_t *)msg_buffer;
              
              __CFRunLoopServiceMachPort(waitSet, &msg, sizeof(msg_buffer), &livePort, poll ? 0 : TIMEOUT_INFINITY, &voucherState, &voucherCopy);
              
              if (modeQueuePort != MACH_PORT_NULL && livePort == modeQueuePort) {
                  // Drain the internal queue. If one of the callout blocks sets the timerFired flag, break out and service the timer.
                  while (_dispatch_runloop_root_queue_perform_4CF(rlm->_queue));
                  if (rlm->_timerFired) {
                      // Leave livePort as the queue port, and service timers below
                      rlm->_timerFired = false;
                      break;
                  } else {
                      if (msg && msg != (mach_msg_header_t *)msg_buffer) free(msg);
                  }
              } else {
                  // Go ahead and leave the inner loop.
                  break;
              }
          } while (1);
  #else
          if (kCFUseCollectableAllocator) {
              // objc_clear_stack(0);
              // <rdar://problem/16393959>
              memset(msg_buffer, 0, sizeof(msg_buffer));
          }
          msg = (mach_msg_header_t *)msg_buffer;
          __CFRunLoopServiceMachPort(waitSet, &msg, sizeof(msg_buffer), &livePort, poll ? 0 : TIMEOUT_INFINITY, &voucherState, &voucherCopy);
  #endif
          
          
  #elif DEPLOYMENT_TARGET_WINDOWS
          // Here, use the app-supplied message queue mask. They will set this if they are interested in having this run loop receive windows messages.
          __CFRunLoopWaitForMultipleObjects(waitSet, NULL, poll ? 0 : TIMEOUT_INFINITY, rlm->_msgQMask, &livePort, &windowsMessageReceived);
  #endif
          
          __CFRunLoopLock(rl);
          __CFRunLoopModeLock(rlm);
          
          rl->_sleepTime += (poll ? 0.0 : (CFAbsoluteTimeGetCurrent() - sleepStart));
          
          // Must remove the local-to-this-activation ports in on every loop
          // iteration, as this mode could be run re-entrantly and we don't
          // want these ports to get serviced. Also, we don't want them left
          // in there if this function returns.
          
          __CFPortSetRemove(dispatchPort, waitSet);
          
          __CFRunLoopSetIgnoreWakeUps(rl);
          
          // user callouts now OK again
          __CFRunLoopUnsetSleeping(rl);
          if (!poll && (rlm->_observerMask & kCFRunLoopAfterWaiting)) __CFRunLoopDoObservers(rl, rlm, kCFRunLoopAfterWaiting);
          
      handle_msg:;
          __CFRunLoopSetIgnoreWakeUps(rl);
          
  #if DEPLOYMENT_TARGET_WINDOWS
          if (windowsMessageReceived) {
              // These Win32 APIs cause a callout, so make sure we're unlocked first and relocked after
              __CFRunLoopModeUnlock(rlm);
              __CFRunLoopUnlock(rl);
              
              if (rlm->_msgPump) {
                  rlm->_msgPump();
              } else {
                  MSG msg;
                  if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE | PM_NOYIELD)) {
                      TranslateMessage(&msg);
                      DispatchMessage(&msg);
                  }
              }
              
              __CFRunLoopLock(rl);
              __CFRunLoopModeLock(rlm);
              sourceHandledThisLoop = true;
              
              // To prevent starvation of sources other than the message queue, we check again to see if any other sources need to be serviced
              // Use 0 for the mask so windows messages are ignored this time. Also use 0 for the timeout, because we're just checking to see if the things are signalled right now -- we will wait on them again later.
              // NOTE: Ignore the dispatch source (it's not in the wait set anymore) and also don't run the observers here since we are polling.
              __CFRunLoopSetSleeping(rl);
              __CFRunLoopModeUnlock(rlm);
              __CFRunLoopUnlock(rl);
              
              __CFRunLoopWaitForMultipleObjects(waitSet, NULL, 0, 0, &livePort, NULL);
              
              __CFRunLoopLock(rl);
              __CFRunLoopModeLock(rlm);
              __CFRunLoopUnsetSleeping(rl);
              // If we have a new live port then it will be handled below as normal
          }
          
          
  #endif
          if (MACH_PORT_NULL == livePort) {
              CFRUNLOOP_WAKEUP_FOR_NOTHING();
              // handle nothing
          } else if (livePort == rl->_wakeUpPort) {
              CFRUNLOOP_WAKEUP_FOR_WAKEUP();
              // do nothing on Mac OS
  #if DEPLOYMENT_TARGET_WINDOWS
              // Always reset the wake up port, or risk spinning forever
              ResetEvent(rl->_wakeUpPort);
  #endif
          }
  #if USE_DISPATCH_SOURCE_FOR_TIMERS
          else if (modeQueuePort != MACH_PORT_NULL && livePort == modeQueuePort) {
              CFRUNLOOP_WAKEUP_FOR_TIMER();
              if (!__CFRunLoopDoTimers(rl, rlm, mach_absolute_time())) {
                  // Re-arm the next timer, because we apparently fired early
                  __CFArmNextTimerInMode(rlm, rl);
              }
          }
  #endif
  #if USE_MK_TIMER_TOO
          else if (rlm->_timerPort != MACH_PORT_NULL && livePort == rlm->_timerPort) {
              CFRUNLOOP_WAKEUP_FOR_TIMER();
              // On Windows, we have observed an issue where the timer port is set before the time which we requested it to be set. For example, we set the fire time to be TSR 167646765860, but it is actually observed firing at TSR 167646764145, which is 1715 ticks early. The result is that, when __CFRunLoopDoTimers checks to see if any of the run loop timers should be firing, it appears to be 'too early' for the next timer, and no timers are handled.
              // In this case, the timer port has been automatically reset (since it was returned from MsgWaitForMultipleObjectsEx), and if we do not re-arm it, then no timers will ever be serviced again unless something adjusts the timer list (e.g. adding or removing timers). The fix for the issue is to reset the timer here if CFRunLoopDoTimers did not handle a timer itself. 9308754
              if (!__CFRunLoopDoTimers(rl, rlm, mach_absolute_time())) {
                  // Re-arm the next timer
                  __CFArmNextTimerInMode(rlm, rl);
              }
          }
  #endif
          else if (livePort == dispatchPort) {
              CFRUNLOOP_WAKEUP_FOR_DISPATCH();
              __CFRunLoopModeUnlock(rlm);
              __CFRunLoopUnlock(rl);
              _CFSetTSD(__CFTSDKeyIsInGCDMainQ, (void *)6, NULL);
  #if DEPLOYMENT_TARGET_WINDOWS
              void *msg = 0;
  #endif
              __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__(msg);
              _CFSetTSD(__CFTSDKeyIsInGCDMainQ, (void *)0, NULL);
              __CFRunLoopLock(rl);
              __CFRunLoopModeLock(rlm);
              sourceHandledThisLoop = true;
              didDispatchPortLastTime = true;
          } else {
              CFRUNLOOP_WAKEUP_FOR_SOURCE();
              
              // If we received a voucher from this mach_msg, then put a copy of the new voucher into TSD. CFMachPortBoost will look in the TSD for the voucher. By using the value in the TSD we tie the CFMachPortBoost to this received mach_msg explicitly without a chance for anything in between the two pieces of code to set the voucher again.
              voucher_t previousVoucher = _CFSetTSD(__CFTSDKeyMachMessageHasVoucher, (void *)voucherCopy, os_release);
              
              // Despite the name, this works for windows handles as well
              CFRunLoopSourceRef rls = __CFRunLoopModeFindSourceForMachPort(rl, rlm, livePort);
              if (rls) {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
                  mach_msg_header_t *reply = NULL;
                  sourceHandledThisLoop = __CFRunLoopDoSource1(rl, rlm, rls, msg, msg->msgh_size, &reply) || sourceHandledThisLoop;
                  if (NULL != reply) {
                      (void)mach_msg(reply, MACH_SEND_MSG, reply->msgh_size, 0, MACH_PORT_NULL, 0, MACH_PORT_NULL);
                      CFAllocatorDeallocate(kCFAllocatorSystemDefault, reply);
                  }
  #elif DEPLOYMENT_TARGET_WINDOWS
                  sourceHandledThisLoop = __CFRunLoopDoSource1(rl, rlm, rls) || sourceHandledThisLoop;
  #endif
              }
              
