Mercurial > sdl-ios-xcode
annotate docs/html/sdlsemwaittimeout.html @ 641:df178851293b
Date: 28 Jun 2003 22:42:52 +0100
From: Alan Swanson
Subject: Re: [SDL] New XFree 4.3 Video Mode Patch
I have a wee amendment that moves the qsort in set_best_resolution
to only occur after failing to find an exact match only. This would
make absolutely sure we get a user set mode.
While I've never had any problems for my normal resolutions (1280x1024,
1024x768, 800x600 & 640,480) while closely examining the output from
qsort I've noticed it doesn't seem to sort the modes fully. These is
one definite wrong at 1152x768 and a few that just look wrong to me.
From a program (attached) I made to examine this more easily. X has
sorted its mode list using the same method as ours (plus frequency),
and our user modes get inserted without any other movement.
On the patch I've made I've also changed cmpmodes to sort on vertical
resolution and then horizontal. Ie vertical is now most significant
bit.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sat, 28 Jun 2003 21:52:26 +0000 |
| parents | e5bc29de3f0a |
| children | 355632dca928 |
| rev | line source |
|---|---|
| 0 | 1 <HTML |
| 2 ><HEAD | |
| 3 ><TITLE | |
| 4 >SDL_SemWaitTimeout</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_SemTryWait" | |
| 17 HREF="sdlsemtrywait.html"><LINK | |
| 18 REL="NEXT" | |
| 19 TITLE="SDL_SemPost" | |
| 20 HREF="sdlsempost.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="sdlsemtrywait.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="sdlsempost.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="SDLSEMWAITTIMEOUT" | |
| 71 >SDL_SemWaitTimeout</A | |
| 72 ></H1 | |
| 73 ><DIV | |
| 74 CLASS="REFNAMEDIV" | |
| 75 ><A | |
|
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76 NAME="AEN7732" |
| 0 | 77 ></A |
| 78 ><H2 | |
| 79 >Name</H2 | |
| 80 >SDL_SemWaitTimeout -- Lock a semaphore, but only wait up to a specified maximum time.</DIV | |
| 81 ><DIV | |
| 82 CLASS="REFSYNOPSISDIV" | |
| 83 ><A | |
|
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84 NAME="AEN7735" |
| 0 | 85 ></A |
| 86 ><H2 | |
| 87 >Synopsis</H2 | |
| 88 ><DIV | |
| 89 CLASS="FUNCSYNOPSIS" | |
| 90 ><A | |
|
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91 NAME="AEN7736" |
| 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_SemWaitTimeout</B | |
| 106 ></CODE | |
| 107 >(SDL_sem *sem, Uint32 timeout);</CODE | |
| 108 ></P | |
| 109 ><P | |
| 110 ></P | |
| 111 ></DIV | |
| 112 ></DIV | |
| 113 ><DIV | |
| 114 CLASS="REFSECT1" | |
| 115 ><A | |
|
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116 NAME="AEN7742" |
| 0 | 117 ></A |
| 118 ><H2 | |
| 119 >Description</H2 | |
| 120 ><P | |
| 121 ><TT | |
| 122 CLASS="FUNCTION" | |
| 123 >SDL_SemWaitTimeout()</TT | |
| 124 > is a varient of | |
| 125 <A | |
| 126 HREF="sdlsemwait.html" | |
| 127 >SDL_SemWait</A | |
| 128 > | |
| 129 with a maximum timeout value. | |
| 130 If the value of the semaphore pointed to by <TT | |
| 131 CLASS="PARAMETER" | |
| 132 ><I | |
| 133 >sem</I | |
| 134 ></TT | |
| 135 > is | |
| 136 positive (greater than zero) it will atomically decrement the semaphore value | |
| 137 and return 0, otherwise it will wait up to <TT | |
| 138 CLASS="PARAMETER" | |
| 139 ><I | |
| 140 >timeout</I | |
| 141 ></TT | |
| 142 > | |
| 143 milliseconds trying to lock the semaphore. This function is to be avoided if | |
| 144 possible since on some platforms it is implemented by polling the semaphore | |
| 145 every millisecond in a busy loop.</P | |
| 146 ><P | |
| 147 >After <TT | |
| 148 CLASS="FUNCTION" | |
| 149 >SDL_SemWaitTimeout()</TT | |
| 150 > is successful, the semaphore | |
| 151 can be released and its count atomically incremented by a successful call to | |
