Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SemWaitTimeout.3 @ 610:95433459fbd2
Date: Mon, 14 Apr 2003 22:08:27 +0100
From: Patrice Mandin
Subject: [SDL][PATCH] 2 patches for sdl
Here are 2 patches for SDL:
- One is to put the dummy video drivers at the end of the
video drivers list. It gave me problems, when
SDL_VIDEODRIVER is not set, and the dummy driver is used
instead of the platform's driver, just because it is
always available. So the dummy driver must always be at
the end of the list. I suppose picogui and dc video
drivers also don't work.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 15 Apr 2003 15:46:56 +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_SemWaitTimeout" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" |
| 0 | 2 .SH "NAME" |
| 3 SDL_SemWaitTimeout\- Lock a semaphore, but only wait up to a specified maximum time\&. | |
| 4 .SH "SYNOPSIS" | |
| 5 .PP | |
| 6 \fB#include "SDL\&.h" | |
| 7 #include "SDL_thread\&.h" | |
| 8 .sp | |
| 9 \fBint \fBSDL_SemWaitTimeout\fP\fR(\fBSDL_sem *sem, Uint32 timeout\fR); | |
| 10 .SH "DESCRIPTION" | |
| 11 .PP | |
| 12 \fBSDL_SemWaitTimeout()\fP is a varient of \fISDL_SemWait\fR with a maximum timeout value\&. If the value of the semaphore pointed to by \fBsem\fR is positive (greater than zero) it will atomically decrement the semaphore value and return 0, otherwise it will wait up to \fBtimeout\fR milliseconds trying to lock the semaphore\&. This function is to be avoided if possible since on some platforms it is implemented by polling the semaphore every millisecond in a busy loop\&. | |
| 13 .PP | |
| 14 After \fBSDL_SemWaitTimeout()\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 timeout period was exceeded 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_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC); | |
| 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_SemTryWait\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 |