Mercurial > sdl-ios-xcode
annotate docs/html/sdlmutexv.html @ 765:4c2ba6161939
Editors Note: The original patch was modified to use SDL_Delay() instead of
nanosleep because nanosleep may not be portable to all systems
using SDL with the ALSA backend. This may be a moot point with
the switch to blocking writes anyway...
Date: Sat, 27 Dec 2003 21:47:36 +0100
From: Michel Daenzer
To: Debian Bug Tracking System
Subject: [SDL] Bug#225252: [PATCH] ALSA fixes
Package: libsdl1.2debian-all
Version: 1.2.6-2
Severity: normal
Tags: patch
For SDL 1.2.6, the ALSA backend was changed to call snd_pcm_open() with
SND_PCM_NONBLOCK. That's a good idea per se, however, it causes high CPU
usage, interrupted sound and stuttering in some games here. Taking a nanosleep
whenever snd_pcm_writei() returns -EAGAIN fixes this, but I think it's more
efficient to use blocking mode for the actual sound playback. Feedback from the
SDL and ALSA lists appreciated.
The patch also fixes the default ALSA device to be used.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 04 Jan 2004 15:40:50 +0000 |
| parents | e5bc29de3f0a |
| children | 355632dca928 |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >SDL_mutexV</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
|
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7 CONTENT="Modular DocBook HTML Stylesheet Version 1.64 |
| 0 | 8 "><LINK |
| 9 REL="HOME" | |
| 10 TITLE="SDL Library Documentation" | |
| 11 HREF="index.html"><LINK | |
| 12 REL="UP" | |
| 13 TITLE="Multi-threaded Programming" | |
| 14 HREF="thread.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_mutexP" | |
| 17 HREF="sdlmutexp.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_CreateSemaphore" | |
| 20 HREF="sdlcreatesemaphore.html"></HEAD | |
| 21 ><BODY | |
| 22 CLASS="REFENTRY" | |
| 23 BGCOLOR="#FFF8DC" | |
| 24 TEXT="#000000" | |
| 25 LINK="#0000ee" | |
| 26 VLINK="#551a8b" | |
| 27 ALINK="#ff0000" | |
| 28 ><DIV | |
| 29 CLASS="NAVHEADER" | |
| 30 ><TABLE | |
| 31 WIDTH="100%" | |
| 32 BORDER="0" | |
| 33 CELLPADDING="0" | |
| 34 CELLSPACING="0" | |
| 35 ><TR | |
| 36 ><TH | |
| 37 COLSPAN="3" | |
| 38 ALIGN="center" | |
| 39 >SDL Library Documentation</TH | |
| 40 ></TR | |
| 41 ><TR | |
| 42 ><TD | |
| 43 WIDTH="10%" | |
| 44 ALIGN="left" | |
| 45 VALIGN="bottom" | |
| 46 ><A | |
| 47 HREF="sdlmutexp.html" | |
| 48 >Prev</A | |
| 49 ></TD | |
| 50 ><TD | |
| 51 WIDTH="80%" | |
| 52 ALIGN="center" | |
| 53 VALIGN="bottom" | |
| 54 ></TD | |
| 55 ><TD | |
| 56 WIDTH="10%" | |
| 57 ALIGN="right" | |
| 58 VALIGN="bottom" | |
| 59 ><A | |
| 60 HREF="sdlcreatesemaphore.html" | |
| 61 >Next</A | |
| 62 ></TD | |
| 63 ></TR | |
| 64 ></TABLE | |
| 65 ><HR | |
| 66 ALIGN="LEFT" | |
| 67 WIDTH="100%"></DIV | |
| 68 ><H1 | |
| 69 ><A | |
| 70 NAME="SDLMUTEXV" | |
| 71 >SDL_mutexV</A | |
| 72 ></H1 | |
| 73 ><DIV | |
| 74 CLASS="REFNAMEDIV" | |
| 75 ><A | |
|
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76 NAME="AEN7517" |
| 0 | 77 ></A |
| 78 ><H2 | |
| 79 >Name</H2 | |
| 80 >SDL_mutexV -- Unlock a mutex</DIV | |
| 81 ><DIV | |
| 82 CLASS="REFSYNOPSISDIV" | |
| 83 ><A | |
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84 NAME="AEN7520" |
