SDL_SemWait(3)

SDL_SemWait3

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

Usage

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

int SDL_SemWait(SDL_sem *sem);

Overview

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);

Releases

11 releases since Debian 3.0 (Woody); the text changed 1 time.

  1. 3.0–5.0
  2. 6.0–12

From libsdl1.2-dev 1.2.15+dfsg2-8 in Debian 12 (Bookworm). Parsed by carta from the page's man source.