              // Restore the previous voucher
              _CFSetTSD(__CFTSDKeyMachMessageHasVoucher, previousVoucher, os_release);
              
          }
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          if (msg && msg != (mach_msg_header_t *)msg_buffer) free(msg);
  #endif
          
          __CFRunLoopDoBlocks(rl, rlm);
          
          
          if (sourceHandledThisLoop && stopAfterHandle) {
              retVal = kCFRunLoopRunHandledSource;
          } else if (timeout_context->termTSR < mach_absolute_time()) {
              // 自身超时时间到了
              retVal = kCFRunLoopRunTimedOut;
          } else if (__CFRunLoopIsStopped(rl)) {
              // 被外部调用CFRunloop停止
              __CFRunLoopUnsetStopped(rl);
              retVal = kCFRunLoopRunStopped;
          } else if (rlm->_stopped) {
              // 被 _CFRunLoopStopMode 停止
              rlm->_stopped = false;
              retVal = kCFRunLoopRunStopped;
          } else if (__CFRunLoopModeIsEmpty(rl, rlm, previousMode)) { // 检查上一个 mode 有没有执行完所有事件源
              retVal = kCFRunLoopRunFinished;
          }
          
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          voucher_mach_msg_revert(voucherState);
          os_release(voucherCopy);
  #endif
          
      } while (0 == retVal);
      
      if (timeout_timer) {
          dispatch_source_cancel(timeout_timer);
          dispatch_release(timeout_timer);
      } else {
          free(timeout_context);
      }
      
      return retVal;
  }
  
  SInt32 CFRunLoopRunSpecific(CFRunLoopRef rl, CFStringRef modeName, CFTimeInterval seconds, Boolean returnAfterSourceHandled) {     /* DOES CALLOUT */
      CHECK_FOR_FORK();
      if (__CFRunLoopIsDeallocating(rl)) return kCFRunLoopRunFinished;
      __CFRunLoopLock(rl);
      CFRunLoopModeRef currentMode = __CFRunLoopFindMode(rl, modeName, false);
      if (NULL == currentMode || __CFRunLoopModeIsEmpty(rl, currentMode, rl->_currentMode)) {
          Boolean did = false;
          if (currentMode) __CFRunLoopModeUnlock(currentMode);
          __CFRunLoopUnlock(rl);
          return did ? kCFRunLoopRunHandledSource : kCFRunLoopRunFinished;
      }
      volatile _per_run_data *previousPerRun = __CFRunLoopPushPerRunData(rl);
      CFRunLoopModeRef previousMode = rl->_currentMode;
      rl->_currentMode = currentMode;
      int32_t result = kCFRunLoopRunFinished;
      
      if (currentMode->_observerMask & kCFRunLoopEntry ) __CFRunLoopDoObservers(rl, currentMode, kCFRunLoopEntry);
      result = __CFRunLoopRun(rl, currentMode, seconds, returnAfterSourceHandled, previousMode);
      if (currentMode->_observerMask & kCFRunLoopExit ) __CFRunLoopDoObservers(rl, currentMode, kCFRunLoopExit);
      
      __CFRunLoopModeUnlock(currentMode);
      __CFRunLoopPopPerRunData(rl, previousPerRun);
      rl->_currentMode = previousMode;
      __CFRunLoopUnlock(rl);
      return result;
  }
  
  void CFRunLoopRun(void) {	/* DOES CALLOUT */
      int32_t result;
      do {
          result = CFRunLoopRunSpecific(CFRunLoopGetCurrent(), kCFRunLoopDefaultMode, 1.0e10, false);
          CHECK_FOR_FORK();
      } while (kCFRunLoopRunStopped != result && kCFRunLoopRunFinished != result);
  }
  
  SInt32 CFRunLoopRunInMode(CFStringRef modeName, CFTimeInterval seconds, Boolean returnAfterSourceHandled) {     /* DOES CALLOUT */
      CHECK_FOR_FORK();
      return CFRunLoopRunSpecific(CFRunLoopGetCurrent(), modeName, seconds, returnAfterSourceHandled);
  }
  
  CFAbsoluteTime CFRunLoopGetNextTimerFireDate(CFRunLoopRef rl, CFStringRef modeName) {
      CHECK_FOR_FORK();
      __CFRunLoopLock(rl);
      CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
      CFAbsoluteTime at = 0.0;
      CFRunLoopTimerRef nextTimer = (rlm && rlm->_timers && 0 < CFArrayGetCount(rlm->_timers)) ? (CFRunLoopTimerRef)CFArrayGetValueAtIndex(rlm->_timers, 0) : NULL;
      if (nextTimer) {
          at = CFRunLoopTimerGetNextFireDate(nextTimer);
      }
      if (rlm) __CFRunLoopModeUnlock(rlm);
      __CFRunLoopUnlock(rl);
      return at;
  }
  
  Boolean CFRunLoopIsWaiting(CFRunLoopRef rl) {
      CHECK_FOR_FORK();
      return __CFRunLoopIsSleeping(rl);
  }
  
  void CFRunLoopWakeUp(CFRunLoopRef rl) {
      CHECK_FOR_FORK();
      // This lock is crucial to ignorable wakeups, do not remove it.
      __CFRunLoopLock(rl);
      if (__CFRunLoopIsIgnoringWakeUps(rl)) {
          __CFRunLoopUnlock(rl);
          return;
      }
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
      kern_return_t ret;
      /* We unconditionally try to send the message, since we don't want
       * to lose a wakeup, but the send may fail if there is already a
       * wakeup pending, since the queue length is 1. */
      ret = __CFSendTrivialMachMessage(rl->_wakeUpPort, 0, MACH_SEND_TIMEOUT, 0);
      if (ret != MACH_MSG_SUCCESS && ret != MACH_SEND_TIMED_OUT) CRASH("*** Unable to send message to wake up port. (%d) ***", ret);
  #elif DEPLOYMENT_TARGET_WINDOWS
      SetEvent(rl->_wakeUpPort);
  #endif
      __CFRunLoopUnlock(rl);
  }
  
  void CFRunLoopStop(CFRunLoopRef rl) {
      Boolean doWake = false;
      CHECK_FOR_FORK();
      __CFRunLoopLock(rl);
      if (rl->_currentMode) {
          __CFRunLoopSetStopped(rl);
          doWake = true;
      }
      __CFRunLoopUnlock(rl);
      if (doWake) {
          CFRunLoopWakeUp(rl);
      }
  }
  
  CF_EXPORT void _CFRunLoopStopMode(CFRunLoopRef rl, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      __CFRunLoopLock(rl);
      rlm = __CFRunLoopFindMode(rl, modeName, true);
      if (NULL != rlm) {
          rlm->_stopped = true;
          __CFRunLoopModeUnlock(rlm);
      }
      __CFRunLoopUnlock(rl);
      CFRunLoopWakeUp(rl);
  }
  
  CF_EXPORT Boolean _CFRunLoopModeContainsMode(CFRunLoopRef rl, CFStringRef modeName, CFStringRef candidateContainedName) {
      CHECK_FOR_FORK();
      return false;
  }
  
