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------- Comment #1 From Max Horn 2006-04-17 03:08 [reply] ------- Created an attachment (id=106) [edit] Patch for src/joystick/win32/SDL_mmjoystick.c I am not even a Windows user, so take the following with a grain of salt: SDL_mmjoystick.c has a function GetJoystickName which obtains the joystick name by looking at the registry. The way it does that seems very fishy to me. Namely, it uses the parameter "index" to construct a registry value name (BTW, those variables used in the code are really badly named). The value of "index" in turn equals the current value of "numdevs", as called from SDL_SYS_JoystickInit. I read through the MSDN docs at <http://msdn.microsoft.com/archive/default.asp?url=/archive/en-us/dnarinput/html/msdn_extdirect.asp>, and I believe the simple fix is to replace line 183 of said file SYS_JoystickName[numdevs] = GetJoystickName(numdevs, joycaps.szRegKey); by the following: SYS_JoystickName[numdevs] = GetJoystickName(SYS_JoystickID[i], joycaps.szRegKey); However, that is only *hiding* the real issue. Problem is, the list of joysticks as returned by windows may contains "gaps", and the code deals incorrectly with that. Namely those gaps occur if joysticks are removed/(re)added, as the reporter observed. The attached patch fixes this and another (off-by-one) issue in the code. But since I have no Windows machine, I can't even test-compile it, so use with caution.
author Sam Lantinga <slouken@libsdl.org>
date Sat, 29 Apr 2006 20:22:31 +0000
parents e5bc29de3f0a
children 546f7c1eb755
line wrap: on
line source

.TH "SDL_SemTryWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SemTryWait\- Attempt to lock a semaphore but don\&'t suspend the thread\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
#include "SDL_thread\&.h"
.sp
\fBint \fBSDL_SemTryWait\fP\fR(\fBSDL_sem *sem\fR);
.SH "DESCRIPTION"
.PP
\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\&.
.PP
After \fBSDL_SemTryWait\fP is successful, the semaphore can be released and its count atomically incremented by a successful call to \fISDL_SemPost\fR\&.
.SH "RETURN VALUE"
.PP
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\&.
.PP
If the semaphore was not successfully locked, the semaphore will be unchanged\&.
.SH "EXAMPLES"
.PP
.PP
.nf
\f(CWres = SDL_SemTryWait(my_sem);

if (res == SDL_MUTEX_TIMEOUT) {
        return TRY_AGAIN;
}
if (res == -1) {
        return WAIT_ERROR;
}

\&.\&.\&.

SDL_SemPost(my_sem);\fR
.fi
.PP
.SH "SEE ALSO"
.PP
\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
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00