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annotate docs/man3/SDL_SemTryWait.3 @ 3950:9d9e15ab1697 SDL-1.2

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Check if yasm supports a nasm-specific syntax we use (it doesn't in 0.5.0, which is still common in Linux distros, and does in 0.6.0). Disable it if we don't, attempting to fallback to using nasm. Thanks to Mike Frysinger for the patch. Fixes Bugzilla #393.
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 04 Jun 2007 11:06:48 +0000
parents e5bc29de3f0a
children 546f7c1eb755
rev   line source
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e5bc29de3f0a Updated from the SDL Documentation Project
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1 .TH "SDL_SemTryWait" "3" "Tue 11 Sep 2001, 23:00" "SDL" "SDL API Reference"
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2 .SH "NAME"
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3 SDL_SemTryWait\- Attempt to lock a semaphore but don\&'t suspend the thread\&.
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4 .SH "SYNOPSIS"
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5 .PP
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6 \fB#include "SDL\&.h"
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7 #include "SDL_thread\&.h"
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8 .sp
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9 \fBint \fBSDL_SemTryWait\fP\fR(\fBSDL_sem *sem\fR);
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10 .SH "DESCRIPTION"
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11 .PP
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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\&.
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13 .PP
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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\&.
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15 .SH "RETURN VALUE"
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16 .PP
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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\&.
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18 .PP
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19 If the semaphore was not successfully locked, the semaphore will be unchanged\&.
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20 .SH "EXAMPLES"
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21 .PP
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22 .PP
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23 .nf
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24 \f(CWres = SDL_SemTryWait(my_sem);
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25
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26 if (res == SDL_MUTEX_TIMEOUT) {
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27 return TRY_AGAIN;
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28 }
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29 if (res == -1) {
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30 return WAIT_ERROR;
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31 }
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32
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33 \&.\&.\&.
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34
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35 SDL_SemPost(my_sem);\fR
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36 .fi
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37 .PP
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38 .SH "SEE ALSO"
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39 .PP
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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
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41 ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:00