sdl

FORK: Simple Directmedia Layer
git clone https://git.neptards.moe/neptards/sdl.git
Log | Files | Refs

SDL_sysmutex.c (2583B)

      1 /*
      2   Simple DirectMedia Layer
      3   Copyright (C) 1997-2020 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 #if __WINRT__
     49         InitializeCriticalSectionEx(&mutex->cs, 2000, 0);
     50 #else
     51         InitializeCriticalSectionAndSpinCount(&mutex->cs, 2000);
     52 #endif
     53     } else {
     54         SDL_OutOfMemory();
     55     }
     56     return (mutex);
     57 }
     58 
     59 /* Free the mutex */
     60 void
     61 SDL_DestroyMutex(SDL_mutex * mutex)
     62 {
     63     if (mutex) {
     64         DeleteCriticalSection(&mutex->cs);
     65         SDL_free(mutex);
     66     }
     67 }
     68 
     69 /* Lock the mutex */
     70 int
     71 SDL_LockMutex(SDL_mutex * mutex)
     72 {
     73     if (mutex == NULL) {
     74         return SDL_SetError("Passed a NULL mutex");
     75     }
     76 
     77     EnterCriticalSection(&mutex->cs);
     78     return (0);
     79 }
     80 
     81 /* TryLock the mutex */
     82 int
     83 SDL_TryLockMutex(SDL_mutex * mutex)
     84 {
     85     int retval = 0;
     86     if (mutex == NULL) {
     87         return SDL_SetError("Passed a NULL mutex");
     88     }
     89 
     90     if (TryEnterCriticalSection(&mutex->cs) == 0) {
     91         retval = SDL_MUTEX_TIMEDOUT;
     92     }
     93     return retval;
     94 }
     95 
     96 /* Unlock the mutex */
     97 int
     98 SDL_UnlockMutex(SDL_mutex * mutex)
     99 {
    100     if (mutex == NULL) {
    101         return SDL_SetError("Passed a NULL mutex");
    102     }
    103 
    104     LeaveCriticalSection(&mutex->cs);
    105     return (0);
    106 }
    107 
    108 #endif /* SDL_THREAD_WINDOWS */
    109 
    110 /* vi: set ts=4 sw=4 expandtab: */