  void CFRunLoopPerformBlock(CFRunLoopRef rl, CFTypeRef mode, void (^block)(void)) {
      CHECK_FOR_FORK();
      if (CFStringGetTypeID() == CFGetTypeID(mode)) {
          mode = CFStringCreateCopy(kCFAllocatorSystemDefault, (CFStringRef)mode);
          __CFRunLoopLock(rl);
          // ensure mode exists
          CFRunLoopModeRef currentMode = __CFRunLoopFindMode(rl, (CFStringRef)mode, true);
          if (currentMode) __CFRunLoopModeUnlock(currentMode);
          __CFRunLoopUnlock(rl);
      } else if (CFArrayGetTypeID() == CFGetTypeID(mode)) {
          CFIndex cnt = CFArrayGetCount((CFArrayRef)mode);
          const void **values = (const void **)malloc(sizeof(const void *) * cnt);
          CFArrayGetValues((CFArrayRef)mode, CFRangeMake(0, cnt), values);
          mode = CFSetCreate(kCFAllocatorSystemDefault, values, cnt, &kCFTypeSetCallBacks);
          __CFRunLoopLock(rl);
          // ensure modes exist
          for (CFIndex idx = 0; idx < cnt; idx++) {
              CFRunLoopModeRef currentMode = __CFRunLoopFindMode(rl, (CFStringRef)values[idx], true);
              if (currentMode) __CFRunLoopModeUnlock(currentMode);
          }
          __CFRunLoopUnlock(rl);
          free(values);
      } else if (CFSetGetTypeID() == CFGetTypeID(mode)) {
          CFIndex cnt = CFSetGetCount((CFSetRef)mode);
          const void **values = (const void **)malloc(sizeof(const void *) * cnt);
          CFSetGetValues((CFSetRef)mode, values);
          mode = CFSetCreate(kCFAllocatorSystemDefault, values, cnt, &kCFTypeSetCallBacks);
          __CFRunLoopLock(rl);
          // ensure modes exist
          for (CFIndex idx = 0; idx < cnt; idx++) {
              CFRunLoopModeRef currentMode = __CFRunLoopFindMode(rl, (CFStringRef)values[idx], true);
              if (currentMode) __CFRunLoopModeUnlock(currentMode);
          }
          __CFRunLoopUnlock(rl);
          free(values);
      } else {
          mode = NULL;
      }
      block = Block_copy(block);
      if (!mode || !block) {
          if (mode) CFRelease(mode);
          if (block) Block_release(block);
          return;
      }
      __CFRunLoopLock(rl);
      struct _block_item *new_item = (struct _block_item *)malloc(sizeof(struct _block_item));
      new_item->_next = NULL;
      new_item->_mode = mode;
      new_item->_block = block;
      if (!rl->_blocks_tail) {
          rl->_blocks_head = new_item;
      } else {
          rl->_blocks_tail->_next = new_item;
      }
      rl->_blocks_tail = new_item;
      __CFRunLoopUnlock(rl);
  }
  
  Boolean CFRunLoopContainsSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      Boolean hasValue = false;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems) {
              hasValue = CFSetContainsValue(rl->_commonModeItems, rls);
          }
      } else {
          rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm) {
              hasValue = (rlm->_sources0 ? CFSetContainsValue(rlm->_sources0, rls) : false) || (rlm->_sources1 ? CFSetContainsValue(rlm->_sources1, rls) : false);
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
      return hasValue;
  }
  
  void CFRunLoopAddSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      if (__CFRunLoopIsDeallocating(rl)) return;
      if (!__CFIsValid(rls)) return;
      Boolean doVer0Callout = false;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
          if (NULL == rl->_commonModeItems) {
              rl->_commonModeItems = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
          }
          CFSetAddValue(rl->_commonModeItems, rls);
          if (NULL != set) {
              CFTypeRef context[2] = {rl, rls};
              /* add new item to all common-modes */
              CFSetApplyFunction(set, (__CFRunLoopAddItemToCommonModes), (void *)context);
              CFRelease(set);
          }
      } else {
          CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true);
          if (NULL != rlm && NULL == rlm->_sources0) {
              rlm->_sources0 = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
              rlm->_sources1 = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
              rlm->_portToV1SourceMap = CFDictionaryCreateMutable(kCFAllocatorSystemDefault, 0, NULL, NULL);
          }
          if (NULL != rlm && !CFSetContainsValue(rlm->_sources0, rls) && !CFSetContainsValue(rlm->_sources1, rls)) {
              if (0 == rls->_context.version0.version) {
                  CFSetAddValue(rlm->_sources0, rls);
              } else if (1 == rls->_context.version0.version) {
                  CFSetAddValue(rlm->_sources1, rls);
                  __CFPort src_port = rls->_context.version1.getPort(rls->_context.version1.info);
                  if (CFPORT_NULL != src_port) {
                      CFDictionarySetValue(rlm->_portToV1SourceMap, (const void *)(uintptr_t)src_port, rls);
                      __CFPortSetInsert(src_port, rlm->_portSet);
                  }
              }
              __CFRunLoopSourceLock(rls);
              if (NULL == rls->_runLoops) {
                  rls->_runLoops = CFBagCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeBagCallBacks); // sources retain run loops!
              }
              CFBagAddValue(rls->_runLoops, rl);
              __CFRunLoopSourceUnlock(rls);
              if (0 == rls->_context.version0.version) {
                  if (NULL != rls->_context.version0.schedule) {
                      doVer0Callout = true;
                  }
              }
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
      if (doVer0Callout) {
          // although it looses some protection for the source, we have no choice but
          // to do this after unlocking the run loop and mode locks, to avoid deadlocks
          // where the source wants to take a lock which is already held in another
          // thread which is itself waiting for a run loop/mode lock
          rls->_context.version0.schedule(rls->_context.version0.info, rl, modeName);	/* CALLOUT */
      }
  }
  
  void CFRunLoopRemoveSource(CFRunLoopRef rl, CFRunLoopSourceRef rls, CFStringRef modeName) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      Boolean doVer0Callout = false, doRLSRelease = false;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems && CFSetContainsValue(rl->_commonModeItems, rls)) {
              CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
              CFSetRemoveValue(rl->_commonModeItems, rls);
              if (NULL != set) {
                  CFTypeRef context[2] = {rl, rls};
                  /* remove new item from all common-modes */
                  CFSetApplyFunction(set, (__CFRunLoopRemoveItemFromCommonModes), (void *)context);
                  CFRelease(set);
              }
          } else {
          }
      } else {
          CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm && ((NULL != rlm->_sources0 && CFSetContainsValue(rlm->_sources0, rls)) || (NULL != rlm->_sources1 && CFSetContainsValue(rlm->_sources1, rls)))) {
              CFRetain(rls);
              if (1 == rls->_context.version0.version) {
                  __CFPort src_port = rls->_context.version1.getPort(rls->_context.version1.info);
                  if (CFPORT_NULL != src_port) {
                      CFDictionaryRemoveValue(rlm->_portToV1SourceMap, (const void *)(uintptr_t)src_port);
                      __CFPortSetRemove(src_port, rlm->_portSet);
                  }
              }
              CFSetRemoveValue(rlm->_sources0, rls);
              CFSetRemoveValue(rlm->_sources1, rls);
              __CFRunLoopSourceLock(rls);
              if (NULL != rls->_runLoops) {
                  CFBagRemoveValue(rls->_runLoops, rl);
              }
              __CFRunLoopSourceUnlock(rls);
              if (0 == rls->_context.version0.version) {
                  if (NULL != rls->_context.version0.cancel) {
                      doVer0Callout = true;
                  }
              }
              doRLSRelease = true;
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
      if (doVer0Callout) {
          // although it looses some protection for the source, we have no choice but
          // to do this after unlocking the run loop and mode locks, to avoid deadlocks
          // where the source wants to take a lock which is already held in another
          // thread which is itself waiting for a run loop/mode lock
          rls->_context.version0.cancel(rls->_context.version0.info, rl, modeName);	/* CALLOUT */
      }
      if (doRLSRelease) CFRelease(rls);
  }
  
  static void __CFRunLoopRemoveSourcesFromCommonMode(const void *value, void *ctx) {
      CFStringRef modeName = (CFStringRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)ctx;
      __CFRunLoopRemoveAllSources(rl, modeName);
  }
  
  static void __CFRunLoopRemoveSourceFromMode(const void *value, void *ctx) {
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)value;
      CFRunLoopRef rl = (CFRunLoopRef)(((CFTypeRef *)ctx)[0]);
      CFStringRef modeName = (CFStringRef)(((CFTypeRef *)ctx)[1]);
      CFRunLoopRemoveSource(rl, rls, modeName);
  }
  
  static void __CFRunLoopRemoveAllSources(CFRunLoopRef rl, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems) {
              CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
              if (NULL != set) {
                  CFSetApplyFunction(set, (__CFRunLoopRemoveSourcesFromCommonMode), (void *)rl);
                  CFRelease(set);
              }
          } else {
          }
      } else {
          rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm && NULL != rlm->_sources0) {
              CFSetRef set = CFSetCreateCopy(kCFAllocatorSystemDefault, rlm->_sources0);
              CFTypeRef context[2] = {rl, modeName};
              CFSetApplyFunction(set, (__CFRunLoopRemoveSourceFromMode), (void *)context);
              CFRelease(set);
          }
          if (NULL != rlm && NULL != rlm->_sources1) {
              CFSetRef set = CFSetCreateCopy(kCFAllocatorSystemDefault, rlm->_sources1);
              CFTypeRef context[2] = {rl, modeName};
              CFSetApplyFunction(set, (__CFRunLoopRemoveSourceFromMode), (void *)context);
              CFRelease(set);
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
  }
  
