Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SemTryWait.3 @ 2763:6fc50bdd88c0
Some cleanups on the new XInput code.
One or two things got moved around, but largely this is hooked up correctly
in the Unix configure system now: it can be dynamically loaded and fallback
gracefully if not available, or libXi can be directly linked to libSDL.
XInput support can be --disable'd from the configure script, too (defaults to
enabled).
Please note that while the framework is in place to gracefully fallback, the
current state of the source requires XInput. We'll need to adjust a few
things still to correct this.
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Wed, 17 Sep 2008 08:20:57 +0000 |
| parents | 546f7c1eb755 |
| children | 1238da4a7112 |
| 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" |
|
2283
546f7c1eb755
Merged revision 3472 from SDL 1.2, fixing bug #493
Sam Lantinga <slouken@libsdl.org>
parents:
181
diff
changeset
|
3 SDL_SemTryWait \- Attempt to lock a semaphore but don\&'t suspend the thread\&. |
| 0 | 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 |