SDL_SemWaitTimeout(3) SDL API Reference SDL_SemWaitTimeout(3)NAME
SDL_SemWaitTimeout- Lock a semaphore, but only wait up to
a specified maximum time.
SYNOPSIS
#include "SDL.h" #include "SDL_thread.h"
int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout);
DESCRIPTIONSDL_SemWaitTimeout() is a varient of SDL_SemWait with a
maximum timeout value. If the value of the semaphore
pointed to by sem is positive (greater than zero) it will
atomically decrement the semaphore value and return 0,
otherwise it will wait up to timeout milliseconds trying
to lock the semaphore. This function is to be avoided if
possible since on some platforms it is implemented by
polling the semaphore every millisecond in a busy loop.
After SDL_SemWaitTimeout() is successful, the semaphore
can be released and its count atomically incremented by a
successful call to SDL_SemPost.
RETURN VALUE
Returns 0 if the semaphore was successfully locked or
either SDL_MUTEX_TIMEOUT or -1 if the timeout period was
exceeded or there was an error, respectivly.
If the semaphore was not successfully locked, the
semaphore will be unchanged.
EXAMPLES
res = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC);
if (res == SDL_MUTEX_TIMEOUT) {
return TRY_AGAIN;
}
if (res == -1) {
return WAIT_ERROR;
}
...
SDL_SemPost(my_sem);
SEE ALSO
SDL_CreateSemaphore, SDL_DestroySemaphore, SDL_SemWait,
SDL_SemTryWait, SDL_SemPost, SDL_SemValue
SDL Tue 11 Sep 2001, 23:00SDL_SemWaitTimeout(3)
