src/thread/windows/SDL_sysmutex.c
author Philipp Wiesemann <philipp.wiesemann@arcor.de>
Sun, 08 Jun 2014 12:51:02 +0200
changeset 8844 d35c1b1798c8
parent 8149 681eb46b8ac4
child 9619 b94b6d0bff0f
permissions -rw-r--r--
Fixed typo in source comment.
     1 /*
     2   Simple DirectMedia Layer
     3   Copyright (C) 1997-2014 Sam Lantinga <slouken@libsdl.org>
     4 
     5   This software is provided 'as-is', without any express or implied
     6   warranty.  In no event will the authors be held liable for any damages
     7   arising from the use of this software.
     8 
     9   Permission is granted to anyone to use this software for any purpose,
    10   including commercial applications, and to alter it and redistribute it
    11   freely, subject to the following restrictions:
    12 
    13   1. The origin of this software must not be misrepresented; you must not
    14      claim that you wrote the original software. If you use this software
    15      in a product, an acknowledgment in the product documentation would be
    16      appreciated but is not required.
    17   2. Altered source versions must be plainly marked as such, and must not be
    18      misrepresented as being the original software.
    19   3. This notice may not be removed or altered from any source distribution.
    20 */
    21 #include "../../SDL_internal.h"
    22 
    23 #if SDL_THREAD_WINDOWS
    24 
    25 /* Mutex functions using the Win32 API */
    26 
    27 #include "../../core/windows/SDL_windows.h"
    28 
    29 #include "SDL_mutex.h"
    30 
    31 
    32 struct SDL_mutex
    33 {
    34     CRITICAL_SECTION cs;
    35 };
    36 
    37 /* Create a mutex */
    38 SDL_mutex *
    39 SDL_CreateMutex(void)
    40 {
    41     SDL_mutex *mutex;
    42 
    43     /* Allocate mutex memory */
    44     mutex = (SDL_mutex *) SDL_malloc(sizeof(*mutex));
    45     if (mutex) {
    46         /* Initialize */
    47         /* On SMP systems, a non-zero spin count generally helps performance */
    48         InitializeCriticalSectionAndSpinCount(&mutex->cs, 2000);
    49     } else {
    50         SDL_OutOfMemory();
    51     }
    52     return (mutex);
    53 }
    54 
    55 /* Free the mutex */
    56 void
    57 SDL_DestroyMutex(SDL_mutex * mutex)
    58 {
    59     if (mutex) {
    60         DeleteCriticalSection(&mutex->cs);
    61         SDL_free(mutex);
    62     }
    63 }
    64 
    65 /* Lock the mutex */
    66 int
    67 SDL_LockMutex(SDL_mutex * mutex)
    68 {
    69     if (mutex == NULL) {
    70         return SDL_SetError("Passed a NULL mutex");
    71     }
    72 
    73     EnterCriticalSection(&mutex->cs);
    74     return (0);
    75 }
    76 
    77 /* TryLock the mutex */
    78 int
    79 SDL_TryLockMutex(SDL_mutex * mutex)
    80 {
    81     int retval = 0;
    82     if (mutex == NULL) {
    83         return SDL_SetError("Passed a NULL mutex");
    84     }
    85 
    86     if (TryEnterCriticalSection(&mutex->cs) == 0) {
    87         retval = SDL_MUTEX_TIMEDOUT;
    88     }
    89     return retval;
    90 }
    91 
    92 /* Unlock the mutex */
    93 int
    94 SDL_UnlockMutex(SDL_mutex * mutex)
    95 {
    96     if (mutex == NULL) {
    97         return SDL_SetError("Passed a NULL mutex");
    98     }
    99 
   100     LeaveCriticalSection(&mutex->cs);
   101     return (0);
   102 }
   103 
   104 #endif /* SDL_THREAD_WINDOWS */
   105 
   106 /* vi: set ts=4 sw=4 expandtab: */