text: /********************************************************************************
   * include/signal.h
   *
   *   Copyright (C) 2007-2009, 2011, 2013-2017 Gregory Nutt. All rights reserved.
   *   Author: Gregory Nutt <gnutt@nuttx.org>
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   * 3. Neither the name NuttX nor the names of its contributors may be
   *    used to endorse or promote products derived from this software
   *    without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
   * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
   * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
   * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   *
   ********************************************************************************/
  
  #ifndef __INCLUDE_SIGNAL_H
  #define __INCLUDE_SIGNAL_H
  
  /********************************************************************************
   * Included Files
   ********************************************************************************/
  
  #include <nuttx/config.h>
  #include <nuttx/compiler.h>
  
  #include <stdint.h>
  #include <time.h>
  
  #ifdef CONFIG_SIG_EVTHREAD
  #  include <pthread.h>  /* Needed for pthread_attr_t, includes this file */
  #endif
  
  /********************************************************************************
   * Pre-processor Definitions
   ********************************************************************************/
  
  /* Signal set management definitions and macros. */
  
  #define NULL_SIGNAL_SET ((sigset_t)0x00000000)
  #define ALL_SIGNAL_SET  ((sigset_t)0xffffffff)
  #define MIN_SIGNO       0
  #define MAX_SIGNO       31
  #define GOOD_SIGNO(s)   ((((unsigned)(s))<=MAX_SIGNO))
  #define SIGNO2SET(s)    ((sigset_t)1 << (s))
  
  /* All signals are "real time" signals */
  
  #define SIGRTMIN        MIN_SIGNO  /* First real time signal */
  #define SIGRTMAX        MAX_SIGNO  /* Last real time signal */
  
  /* A few of the real time signals are used within the OS.  They have
   * default values that can be overridden from the configuration file. The
   * rest are all user signals.
   *
   * The signal number zero is wasted for the most part.  It is a valid
   * signal number, but has special meaning at many interfaces (e.g., Kill()).
   *
   * These are the semi-standard signal definitions:
   */
  
  #ifndef CONFIG_SIG_SIGUSR1
  #  define SIGUSR1       1  /* User signal 1 */
  #else
  #  define SIGUSR1       CONFIG_SIG_SIGUSR1
  #endif
  
  #ifndef CONFIG_SIG_SIGUSR2
  #  define SIGUSR2       2  /* User signal 2 */
  #else
  #  define SIGUSR2       CONFIG_SIG_SIGUSR2
  #endif
  
  #ifndef CONFIG_SIG_SIGALARM
  #  define SIGALRM       3  /* Default signal used with POSIX timers (used only */
                             /* no other signal is provided) */
  #else
  #  define SIGALRM       CONFIG_SIG_SIGALARM
  #endif
  
  #ifdef CONFIG_SCHED_HAVE_PARENT
  #  ifndef CONFIG_SIG_SIGCHLD
  #    define SIGCHLD     4  /* Used by child threads to signal parent thread */
  #  else
  #    define SIGCHLD     CONFIG_SIG_SIGCHLD
  #  endif
  #endif
  
  #ifdef CONFIG_FS_AIO
  #  ifndef CONFIG_SIG_POLL
  #    define SIGPOLL     5  /* Sent when an asynchronous I/O event occurs */
  #  else
  #    define SIGPOLL     CONFIG_SIG_POLL
  #  endif
  #endif
  
  /* The following are non-standard signal definitions */
  
  #ifndef CONFIG_DISABLE_PTHREAD
  #  ifndef CONFIG_SIG_SIGCONDTIMEDOUT
  #    define SIGCONDTIMEDOUT 16  /* Used in the implementation of pthread_cond_timedwait */
  #  else
  #    define SIGCONDTIMEDOUT CONFIG_SIG_SIGCONDTIMEDOUT
  #  endif
  #endif
  
  /* SIGWORK is used to wake up various internal, NuttX worker thread */
  
  #if defined(CONFIG_SCHED_WORKQUEUE) || defined(CONFIG_PAGING)
  #  ifndef CONFIG_SIG_SIGWORK
  #    define SIGWORK     17  /* Used to wake up the work queue */
  #  else
  #    define SIGWORK     CONFIG_SIG_SIGWORK
  #  endif
  #endif
  
