Mercurial > sdl-ios-xcode
annotate docs/html/sdldelay.html @ 1157:baf35853ad54
Date: Mon, 10 Oct 2005 13:09:32 +0300
From: Tommi Kyntola <tommi.kyntola@ray.fi>
To: sdl@libsdl.org
Subject: [SDL] [RFC] get_ticks broken on linux
It uses gettimeofday to calculate the timedifference.
Gettimeofday returns current time which is seldom monotonous.
This breaks SDL timer subsystem. (time callbacks and all that
get borked when the time difference ms is suddenly ~ 2^32)
I posted a message about this earlier but got no response.
Some thoughts on this matter would be appreciated.
(Or even an explanation for the lack of interest.)
A patch below would use the posix timers that have been around
since posix 93 and do provide a good source of monotonous time
on linux boxes (and on few others too).
The following patch is also availabe at:
http://www.hut.fi/u/tkyntola/SDL-1.2.9-clockfix.patch
It's against 1.2.9, but I can easily rediffit against
the cvs branch is needed.
cheers,
Tommi Kyntola tommi.kyntola@ray.fi
| author | Ryan C. Gordon <icculus@icculus.org> |
|---|---|
| date | Tue, 11 Oct 2005 18:16:12 +0000 |
| parents | 355632dca928 |
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| 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 1.76b+ |
| 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 | |
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31 SUMMARY="Header navigation table" |
| 0 | 32 WIDTH="100%" |
| 33 BORDER="0" | |
| 34 CELLPADDING="0" | |
| 35 CELLSPACING="0" | |
| 36 ><TR | |
| 37 ><TH | |
| 38 COLSPAN="3" | |
| 39 ALIGN="center" | |
| 40 >SDL Library Documentation</TH | |
| 41 ></TR | |
| 42 ><TR | |
| 43 ><TD | |
| 44 WIDTH="10%" | |
| 45 ALIGN="left" | |
| 46 VALIGN="bottom" | |
| 47 ><A | |
| 48 HREF="sdlgetticks.html" | |
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49 ACCESSKEY="P" |
| 0 | 50 >Prev</A |
| 51 ></TD | |
| 52 ><TD | |
| 53 WIDTH="80%" | |
| 54 ALIGN="center" | |
| 55 VALIGN="bottom" | |
| 56 ></TD | |
| 57 ><TD | |
| 58 WIDTH="10%" | |
| 59 ALIGN="right" | |
| 60 VALIGN="bottom" | |
| 61 ><A | |
| 62 HREF="sdladdtimer.html" | |
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63 ACCESSKEY="N" |
| 0 | 64 >Next</A |
| 65 ></TD | |
| 66 ></TR | |
| 67 ></TABLE | |
| 68 ><HR | |
| 69 ALIGN="LEFT" | |
| 70 WIDTH="100%"></DIV | |
| 71 ><H1 | |
| 72 ><A | |
| 73 NAME="SDLDELAY" | |
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74 ></A |
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75 >SDL_Delay</H1 |
| 0 | 76 ><DIV |
| 77 CLASS="REFNAMEDIV" | |
| 78 ><A | |
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79 NAME="AEN8455" |
| 0 | 80 ></A |
| 81 ><H2 | |
| 82 >Name</H2 | |
| 83 >SDL_Delay -- Wait a specified number of milliseconds before returning.</DIV | |
| 84 ><DIV | |
| 85 CLASS="REFSYNOPSISDIV" | |
| 86 ><A | |
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87 NAME="AEN8458" |
| 0 | 88 ></A |
| 89 ><H2 | |
| 90 >Synopsis</H2 | |
| 91 ><DIV | |
| 92 CLASS="FUNCSYNOPSIS" | |
| 93 ><A | |
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94 NAME="AEN8459" |
| 0 | 95 ></A |
| 96 ><P | |
| 97 ></P | |
| 98 ><PRE | |
| 99 CLASS="FUNCSYNOPSISINFO" | |
| 100 >#include "SDL.h"</PRE | |
| 101 ><P | |
| 102 ><CODE | |
| 103 ><CODE | |
| 104 CLASS="FUNCDEF" | |
| 105 >void <B | |
| 106 CLASS="FSFUNC" | |
| 107 >SDL_Delay</B | |
| 108 ></CODE | |
| 109 >(Uint32 ms);</CODE | |
| 110 ></P | |
| 111 ><P | |
| 112 ></P | |
| 113 ></DIV | |
| 114 ></DIV | |
| 115 ><DIV | |
| 116 CLASS="REFSECT1" | |
| 117 ><A | |
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118 NAME="AEN8465" |
| 0 | 119 ></A |
| 120 ><H2 | |
| 121 >Description</H2 | |
