SDL_SemPost -- Unlock a semaphore.
#include "SDL.h" #include "SDL_thread.h" int SDL_SemPost(SDL_sem *sem);
SDL_SemPost unlocks the semaphore pointed to by sem and atomically increments the semaphore's value. Threads that were blocking on the semaphore may be scheduled after this call succeeds.
Returns 0 if successful or -1 if there was an error (leaving the semaphore unchanged).