NAME

       SDL_SemWait - Lock a semaphore and suspend the thread if the semaphore value is zero.

SYNOPSIS

       #include "SDL.h" #include "SDL_thread.h"

       int SDL_SemWait(SDL_sem *sem);

DESCRIPTION

       SDL_SemWait()  suspends  the  calling  thread until either the semaphore pointed to by sem has a positive
       value, the call is interrupted by a signal or error.  If  the  call  is  successful  it  will  atomically
       decrement the semaphore value.

       After  SDL_SemWait() is successful, the semaphore can be released and its count atomically incremented by
       a successful call to SDL_SemPost.

RETURN VALUE

       Returns 0 if successful or -1 if there was an error (leaving the semaphore unchanged).

EXAMPLES

       if (SDL_SemWait(my_sem) == -1) {
               return WAIT_FAILED;
       }

       ...

       SDL_SemPost(my_sem);

SEE ALSO

       SDL_CreateSemaphore, SDL_DestroySemaphore, SDL_SemTryWait, SDL_SemWaitTimeout, SDL_SemPost, SDL_SemValue