(This is the legacy documentation for SDL2, the previous stable version; SDL3 is the current stable version.)

SDL_SemTryWait

See if a semaphore has a positive value and decrement it if it does.

Header File

Syntax

int SDL_SemTryWait(SDL_sem * sem);

Function Parameters

SDL_sem *

sem

the semaphore to wait on.

Return Value

(int) Returns 0 if the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait would block, or a negative error code on failure; call SDL_GetError() for more information.

Remarks

This function checks to see if the semaphore pointed to by sem has a positive value and atomically decrements the semaphore value if it does. If the semaphore doesn't have a positive value, the function immediately returns SDL_MUTEX_TIMEDOUT.

Version

This function is available since SDL 2.0.0.