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);

DESCRIPTION

       SDL_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