| 152 <A | |
| 153 HREF="sdlsempost.html" | |
| 154 >SDL_SemPost</A | |
| 155 >.</P | |
| 156 ></DIV | |
| 157 ><DIV | |
| 158 CLASS="REFSECT1" | |
| 159 ><A | |
|
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160 NAME="AEN7752" |
| 0 | 161 ></A |
| 162 ><H2 | |
| 163 >Return Value</H2 | |
| 164 ><P | |
| 165 >Returns <SPAN | |
| 166 CLASS="RETURNVALUE" | |
| 167 >0</SPAN | |
| 168 > if the semaphore was successfully locked or | |
| 169 either <SPAN | |
| 170 CLASS="RETURNVALUE" | |
| 171 >SDL_MUTEX_TIMEOUT</SPAN | |
| 172 > or <SPAN | |
| 173 CLASS="RETURNVALUE" | |
| 174 >-1</SPAN | |
| 175 > | |
| 176 if the timeout period was exceeded or there was an error, respectivly.</P | |
| 177 ><P | |
| 178 >If the semaphore was not successfully locked, the semaphore will be unchanged.</P | |
| 179 ></DIV | |
| 180 ><DIV | |
| 181 CLASS="REFSECT1" | |
| 182 ><A | |
|
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183 NAME="AEN7759" |
| 0 | 184 ></A |
| 185 ><H2 | |
| 186 >Examples</H2 | |
| 187 ><P | |
| 188 ><PRE | |
| 189 CLASS="PROGRAMLISTING" | |
| 190 >res = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC); | |
| 191 | |
| 192 if (res == SDL_MUTEX_TIMEOUT) { | |
| 193 return TRY_AGAIN; | |
| 194 } | |
| 195 if (res == -1) { | |
| 196 return WAIT_ERROR; | |
| 197 } | |
| 198 | |
| 199 ... | |
| 200 | |
| 201 SDL_SemPost(my_sem);</PRE | |
| 202 ></P | |
| 203 ></DIV | |
| 204 ><DIV | |
| 205 CLASS="REFSECT1" | |
| 206 ><A | |
|
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207 NAME="AEN7763" |
| 0 | 208 ></A |
| 209 ><H2 | |
| 210 >See Also</H2 | |
| 211 ><P | |
| 212 ><A | |
| 213 HREF="sdlcreatesemaphore.html" | |
| 214 ><TT | |
| 215 CLASS="FUNCTION" | |
| 216 >SDL_CreateSemaphore</TT | |
| 217 ></A | |
| 218 >, | |
| 219 <A | |
| 220 HREF="sdldestroysemaphore.html" | |
| 221 ><TT | |
| 222 CLASS="FUNCTION" | |
| 223 >SDL_DestroySemaphore</TT | |
| 224 ></A | |
| 225 >, | |
| 226 <A | |
| 227 HREF="sdlsemwait.html" | |
| 228 ><TT | |
| 229 CLASS="FUNCTION" | |
| 230 >SDL_SemWait</TT | |
| 231 ></A | |
| 232 >, | |
| 233 <A | |
| 234 HREF="sdlsemtrywait.html" | |
| 235 ><TT | |
| 236 CLASS="FUNCTION" | |
| 237 >SDL_SemTryWait</TT | |
| 238 ></A | |
| 239 >, | |
| 240 <A | |
| 241 HREF="sdlsempost.html" | |
| 242 ><TT | |
| 243 CLASS="FUNCTION" | |
| 244 >SDL_SemPost</TT | |
| 245 ></A | |
| 246 >, | |
| 247 <A | |
| 248 HREF="sdlsemvalue.html" | |
| 249 ><TT | |
| 250 CLASS="FUNCTION" | |
| 251 >SDL_SemValue</TT | |
| 252 ></A | |
| 253 ></P | |
| 254 ></DIV | |
| 255 ><DIV | |
| 256 CLASS="NAVFOOTER" | |
| 257 ><HR | |
| 258 ALIGN="LEFT" | |
| 259 WIDTH="100%"><TABLE | |
| 260 WIDTH="100%" | |
| 261 BORDER="0" | |
| 262 CELLPADDING="0" | |
| 263 CELLSPACING="0" | |
| 264 ><TR | |
| 265 ><TD | |
| 266 WIDTH="33%" | |
| 267 ALIGN="left" | |
| 268 VALIGN="top" | |
| 269 ><A | |
| 270 HREF="sdlsemtrywait.html" | |
| 271 >Prev</A | |
| 272 ></TD | |
| 273 ><TD | |
| 274 WIDTH="34%" | |
| 275 ALIGN="center" | |
| 276 VALIGN="top" | |
| 277 ><A | |
| 278 HREF="index.html" | |
| 279 >Home</A | |
| 280 ></TD | |
| 281 ><TD | |
| 282 WIDTH="33%" | |
| 283 ALIGN="right" | |
| 284 VALIGN="top" | |
| 285 ><A | |
| 286 HREF="sdlsempost.html" | |
| 287 >Next</A | |
| 288 ></TD | |
| 289 ></TR | |
| 290 ><TR | |
| 291 ><TD | |
| 292 WIDTH="33%" | |
| 293 ALIGN="left" | |
| 294 VALIGN="top" | |
| 295 >SDL_SemTryWait</TD | |
| 296 ><TD | |
| 297 WIDTH="34%" | |
| 298 ALIGN="center" | |
| 299 VALIGN="top" | |
| 300 ><A | |
| 301 HREF="thread.html" | |
| 302 >Up</A | |
| 303 ></TD | |
| 304 ><TD | |
| 305 WIDTH="33%" | |
| 306 ALIGN="right" | |
| 307 VALIGN="top" | |
| 308 >SDL_SemPost</TD | |
| 309 ></TR | |
| 310 ></TABLE | |
| 311 ></DIV | |
| 312 ></BODY | |
| 313 ></HTML | |
| 314 > |