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view docs/man3/SDL_SemWaitTimeout.3 @ 4391:07b330419439 SDL-1.2

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Fixed bug #849 some more: Tim Angus 2009-11-26 14:41:04 PST Fix to the cursor not being responsive when the app doesn't have SDL_APPINPUTFOCUS The problems with the directx driver are similar to the ones I introduced in the windib driver with r4478. Basically if the application did not have focus, the mouse position is not updated. It's not really that the mouse cursor was invisible, it's that it is stuck underneath another window where you can't see it. This behaviour predates my r4478 changes and is the reason I unwittingly broke the windib driver as I had been replicating the way the directx driver deals with focus. Prior to r4478 the directx driver could not be used in windowed mode, so the broken focusing would not have actually been observable. Anyway, the attached patch makes the directx driver behaves like the windib driver in terms of focus. Time for 1.2.15? ;) I've added an additional change of moving the calls to WIN_GrabInput that are made on WM_ACTIVATE messages so that they only occur when the state is SDL_APPINPUTFOCUS. When a fullscreen application is minimised using alt-tab, it still receives WM_ACTIVATE messages when other applications are selected. If WIN_GrabInput is called when the SDL application doesn't have input focus, bad things happen; it shouldn't be being called at all. I've also added a line to make sure that SDL_APPMOUSEFOCUS state is dropped when the application is minimised following an alt-tab.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 11 Dec 2009 15:24:53 +0000
parents 1238da4a7112
children
line wrap: on
line source

.TH "SDL_SemWaitTimeout" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SemWaitTimeout \- Lock a semaphore, but only wait up to a specified maximum time\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
#include "SDL_thread\&.h"
.sp
\fBint \fBSDL_SemWaitTimeout\fP\fR(\fBSDL_sem *sem, Uint32 timeout\fR);
.SH "DESCRIPTION"
.PP
\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\&.
.PP
After \fBSDL_SemWaitTimeout()\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 timeout period was exceeded 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_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC);

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_SemTryWait\fP\fR, \fI\fBSDL_SemPost\fP\fR, \fI\fBSDL_SemValue\fP\fR
.\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00