###### (This is the documentation for SDL3, which is under heavy development and the API is changing! [SDL2](https://wiki.libsdl.org/SDL2/) is the current stable version!) # SDL_PostSemaphore Atomically increment a semaphore's value and wake waiting threads. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_mutex.h) ## Syntax ```c int SDL_PostSemaphore(SDL_Semaphore *sem); ``` ## Function Parameters | | | | ----------- | -------------------------- | | **sem** | the semaphore to increment | ## Return Value Returns 0 on success or a negative error code on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Version This function is available since SDL 3.0.0. ## See Also - [SDL_TryWaitSemaphore](SDL_TryWaitSemaphore) - [SDL_WaitSemaphore](SDL_WaitSemaphore) - [SDL_WaitSemaphoreTimeout](SDL_WaitSemaphoreTimeout) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryMutex](CategoryMutex)