/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library 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

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

/* Mutex functions using the OS/2 API */

#define INCL_DOSERRORS

#define INCL_DOSSEMAPHORES

#include <os2.h>

#include "SDL_mutex.h"

struct SDL_mutex {

	HMTX hmtxID;

};

/* Create a mutex */

DECLSPEC SDL_mutex * SDLCALL SDL_CreateMutex(void)

{

  SDL_mutex *mutex;

  APIRET ulrc;

  /* Allocate mutex memory */

  mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex));

  if (mutex)

  {

    /* Create the mutex, with initial value signaled */

    ulrc = DosCreateMutexSem(NULL,                  // Create unnamed semaphore

                             &(mutex->hmtxID),      // Pointer to handle

                             0L,                    // Flags: create it private (not shared)

                             FALSE);                // Initial value: unowned

    if (ulrc!=NO_ERROR)

    {

      SDL_SetError("Couldn't create mutex");

      SDL_free(mutex);

      mutex = NULL;

    }

  } else {

    SDL_OutOfMemory();

  }

  return(mutex);

}

/* Free the mutex */

DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex)

{

  if ( mutex )

  {

    if ( mutex->hmtxID )

    {

      DosCloseMutexSem(mutex->hmtxID);

      mutex->hmtxID = 0;

    }

    SDL_free(mutex);

  }

}

/* Lock the mutex */

DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex)

{

  if ( mutex == NULL )

  {

    SDL_SetError("Passed a NULL mutex");

    return -1;

  }

  if ( DosRequestMutexSem(mutex->hmtxID, SEM_INDEFINITE_WAIT) != NO_ERROR )

  {

    SDL_SetError("Couldn't wait on mutex");

    return -1;

  }

  return(0);

}

/* Unlock the mutex */

DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex)

{

  if ( mutex == NULL )

  {

    SDL_SetError("Passed a NULL mutex");

    return -1;

  }

  if ( DosReleaseMutexSem(mutex->hmtxID) != NO_ERROR )

  {

    SDL_SetError("Couldn't release mutex");

    return -1;

  }

  return(0);

}