| 122 ><P | |
| 123 >Wait a specified number of milliseconds before returning. <TT | |
| 124 CLASS="FUNCTION" | |
| 125 >SDL_Delay</TT | |
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126 > will wait at <SPAN |
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127 CLASS="emphasis" |
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128 ><I |
| 0 | 129 CLASS="EMPHASIS" |
| 130 >least</I | |
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131 ></SPAN |
| 0 | 132 > the specified time, but possible longer due to OS scheduling.</P |
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133 ><DIV |
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134 CLASS="NOTE" |
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135 ><BLOCKQUOTE |
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136 CLASS="NOTE" |
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137 ><P |
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138 ><B |
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139 >Note: </B |
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140 >Count on a delay granularity of <SPAN |
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141 CLASS="emphasis" |
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142 ><I |
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143 CLASS="EMPHASIS" |
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144 >at least</I |
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145 ></SPAN |
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146 > 10 ms. |
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147 Some platforms have shorter clock ticks but this is the most common.</P |
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148 ></BLOCKQUOTE |
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149 ></DIV |
| 0 | 150 ></DIV |
| 151 ><DIV | |
| 152 CLASS="REFSECT1" | |
| 153 ><A | |
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154 NAME="AEN8473" |
| 0 | 155 ></A |
| 156 ><H2 | |
| 157 >See Also</H2 | |
| 158 ><P | |
| 159 ><A | |
| 160 HREF="sdladdtimer.html" | |
| 161 ><TT | |
| 162 CLASS="FUNCTION" | |
| 163 >SDL_AddTimer</TT | |
| 164 ></A | |
| 165 ></P | |
| 166 ></DIV | |
| 167 ><DIV | |
| 168 CLASS="NAVFOOTER" | |
| 169 ><HR | |
| 170 ALIGN="LEFT" | |
| 171 WIDTH="100%"><TABLE | |
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172 SUMMARY="Footer navigation table" |
| 0 | 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="sdlgetticks.html" | |
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184 ACCESSKEY="P" |
| 0 | 185 >Prev</A |
| 186 ></TD | |
| 187 ><TD | |
| 188 WIDTH="34%" | |
| 189 ALIGN="center" | |
| 190 VALIGN="top" | |
| 191 ><A | |
| 192 HREF="index.html" | |
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193 ACCESSKEY="H" |
| 0 | 194 >Home</A |
| 195 ></TD | |
| 196 ><TD | |
| 197 WIDTH="33%" | |
| 198 ALIGN="right" | |
| 199 VALIGN="top" | |
| 200 ><A | |
| 201 HREF="sdladdtimer.html" | |
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202 ACCESSKEY="N" |
| 0 | 203 >Next</A |
| 204 ></TD | |
| 205 ></TR | |
| 206 ><TR | |
| 207 ><TD | |
| 208 WIDTH="33%" | |
| 209 ALIGN="left" | |
| 210 VALIGN="top" | |
| 211 >SDL_GetTicks</TD | |
| 212 ><TD | |
| 213 WIDTH="34%" | |
| 214 ALIGN="center" | |
| 215 VALIGN="top" | |
| 216 ><A | |
| 217 HREF="time.html" | |
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218 ACCESSKEY="U" |
| 0 | 219 >Up</A |
| 220 ></TD | |
| 221 ><TD | |
| 222 WIDTH="33%" | |
| 223 ALIGN="right" | |
| 224 VALIGN="top" | |
| 225 >SDL_AddTimer</TD | |
| 226 ></TR | |
| 227 ></TABLE | |
| 228 ></DIV | |
| 229 ></BODY | |
| 230 ></HTML | |
| 231 > |