Mercurial > sdl-ios-xcode
annotate docs/html/sdldelay.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_Delay</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="Time" | |
| 14 HREF="time.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_GetTicks" | |
| 17 HREF="sdlgetticks.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_AddTimer" | |
| 20 HREF="sdladdtimer.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="sdlgetticks.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="sdladdtimer.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="SDLDELAY" | |
| 71 >SDL_Delay</A | |
| 72 ></H1 | |
| 73 ><DIV | |
| 74 CLASS="REFNAMEDIV" | |
| 75 ><A | |
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76 NAME="AEN8067" |
| 0 | 77 ></A |
| 78 ><H2 | |
| 79 >Name</H2 | |
| 80 >SDL_Delay -- Wait a specified number of milliseconds before returning.</DIV | |
| 81 ><DIV | |
| 82 CLASS="REFSYNOPSISDIV" | |
| 83 ><A | |
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84 NAME="AEN8070" |
| 0 | 85 ></A |
| 86 ><H2 | |
| 87 >Synopsis</H2 | |
| 88 ><DIV | |
| 89 CLASS="FUNCSYNOPSIS" | |
| 90 ><A | |
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91 NAME="AEN8071" |
| 0 | 92 ></A |
| 93 ><P | |
| 94 ></P | |
| 95 ><PRE | |
| 96 CLASS="FUNCSYNOPSISINFO" | |
| 97 >#include "SDL.h"</PRE | |
| 98 ><P | |
| 99 ><CODE | |
| 100 ><CODE | |
| 101 CLASS="FUNCDEF" | |
| 102 >void <B | |
| 103 CLASS="FSFUNC" | |
| 104 >SDL_Delay</B | |
| 105 ></CODE | |
| 106 >(Uint32 ms);</CODE | |
| 107 ></P | |
| 108 ><P | |
| 109 ></P | |
| 110 ></DIV | |
| 111 ></DIV | |
| 112 ><DIV | |
| 113 CLASS="REFSECT1" | |
| 114 ><A | |
|
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115 NAME="AEN8077" |
| 0 | 116 ></A |
| 117 ><H2 | |
| 118 >Description</H2 | |
| 119 ><P | |
| 120 >Wait a specified number of milliseconds before returning. <TT | |
| 121 CLASS="FUNCTION" | |
| 122 >SDL_Delay</TT | |
| 123 > will wait at <I | |
| 124 CLASS="EMPHASIS" | |
| 125 >least</I | |
| 126 > the specified time, but possible longer due to OS scheduling.</P | |
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127 ><DIV |
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128 CLASS="NOTE" |
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129 ><BLOCKQUOTE |
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130 CLASS="NOTE" |
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131 ><P |
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132 ><B |
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133 >Note: </B |
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134 >Count on a delay granularity of <I |
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135 CLASS="EMPHASIS" |
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136 >at least</I |
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137 > 10 ms. |
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138 Some platforms have shorter clock ticks but this is the most common.</P |
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139 ></BLOCKQUOTE |
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140 ></DIV |
| 0 | 141 ></DIV |
| 142 ><DIV | |
| 143 CLASS="REFSECT1" | |
| 144 ><A | |
|
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145 NAME="AEN8085" |
| 0 | 146 ></A |
| 147 ><H2 | |
| 148 >See Also</H2 | |
| 149 ><P | |
| 150 ><A | |
| 151 HREF="sdladdtimer.html" | |
| 152 ><TT | |
| 153 CLASS="FUNCTION" | |
| 154 >SDL_AddTimer</TT | |
| 155 ></A | |
| 156 ></P | |
| 157 ></DIV | |
| 158 ><DIV | |
| 159 CLASS="NAVFOOTER" | |
| 160 ><HR | |
| 161 ALIGN="LEFT" | |
| 162 WIDTH="100%"><TABLE | |
| 163 WIDTH="100%" | |
| 164 BORDER="0" | |
| 165 CELLPADDING="0" | |
| 166 CELLSPACING="0" | |
| 167 ><TR | |
| 168 ><TD | |
| 169 WIDTH="33%" | |
| 170 ALIGN="left" | |
| 171 VALIGN="top" | |
| 172 ><A | |
| 173 HREF="sdlgetticks.html" | |
| 174 >Prev</A | |
| 175 ></TD | |
| 176 ><TD | |
| 177 WIDTH="34%" | |
| 178 ALIGN="center" | |
| 179 VALIGN="top" | |
| 180 ><A | |
| 181 HREF="index.html" | |
| 182 >Home</A | |
| 183 ></TD | |
| 184 ><TD | |
| 185 WIDTH="33%" | |
| 186 ALIGN="right" | |
| 187 VALIGN="top" | |
| 188 ><A | |
| 189 HREF="sdladdtimer.html" | |
| 190 >Next</A | |
| 191 ></TD | |
| 192 ></TR | |
| 193 ><TR | |
| 194 ><TD | |
| 195 WIDTH="33%" | |
| 196 ALIGN="left" | |
| 197 VALIGN="top" | |
| 198 >SDL_GetTicks</TD | |
| 199 ><TD | |
| 200 WIDTH="34%" | |
| 201 ALIGN="center" | |
| 202 VALIGN="top" | |
| 203 ><A | |
| 204 HREF="time.html" | |
| 205 >Up</A | |
| 206 ></TD | |
| 207 ><TD | |
| 208 WIDTH="33%" | |
| 209 ALIGN="right" | |
| 210 VALIGN="top" | |
| 211 >SDL_AddTimer</TD | |
| 212 ></TR | |
| 213 ></TABLE | |
| 214 ></DIV | |
| 215 ></BODY | |
| 216 ></HTML | |
| 217 > |