Mercurial > sdl-ios-xcode
annotate docs/man3/SDL_SemTryWait.3 @ 914:bbf8dcc8aed6
Date: Wed, 23 Jun 2004 17:05:33 -0400
From: Chris Nelson
Subject: [SDL] [Patch] WiseGroup MP-8800 / MP-8866 (PS2 Joystick)
In the current cvs version, SDL doesn't handle these Playstation2
controller => USB adapters correctly, in linux.
It will always assume that the maximum number of joysticks (2 in the
case of the MP-8866, 4 in the case of the 8800) are plugged in. This is
bad not only because it allows SDL to exaggerate the number of logical
joysticks, but primarily because the joystick axes are mapped
incorrectly, all over the place, such that the devices are effectively
unusable unless you have the maximum number of joysticks plugged in.
My changes to src/joystick/linux/SDL_sysjoystick.c build on another's
previous work (which was a special case for this very joystick,
actually), and fix both of these problems, as well as making the current
code a little more general, to allow for others to more easily drop in
code for quirky joysticks such as these.
I've tested this code under 2.6.7 as well as 2.4.24... Both work as
advertised (provided you load the JOYDEV linux code as a module,
otherwise they won't work at all, new code or old, but that's another
issue entirely).
Though this sounds horribly formal, you have my permission to distribute
all of my work on this issue under the LGPL. So there.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sun, 25 Jul 2004 18:31:50 +0000 |
parents | e5bc29de3f0a |
children | 546f7c1eb755 |
rev | line source |
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181
e5bc29de3f0a
Updated from the SDL Documentation Project
Sam Lantinga <slouken@libsdl.org>
parents:
55
diff
changeset
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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 |