Mercurial > sdl-ios-xcode
annotate docs/html/time.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 | 55f1f1b3e27d |
| children | 355632dca928 |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >Time</TITLE | |
| 5 ><META | |
| 6 NAME="GENERATOR" | |
|
55
55f1f1b3e27d
Added new docs for SDL 1.2.1
Sam Lantinga <slouken@lokigames.com>
parents:
0
diff
changeset
|
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="SDL Reference" | |
| 14 HREF="reference.html"><LINK | |
| 15 REL="PREVIOUS" | |
| 16 TITLE="SDL_CondWaitTimeout" | |
| 17 HREF="sdlcondwaittimeout.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_GetTicks" | |
| 20 HREF="sdlgetticks.html"><META | |
| 21 NAME="KEYWORD" | |
| 22 CONTENT="time"><META | |
| 23 NAME="KEYWORD" | |
| 24 CONTENT="function"></HEAD | |
| 25 ><BODY | |
| 26 CLASS="CHAPTER" | |
| 27 BGCOLOR="#FFF8DC" | |
| 28 TEXT="#000000" | |
| 29 LINK="#0000ee" | |
| 30 VLINK="#551a8b" | |
| 31 ALINK="#ff0000" | |
| 32 ><DIV | |
| 33 CLASS="NAVHEADER" | |
| 34 ><TABLE | |
| 35 WIDTH="100%" | |
| 36 BORDER="0" | |
| 37 CELLPADDING="0" | |
| 38 CELLSPACING="0" | |
| 39 ><TR | |
| 40 ><TH | |
| 41 COLSPAN="3" | |
| 42 ALIGN="center" | |
| 43 >SDL Library Documentation</TH | |
| 44 ></TR | |
| 45 ><TR | |
| 46 ><TD | |
| 47 WIDTH="10%" | |
| 48 ALIGN="left" | |
| 49 VALIGN="bottom" | |
| 50 ><A | |
| 51 HREF="sdlcondwaittimeout.html" | |
| 52 >Prev</A | |
| 53 ></TD | |
| 54 ><TD | |
| 55 WIDTH="80%" | |
| 56 ALIGN="center" | |
| 57 VALIGN="bottom" | |
| 58 ></TD | |
| 59 ><TD | |
| 60 WIDTH="10%" | |
| 61 ALIGN="right" | |
| 62 VALIGN="bottom" | |
| 63 ><A | |
| 64 HREF="sdlgetticks.html" | |
| 65 >Next</A | |
| 66 ></TD | |
| 67 ></TR | |
| 68 ></TABLE | |
| 69 ><HR | |
| 70 ALIGN="LEFT" | |
| 71 WIDTH="100%"></DIV | |
| 72 ><DIV | |
| 73 CLASS="CHAPTER" | |
| 74 ><H1 | |
| 75 ><A | |
| 76 NAME="TIME" | |
| 77 >Chapter 13. Time</A | |
| 78 ></H1 | |
| 79 ><DIV | |
| 80 CLASS="TOC" | |
| 81 ><DL | |
| 82 ><DT | |
| 83 ><B | |
| 84 >Table of Contents</B | |
| 85 ></DT | |
| 86 ><DT | |
| 87 ><A | |
| 88 HREF="sdlgetticks.html" | |
| 89 >SDL_GetTicks</A | |
| 90 > — Get the number of milliseconds since the SDL library initialization.</DT | |
| 91 ><DT | |
| 92 ><A | |
| 93 HREF="sdldelay.html" | |
| 94 >SDL_Delay</A | |
| 95 > — Wait a specified number of milliseconds before returning.</DT | |
| 96 ><DT | |
| 97 ><A | |
| 98 HREF="sdladdtimer.html" | |
| 99 >SDL_AddTimer</A | |
| 100 > — Add a timer which will call a callback after the specified number of milliseconds has | |
| 101 elapsed.</DT | |
| 102 ><DT | |
| 103 ><A | |
| 104 HREF="sdlremovetimer.html" | |
| 105 >SDL_RemoveTimer</A | |
| 106 > — Remove a timer which was added with | |
| 107 <A | |
| 108 HREF="sdladdtimer.html" | |
| 109 >SDL_AddTimer</A | |
| 110 >.</DT | |
| 111 ><DT | |
| 112 ><A | |
| 113 HREF="sdlsettimer.html" | |
| 114 >SDL_SetTimer</A | |
| 115 > — Set a callback to run after the specified number of milliseconds has | |
| 116 elapsed.</DT | |
| 117 ></DL | |
| 118 ></DIV | |
| 119 ><P | |
| 120 >SDL provides several cross-platform functions for dealing with time. | |
| 121 It provides a way to get the current time, a way to wait a little while, | |
| 122 and a simple timer mechanism. These functions give you two ways of moving an | |
| 123 object every x milliseconds: | |
| 124 | |
| 125 <P | |
| 126 ></P | |
| 127 ><UL | |
| 128 ><LI | |
| 129 ><P | |
| 130 >Use a timer callback function. This may have the bad effect that it runs in a seperate thread or uses alarm signals, but it's easier to implement.</P | |
| 131 ></LI | |
| 132 ><LI | |
| 133 ><P | |
| 134 >Or you can get the number of milliseconds passed, and move the object if, for example, 30 ms passed.</P | |
| 135 ></LI | |
| 136 ></UL | |
| 137 > </P | |
| 138 ></DIV | |
| 139 ><DIV | |
| 140 CLASS="NAVFOOTER" | |
| 141 ><HR | |
| 142 ALIGN="LEFT" | |
| 143 WIDTH="100%"><TABLE | |
| 144 WIDTH="100%" | |
| 145 BORDER="0" | |
| 146 CELLPADDING="0" | |
| 147 CELLSPACING="0" | |
| 148 ><TR | |
| 149 ><TD | |
| 150 WIDTH="33%" | |
| 151 ALIGN="left" | |
| 152 VALIGN="top" | |
| 153 ><A | |
| 154 HREF="sdlcondwaittimeout.html" | |
| 155 >Prev</A | |
| 156 ></TD | |
| 157 ><TD | |
| 158 WIDTH="34%" | |
| 159 ALIGN="center" | |
| 160 VALIGN="top" | |
| 161 ><A | |
| 162 HREF="index.html" | |
| 163 >Home</A | |
| 164 ></TD | |
| 165 ><TD | |
| 166 WIDTH="33%" | |
| 167 ALIGN="right" | |
| 168 VALIGN="top" | |
| 169 ><A | |
| 170 HREF="sdlgetticks.html" | |
| 171 >Next</A | |
| 172 ></TD | |
| 173 ></TR | |
| 174 ><TR | |
| 175 ><TD | |
| 176 WIDTH="33%" | |
| 177 ALIGN="left" | |
| 178 VALIGN="top" | |
| 179 >SDL_CondWaitTimeout</TD | |
| 180 ><TD | |
| 181 WIDTH="34%" | |
| 182 ALIGN="center" | |
| 183 VALIGN="top" | |
| 184 ><A | |
| 185 HREF="reference.html" | |
| 186 >Up</A | |
| 187 ></TD | |
| 188 ><TD | |
| 189 WIDTH="33%" | |
| 190 ALIGN="right" | |
| 191 VALIGN="top" | |
| 192 >SDL_GetTicks</TD | |
| 193 ></TR | |
| 194 ></TABLE | |
| 195 ></DIV | |
| 196 ></BODY | |
| 197 ></HTML | |
| 198 > |