src/thread/win32/SDL_sysmutex.c
author Sam Lantinga <slouken@libsdl.org>
Wed, 06 Mar 2002 11:23:08 +0000
changeset 297 f6ffac90895c
parent 252 e8157fcb3114
child 769 b8d311d90021
permissions -rw-r--r--
Updated copyright information for 2002
     1 /*
     2     SDL - Simple DirectMedia Layer
     3     Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002  Sam Lantinga
     4 
     5     This library is free software; you can redistribute it and/or
     6     modify it under the terms of the GNU Library General Public
     7     License as published by the Free Software Foundation; either
     8     version 2 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     Library General Public License for more details.
    14 
    15     You should have received a copy of the GNU Library General Public
    16     License along with this library; if not, write to the Free
    17     Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    18 
    19     Sam Lantinga
    20     slouken@libsdl.org
    21 */
    22 
    23 #ifdef SAVE_RCSID
    24 static char rcsid =
    25  "@(#) $Id$";
    26 #endif
    27 
    28 /* Mutex functions using the Win32 API */
    29 
    30 #include <stdio.h>
    31 #include <stdlib.h>
    32 #include <windows.h>
    33 
    34 #include "SDL_error.h"
    35 #include "SDL_mutex.h"
    36 
    37 
    38 struct SDL_mutex {
    39 	HANDLE id;
    40 };
    41 
    42 /* Create a mutex */
    43 SDL_mutex *SDL_CreateMutex(void)
    44 {
    45 	SDL_mutex *mutex;
    46 
    47 	/* Allocate mutex memory */
    48 	mutex = (SDL_mutex *)malloc(sizeof(*mutex));
    49 	if ( mutex ) {
    50 		/* Create the mutex, with initial value signaled */
    51 		mutex->id = CreateMutex(NULL, FALSE, NULL);
    52 		if ( ! mutex->id ) {
    53 			SDL_SetError("Couldn't create mutex");
    54 			free(mutex);
    55 			mutex = NULL;
    56 		}
    57 	} else {
    58 		SDL_OutOfMemory();
    59 	}
    60 	return(mutex);
    61 }
    62 
    63 /* Free the mutex */
    64 void SDL_DestroyMutex(SDL_mutex *mutex)
    65 {
    66 	if ( mutex ) {
    67 		if ( mutex->id ) {
    68 			CloseHandle(mutex->id);
    69 			mutex->id = 0;
    70 		}
    71 		free(mutex);
    72 	}
    73 }
    74 
    75 /* Lock the mutex */
    76 int SDL_mutexP(SDL_mutex *mutex)
    77 {
    78 	if ( mutex == NULL ) {
    79 		SDL_SetError("Passed a NULL mutex");
    80 		return -1;
    81 	}
    82 	if ( WaitForSingleObject(mutex->id, INFINITE) == WAIT_FAILED ) {
    83 		SDL_SetError("Couldn't wait on mutex");
    84 		return -1;
    85 	}
    86 	return(0);
    87 }
    88 
    89 /* Unlock the mutex */
    90 int SDL_mutexV(SDL_mutex *mutex)
    91 {
    92 	if ( mutex == NULL ) {
    93 		SDL_SetError("Passed a NULL mutex");
    94 		return -1;
    95 	}
    96 	if ( ReleaseMutex(mutex->id) == FALSE ) {
    97 		SDL_SetError("Couldn't release mutex");
    98 		return -1;
    99 	}
   100 	return(0);
   101 }