  Boolean CFRunLoopContainsObserver(CFRunLoopRef rl, CFRunLoopObserverRef rlo, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      Boolean hasValue = false;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems) {
              hasValue = CFSetContainsValue(rl->_commonModeItems, rlo);
          }
      } else {
          rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm && NULL != rlm->_observers) {
              hasValue = CFArrayContainsValue(rlm->_observers, CFRangeMake(0, CFArrayGetCount(rlm->_observers)), rlo);
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
      return hasValue;
  }
  
  void CFRunLoopAddObserver(CFRunLoopRef rl, CFRunLoopObserverRef rlo, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      if (__CFRunLoopIsDeallocating(rl)) return;
      if (!__CFIsValid(rlo) || (NULL != rlo->_runLoop && rlo->_runLoop != rl)) return;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
          if (NULL == rl->_commonModeItems) {
              rl->_commonModeItems = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
          }
          CFSetAddValue(rl->_commonModeItems, rlo);
          if (NULL != set) {
              CFTypeRef context[2] = {rl, rlo};
              /* add new item to all common-modes */
              CFSetApplyFunction(set, (__CFRunLoopAddItemToCommonModes), (void *)context);
              CFRelease(set);
          }
      } else {
          rlm = __CFRunLoopFindMode(rl, modeName, true);
          if (NULL != rlm && NULL == rlm->_observers) {
              rlm->_observers = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeArrayCallBacks);
          }
          if (NULL != rlm && !CFArrayContainsValue(rlm->_observers, CFRangeMake(0, CFArrayGetCount(rlm->_observers)), rlo)) {
              Boolean inserted = false;
              for (CFIndex idx = CFArrayGetCount(rlm->_observers); idx--; ) {
                  CFRunLoopObserverRef obs = (CFRunLoopObserverRef)CFArrayGetValueAtIndex(rlm->_observers, idx);
                  if (obs->_order <= rlo->_order) {
                      CFArrayInsertValueAtIndex(rlm->_observers, idx + 1, rlo);
                      inserted = true;
                      break;
                  }
              }
              if (!inserted) {
                  CFArrayInsertValueAtIndex(rlm->_observers, 0, rlo);
              }
              rlm->_observerMask |= rlo->_activities;
              __CFRunLoopObserverSchedule(rlo, rl, rlm);
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
  }
  
  void CFRunLoopRemoveObserver(CFRunLoopRef rl, CFRunLoopObserverRef rlo, CFStringRef modeName) {
      CHECK_FOR_FORK();
      CFRunLoopModeRef rlm;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems && CFSetContainsValue(rl->_commonModeItems, rlo)) {
              CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
              CFSetRemoveValue(rl->_commonModeItems, rlo);
              if (NULL != set) {
                  CFTypeRef context[2] = {rl, rlo};
                  /* remove new item from all common-modes */
                  CFSetApplyFunction(set, (__CFRunLoopRemoveItemFromCommonModes), (void *)context);
                  CFRelease(set);
              }
          } else {
          }
      } else {
          rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm && NULL != rlm->_observers) {
              CFRetain(rlo);
              CFIndex idx = CFArrayGetFirstIndexOfValue(rlm->_observers, CFRangeMake(0, CFArrayGetCount(rlm->_observers)), rlo);
              if (kCFNotFound != idx) {
                  CFArrayRemoveValueAtIndex(rlm->_observers, idx);
                  __CFRunLoopObserverCancel(rlo, rl, rlm);
              }
              CFRelease(rlo);
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
  }
  
  Boolean CFRunLoopContainsTimer(CFRunLoopRef rl, CFRunLoopTimerRef rlt, CFStringRef modeName) {
      CHECK_FOR_FORK();
      if (NULL == rlt->_runLoop || rl != rlt->_runLoop) return false;
      Boolean hasValue = false;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems) {
              hasValue = CFSetContainsValue(rl->_commonModeItems, rlt);
          }
      } else {
          CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
          if (NULL != rlm) {
              if (NULL != rlm->_timers) {
                  CFIndex idx = CFArrayGetFirstIndexOfValue(rlm->_timers, CFRangeMake(0, CFArrayGetCount(rlm->_timers)), rlt);
                  hasValue = (kCFNotFound != idx);
              }
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
      return hasValue;
  }
  
  void CFRunLoopAddTimer(CFRunLoopRef rl, CFRunLoopTimerRef rlt, CFStringRef modeName) {    
      CHECK_FOR_FORK();
      if (__CFRunLoopIsDeallocating(rl)) return;
      if (!__CFIsValid(rlt) || (NULL != rlt->_runLoop && rlt->_runLoop != rl)) return;
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
          if (NULL == rl->_commonModeItems) {
              rl->_commonModeItems = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
          }
          CFSetAddValue(rl->_commonModeItems, rlt);
          if (NULL != set) {
              CFTypeRef context[2] = {rl, rlt};
              /* add new item to all common-modes */
              CFSetApplyFunction(set, (__CFRunLoopAddItemToCommonModes), (void *)context);
              CFRelease(set);
          }
      } else {
          CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, true);
          if (NULL != rlm) {
              if (NULL == rlm->_timers) {
                  CFArrayCallBacks cb = kCFTypeArrayCallBacks;
                  cb.equal = NULL;
                  rlm->_timers = CFArrayCreateMutable(kCFAllocatorSystemDefault, 0, &cb);
              }
          }
          if (NULL != rlm && !CFSetContainsValue(rlt->_rlModes, rlm->_name)) {
              __CFRunLoopTimerLock(rlt);
              if (NULL == rlt->_runLoop) {
                  rlt->_runLoop = rl;
              } else if (rl != rlt->_runLoop) {
                  __CFRunLoopTimerUnlock(rlt);
                  __CFRunLoopModeUnlock(rlm);
                  __CFRunLoopUnlock(rl);
                  return;
              }
              CFSetAddValue(rlt->_rlModes, rlm->_name);
              __CFRunLoopTimerUnlock(rlt);
              __CFRunLoopTimerFireTSRLock();
              __CFRepositionTimerInMode(rlm, rlt, false);
              __CFRunLoopTimerFireTSRUnlock();
              if (!_CFExecutableLinkedOnOrAfter(CFSystemVersionLion)) {
                  // Normally we don't do this on behalf of clients, but for
                  // backwards compatibility due to the change in timer handling...
                  if (rl != CFRunLoopGetCurrent()) CFRunLoopWakeUp(rl);
              }
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
  }
  
  void CFRunLoopRemoveTimer(CFRunLoopRef rl, CFRunLoopTimerRef rlt, CFStringRef modeName) {
      CHECK_FOR_FORK();
      __CFRunLoopLock(rl);
      if (modeName == kCFRunLoopCommonModes) {
          if (NULL != rl->_commonModeItems && CFSetContainsValue(rl->_commonModeItems, rlt)) {
              CFSetRef set = rl->_commonModes ? CFSetCreateCopy(kCFAllocatorSystemDefault, rl->_commonModes) : NULL;
              CFSetRemoveValue(rl->_commonModeItems, rlt);
              if (NULL != set) {
                  CFTypeRef context[2] = {rl, rlt};
                  /* remove new item from all common-modes */
                  CFSetApplyFunction(set, (__CFRunLoopRemoveItemFromCommonModes), (void *)context);
                  CFRelease(set);
              }
          } else {
          }
      } else {
          CFRunLoopModeRef rlm = __CFRunLoopFindMode(rl, modeName, false);
          CFIndex idx = kCFNotFound;
          CFMutableArrayRef timerList = NULL;
          if (NULL != rlm) {
              timerList = rlm->_timers;
              if (NULL != timerList) {
                  idx = CFArrayGetFirstIndexOfValue(timerList, CFRangeMake(0, CFArrayGetCount(timerList)), rlt);
              }
          }
          if (kCFNotFound != idx) {
              __CFRunLoopTimerLock(rlt);
              CFSetRemoveValue(rlt->_rlModes, rlm->_name);
              if (0 == CFSetGetCount(rlt->_rlModes)) {
                  rlt->_runLoop = NULL;
              }
              __CFRunLoopTimerUnlock(rlt);
              CFArrayRemoveValueAtIndex(timerList, idx);
              __CFArmNextTimerInMode(rlm, rl);
          }
          if (NULL != rlm) {
              __CFRunLoopModeUnlock(rlm);
          }
      }
      __CFRunLoopUnlock(rl);
  }
  
