diff options
Diffstat (limited to 'contrib/SDL-3.2.8/src/thread/pthread/SDL_sysmutex.c')
| -rw-r--r-- | contrib/SDL-3.2.8/src/thread/pthread/SDL_sysmutex.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/contrib/SDL-3.2.8/src/thread/pthread/SDL_sysmutex.c b/contrib/SDL-3.2.8/src/thread/pthread/SDL_sysmutex.c new file mode 100644 index 0000000..7bba286 --- /dev/null +++ b/contrib/SDL-3.2.8/src/thread/pthread/SDL_sysmutex.c | |||
| @@ -0,0 +1,154 @@ | |||
| 1 | /* | ||
| 2 | Simple DirectMedia Layer | ||
| 3 | Copyright (C) 1997-2025 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 | #include <errno.h> | ||
| 24 | #include <pthread.h> | ||
| 25 | |||
| 26 | #include "SDL_sysmutex_c.h" | ||
| 27 | |||
| 28 | SDL_Mutex *SDL_CreateMutex(void) | ||
| 29 | { | ||
| 30 | SDL_Mutex *mutex; | ||
| 31 | pthread_mutexattr_t attr; | ||
| 32 | |||
| 33 | // Allocate the structure | ||
| 34 | mutex = (SDL_Mutex *)SDL_calloc(1, sizeof(*mutex)); | ||
| 35 | if (mutex) { | ||
| 36 | pthread_mutexattr_init(&attr); | ||
| 37 | #ifdef SDL_THREAD_PTHREAD_RECURSIVE_MUTEX | ||
| 38 | pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE); | ||
| 39 | #elif defined(SDL_THREAD_PTHREAD_RECURSIVE_MUTEX_NP) | ||
| 40 | pthread_mutexattr_setkind_np(&attr, PTHREAD_MUTEX_RECURSIVE_NP); | ||
| 41 | #else | ||
| 42 | // No extra attributes necessary | ||
| 43 | #endif | ||
| 44 | if (pthread_mutex_init(&mutex->id, &attr) != 0) { | ||
| 45 | SDL_SetError("pthread_mutex_init() failed"); | ||
| 46 | SDL_free(mutex); | ||
| 47 | mutex = NULL; | ||
| 48 | } | ||
| 49 | } | ||
| 50 | return mutex; | ||
| 51 | } | ||
| 52 | |||
| 53 | void SDL_DestroyMutex(SDL_Mutex *mutex) | ||
| 54 | { | ||
| 55 | if (mutex) { | ||
| 56 | pthread_mutex_destroy(&mutex->id); | ||
| 57 | SDL_free(mutex); | ||
| 58 | } | ||
| 59 | } | ||
| 60 | |||
| 61 | void SDL_LockMutex(SDL_Mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS // clang doesn't know about NULL mutexes | ||
| 62 | { | ||
| 63 | if (mutex) { | ||
| 64 | #ifdef FAKE_RECURSIVE_MUTEX | ||
| 65 | pthread_t this_thread = pthread_self(); | ||
| 66 | if (mutex->owner == this_thread) { | ||
| 67 | ++mutex->recursive; | ||
| 68 | } else { | ||
| 69 | /* The order of operations is important. | ||
| 70 | We set the locking thread id after we obtain the lock | ||
| 71 | so unlocks from other threads will fail. | ||
| 72 | */ | ||
| 73 | const int rc = pthread_mutex_lock(&mutex->id); | ||
| 74 | SDL_assert(rc == 0); // assume we're in a lot of trouble if this assert fails. | ||
| 75 | mutex->owner = this_thread; | ||
| 76 | mutex->recursive = 0; | ||
| 77 | } | ||
| 78 | #else | ||
| 79 | const int rc = pthread_mutex_lock(&mutex->id); | ||
| 80 | SDL_assert(rc == 0); // assume we're in a lot of trouble if this assert fails. | ||
| 81 | #endif | ||
| 82 | } | ||
| 83 | } | ||
| 84 | |||
| 85 | bool SDL_TryLockMutex(SDL_Mutex *mutex) | ||
| 86 | { | ||
| 87 | bool result = true; | ||
| 88 | |||
| 89 | if (mutex) { | ||
| 90 | #ifdef FAKE_RECURSIVE_MUTEX | ||
| 91 | pthread_t this_thread = pthread_self(); | ||
| 92 | if (mutex->owner == this_thread) { | ||
| 93 | ++mutex->recursive; | ||
| 94 | } else { | ||
| 95 | /* The order of operations is important. | ||
| 96 | We set the locking thread id after we obtain the lock | ||
| 97 | so unlocks from other threads will fail. | ||
| 98 | */ | ||
| 99 | const int rc = pthread_mutex_trylock(&mutex->id); | ||
| 100 | if (rc == 0) { | ||
| 101 | mutex->owner = this_thread; | ||
| 102 | mutex->recursive = 0; | ||
| 103 | } else if (rc == EBUSY) { | ||
| 104 | result = false; | ||
| 105 | } else { | ||
| 106 | SDL_assert(!"Error trying to lock mutex"); // assume we're in a lot of trouble if this assert fails. | ||
| 107 | result = false; | ||
| 108 | } | ||
| 109 | } | ||
| 110 | #else | ||
| 111 | const int rc = pthread_mutex_trylock(&mutex->id); | ||
| 112 | if (rc != 0) { | ||
| 113 | if (rc == EBUSY) { | ||
| 114 | result = false; | ||
| 115 | } else { | ||
| 116 | SDL_assert(!"Error trying to lock mutex"); // assume we're in a lot of trouble if this assert fails. | ||
| 117 | result = false; | ||
| 118 | } | ||
| 119 | } | ||
| 120 | #endif | ||
| 121 | } | ||
| 122 | |||
| 123 | return result; | ||
| 124 | } | ||
| 125 | |||
| 126 | void SDL_UnlockMutex(SDL_Mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS // clang doesn't know about NULL mutexes | ||
| 127 | { | ||
| 128 | if (mutex) { | ||
| 129 | #ifdef FAKE_RECURSIVE_MUTEX | ||
| 130 | // We can only unlock the mutex if we own it | ||
| 131 | if (pthread_self() == mutex->owner) { | ||
| 132 | if (mutex->recursive) { | ||
| 133 | --mutex->recursive; | ||
| 134 | } else { | ||
| 135 | /* The order of operations is important. | ||
| 136 | First reset the owner so another thread doesn't lock | ||
| 137 | the mutex and set the ownership before we reset it, | ||
| 138 | then release the lock semaphore. | ||
| 139 | */ | ||
| 140 | mutex->owner = 0; | ||
| 141 | pthread_mutex_unlock(&mutex->id); | ||
| 142 | } | ||
| 143 | } else { | ||
| 144 | SDL_SetError("mutex not owned by this thread"); | ||
| 145 | return; | ||
| 146 | } | ||
| 147 | |||
| 148 | #else | ||
| 149 | const int rc = pthread_mutex_unlock(&mutex->id); | ||
| 150 | SDL_assert(rc == 0); // assume we're in a lot of trouble if this assert fails. | ||
| 151 | #endif // FAKE_RECURSIVE_MUTEX | ||
| 152 | } | ||
| 153 | } | ||
| 154 | |||
