text: ﻿/*
    Simple DirectMedia Layer
    Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
  
    This software is provided 'as-is', without any express or implied
    warranty.  In no event will the authors be held liable for any damages
    arising from the use of this software.
  
    Permission is granted to anyone to use this software for any purpose,
    including commercial applications, and to alter it and redistribute it
    freely, subject to the following restrictions:
  
    1. The origin of this software must not be misrepresented; you must not
       claim that you wrote the original software. If you use this software
       in a product, an acknowledgment in the product documentation would be
       appreciated but is not required.
    2. Altered source versions must be plainly marked as such, and must not be
       misrepresented as being the original software.
    3. This notice may not be removed or altered from any source distribution.
  */
  #include "SDL_config.h"
  
  #ifdef SDL_THREAD_BEOS
  
  /* Semaphores in the BeOS environment */
  
  #include <be/kernel/OS.h>
  
  #include "SDL_thread.h"
  
  
  struct SDL_semaphore
  {
      sem_id id;
  };
  
  /* Create a counting semaphore */
  SDL_sem *
  SDL_CreateSemaphore(Uint32 initial_value)
  {
      SDL_sem *sem;
  
      sem = (SDL_sem *) SDL_malloc(sizeof(*sem));
      if (sem) {
          sem->id = create_sem(initial_value, "SDL semaphore");
          if (sem->id < B_NO_ERROR) {
              SDL_SetError("create_sem() failed");
              SDL_free(sem);
              sem = NULL;
          }
      } else {
          SDL_OutOfMemory();
      }
      return (sem);
  }
  
  /* Free the semaphore */
  void
  SDL_DestroySemaphore(SDL_sem * sem)
  {
      if (sem) {
          if (sem->id >= B_NO_ERROR) {
              delete_sem(sem->id);
          }
          SDL_free(sem);
      }
  }
  
  int
  SDL_SemWaitTimeout(SDL_sem * sem, Uint32 timeout)
  {
      int32 val;
      int retval;
  
      if (!sem) {
          SDL_SetError("Passed a NULL semaphore");
          return -1;
      }
  
    tryagain:
      if (timeout == SDL_MUTEX_MAXWAIT) {
          val = acquire_sem(sem->id);
      } else {
          timeout *= 1000;        /* BeOS uses a timeout in microseconds */
          val = acquire_sem_etc(sem->id, 1, B_RELATIVE_TIMEOUT, timeout);
      }
      switch (val) {
      case B_INTERRUPTED:
          goto tryagain;
      case B_NO_ERROR:
          retval = 0;
          break;
      case B_TIMED_OUT:
          retval = SDL_MUTEX_TIMEDOUT;
          break;
      case B_WOULD_BLOCK:
          retval = SDL_MUTEX_TIMEDOUT;
          break;
      default:
          SDL_SetError("acquire_sem() failed");
          retval = -1;
          break;
      }
  
      return retval;
  }
  
  int
  SDL_SemTryWait(SDL_sem * sem)
  {
      return SDL_SemWaitTimeout(sem, 0);
  }
  
  int
  SDL_SemWait(SDL_sem * sem)
  {
      return SDL_SemWaitTimeout(sem, SDL_MUTEX_MAXWAIT);
  }
  
  /* Returns the current count of the semaphore */
  Uint32
  SDL_SemValue(SDL_sem * sem)
  {
      int32 count;
      Uint32 value;
  
      value = 0;
      if (sem) {
          get_sem_count(sem->id, &count);
          if (count > 0) {
              value = (Uint32) count;
          }
      }
      return value;
  }
  
  /* Atomically increases the semaphore's count (not blocking) */
  int
  SDL_SemPost(SDL_sem * sem)
  {
      if (!sem) {
          SDL_SetError("Passed a NULL semaphore");
          return -1;
      }
  
      if (release_sem(sem->id) != B_NO_ERROR) {
          SDL_SetError("release_sem() failed");
          return -1;
      }
      return 0;
  }
  
  #endif /* SDL_THREAD_BEOS */
  
  /* vi: set ts=4 sw=4 expandtab: */
  