src/thread/win32/SDL_sysmutex.c
author Sam Lantinga <slouken@libsdl.org>
Fri, 10 Feb 2006 06:48:43 +0000
changeset 1358 c71e05b4dc2e
parent 1338 604d73db6802
child 1402 d910939febfa
permissions -rw-r--r--
More header massaging... works great on Windows. ;-)
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997-2006 Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Lesser General Public
     7     License as published by the Free Software Foundation; either
     8     version 2.1 of the License, or (at your option) any later version.
     9 
    10     This library is distributed in the hope that it will be useful,
    11     but WITHOUT ANY WARRANTY; without even the implied warranty of
    12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    13     Lesser General Public License for more details.
    14 
    15     You should have received a copy of the GNU Lesser General Public
    16     License along with this library; if not, write to the Free Software
    17     Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 /* Mutex functions using the Win32 API */
    24 
    25 #include "SDL_windows.h"
    26 
    27 #include "SDL_mutex.h"
    28 
    29 
    30 struct SDL_mutex {
    31 	HANDLE id;
    32 };
    33 
    34 /* Create a mutex */
    35 SDL_mutex *SDL_CreateMutex(void)
    36 {
    37 	SDL_mutex *mutex;
    38 
    39 	/* Allocate mutex memory */
    40 	mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex));
    41 	if ( mutex ) {
    42 		/* Create the mutex, with initial value signaled */
    43 		mutex->id = CreateMutex(NULL, FALSE, NULL);
    44 		if ( ! mutex->id ) {
    45 			SDL_SetError("Couldn't create mutex");
    46 			SDL_free(mutex);
    47 			mutex = NULL;
    48 		}
    49 	} else {
    50 		SDL_OutOfMemory();
    51 	}
    52 	return(mutex);
    53 }
    54 
    55 /* Free the mutex */
    56 void SDL_DestroyMutex(SDL_mutex *mutex)
    57 {
    58 	if ( mutex ) {
    59 		if ( mutex->id ) {
    60 			CloseHandle(mutex->id);
    61 			mutex->id = 0;
    62 		}
    63 		SDL_free(mutex);
    64 	}
    65 }
    66 
    67 /* Lock the mutex */
    68 int SDL_mutexP(SDL_mutex *mutex)
    69 {
    70 	if ( mutex == NULL ) {
    71 		SDL_SetError("Passed a NULL mutex");
    72 		return -1;
    73 	}
    74 	if ( WaitForSingleObject(mutex->id, INFINITE) == WAIT_FAILED ) {
    75 		SDL_SetError("Couldn't wait on mutex");
    76 		return -1;
    77 	}
    78 	return(0);
    79 }
    80 
    81 /* Unlock the mutex */
    82 int SDL_mutexV(SDL_mutex *mutex)
    83 {
    84 	if ( mutex == NULL ) {
    85 		SDL_SetError("Passed a NULL mutex");
    86 		return -1;
    87 	}
    88 	if ( ReleaseMutex(mutex->id) == FALSE ) {
    89 		SDL_SetError("Couldn't release mutex");
    90 		return -1;
    91 	}
    92 	return(0);
    93 }