###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_WaitSemaphoreTimeout Wait until a semaphore has a positive value and then decrements it. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_mutex.h) ## Syntax ```c bool SDL_WaitSemaphoreTimeout(SDL_Semaphore *sem, Sint32 timeoutMS); ``` ## Function Parameters | | | | | -------------------------------- | ------------- | ----------------------------------------------------------------------- | | [SDL_Semaphore](SDL_Semaphore) * | **sem** | the semaphore to wait on. | | [Sint32](Sint32) | **timeoutMS** | the length of the timeout, in milliseconds, or -1 to wait indefinitely. | ## Return Value (bool) Returns true if the wait succeeds or false if the wait times out. ## Remarks This function suspends the calling thread until either the semaphore pointed to by `sem` has a positive value or the specified time has elapsed. If the call is successful it will atomically decrement the semaphore value. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_SignalSemaphore](SDL_SignalSemaphore) - [SDL_TryWaitSemaphore](SDL_TryWaitSemaphore) - [SDL_WaitSemaphore](SDL_WaitSemaphore) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryMutex](CategoryMutex)