SDL_sysmutex.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 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
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slouken@libsdl.org
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*/
/* Mutex functions using the Win32 API */
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#include "SDL_windows.h"
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#include "SDL_error.h"
#include "SDL_mutex.h"
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#include "SDL_stdlib.h"
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struct SDL_mutex {
HANDLE id;
};
/* Create a mutex */
SDL_mutex *SDL_CreateMutex(void)
{
SDL_mutex *mutex;
/* Allocate mutex memory */
mutex = (SDL_mutex *)malloc(sizeof(*mutex));
if ( mutex ) {
/* Create the mutex, with initial value signaled */
mutex->id = CreateMutex(NULL, FALSE, NULL);
if ( ! mutex->id ) {
SDL_SetError("Couldn't create mutex");
free(mutex);
mutex = NULL;
}
} else {
SDL_OutOfMemory();
}
return(mutex);
}
/* Free the mutex */
void SDL_DestroyMutex(SDL_mutex *mutex)
{
if ( mutex ) {
if ( mutex->id ) {
CloseHandle(mutex->id);
mutex->id = 0;
}
free(mutex);
}
}
/* Lock the mutex */
int SDL_mutexP(SDL_mutex *mutex)
{
if ( mutex == NULL ) {
SDL_SetError("Passed a NULL mutex");
return -1;
}
if ( WaitForSingleObject(mutex->id, INFINITE) == WAIT_FAILED ) {
SDL_SetError("Couldn't wait on mutex");
return -1;
}
return(0);
}
/* Unlock the mutex */
int SDL_mutexV(SDL_mutex *mutex)
{
if ( mutex == NULL ) {
SDL_SetError("Passed a NULL mutex");
return -1;
}
if ( ReleaseMutex(mutex->id) == FALSE ) {
SDL_SetError("Couldn't release mutex");
return -1;
}
return(0);
}