(This is the legacy documentation for stable SDL2, the current stable version; SDL3 is the current development 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

sem

the semaphore to wait on

Return Value

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.