We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

[patch] Implementation of MutexTryLock for all supported platforms.

commit-7925f0f (text/plain), 4.92 KB, created by Edward Rudd on 2012-10-17 12:32:37 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Edward Rudd

Created: 2012-10-17 12:32:37 UTC

Size: 4.92 KB

patch

obsolete

>tree 3bfba475a90d
>parent 46d985073364
>author Edward Rudd <urkle@outoforder.cc> 1350500520 14400
>committer Edward Rudd <urkle@outoforder.cc> 1350500520 14400
>revision 6590
>branch default
>
>Add SDL_MutexTryLock and implementations for all platforms
>diff --git a/include/SDL_mutex.h b/include/SDL_mutex.h
>--- a/include/SDL_mutex.h
>+++ b/include/SDL_mutex.h
>@@ -74,6 +74,13 @@
> extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex * mutex);
> 
> /**
>+ *  Try to lock the mutex
>+ *  
>+ *  \return 0, SDL_MUTEX_TIMEDOUT, or -1 on error
>+ */
>+extern DECLSPEC int SDLCALL SDL_MutexTryLock(SDL_mutex * mutex);
>+
>+/**
>  *  Unlock the mutex.
>  *  
>  *  \return 0, or -1 on error.
>diff --git a/src/thread/generic/SDL_sysmutex.c b/src/thread/generic/SDL_sysmutex.c
>--- a/src/thread/generic/SDL_sysmutex.c
>+++ b/src/thread/generic/SDL_sysmutex.c
>@@ -68,7 +68,7 @@
>     }
> }
> 
>-/* Lock the semaphore */
>+/* Lock the mutex */
> int
> SDL_mutexP(SDL_mutex * mutex)
> {
>@@ -99,6 +99,40 @@
> #endif /* SDL_THREADS_DISABLED */
> }
> 
>+/* try Lock the mutex */
>+int
>+SDL_MutexTryLock(SDL_mutex * mutex)
>+{
>+#if SDL_THREADS_DISABLED
>+    return 0;
>+#else
>+    int retval = 0;
>+    SDL_threadID this_thread;
>+
>+    if (mutex == NULL) {
>+        SDL_SetError("Passed a NULL mutex");
>+        return -1;
>+    }
>+
>+    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)
>diff --git a/src/thread/nds/SDL_sysmutex.c b/src/thread/nds/SDL_sysmutex.c
>--- a/src/thread/nds/SDL_sysmutex.c
>+++ b/src/thread/nds/SDL_sysmutex.c
>@@ -76,7 +76,7 @@
>     }
> }
> 
>-/* Lock the semaphore */
>+/* Lock the mutex */
> int
> SDL_mutexP(SDL_mutex * mutex)
> {
>@@ -107,6 +107,40 @@
> #endif /* DISABLE_THREADS */
> }
> 
>+/* Try Lock the mutex */
>+int
>+SDL_MutexTryLock(SDL_mutex * mutex)
>+{
>+#ifdef DISABLE_THREADS
>+    return 0;
>+#else
>+    int retval = 0;
>+    SDL_threadID this_thread;
>+
>+    if (mutex == NULL) {
>+        SDL_SetError("Passed a NULL mutex");
>+        return -1;
>+    }
>+
>+    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_SemTryWait(mutex->sem);
>+        if (ret == 0) {
>+            mutex->owner = this_thread;
>+            mutex->recursive = 0;
>+        }
>+    }
>+
>+    return retval;
>+#endif /* DISABLE_THREADS */
>+}
>+
> /* Unlock the mutex */
> int
> SDL_mutexV(SDL_mutex * mutex)
>diff --git a/src/thread/pthread/SDL_sysmutex.c b/src/thread/pthread/SDL_sysmutex.c
>--- a/src/thread/pthread/SDL_sysmutex.c
>+++ b/src/thread/pthread/SDL_sysmutex.c
>@@ -118,6 +118,52 @@
> }
> 
> int
>+SDL_MutexTryLock(SDL_mutex * mutex)
>+{
>+    int retval;
>+#if FAKE_RECURSIVE_MUTEX
>+    pthread_t this_thread;
>+#endif
>+
>+    if (mutex == NULL) {
>+        SDL_SetError("Passed a NULL mutex");
>+        return -1;
>+    }
>+
>+    retval = 0;
>+#if FAKE_RECURSIVE_MUTEX
>+    this_thread = pthread_self();
>+    if (mutex->owner == this_thead) {
>+        ++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.
>+         */
>+        if (pthread_mutex_lock(&mutex->id) == 0) {
>+            mutex->owner = this_thread;
>+            mutex->recursive = 0;
>+        } else if (errno == EBUSY) {
>+            retval = SDL_MUTEX_TIMEDOUT;
>+        } else {
>+            SDL_SetError("pthread_mutex_trylock() failed");
>+            retval = -1;
>+        }
>+    }
>+#else
>+    if (pthread_mutex_trylock(&mutex->id) != 0) {
>+        if (errno == EBUSY) {
>+            retval = SDL_MUTEX_TIMEDOUT;
>+        } else {
>+            SDL_SetError("pthread_mutex_trylock() failed");
>+            retval = -1;
>+        }
>+    }
>+#endif
>+    return retval;
>+}
>+
>+int
> SDL_mutexV(SDL_mutex * mutex)
> {
>     int retval;
>diff --git a/src/thread/windows/SDL_sysmutex.c b/src/thread/windows/SDL_sysmutex.c
>--- a/src/thread/windows/SDL_sysmutex.c
>+++ b/src/thread/windows/SDL_sysmutex.c
>@@ -75,6 +75,22 @@
>     return (0);
> }
> 
>+/* TryLock the mutex */
>+int
>+SDL_MutexTryLock(SDL_mutex * mutex)
>+{
>+    if (mutex == NULL) {
>+        SDL_SetError("Passed a NULL mutex");
>+        return -1;
>+    }
>+
>+    int retval = 0;
>+    if (TryEnterCriticalSection(&mutex->cs) == 0) {
>+        retval = SDL_MUTEX_TIMEDOUT;
>+    }
>+    return retval;
>+}
>+
> /* Unlock the mutex */
> int
> SDL_mutexV(SDL_mutex * mutex)

Actions: View | Diff

Attachments on bug 1623: 972 | 975 | 1007

We are currently migrating Bugzilla to GitHub issues.Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.

We are currently migrating Bugzilla to GitHub issues.
Any changes made to the bug tracker now will be lost, so please do not post new bugs or make changes to them.
When we're done, all bug URLs will redirect to their equivalent location on the new bug tracker.