  /* CFRunLoopSource */
  
  static Boolean __CFRunLoopSourceEqual(CFTypeRef cf1, CFTypeRef cf2) {	/* DOES CALLOUT */
      CFRunLoopSourceRef rls1 = (CFRunLoopSourceRef)cf1;
      CFRunLoopSourceRef rls2 = (CFRunLoopSourceRef)cf2;
      if (rls1 == rls2) return true;
      if (__CFIsValid(rls1) != __CFIsValid(rls2)) return false;
      if (rls1->_order != rls2->_order) return false;
      if (rls1->_context.version0.version != rls2->_context.version0.version) return false;
      if (rls1->_context.version0.hash != rls2->_context.version0.hash) return false;
      if (rls1->_context.version0.equal != rls2->_context.version0.equal) return false;
      if (0 == rls1->_context.version0.version && rls1->_context.version0.perform != rls2->_context.version0.perform) return false;
      if (1 == rls1->_context.version0.version && rls1->_context.version1.perform != rls2->_context.version1.perform) return false;
      if (rls1->_context.version0.equal)
          return rls1->_context.version0.equal(rls1->_context.version0.info, rls2->_context.version0.info);
      return (rls1->_context.version0.info == rls2->_context.version0.info);
  }
  
  static CFHashCode __CFRunLoopSourceHash(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)cf;
      if (rls->_context.version0.hash)
          return rls->_context.version0.hash(rls->_context.version0.info);
      return (CFHashCode)rls->_context.version0.info;
  }
  
  static CFStringRef __CFRunLoopSourceCopyDescription(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)cf;
      CFStringRef result;
      CFStringRef contextDesc = NULL;
      if (NULL != rls->_context.version0.copyDescription) {
          contextDesc = rls->_context.version0.copyDescription(rls->_context.version0.info);
      }
      if (NULL == contextDesc) {
          void *addr = rls->_context.version0.version == 0 ? (void *)rls->_context.version0.perform : (rls->_context.version0.version == 1 ? (void *)rls->_context.version1.perform : NULL);
  #if DEPLOYMENT_TARGET_WINDOWS
          contextDesc = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopSource context>{version = %ld, info = %p, callout = %p}"), rls->_context.version0.version, rls->_context.version0.info, addr);
  #elif DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
          Dl_info info;
          const char *name = (dladdr(addr, &info) && info.dli_saddr == addr && info.dli_sname) ? info.dli_sname : "???";
          contextDesc = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopSource context>{version = %ld, info = %p, callout = %s (%p)}"), rls->_context.version0.version, rls->_context.version0.info, name, addr);
  #endif
      }
  #if DEPLOYMENT_TARGET_WINDOWS
      result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopSource %p [%p]>{signalled = %s, valid = %s, order = %d, context = %@}"), cf, CFGetAllocator(rls), __CFRunLoopSourceIsSignaled(rls) ? "Yes" : "No", __CFIsValid(rls) ? "Yes" : "No", rls->_order, contextDesc);
  #else
      result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopSource %p [%p]>{signalled = %s, valid = %s, order = %ld, context = %@}"), cf, CFGetAllocator(rls), __CFRunLoopSourceIsSignaled(rls) ? "Yes" : "No", __CFIsValid(rls) ? "Yes" : "No", (unsigned long)rls->_order, contextDesc);
  #endif
      CFRelease(contextDesc);
      return result;
  }
  
  static void __CFRunLoopSourceDeallocate(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)cf;
      CFRunLoopSourceInvalidate(rls);
      if (rls->_context.version0.release) {
          rls->_context.version0.release(rls->_context.version0.info);
      }
      pthread_mutex_destroy(&rls->_lock);
      memset((char *)cf + sizeof(CFRuntimeBase), 0, sizeof(struct __CFRunLoopSource) - sizeof(CFRuntimeBase));
  }
  
  static const CFRuntimeClass __CFRunLoopSourceClass = {
      _kCFRuntimeScannedObject,
      "CFRunLoopSource",
      NULL,      // init
      NULL,      // copy
      __CFRunLoopSourceDeallocate,
      __CFRunLoopSourceEqual,
      __CFRunLoopSourceHash,
      NULL,      //
      __CFRunLoopSourceCopyDescription
  };
  
  CFTypeID CFRunLoopSourceGetTypeID(void) {
      static dispatch_once_t initOnce;
      dispatch_once(&initOnce, ^{ __kCFRunLoopSourceTypeID = _CFRuntimeRegisterClass(&__CFRunLoopSourceClass); });
      return __kCFRunLoopSourceTypeID;
  }
  
  CFRunLoopSourceRef CFRunLoopSourceCreate(CFAllocatorRef allocator, CFIndex order, CFRunLoopSourceContext *context) {
      CHECK_FOR_FORK();
      CFRunLoopSourceRef memory;
      uint32_t size;
      if (NULL == context) CRASH("*** NULL context value passed to CFRunLoopSourceCreate(). (%d) ***", -1);
      
      size = sizeof(struct __CFRunLoopSource) - sizeof(CFRuntimeBase);
      memory = (CFRunLoopSourceRef)_CFRuntimeCreateInstance(allocator, CFRunLoopSourceGetTypeID(), size, NULL);
      if (NULL == memory) {
          return NULL;
      }
      __CFSetValid(memory);
      __CFRunLoopSourceUnsetSignaled(memory);
      __CFRunLoopLockInit(&memory->_lock);
      memory->_bits = 0;
      memory->_order = order;
      memory->_runLoops = NULL;
      size = 0;
      switch (context->version) {
          case 0:
              size = sizeof(CFRunLoopSourceContext);
              break;
          case 1:
              size = sizeof(CFRunLoopSourceContext1);
              break;
      }
      objc_memmove_collectable(&memory->_context, context, size);
      if (context->retain) {
          memory->_context.version0.info = (void *)context->retain(context->info);
      }
      return memory;
  }
  
  CFIndex CFRunLoopSourceGetOrder(CFRunLoopSourceRef rls) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rls, CFRunLoopSourceGetTypeID());
      return rls->_order;
  }
  
  static void __CFRunLoopSourceWakeUpLoop(const void *value, void *context) {
      CFRunLoopWakeUp((CFRunLoopRef)value);
  }
  
  static void __CFRunLoopSourceRemoveFromRunLoop(const void *value, void *context) {
      CFRunLoopRef rl = (CFRunLoopRef)value;
      CFTypeRef *params = (CFTypeRef *)context;
      CFRunLoopSourceRef rls = (CFRunLoopSourceRef)params[0];
      CFIndex idx;
      if (rl == params[1]) return;
      
      // CFRunLoopRemoveSource will lock the run loop while it
      // needs that, but we also lock it out here to keep
      // changes from occurring for this whole sequence.
      __CFRunLoopLock(rl);
      CFArrayRef array = CFRunLoopCopyAllModes(rl);
      for (idx = CFArrayGetCount(array); idx--;) {
          CFStringRef modeName = (CFStringRef)CFArrayGetValueAtIndex(array, idx);
          CFRunLoopRemoveSource(rl, rls, modeName);
      }
      CFRunLoopRemoveSource(rl, rls, kCFRunLoopCommonModes);
      __CFRunLoopUnlock(rl);
      CFRelease(array);
      params[1] = rl;
  }
  
  void CFRunLoopSourceInvalidate(CFRunLoopSourceRef rls) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rls, CFRunLoopSourceGetTypeID());
      __CFRunLoopSourceLock(rls);
      CFRetain(rls);
      if (__CFIsValid(rls)) {
          CFBagRef rloops = rls->_runLoops;
          __CFUnsetValid(rls);
          __CFRunLoopSourceUnsetSignaled(rls);
          if (NULL != rloops) {
              // To avoid A->B, B->A lock ordering issues when coming up
              // towards the run loop from a source, the source has to be
              // unlocked, which means we have to protect from object
              // invalidation.
              rls->_runLoops = NULL; // transfer ownership to local stack
              __CFRunLoopSourceUnlock(rls);
              CFTypeRef params[2] = {rls, NULL};
              CFBagApplyFunction(rloops, (__CFRunLoopSourceRemoveFromRunLoop), params);
              CFRelease(rloops);
              __CFRunLoopSourceLock(rls);
          }
          /* for hashing- and equality-use purposes, can't actually release the context here */
      }
      __CFRunLoopSourceUnlock(rls);
      CFRelease(rls);
  }
  