  /* sigprocmask() "how" definitions. Only one of the following can be specified: */
  
  #define SIG_BLOCK       1  /* Block the given signals */
  #define SIG_UNBLOCK     2  /* Unblock the given signals */
  #define SIG_SETMASK     3  /* Set the signal mask to the current set */
  
  /* struct sigaction flag values */
  
  #define SA_NOCLDSTOP    (1 << 0) /* Do not generate SIGCHILD when
                                    * children stop (ignored) */
  #define SA_SIGINFO      (1 << 1) /* Invoke the signal-catching function
                                    * with 3 args instead of 1
                                    * (always assumed) */
  #define SA_NOCLDWAIT    (1 << 2) /* If signo=SIGCHLD, exit status of child
                                    * processes will be discarded */
  
  /* These are the possible values of the signfo si_code field */
  
  #define SI_USER         0  /* Signal sent from kill, raise, or abort */
  #define SI_QUEUE        1  /* Signal sent from sigqueue */
  #define SI_TIMER        2  /* Signal is result of timer expiration */
  #define SI_ASYNCIO      3  /* Signal is the result of asynch IO completion */
  #define SI_MESGQ        4  /* Signal generated by arrival of a message on an */
                             /* empty message queue */
  #define CLD_EXITED      5  /* Child has exited (SIGCHLD only) */
  #define CLD_KILLED      6  /* Child was killed (SIGCHLD only) */
  #define CLD_DUMPED      7  /* Child terminated abnormally (SIGCHLD only) */
  #define CLD_TRAPPED     8  /* Traced child has trapped (SIGCHLD only) */
  #define CLD_STOPPED     9  /* Child has stopped (SIGCHLD only) */
  #define CLD_CONTINUED   10 /* Stopped child had continued (SIGCHLD only) */
  
  /* Values for the sigev_notify field of struct sigevent */
  
  #define SIGEV_NONE      0 /* No asynchronous notification is delivered */
  #define SIGEV_SIGNAL    1 /* Notify via signal,with an application-defined value */
  #ifdef CONFIG_SIG_EVTHREAD
  #  define SIGEV_THREAD  3 /* A notification function is called */
  #endif
  
  /* Special values of of sa_handler used by sigaction and sigset.  They are all
   * treated like NULL for now.  This is okay for SIG_DFL and SIG_IGN because
   * in NuttX, the default action for all signals is to ignore them.
   */
  
  #define SIG_ERR         ((_sa_handler_t)-1)  /* And error occurred */
  #define SIG_DFL         ((_sa_handler_t)0)   /* Default is SIG_IGN for all signals */
  #define SIG_IGN         ((_sa_handler_t)0)   /* Ignore the signal */
  #define SIG_HOLD        ((_sa_handler_t)1)   /* Used only with sigset() */
  
  /********************************************************************************
   * Public Type Definitions
   ********************************************************************************/
  
  /* This defines a set of 32 signals (numbered 0 through 31).
   * REVISIT: Signal 0 is, however, not generally usable since that value has
   * special meaning in some circumstances (e.g., kill()).
   */
  
  typedef uint32_t sigset_t;   /* Bit set of 32 signals */
  #define __SIGSET_T_DEFINED 1
  
  /* Possibly volatile-qualified integer type of an object that can be accessed
   * as an atomic entity, even in the presence of asynchronous interrupts.
   */
  
  typedef volatile int sig_atomic_t;
  
  /* This defines the type of the siginfo si_value field */
  
  union sigval
  {
    int       sival_int;       /* Integer value */
    FAR void *sival_ptr;       /* Pointer value */
  };
  
  /* This structure contains elements that define a queue signal. The following is
   * used to attach a signal to a message queue to notify a task when a message is
   * available on a queue
   */
  
  #ifdef CONFIG_CAN_PASS_STRUCTS
  typedef CODE void (*sigev_notify_function_t)(union sigval value);
  #else
  typedef CODE void (*sigev_notify_function_t)(FAR void *sival_ptr);
  #endif
  
  struct sigevent
  {
    uint8_t      sigev_notify; /* Notification method: SIGEV_SIGNAL, SIGEV_NONE, or SIGEV_THREAD */
    uint8_t      sigev_signo;  /* Notification signal */
    union sigval sigev_value;  /* Data passed with notification */
  
