text: /*
      Copyright 2005-2016 Intel Corporation.  All Rights Reserved.
  
      This file is part of Threading Building Blocks. Threading Building Blocks is free software;
      you can redistribute it and/or modify it under the terms of the GNU General Public License
      version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks is
      distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the
      implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
      See  the GNU General Public License for more details.   You should have received a copy of
      the  GNU General Public License along with Threading Building Blocks; if not, write to the
      Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA
  
      As a special exception,  you may use this file  as part of a free software library without
      restriction.  Specifically,  if other files instantiate templates  or use macros or inline
      functions from this file, or you compile this file and link it with other files to produce
      an executable,  this file does not by itself cause the resulting executable to be covered
      by the GNU General Public License. This exception does not however invalidate any other
      reasons why the executable file might be covered by the GNU General Public License.
  */
  
  #ifndef __TBB_mutex_H
  #define __TBB_mutex_H
  
  #if _WIN32||_WIN64
  #include "machine/windows_api.h"
  #else
  #include <pthread.h>
  #endif /* _WIN32||_WIN64 */
  
  #include <new>
  #include "aligned_space.h"
  #include "tbb_stddef.h"
  #include "tbb_profiling.h"
  
  namespace tbb {
  
  //! Wrapper around the platform's native reader-writer lock.
  /** For testing purposes only.
      @ingroup synchronization */
  class mutex : internal::mutex_copy_deprecated_and_disabled {
  public:
      //! Construct unacquired mutex.
      mutex() {
  #if TBB_USE_ASSERT || TBB_USE_THREADING_TOOLS
      internal_construct();
  #else
    #if _WIN32||_WIN64
          InitializeCriticalSectionEx(&impl, 4000, 0);
    #else
          int error_code = pthread_mutex_init(&impl,NULL);
          if( error_code )
              tbb::internal::handle_perror(error_code,"mutex: pthread_mutex_init failed");
    #endif /* _WIN32||_WIN64*/
  #endif /* TBB_USE_ASSERT */
      };
  
      ~mutex() {
  #if TBB_USE_ASSERT
          internal_destroy();
  #else
    #if _WIN32||_WIN64
          DeleteCriticalSection(&impl);
    #else
          pthread_mutex_destroy(&impl);
  
    #endif /* _WIN32||_WIN64 */
  #endif /* TBB_USE_ASSERT */
      };
  
      class scoped_lock;
      friend class scoped_lock;
  
      //! The scoped locking pattern
      /** It helps to avoid the common problem of forgetting to release lock.
          It also nicely provides the "node" for queuing locks. */
      class scoped_lock : internal::no_copy {
      public:
          //! Construct lock that has not acquired a mutex.
          scoped_lock() : my_mutex(NULL) {};
  
          //! Acquire lock on given mutex.
          scoped_lock( mutex& mutex ) {
              acquire( mutex );
          }
  
          //! Release lock (if lock is held).
          ~scoped_lock() {
              if( my_mutex )
                  release();
          }
  
          //! Acquire lock on given mutex.
          void acquire( mutex& mutex ) {
  #if TBB_USE_ASSERT
              internal_acquire(mutex);
  #else
              mutex.lock();
              my_mutex = &mutex;
  #endif /* TBB_USE_ASSERT */
          }
  
          //! Try acquire lock on given mutex.
          bool try_acquire( mutex& mutex ) {
  #if TBB_USE_ASSERT
              return internal_try_acquire (mutex);
  #else
              bool result = mutex.try_lock();
              if( result )
                  my_mutex = &mutex;
              return result;
  #endif /* TBB_USE_ASSERT */
          }
  
          //! Release lock
          void release() {
  #if TBB_USE_ASSERT
              internal_release ();
  #else
              my_mutex->unlock();
              my_mutex = NULL;
  #endif /* TBB_USE_ASSERT */
          }
  
      private:
          //! The pointer to the current mutex to work
          mutex* my_mutex;
  
          //! All checks from acquire using mutex.state were moved here
          void __TBB_EXPORTED_METHOD internal_acquire( mutex& m );
  
          //! All checks from try_acquire using mutex.state were moved here
          bool __TBB_EXPORTED_METHOD internal_try_acquire( mutex& m );
  
          //! All checks from release using mutex.state were moved here
          void __TBB_EXPORTED_METHOD internal_release();
  
          friend class mutex;
      };
  
      // Mutex traits
      static const bool is_rw_mutex = false;
      static const bool is_recursive_mutex = false;
      static const bool is_fair_mutex = false;
  
      // ISO C++0x compatibility methods
  
      //! Acquire lock
      void lock() {
  #if TBB_USE_ASSERT
          aligned_space<scoped_lock> tmp;
          new(tmp.begin()) scoped_lock(*this);
  #else
    #if _WIN32||_WIN64
          EnterCriticalSection(&impl);
    #else
          int error_code = pthread_mutex_lock(&impl);
          if( error_code )
              tbb::internal::handle_perror(error_code,"mutex: pthread_mutex_lock failed");
    #endif /* _WIN32||_WIN64 */
  #endif /* TBB_USE_ASSERT */
      }
  
      //! Try acquiring lock (non-blocking)
      /** Return true if lock acquired; false otherwise. */
      bool try_lock() {
  #if TBB_USE_ASSERT
          aligned_space<scoped_lock> tmp;
          scoped_lock& s = *tmp.begin();
          s.my_mutex = NULL;
          return s.internal_try_acquire(*this);
  #else
    #if _WIN32||_WIN64
          return TryEnterCriticalSection(&impl)!=0;
    #else
          return pthread_mutex_trylock(&impl)==0;
    #endif /* _WIN32||_WIN64 */
  #endif /* TBB_USE_ASSERT */
      }
  
      //! Release lock
      void unlock() {
  #if TBB_USE_ASSERT
          aligned_space<scoped_lock> tmp;
          scoped_lock& s = *tmp.begin();
          s.my_mutex = this;
          s.internal_release();
  #else
    #if _WIN32||_WIN64
          LeaveCriticalSection(&impl);
    #else
          pthread_mutex_unlock(&impl);
    #endif /* _WIN32||_WIN64 */
  #endif /* TBB_USE_ASSERT */
      }
  
      //! Return native_handle
    #if _WIN32||_WIN64
      typedef LPCRITICAL_SECTION native_handle_type;
    #else
      typedef pthread_mutex_t* native_handle_type;
    #endif
      native_handle_type native_handle() { return (native_handle_type) &impl; }
  
      enum state_t {
          INITIALIZED=0x1234,
          DESTROYED=0x789A,
          HELD=0x56CD
      };
  private:
  #if _WIN32||_WIN64
      CRITICAL_SECTION impl;
      enum state_t state;
  #else
      pthread_mutex_t impl;
  #endif /* _WIN32||_WIN64 */
  
      //! All checks from mutex constructor using mutex.state were moved here
      void __TBB_EXPORTED_METHOD internal_construct();
  
      //! All checks from mutex destructor using mutex.state were moved here
      void __TBB_EXPORTED_METHOD internal_destroy();
  
  #if _WIN32||_WIN64
  public:
      //!  Set the internal state
      void set_state( state_t to ) { state = to; }
  #endif
  };
  
  __TBB_DEFINE_PROFILING_SET_NAME(mutex)
  
  } // namespace tbb
  
  #endif /* __TBB_mutex_H */
  