|
Size: 765
Comment: update content - standard return value
|
← Revision 7 as of 2013-08-12 05:48:11 ⇥
Size: 852
Comment:
|
| Deletions are marked like this. | Additions are marked like this. |
| Line 2: | Line 2: |
| #pragma disable-camelcase ||<tablewidth="100%" style="color: #FF0000;" :> DRAFT|| |
#pragma camelcase off |
| Line 6: | Line 5: |
| Use this function to atomically (?? automatically ??) increase the semaphore's count (not blocking). | Use this function to atomically increment a semaphore's value and wake waiting threads. |
| Line 16: | Line 15: |
| ||'''sem'''||^a pointer to the SDL_sem structure to be affected^|| | ||'''sem'''||the semaphore to increment|| |
| Line 19: | Line 18: |
| Returns 0 on success or a negative error code on failure; call [[SDL_GetError]]() for more information. | Returns 0 on success or a negative error code on failure ; call [[SDL_GetError]]() for more information. |
| Line 22: | Line 21: |
| {{{#!highlight cpp You can add your code example here }}} |
<<Include(SDL_CreateSemaphore, , , from="## Begin Semaphore Example", to="## End Semaphore Example")>> |
| Line 30: | Line 27: |
| .[[SDL_CreateSemaphore]] .[[SDL_DestroySemaphore]] .[[SDL_SemTryWait]] .[[SDL_SemValue]] .[[SDL_SemWait]] .[[SDL_SemWaitTimeout]] |
SDL_SemPost
Use this function to atomically increment a semaphore's value and wake waiting threads.
Contents
Syntax
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() for more information.
Code Examples
Typical use of semaphores:
SDL_atomic_t done;
SDL_sem *sem;
SDL_AtomicSet(&done, 0);
sem = SDL_CreateSemaphore(0);
.
.
Thread A:
while (!SDL_AtomicGet(&done)) {
add_data_to_queue();
SDL_SemPost(sem);
}
Thread B:
while (!SDL_AtomicGet(&done)) {
SDL_SemWait(sem);
if (data_available()) {
get_data_from_queue();
}
}
.
.
SDL_AtomicSet(&done, 1);
SDL_SemPost(sem);
wait_for_threads();
SDL_DestroySemaphore(sem);
Remarks
You can add useful comments here