  #ifdef CONFIG_SIG_EVTHREAD
    sigev_notify_function_t sigev_notify_function; /* Notification function */
    FAR pthread_attr_t *sigev_notify_attributes;   /* Notification attributes (not used) */
  #endif
  };
  
  /* The following types is used to pass parameters to/from signal handlers */
  
  struct siginfo
  {
    uint8_t      si_signo;     /* Identifies signal */
    uint8_t      si_code;      /* Source: SI_USER, SI_QUEUE, SI_TIMER, SI_ASYNCIO, or SI_MESGQ */
    uint8_t      si_errno;     /* Zero or errno value associated with signal */
    union sigval si_value;     /* Data passed with signal */
  #ifdef CONFIG_SCHED_HAVE_PARENT
    pid_t        si_pid;       /* Sending task ID */
    int          si_status;    /* Exit value or signal (SIGCHLD only). */
  #endif
  };
  
  typedef struct siginfo siginfo_t;
  #define __SIGINFO_T_DEFINED 1
  
  /* Non-standard convenience definition of signal handling function types.
   * These should be used only internally within the NuttX signal logic.
   */
  
  typedef CODE void (*_sa_handler_t)(int signo);
  typedef CODE void (*_sa_sigaction_t)(int signo, FAR siginfo_t *siginfo,
                                       FAR void *context);
  
  /* The following structure defines the action to take for given signal */
  
  struct sigaction
  {
    union
    {
      _sa_handler_t   _sa_handler;
      _sa_sigaction_t _sa_sigaction;
    } sa_u;
    sigset_t          sa_mask;
    int               sa_flags;
  };
  
  /* Definitions that adjust the non-standard naming */
  
  #define sa_handler   sa_u._sa_handler
  #define sa_sigaction sa_u._sa_sigaction
  
  /********************************************************************************
   * Public Function Prototypes
   ********************************************************************************/
  
  #ifdef __cplusplus
  #define EXTERN extern "C"
  extern "C"
  {
  #else
  #define EXTERN extern
  #endif
  
  int kill(pid_t pid, int signo);
  int raise(int signo);
  int sigaction(int signo, FAR const struct sigaction *act,
                FAR struct sigaction *oact);
  int sigaddset(FAR sigset_t *set, int signo);
  int sigdelset(FAR sigset_t *set, int signo);
  int sigemptyset(FAR sigset_t *set);
  int sigfillset(FAR sigset_t *set);
  int sighold(int signo);
  int sigismember(FAR const sigset_t *set, int signo);
  int sigignore(int signo);
  _sa_handler_t signal(int signo, _sa_handler_t func);
  int sigpause(int signo);
  int sigpending(FAR sigset_t *set);
  int sigprocmask(int how, FAR const sigset_t *set, FAR sigset_t *oset);
  #ifdef CONFIG_CAN_PASS_STRUCTS
  int sigqueue(int pid, int signo, union sigval value);
  #else
  int sigqueue(int pid, int signo, FAR void *sival_ptr);
  #endif
  int sigrelse(int signo);
  _sa_handler_t sigset(int signo, _sa_handler_t func);
  int sigwait(FAR const sigset_t *set, FAR int *sig);
  int sigtimedwait(FAR const sigset_t *set, FAR struct siginfo *value,
                   FAR const struct timespec *timeout);
  int sigsuspend(FAR const sigset_t *sigmask);
  int sigwaitinfo(FAR const sigset_t *set, FAR struct siginfo *value);
  
  #undef EXTERN
  #ifdef __cplusplus
  }
  #endif
  
  /********************************************************************************
   * Minimal Type Definitions
   ********************************************************************************/
  
  #else /* __INCLUDE_SIGNAL_H */
  
  #include <stdint.h>
  
  /* Avoid circular dependencies by assuring that simple type definitions are
   * available in any inclusion ordering.
   */
  
  #ifndef __SIGSET_T_DEFINED
  typedef uint32_t sigset_t;
  #  define __SIGSET_T_DEFINED 1
  #endif
  
  #ifndef __SIGINFO_T_DEFINED
  struct siginfo;
  typedef struct siginfo siginfo_t;
  #  define __SIGINFO_T_DEFINED 1
  #endif
  
  #endif /* __INCLUDE_SIGNAL_H */
  