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author Miodrag Milanovic <mmicko@gmail.com>2016-02-27 16:28:05 +0100
committer Miodrag Milanovic <mmicko@gmail.com>2016-02-27 16:53:49 +0100
commitcf6dc7d370407914020f3e623719f09c8668c692 (patch)
tree46b3416d091b4c09b50fba7ffcbd310aed032cc8 /3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c
parent64135e73f973d9b95beb0c60b65feb34fbfec64a (diff)
Placed SDL2 source since we need it on some platforms (nw)
Diffstat (limited to '3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c')
-rw-r--r--3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c165
1 files changed, 165 insertions, 0 deletions
diff --git a/3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c b/3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c
new file mode 100644
index 00000000000..f2f6689700d
--- /dev/null
+++ b/3rdparty/SDL2/src/thread/generic/SDL_sysmutex.c
@@ -0,0 +1,165 @@
+/*
+ Simple DirectMedia Layer
+ Copyright (C) 1997-2016 Sam Lantinga <slouken@libsdl.org>
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the authors be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+*/
+#include "../../SDL_internal.h"
+
+/* An implementation of mutexes using semaphores */
+
+#include "SDL_thread.h"
+#include "SDL_systhread_c.h"
+
+
+struct SDL_mutex
+{
+ int recursive;
+ SDL_threadID owner;
+ SDL_sem *sem;
+};
+
+/* Create a mutex */
+SDL_mutex *
+SDL_CreateMutex(void)
+{
+ SDL_mutex *mutex;
+
+ /* Allocate mutex memory */
+ mutex = (SDL_mutex *) SDL_malloc(sizeof(*mutex));
+ if (mutex) {
+ /* Create the mutex semaphore, with initial value 1 */
+ mutex->sem = SDL_CreateSemaphore(1);
+ mutex->recursive = 0;
+ mutex->owner = 0;
+ if (!mutex->sem) {
+ SDL_free(mutex);
+ mutex = NULL;
+ }
+ } else {
+ SDL_OutOfMemory();
+ }
+ return mutex;
+}
+
+/* Free the mutex */
+void
+SDL_DestroyMutex(SDL_mutex * mutex)
+{
+ if (mutex) {
+ if (mutex->sem) {
+ SDL_DestroySemaphore(mutex->sem);
+ }
+ SDL_free(mutex);
+ }
+}
+
+/* Lock the mutex */
+int
+SDL_LockMutex(SDL_mutex * mutex)
+{
+#if SDL_THREADS_DISABLED
+ return 0;
+#else
+ SDL_threadID this_thread;
+
+ if (mutex == NULL) {
+ return SDL_SetError("Passed a NULL mutex");
+ }
+
+ this_thread = SDL_ThreadID();
+ if (mutex->owner == this_thread) {
+ ++mutex->recursive;
+ } else {
+ /* The order of operations is important.
+ We set the locking thread id after we obtain the lock
+ so unlocks from other threads will fail.
+ */
+ SDL_SemWait(mutex->sem);
+ mutex->owner = this_thread;
+ mutex->recursive = 0;
+ }
+
+ return 0;
+#endif /* SDL_THREADS_DISABLED */
+}
+
+/* try Lock the mutex */
+int
+SDL_TryLockMutex(SDL_mutex * mutex)
+{
+#if SDL_THREADS_DISABLED
+ return 0;
+#else
+ int retval = 0;
+ SDL_threadID this_thread;
+
+ if (mutex == NULL) {
+ return SDL_SetError("Passed a NULL mutex");
+ }
+
+ this_thread = SDL_ThreadID();
+ if (mutex->owner == this_thread) {
+ ++mutex->recursive;
+ } else {
+ /* The order of operations is important.
+ We set the locking thread id after we obtain the lock
+ so unlocks from other threads will fail.
+ */
+ retval = SDL_SemWait(mutex->sem);
+ if (retval == 0) {
+ mutex->owner = this_thread;
+ mutex->recursive = 0;
+ }
+ }
+
+ return retval;
+#endif /* SDL_THREADS_DISABLED */
+}
+
+/* Unlock the mutex */
+int
+SDL_mutexV(SDL_mutex * mutex)
+{
+#if SDL_THREADS_DISABLED
+ return 0;
+#else
+ if (mutex == NULL) {
+ return SDL_SetError("Passed a NULL mutex");
+ }
+
+ /* If we don't own the mutex, we can't unlock it */
+ if (SDL_ThreadID() != mutex->owner) {
+ return SDL_SetError("mutex not owned by this thread");
+ }
+
+ if (mutex->recursive) {
+ --mutex->recursive;
+ } else {
+ /* The order of operations is important.
+ First reset the owner so another thread doesn't lock
+ the mutex and set the ownership before we reset it,
+ then release the lock semaphore.
+ */
+ mutex->owner = 0;
+ SDL_SemPost(mutex->sem);
+ }
+ return 0;
+#endif /* SDL_THREADS_DISABLED */
+}
+
+/* vi: set ts=4 sw=4 expandtab: */