###### (This is the legacy documentation for stable SDL2, the current stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current development version.) # SDL_SemPost Atomically increment a semaphore's value and wake waiting threads. ## Syntax ```c int SDL_SemPost(SDL_sem * 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 2.0.0. ## Related Functions * [SDL_CreateSemaphore](SDL_CreateSemaphore) * [SDL_DestroySemaphore](SDL_DestroySemaphore) * [SDL_SemTryWait](SDL_SemTryWait) * [SDL_SemValue](SDL_SemValue) * [SDL_SemWait](SDL_SemWait) * [SDL_SemWaitTimeout](SDL_SemWaitTimeout) ---- [CategoryAPI](CategoryAPI)