NAME
SDL_CreateSemaphore - Creates a new semaphore and assigns an initial
value to it.
SYNOPSIS
#include "SDL.h" #include "SDL_thread.h"
SDL_sem *SDL_CreateSemaphore(Uint32 initial_value);
DESCRIPTION
SDL_CreateSemaphore() creates a new semaphore and initializes it with
the value initial_value. Each locking operation on the semaphore by
SDL_SemWait, SDL_SemTryWait or SDL_SemWaitTimeout will atomically
decrement the semaphore value. The locking operation will be blocked if
the semaphore value is not positive (greater than zero). Each unlock
operation by SDL_SemPost will atomically increment the semaphore value.
RETURN VALUE
Returns a pointer to an initialized semaphore or NULL if there was an
error.
EXAMPLES
SDL_sem *my_sem;
my_sem = SDL_CreateSemaphore(INITIAL_SEM_VALUE);
if (my_sem == NULL) {
return CREATE_SEM_FAILED;
}
SEE ALSO
SDL_DestroySemaphore, SDL_SemWait, SDL_SemTryWait, SDL_SemWaitTimeout,
SDL_SemPost, SDL_SemValue