  Boolean CFRunLoopSourceIsValid(CFRunLoopSourceRef rls) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rls, CFRunLoopSourceGetTypeID());
      return __CFIsValid(rls);
  }
  
  void CFRunLoopSourceGetContext(CFRunLoopSourceRef rls, CFRunLoopSourceContext *context) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rls, CFRunLoopSourceGetTypeID());
      CFAssert1(0 == context->version || 1 == context->version, __kCFLogAssertion, "%s(): context version not initialized to 0 or 1", __PRETTY_FUNCTION__);
      CFIndex size = 0;
      switch (context->version) {
          case 0:
              size = sizeof(CFRunLoopSourceContext);
              break;
          case 1:
              size = sizeof(CFRunLoopSourceContext1);
              break;
      }
      memmove(context, &rls->_context, size);
  }
  
  void CFRunLoopSourceSignal(CFRunLoopSourceRef rls) {
      CHECK_FOR_FORK();
      __CFRunLoopSourceLock(rls);
      if (__CFIsValid(rls)) {
          __CFRunLoopSourceSetSignaled(rls);
      }
      __CFRunLoopSourceUnlock(rls);
  }
  
  Boolean CFRunLoopSourceIsSignalled(CFRunLoopSourceRef rls) {
      CHECK_FOR_FORK();
      __CFRunLoopSourceLock(rls);
      Boolean ret = __CFRunLoopSourceIsSignaled(rls) ? true : false;
      __CFRunLoopSourceUnlock(rls);
      return ret;
  }
  
  CF_PRIVATE void _CFRunLoopSourceWakeUpRunLoops(CFRunLoopSourceRef rls) {
      CFBagRef loops = NULL;
      __CFRunLoopSourceLock(rls);
      if (__CFIsValid(rls) && NULL != rls->_runLoops) {
          loops = CFBagCreateCopy(kCFAllocatorSystemDefault, rls->_runLoops);
      }
      __CFRunLoopSourceUnlock(rls);
      if (loops) {
          CFBagApplyFunction(loops, __CFRunLoopSourceWakeUpLoop, NULL);
          CFRelease(loops);
      }
  }
  
  /* CFRunLoopObserver */
  
  static CFStringRef __CFRunLoopObserverCopyDescription(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopObserverRef rlo = (CFRunLoopObserverRef)cf;
      CFStringRef result;
      CFStringRef contextDesc = NULL;
      if (NULL != rlo->_context.copyDescription) {
          contextDesc = rlo->_context.copyDescription(rlo->_context.info);
      }
      if (!contextDesc) {
          contextDesc = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopObserver context %p>"), rlo->_context.info);
      }
  #if DEPLOYMENT_TARGET_WINDOWS
      result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopObserver %p [%p]>{valid = %s, activities = 0x%x, repeats = %s, order = %d, callout = %p, context = %@}"), cf, CFGetAllocator(rlo), __CFIsValid(rlo) ? "Yes" : "No", rlo->_activities, __CFRunLoopObserverRepeats(rlo) ? "Yes" : "No", rlo->_order, rlo->_callout, contextDesc);
  #elif DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
      void *addr = rlo->_callout;
      Dl_info info;
      const char *name = (dladdr(addr, &info) && info.dli_saddr == addr && info.dli_sname) ? info.dli_sname : "???";
      result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopObserver %p [%p]>{valid = %s, activities = 0x%lx, repeats = %s, order = %ld, callout = %s (%p), context = %@}"), cf, CFGetAllocator(rlo), __CFIsValid(rlo) ? "Yes" : "No", (long)rlo->_activities, __CFRunLoopObserverRepeats(rlo) ? "Yes" : "No", (long)rlo->_order, name, addr, contextDesc);
  #endif
      CFRelease(contextDesc);
      return result;
  }
  
  static void __CFRunLoopObserverDeallocate(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopObserverRef rlo = (CFRunLoopObserverRef)cf;
      CFRunLoopObserverInvalidate(rlo);
      pthread_mutex_destroy(&rlo->_lock);
  }
  
  static const CFRuntimeClass __CFRunLoopObserverClass = {
      0,
      "CFRunLoopObserver",
      NULL,      // init
      NULL,      // copy
      __CFRunLoopObserverDeallocate,
      NULL,
      NULL,
      NULL,      //
      __CFRunLoopObserverCopyDescription
  };
  
  CFTypeID CFRunLoopObserverGetTypeID(void) {
      static dispatch_once_t initOnce;
      dispatch_once(&initOnce, ^{ __kCFRunLoopObserverTypeID = _CFRuntimeRegisterClass(&__CFRunLoopObserverClass); });
      return __kCFRunLoopObserverTypeID;
  }
  
  CFRunLoopObserverRef CFRunLoopObserverCreate(CFAllocatorRef allocator, CFOptionFlags activities, Boolean repeats, CFIndex order, CFRunLoopObserverCallBack callout, CFRunLoopObserverContext *context) {
      CHECK_FOR_FORK();
      CFRunLoopObserverRef memory;
      UInt32 size;
      size = sizeof(struct __CFRunLoopObserver) - sizeof(CFRuntimeBase);
      memory = (CFRunLoopObserverRef)_CFRuntimeCreateInstance(allocator, CFRunLoopObserverGetTypeID(), size, NULL);
      if (NULL == memory) {
          return NULL;
      }
      __CFSetValid(memory);
      __CFRunLoopObserverUnsetFiring(memory);
      if (repeats) {
          __CFRunLoopObserverSetRepeats(memory);
      } else {
          __CFRunLoopObserverUnsetRepeats(memory);
      }
      __CFRunLoopLockInit(&memory->_lock);
      memory->_runLoop = NULL;
      memory->_rlCount = 0;
      memory->_activities = activities;
      memory->_order = order;
      memory->_callout = callout;
      if (context) {
          if (context->retain) {
              memory->_context.info = (void *)context->retain(context->info);
          } else {
              memory->_context.info = context->info;
          }
          memory->_context.retain = context->retain;
          memory->_context.release = context->release;
          memory->_context.copyDescription = context->copyDescription;
      } else {
          memory->_context.info = 0;
          memory->_context.retain = 0;
          memory->_context.release = 0;
          memory->_context.copyDescription = 0;
      }
      return memory;
  }
  
  static void _runLoopObserverWithBlockContext(CFRunLoopObserverRef observer, CFRunLoopActivity activity, void *opaqueBlock) {
      typedef void (^observer_block_t) (CFRunLoopObserverRef observer, CFRunLoopActivity activity);
      observer_block_t block = (observer_block_t)opaqueBlock;
      block(observer, activity);
  }
  
  CFRunLoopObserverRef CFRunLoopObserverCreateWithHandler(CFAllocatorRef allocator, CFOptionFlags activities, Boolean repeats, CFIndex order,
                                                          void (^block) (CFRunLoopObserverRef observer, CFRunLoopActivity activity)) {
      CFRunLoopObserverContext blockContext;
      blockContext.version = 0;
      blockContext.info = (void *)block;
      blockContext.retain = (const void *(*)(const void *info))_Block_copy;
      blockContext.release = (void (*)(const void *info))_Block_release;
      blockContext.copyDescription = NULL;
      return CFRunLoopObserverCreate(allocator, activities, repeats, order, _runLoopObserverWithBlockContext, &blockContext);
  }
  
  CFOptionFlags CFRunLoopObserverGetActivities(CFRunLoopObserverRef rlo) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlo, CFRunLoopObserverGetTypeID());
      return rlo->_activities;
  }
  
  CFIndex CFRunLoopObserverGetOrder(CFRunLoopObserverRef rlo) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlo, CFRunLoopObserverGetTypeID());
      return rlo->_order;
  }
  