| 0 | 85 ></A |
| 86 ><H2 | |
| 87 >Synopsis</H2 | |
| 88 ><DIV | |
| 89 CLASS="FUNCSYNOPSIS" | |
| 90 ><A | |
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91 NAME="AEN7521" |
| 0 | 92 ></A |
| 93 ><P | |
| 94 ></P | |
| 95 ><PRE | |
| 96 CLASS="FUNCSYNOPSISINFO" | |
| 97 >#include "SDL.h" | |
| 98 #include "SDL_thread.h"</PRE | |
| 99 ><P | |
| 100 ><CODE | |
| 101 ><CODE | |
| 102 CLASS="FUNCDEF" | |
| 103 >int <B | |
| 104 CLASS="FSFUNC" | |
| 105 >SDL_mutexV</B | |
| 106 ></CODE | |
| 107 >(SDL_mutex *mutex);</CODE | |
| 108 ></P | |
| 109 ><P | |
| 110 ></P | |
| 111 ></DIV | |
| 112 ></DIV | |
| 113 ><DIV | |
| 114 CLASS="REFSECT1" | |
| 115 ><A | |
|
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116 NAME="AEN7527" |
| 0 | 117 ></A |
| 118 ><H2 | |
| 119 >Description</H2 | |
| 120 ><P | |
| 121 >Unlocks the <TT | |
| 122 CLASS="PARAMETER" | |
| 123 ><I | |
| 124 >mutex</I | |
| 125 ></TT | |
| 126 >, which was previously created with <A | |
| 127 HREF="sdlcreatemutex.html" | |
| 128 ><TT | |
| 129 CLASS="FUNCTION" | |
| 130 >SDL_CreateMutex</TT | |
| 131 ></A | |
| 132 >. Returns <SPAN | |
| 133 CLASS="RETURNVALUE" | |
| 134 >0</SPAN | |
| 135 > on success, or <SPAN | |
| 136 CLASS="RETURNVALUE" | |
| 137 >-1</SPAN | |
| 138 > on an error.</P | |
| 139 ><P | |
| 140 >SDL also defines a macro <TT | |
| 141 CLASS="LITERAL" | |
| 142 >#define SDL_UnlockMutex(m) SDL_mutexV(m)</TT | |
| 143 >.</P | |
| 144 ></DIV | |
| 145 ><DIV | |
| 146 CLASS="REFSECT1" | |
| 147 ><A | |
|
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148 NAME="AEN7537" |
| 0 | 149 ></A |
| 150 ><H2 | |
| 151 >See Also</H2 | |
| 152 ><P | |
| 153 ><A | |
| 154 HREF="sdlcreatemutex.html" | |
| 155 ><TT | |
| 156 CLASS="FUNCTION" | |
| 157 >SDL_CreateMutex</TT | |
| 158 ></A | |
| 159 >, | |
| 160 <A | |
| 161 HREF="sdlmutexp.html" | |
| 162 ><TT | |
| 163 CLASS="FUNCTION" | |
| 164 >SDL_mutexP</TT | |
| 165 ></A | |
| 166 ></P | |
| 167 ></DIV | |
| 168 ><DIV | |
| 169 CLASS="NAVFOOTER" | |
| 170 ><HR | |
| 171 ALIGN="LEFT" | |
| 172 WIDTH="100%"><TABLE | |
| 173 WIDTH="100%" | |
| 174 BORDER="0" | |
| 175 CELLPADDING="0" | |
| 176 CELLSPACING="0" | |
| 177 ><TR | |
| 178 ><TD | |
| 179 WIDTH="33%" | |
| 180 ALIGN="left" | |
| 181 VALIGN="top" | |
| 182 ><A | |
| 183 HREF="sdlmutexp.html" | |
| 184 >Prev</A | |
| 185 ></TD | |
| 186 ><TD | |
| 187 WIDTH="34%" | |
| 188 ALIGN="center" | |
| 189 VALIGN="top" | |
| 190 ><A | |
| 191 HREF="index.html" | |
| 192 >Home</A | |
| 193 ></TD | |
| 194 ><TD | |
| 195 WIDTH="33%" | |
| 196 ALIGN="right" | |
| 197 VALIGN="top" | |
| 198 ><A | |
| 199 HREF="sdlcreatesemaphore.html" | |
| 200 >Next</A | |
| 201 ></TD | |
| 202 ></TR | |
| 203 ><TR | |
| 204 ><TD | |
| 205 WIDTH="33%" | |
| 206 ALIGN="left" | |
| 207 VALIGN="top" | |
| 208 >SDL_mutexP</TD | |
| 209 ><TD | |
| 210 WIDTH="34%" | |
| 211 ALIGN="center" | |
| 212 VALIGN="top" | |
| 213 ><A | |
| 214 HREF="thread.html" | |
| 215 >Up</A | |
| 216 ></TD | |
| 217 ><TD | |
| 218 WIDTH="33%" | |
| 219 ALIGN="right" | |
| 220 VALIGN="top" | |
| 221 >SDL_CreateSemaphore</TD | |
| 222 ></TR | |
| 223 ></TABLE | |
| 224 ></DIV | |
| 225 ></BODY | |
| 226 ></HTML | |
| 227 > |