Mercurial > sdl-ios-xcode

annotate docs/man3/SDL_SemWaitTimeout.3 @ 518:300b46757b7a

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fixed compiler warning
author Sam Lantinga <slouken@libsdl.org>
date Mon, 07 Oct 2002 15:19:34 +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
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
2 .SH "NAME"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
3 SDL_SemWaitTimeout\- Lock a semaphore, but only wait up to a specified maximum time\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
4 .SH "SYNOPSIS"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
5 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
6 \fB#include "SDL\&.h"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
7 #include "SDL_thread\&.h"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
8 .sp
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
9 \fBint \fBSDL_SemWaitTimeout\fP\fR(\fBSDL_sem *sem, Uint32 timeout\fR);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
10 .SH "DESCRIPTION"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
11 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
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\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
13 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
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\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
15 .SH "RETURN VALUE"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
16 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
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\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
18 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
19 If the semaphore was not successfully locked, the semaphore will be unchanged\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
20 .SH "EXAMPLES"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
21 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
22 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
23 .nf
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
24 \f(CWres = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC);
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
25
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
26 if (res == SDL_MUTEX_TIMEOUT) {
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
27 return TRY_AGAIN;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
28 }
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
29 if (res == -1) {
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
30 return WAIT_ERROR;
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
31 }
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
32
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
33 \&.\&.\&.
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
34
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
35 SDL_SemPost(my_sem);\fR
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
36 .fi
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
37 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
38 .SH "SEE ALSO"
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
39 .PP
74212992fb08 Initial revision
Sam Lantinga <slouken@lokigames.com>
parents:
diff changeset
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