---
name: "SDL_TryWaitSemaphore"
section: "3"
platform: "linux"
package: "libsdl3-doc"
version: "3.2.10+ds-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/SDL_TryWaitSemaphore"
---

# SDL\_TryWaitSemaphore(3)

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

## NAME

SDL\_TryWaitSemaphore - See if a semaphore has a positive value and decrement it if it does.

## HEADER FILE

Defined in SDL3/SDL\_mutex.h

## SYNOPSIS

```
#include "SDL3/SDL.h"
```

**bool SDL\_TryWaitSemaphore(SDL\_Semaphore \*sem);**

## DESCRIPTION

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 false.

## FUNCTION PARAMETERS

- *sem*

  the semaphore to wait on.

## RETURN VALUE

Returns true if the wait succeeds, false if the wait would block.

## AVAILABILITY

This function is available since SDL 3.2.0.

## SEE ALSO

**•**(3), [**SDL\_SignalSemaphore**(3)](/SDL_SignalSemaphore/3.md), **•**(3), [**SDL\_WaitSemaphore**(3)](/SDL_WaitSemaphore/3.md), **•**(3), [**SDL\_WaitSemaphoreTimeout**(3)](/SDL_WaitSemaphoreTimeout/3.md)