  Boolean CFRunLoopObserverDoesRepeat(CFRunLoopObserverRef rlo) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlo, CFRunLoopObserverGetTypeID());
      return __CFRunLoopObserverRepeats(rlo);
  }
  
  void CFRunLoopObserverInvalidate(CFRunLoopObserverRef rlo) {    /* DOES CALLOUT */
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlo, CFRunLoopObserverGetTypeID());
      __CFRunLoopObserverLock(rlo);
      CFRetain(rlo);
      if (__CFIsValid(rlo)) {
          CFRunLoopRef rl = rlo->_runLoop;
          void *info = rlo->_context.info;
          rlo->_context.info = NULL;
          __CFUnsetValid(rlo);
          if (NULL != rl) {
              // To avoid A->B, B->A lock ordering issues when coming up
              // towards the run loop from an observer, it has to be
              // unlocked, which means we have to protect from object
              // invalidation.
              CFRetain(rl);
              __CFRunLoopObserverUnlock(rlo);
              // CFRunLoopRemoveObserver will lock the run loop while it
              // needs that, but we also lock it out here to keep
              // changes from occurring for this whole sequence.
              __CFRunLoopLock(rl);
              CFArrayRef array = CFRunLoopCopyAllModes(rl);
              for (CFIndex idx = CFArrayGetCount(array); idx--;) {
                  CFStringRef modeName = (CFStringRef)CFArrayGetValueAtIndex(array, idx);
                  CFRunLoopRemoveObserver(rl, rlo, modeName);
              }
              CFRunLoopRemoveObserver(rl, rlo, kCFRunLoopCommonModes);
              __CFRunLoopUnlock(rl);
              CFRelease(array);
              CFRelease(rl);
              __CFRunLoopObserverLock(rlo);
          }
          if (NULL != rlo->_context.release) {
              rlo->_context.release(info);        /* CALLOUT */
          }
      }
      __CFRunLoopObserverUnlock(rlo);
      CFRelease(rlo);
  }
  
  Boolean CFRunLoopObserverIsValid(CFRunLoopObserverRef rlo) {
      CHECK_FOR_FORK();
      return __CFIsValid(rlo);
  }
  
  void CFRunLoopObserverGetContext(CFRunLoopObserverRef rlo, CFRunLoopObserverContext *context) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlo, CFRunLoopObserverGetTypeID());
      CFAssert1(0 == context->version, __kCFLogAssertion, "%s(): context version not initialized to 0", __PRETTY_FUNCTION__);
      *context = rlo->_context;
  }
  
  #pragma mark -
  #pragma mark CFRunLoopTimer
  
  static CFStringRef __CFRunLoopTimerCopyDescription(CFTypeRef cf) {	/* DOES CALLOUT */
      CFRunLoopTimerRef rlt = (CFRunLoopTimerRef)cf;
      CFStringRef contextDesc = NULL;
      if (NULL != rlt->_context.copyDescription) {
          contextDesc = rlt->_context.copyDescription(rlt->_context.info);
      }
      if (NULL == contextDesc) {
          contextDesc = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL, CFSTR("<CFRunLoopTimer context %p>"), rlt->_context.info);
      }
      void *addr = (void *)rlt->_callout;
      char libraryName[2048];
      char functionName[2048];
      void *functionPtr = NULL;
      libraryName[0] = '?'; libraryName[1] = '\0';
      functionName[0] = '?'; functionName[1] = '\0';
      CFStringRef result = CFStringCreateWithFormat(kCFAllocatorSystemDefault, NULL,
                                                    CFSTR("<CFRunLoopTimer %p [%p]>{valid = %s, firing = %s, interval = %0.09g, tolerance = %0.09g, next fire date = %0.09g (%0.09g @ %lld), callout = %s (%p / %p) (%s), context = %@}"),
                                                    cf,
                                                    CFGetAllocator(rlt),
                                                    __CFIsValid(rlt) ? "Yes" : "No",
                                                    __CFRunLoopTimerIsFiring(rlt) ? "Yes" : "No",
                                                    rlt->_interval,
                                                    rlt->_tolerance,
                                                    rlt->_nextFireDate,
                                                    rlt->_nextFireDate - CFAbsoluteTimeGetCurrent(),
                                                    rlt->_fireTSR,
                                                    functionName,
                                                    addr,
                                                    functionPtr,
                                                    libraryName,
                                                    contextDesc);
      CFRelease(contextDesc);
      return result;
  }
  
  static void __CFRunLoopTimerDeallocate(CFTypeRef cf) {	/* DOES CALLOUT */
      //CFLog(6, CFSTR("__CFRunLoopTimerDeallocate(%p)"), cf);
      CFRunLoopTimerRef rlt = (CFRunLoopTimerRef)cf;
      __CFRunLoopTimerSetDeallocating(rlt);
      CFRunLoopTimerInvalidate(rlt);	/* DOES CALLOUT */
      CFRelease(rlt->_rlModes);
      rlt->_rlModes = NULL;
      pthread_mutex_destroy(&rlt->_lock);
  }
  
  static const CFRuntimeClass __CFRunLoopTimerClass = {
      0,
      "CFRunLoopTimer",
      NULL,      // init
      NULL,      // copy
      __CFRunLoopTimerDeallocate,
      NULL,	// equal
      NULL,
      NULL,      //
      __CFRunLoopTimerCopyDescription
  };
  
  CFTypeID CFRunLoopTimerGetTypeID(void) {
      static dispatch_once_t initOnce;
      dispatch_once(&initOnce, ^{ __kCFRunLoopTimerTypeID = _CFRuntimeRegisterClass(&__CFRunLoopTimerClass); });
      return __kCFRunLoopTimerTypeID;
  }
  
  CFRunLoopTimerRef CFRunLoopTimerCreate(CFAllocatorRef allocator, CFAbsoluteTime fireDate, CFTimeInterval interval, CFOptionFlags flags, CFIndex order, CFRunLoopTimerCallBack callout, CFRunLoopTimerContext *context) {
      CHECK_FOR_FORK();
      if (isnan(interval)) {
          CRSetCrashLogMessage("NaN was used as an interval for a CFRunLoopTimer");
          HALT;
      }
      CFRunLoopTimerRef memory;
      UInt32 size;
      size = sizeof(struct __CFRunLoopTimer) - sizeof(CFRuntimeBase);
      memory = (CFRunLoopTimerRef)_CFRuntimeCreateInstance(allocator, CFRunLoopTimerGetTypeID(), size, NULL);
      if (NULL == memory) {
          return NULL;
      }
      __CFSetValid(memory);
      __CFRunLoopTimerUnsetFiring(memory);
      __CFRunLoopLockInit(&memory->_lock);
      memory->_runLoop = NULL;
      memory->_rlModes = CFSetCreateMutable(kCFAllocatorSystemDefault, 0, &kCFTypeSetCallBacks);
      memory->_order = order;
      if (interval < 0.0) interval = 0.0;
      memory->_interval = interval;
      memory->_tolerance = 0.0;
      if (TIMER_DATE_LIMIT < fireDate) fireDate = TIMER_DATE_LIMIT;
      memory->_nextFireDate = fireDate;
      memory->_fireTSR = 0ULL;
      uint64_t now2 = mach_absolute_time();
      CFAbsoluteTime now1 = CFAbsoluteTimeGetCurrent();
      if (fireDate < now1) {
          memory->_fireTSR = now2;
      } else if (TIMER_INTERVAL_LIMIT < fireDate - now1) {
          memory->_fireTSR = now2 + __CFTimeIntervalToTSR(TIMER_INTERVAL_LIMIT);
      } else {
          memory->_fireTSR = now2 + __CFTimeIntervalToTSR(fireDate - now1);
      }
      memory->_callout = callout;
      if (NULL != context) {
          if (context->retain) {
              memory->_context.info = (void *)context->retain(context->info);
          } else {
              memory->_context.info = context->info;
          }
          memory->_context.retain = context->retain;
          memory->_context.release = context->release;
          memory->_context.copyDescription = context->copyDescription;
      } else {
          memory->_context.info = 0;
          memory->_context.retain = 0;
          memory->_context.release = 0;
          memory->_context.copyDescription = 0;
      }
      return memory;
  }
  
  static void _runLoopTimerWithBlockContext(CFRunLoopTimerRef timer, void *opaqueBlock) {
      typedef void (^timer_block_t) (CFRunLoopTimerRef timer);
      timer_block_t block = (timer_block_t)opaqueBlock;
      block(timer);
  }
  
  CFRunLoopTimerRef CFRunLoopTimerCreateWithHandler(CFAllocatorRef allocator, CFAbsoluteTime fireDate, CFTimeInterval interval, CFOptionFlags flags, CFIndex order,
                                                    void (^block) (CFRunLoopTimerRef timer)) {
      
      CFRunLoopTimerContext blockContext;
      blockContext.version = 0;
      blockContext.info = (void *)block;
      blockContext.retain = (const void *(*)(const void *info))_Block_copy;
      blockContext.release = (void (*)(const void *info))_Block_release;
      blockContext.copyDescription = NULL;
      return CFRunLoopTimerCreate(allocator, fireDate, interval, flags, order, _runLoopTimerWithBlockContext, &blockContext);
  }
  
