SDL_sysmutex.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2012 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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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
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Sam Lantinga
slouken@libsdl.org
*/
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#include "SDL_config.h"
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/* 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 */
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mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex));
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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");
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SDL_free(mutex);
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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;
}
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SDL_free(mutex);
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}
}
/* 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);
}