TryLockMutex: Fix error handling for TryLockMutex

Christian Herzig

pthread_mutex_trylock() and by the way, pthread_mutex_lock() do not set errno.
Pthread-methods directly return error code as int. See related man-pages for
details.
This commit is contained in:
Sam Lantinga 2018-04-23 21:50:03 -07:00
parent a9ae1b508d
commit a1b8fa6071

View File

@ -116,6 +116,7 @@ int
SDL_TryLockMutex(SDL_mutex * mutex) SDL_TryLockMutex(SDL_mutex * mutex)
{ {
int retval; int retval;
int result;
#if FAKE_RECURSIVE_MUTEX #if FAKE_RECURSIVE_MUTEX
pthread_t this_thread; pthread_t this_thread;
#endif #endif
@ -134,18 +135,20 @@ SDL_TryLockMutex(SDL_mutex * mutex)
We set the locking thread id after we obtain the lock We set the locking thread id after we obtain the lock
so unlocks from other threads will fail. so unlocks from other threads will fail.
*/ */
if (pthread_mutex_trylock(&mutex->id) == 0) { result = pthread_mutex_trylock(&mutex->id);
if (result == 0) {
mutex->owner = this_thread; mutex->owner = this_thread;
mutex->recursive = 0; mutex->recursive = 0;
} else if (errno == EBUSY) { } else if (result == EBUSY) {
retval = SDL_MUTEX_TIMEDOUT; retval = SDL_MUTEX_TIMEDOUT;
} else { } else {
retval = SDL_SetError("pthread_mutex_trylock() failed"); retval = SDL_SetError("pthread_mutex_trylock() failed");
} }
} }
#else #else
if (pthread_mutex_trylock(&mutex->id) != 0) { result = pthread_mutex_trylock(&mutex->id);
if (errno == EBUSY) { if (result != 0) {
if (result == EBUSY) {
retval = SDL_MUTEX_TIMEDOUT; retval = SDL_MUTEX_TIMEDOUT;
} else { } else {
retval = SDL_SetError("pthread_mutex_trylock() failed"); retval = SDL_SetError("pthread_mutex_trylock() failed");