#pragma section-numbers off
#pragma camelcase off

= SDL_SemWait =
Use this function to wait until a semaphore has a positive value and then decrements it.

<<TableOfContents()>>

== Syntax ==
{{{#!highlight cpp
int SDL_SemWait(SDL_sem* sem)
}}}

== Function Parameters ==
||'''sem'''||the semaphore wait on||

== Return Value ==
Returns 0 on success or a negative error code on failure; call [[SDL_GetError]]() for more information.

== Code Examples ==
<<Include(SDL_CreateSemaphore, , , from="## Begin Semaphore Example", to="## End Semaphore Example")>>

== Remarks ==
This function suspends the calling thread until either the semaphore pointed to by '''sem''' has a positive value or the call is interrupted by a signal or error. If the call is successful it will atomically decrement the semaphore value.

This function is the equivalent of calling [[SDL_SemWaitTimeout]]() with a time length of SDL_MUTEX_MAXWAIT.

== Related Functions ==
 .[[SDL_CreateSemaphore]]
 .[[SDL_DestroySemaphore]]
 .[[SDL_SemPost]]
 .[[SDL_SemTryWait]]
 .[[SDL_SemValue]]
 .[[SDL_SemWait]]
 .[[SDL_SemWaitTimeout]]

----
[[CategoryAPI]], [[CategoryMutex]]