Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SemTryWait.3 @ 1795:398ac0f88e4d
Fixed bug #220
The AltiVec blitters don't compile, since they require __VEC__ to be enabled in
order for the compiler to understand "vector" and friends (i.e. do AltiVec)
But you don't want to turn AltiVec on globally, since then the code would only
run on a G4 (there are already runtime tests, before using the AltiVec
variants)
The solution here is to enable AltiVec locally, for the actual AltiVec code.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 09 May 2006 15:09:47 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
| rev | line source |
|---|---|
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
1 .TH "SDL_SemTryWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
| 3 SDL_SemTryWait\- Attempt to lock a semaphore but don\&'t suspend the thread\&. | |
| 4 .SH "SYNOPSIS" | |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 #include "SDL_thread\&.h" | |
| 8 .sp | |
| 9 \fBint \fBSDL_SemTryWait\fP\fR(\fBSDL_sem *sem\fR); | |
| 10 .SH "DESCRIPTION" | |
| 11 .PP | |
| 12 \fBSDL_SemTryWait\fP is a non-blocking varient of \fI\fBSDL_SemWait\fP\fR\&. If the value of the semaphore pointed to by \fBsem\fR is positive it will atomically decrement the semaphore value and return 0, otherwise it will return \fBSDL_MUTEX_TIMEOUT\fR instead of suspending the thread\&. | |
| 13 .PP | |
| 14 After \fBSDL_SemTryWait\fP is successful, the semaphore can be released and its count atomically incremented by a successful call to \fISDL_SemPost\fR\&. | |
| 15 .SH "RETURN VALUE" | |
| 16 .PP | |
| 17 Returns \fB0\fR if the semaphore was successfully locked or either \fBSDL_MUTEX_TIMEOUT\fR or \fB-1\fR if the thread would have suspended or there was an error, respectivly\&. | |
| 18 .PP | |
| 19 If the semaphore was not successfully locked, the semaphore will be unchanged\&. | |
| 20 .SH "EXAMPLES" | |
| 21 .PP | |
| 22 .PP | |
| 23 .nf | |
| 24 \f(CWres = SDL_SemTryWait(my_sem); | |
| 25 | |
| 26 if (res == SDL_MUTEX_TIMEOUT) { | |
| 27 return TRY_AGAIN; | |
| 28 } | |
| 29 if (res == -1) { | |
| 30 return WAIT_ERROR; | |
| 31 } | |
| 32 | |
| 33 \&.\&.\&. | |
| 34 | |
| 35 SDL_SemPost(my_sem);\fR | |
| 36 .fi | |
| 37 .PP | |
| 38 .SH "SEE ALSO" | |
| 39 .PP | |
| 40 \fI\fBSDL_CreateSemaphore\fP\fR, \fI\fBSDL_DestroySemaphore\fP\fR, \fI\fBSDL_SemWait\fP\fR, \fI\fBSDL_SemWaitTimeout\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR | |
|
181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
|
41 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00 |