  CFAbsoluteTime CFRunLoopTimerGetNextFireDate(CFRunLoopTimerRef rlt) {
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), CFAbsoluteTime, (NSTimer *)rlt, _cffireTime);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      CFAbsoluteTime at = 0.0;
      __CFRunLoopTimerLock(rlt);
      __CFRunLoopTimerFireTSRLock();
      if (__CFIsValid(rlt)) {
          at = rlt->_nextFireDate;
      }
      __CFRunLoopTimerFireTSRUnlock();
      __CFRunLoopTimerUnlock(rlt);
      return at;
  }
  
  void CFRunLoopTimerSetNextFireDate(CFRunLoopTimerRef rlt, CFAbsoluteTime fireDate) {
      CHECK_FOR_FORK();
      if (!__CFIsValid(rlt)) return;
      if (TIMER_DATE_LIMIT < fireDate) fireDate = TIMER_DATE_LIMIT;
      uint64_t nextFireTSR = 0ULL;
      uint64_t now2 = mach_absolute_time();
      CFAbsoluteTime now1 = CFAbsoluteTimeGetCurrent();
      if (fireDate < now1) {
          nextFireTSR = now2;
      } else if (TIMER_INTERVAL_LIMIT < fireDate - now1) {
          nextFireTSR = now2 + __CFTimeIntervalToTSR(TIMER_INTERVAL_LIMIT);
      } else {
          nextFireTSR = now2 + __CFTimeIntervalToTSR(fireDate - now1);
      }
      __CFRunLoopTimerLock(rlt);
      if (NULL != rlt->_runLoop) {
          CFIndex cnt = CFSetGetCount(rlt->_rlModes);
          STACK_BUFFER_DECL(CFTypeRef, modes, cnt);
          CFSetGetValues(rlt->_rlModes, (const void **)modes);
          // To avoid A->B, B->A lock ordering issues when coming up
          // towards the run loop from a source, the timer has to be
          // unlocked, which means we have to protect from object
          // invalidation, although that's somewhat expensive.
          for (CFIndex idx = 0; idx < cnt; idx++) {
              CFRetain(modes[idx]);
          }
          CFRunLoopRef rl = (CFRunLoopRef)CFRetain(rlt->_runLoop);
          __CFRunLoopTimerUnlock(rlt);
          __CFRunLoopLock(rl);
          for (CFIndex idx = 0; idx < cnt; idx++) {
              CFStringRef name = (CFStringRef)modes[idx];
              modes[idx] = __CFRunLoopFindMode(rl, name, false);
              CFRelease(name);
          }
          __CFRunLoopTimerFireTSRLock();
          rlt->_fireTSR = nextFireTSR;
          rlt->_nextFireDate = fireDate;
          for (CFIndex idx = 0; idx < cnt; idx++) {
              CFRunLoopModeRef rlm = (CFRunLoopModeRef)modes[idx];
              if (rlm) {
                  __CFRepositionTimerInMode(rlm, rlt, true);
              }
          }
          __CFRunLoopTimerFireTSRUnlock();
          for (CFIndex idx = 0; idx < cnt; idx++) {
              __CFRunLoopModeUnlock((CFRunLoopModeRef)modes[idx]);
          }
          __CFRunLoopUnlock(rl);
          // This is setting the date of a timer, not a direct
          // interaction with a run loop, so we'll do a wakeup
          // (which may be costly) for the caller, just in case.
          // (And useful for binary compatibility with older
          // code used to the older timer implementation.)
          if (rl != CFRunLoopGetCurrent()) CFRunLoopWakeUp(rl);
          CFRelease(rl);
      } else {
          __CFRunLoopTimerFireTSRLock();
          rlt->_fireTSR = nextFireTSR;
          rlt->_nextFireDate = fireDate;
          __CFRunLoopTimerFireTSRUnlock();
          __CFRunLoopTimerUnlock(rlt);
      }
  }
  
  CFTimeInterval CFRunLoopTimerGetInterval(CFRunLoopTimerRef rlt) {
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), CFTimeInterval, (NSTimer *)rlt, timeInterval);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      return rlt->_interval;
  }
  
  Boolean CFRunLoopTimerDoesRepeat(CFRunLoopTimerRef rlt) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      return (0.0 < rlt->_interval);
  }
  
  CFIndex CFRunLoopTimerGetOrder(CFRunLoopTimerRef rlt) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      return rlt->_order;
  }
  
  void CFRunLoopTimerInvalidate(CFRunLoopTimerRef rlt) {	/* DOES CALLOUT */
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), void, (NSTimer *)rlt, invalidate);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      __CFRunLoopTimerLock(rlt);
      if (!__CFRunLoopTimerIsDeallocating(rlt)) {
          CFRetain(rlt);
      }
      if (__CFIsValid(rlt)) {
          CFRunLoopRef rl = rlt->_runLoop;
          void *info = rlt->_context.info;
          rlt->_context.info = NULL;
          __CFUnsetValid(rlt);
          if (NULL != rl) {
              CFIndex cnt = CFSetGetCount(rlt->_rlModes);
              STACK_BUFFER_DECL(CFStringRef, modes, cnt);
              CFSetGetValues(rlt->_rlModes, (const void **)modes);
              // To avoid A->B, B->A lock ordering issues when coming up
              // towards the run loop from a source, the timer has to be
              // unlocked, which means we have to protect from object
              // invalidation, although that's somewhat expensive.
              for (CFIndex idx = 0; idx < cnt; idx++) {
                  CFRetain(modes[idx]);
              }
              CFRetain(rl);
              __CFRunLoopTimerUnlock(rlt);
              // CFRunLoopRemoveTimer will lock the run loop while it
              // needs that, but we also lock it out here to keep
              // changes from occurring for this whole sequence.
              __CFRunLoopLock(rl);
              for (CFIndex idx = 0; idx < cnt; idx++) {
                  CFRunLoopRemoveTimer(rl, rlt, modes[idx]);
              }
              CFRunLoopRemoveTimer(rl, rlt, kCFRunLoopCommonModes);
              __CFRunLoopUnlock(rl);
              for (CFIndex idx = 0; idx < cnt; idx++) {
                  CFRelease(modes[idx]);
              }
              CFRelease(rl);
              __CFRunLoopTimerLock(rlt);
          }
          if (NULL != rlt->_context.release) {
              rlt->_context.release(info);	/* CALLOUT */
          }
      }
      __CFRunLoopTimerUnlock(rlt);
      if (!__CFRunLoopTimerIsDeallocating(rlt)) {
          CFRelease(rlt);
      }
  }
  
  Boolean CFRunLoopTimerIsValid(CFRunLoopTimerRef rlt) {
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), Boolean, (NSTimer *)rlt, isValid);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      return __CFIsValid(rlt);
  }
  
  void CFRunLoopTimerGetContext(CFRunLoopTimerRef rlt, CFRunLoopTimerContext *context) {
      CHECK_FOR_FORK();
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      CFAssert1(0 == context->version, __kCFLogAssertion, "%s(): context version not initialized to 0", __PRETTY_FUNCTION__);
      *context = rlt->_context;
  }
  
  CFTimeInterval CFRunLoopTimerGetTolerance(CFRunLoopTimerRef rlt) {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), CFTimeInterval, (NSTimer *)rlt, tolerance);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      return rlt->_tolerance;
  #else
      return 0.0;
  #endif
  }
  
  void CFRunLoopTimerSetTolerance(CFRunLoopTimerRef rlt, CFTimeInterval tolerance) {
  #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_EMBEDDED || DEPLOYMENT_TARGET_EMBEDDED_MINI
      CHECK_FOR_FORK();
      CF_OBJC_FUNCDISPATCHV(CFRunLoopTimerGetTypeID(), void, (NSTimer *)rlt, setTolerance:tolerance);
      __CFGenericValidateType(rlt, CFRunLoopTimerGetTypeID());
      /*
       * dispatch rules:
       *
       * For the initial timer fire at 'start', the upper limit to the allowable
       * delay is set to 'leeway' nanoseconds. For the subsequent timer fires at
       * 'start' + N * 'interval', the upper limit is MIN('leeway','interval'/2).
       */
      if (rlt->_interval > 0) {
          rlt->_tolerance = MIN(tolerance, rlt->_interval / 2);
      } else {
          // Tolerance must be a positive value or zero
          if (tolerance < 0) tolerance = 0.0;
          rlt->_tolerance = tolerance;
      }
  #endif
  }
  
  