Mercurial > sdl-ios-xcode
annotate docs/html/sdlsemwaittimeout.html @ 1282:217f5d5a49e5
Date: Sat, 15 Jan 2005 02:01:51 +0000 (UTC)
From: jimrandomh
Subject: [SDL] Re: Modifier keys pressed during initialization stick
I wrote a simple test program which initializes SDL, prints the SDL
version number, then prints any keydown and keyup events with their
modifiers. (Source code below). Compilation was done using Visual
Studio 6, release mode.
My test sequence was:
Start a command prompt. Type the name of the test program.
shift down
enter down (program starts)
Wait for window to appear
enter up
shift up
spacebar down
spacebar up
Under Windows 98, the output was correct:
SDL 1.2.8
left shift down
shift-return down
shift-return up
left shift up
space down
space up
Under Windows 2000 and under Windows XP, the output was:
SDL 1.2.8
shift-space down
shift-space up
Since shift was not held at the time space was pressed, this is
incorrect. Similar results were observed with launching in different
ways (including double-clicking in Windows Explorer), so it does not
depend on the launching terminal.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Sun, 29 Jan 2006 07:57:13 +0000 |
parents | 355632dca928 |
children |
rev | line source |
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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 1.76b+ |
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 | |
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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="sdlsemtrywait.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="sdlsempost.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="SDLSEMWAITTIMEOUT" | |
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74 ></A |
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75 >SDL_SemWaitTimeout</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN8120" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_SemWaitTimeout -- Lock a semaphore, but only wait up to a specified maximum time.</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN8123" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN8124" |
0 | 95 ></A |
96 ><P | |
97 ></P | |
98 ><PRE | |
99 CLASS="FUNCSYNOPSISINFO" | |
100 >#include "SDL.h" | |
101 #include "SDL_thread.h"</PRE | |
102 ><P | |
103 ><CODE | |
104 ><CODE | |
105 CLASS="FUNCDEF" | |
106 >int <B | |
107 CLASS="FSFUNC" | |
108 >SDL_SemWaitTimeout</B | |
109 ></CODE | |
110 >(SDL_sem *sem, Uint32 timeout);</CODE | |
111 ></P | |
112 ><P | |
113 ></P | |
114 ></DIV | |
115 ></DIV | |
116 ><DIV | |
117 CLASS="REFSECT1" | |
118 ><A | |
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119 NAME="AEN8130" |
0 | 120 ></A |
121 ><H2 | |
122 >Description</H2 | |
123 ><P | |
124 ><TT | |
125 CLASS="FUNCTION" | |
126 >SDL_SemWaitTimeout()</TT | |
127 > is a varient of | |
128 <A | |
129 HREF="sdlsemwait.html" | |
130 >SDL_SemWait</A | |
131 > | |
132 with a maximum timeout value. | |
133 If the value of the semaphore pointed to by <TT | |
134 CLASS="PARAMETER" | |
135 ><I | |
136 >sem</I | |
137 ></TT | |
138 > is | |
139 positive (greater than zero) it will atomically decrement the semaphore value | |
140 and return 0, otherwise it will wait up to <TT | |
141 CLASS="PARAMETER" | |
142 ><I | |
143 >timeout</I | |
144 ></TT | |
145 > | |
146 milliseconds trying to lock the semaphore. This function is to be avoided if | |
147 possible since on some platforms it is implemented by polling the semaphore | |
148 every millisecond in a busy loop.</P | |
149 ><P | |
150 >After <TT | |
151 CLASS="FUNCTION" | |
152 >SDL_SemWaitTimeout()</TT | |
153 > is successful, the semaphore | |
154 can be released and its count atomically incremented by a successful call to | |
155 <A | |
156 HREF="sdlsempost.html" | |
157 >SDL_SemPost</A | |
158 >.</P | |
159 ></DIV | |
160 ><DIV | |
161 CLASS="REFSECT1" | |
162 ><A | |
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163 NAME="AEN8140" |
0 | 164 ></A |
165 ><H2 | |
166 >Return Value</H2 | |
167 ><P | |
168 >Returns <SPAN | |
169 CLASS="RETURNVALUE" | |
170 >0</SPAN | |
171 > if the semaphore was successfully locked or | |
172 either <SPAN | |
173 CLASS="RETURNVALUE" | |
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174 >SDL_MUTEX_TIMEDOUT</SPAN |
0 | 175 > or <SPAN |
176 CLASS="RETURNVALUE" | |
177 >-1</SPAN | |
178 > | |
179 if the timeout period was exceeded or there was an error, respectivly.</P | |
180 ><P | |
181 >If the semaphore was not successfully locked, the semaphore will be unchanged.</P | |
182 ></DIV | |
183 ><DIV | |
184 CLASS="REFSECT1" | |
185 ><A | |
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186 NAME="AEN8147" |
0 | 187 ></A |
188 ><H2 | |
189 >Examples</H2 | |
190 ><P | |
191 ><PRE | |
192 CLASS="PROGRAMLISTING" | |
193 >res = SDL_SemWaitTimeout(my_sem, WAIT_TIMEOUT_MILLISEC); | |
194 | |
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195 if (res == SDL_MUTEX_TIMEDOUT) { |
0 | 196 return TRY_AGAIN; |
197 } | |
198 if (res == -1) { | |
199 return WAIT_ERROR; | |
200 } | |
201 | |
202 ... | |
203 | |
204 SDL_SemPost(my_sem);</PRE | |
205 ></P | |
206 ></DIV | |
207 ><DIV | |
208 CLASS="REFSECT1" | |
209 ><A | |
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210 NAME="AEN8151" |
0 | 211 ></A |
212 ><H2 | |
213 >See Also</H2 | |
214 ><P | |
215 ><A | |
216 HREF="sdlcreatesemaphore.html" | |
217 ><TT | |
218 CLASS="FUNCTION" | |
219 >SDL_CreateSemaphore</TT | |
220 ></A | |
221 >, | |
222 <A | |
223 HREF="sdldestroysemaphore.html" | |
224 ><TT | |
225 CLASS="FUNCTION" | |
226 >SDL_DestroySemaphore</TT | |
227 ></A | |
228 >, | |
229 <A | |
230 HREF="sdlsemwait.html" | |
231 ><TT | |
232 CLASS="FUNCTION" | |
233 >SDL_SemWait</TT | |
234 ></A | |
235 >, | |
236 <A | |
237 HREF="sdlsemtrywait.html" | |
238 ><TT | |
239 CLASS="FUNCTION" | |
240 >SDL_SemTryWait</TT | |
241 ></A | |
242 >, | |
243 <A | |
244 HREF="sdlsempost.html" | |
245 ><TT | |
246 CLASS="FUNCTION" | |
247 >SDL_SemPost</TT | |
248 ></A | |
249 >, | |
250 <A | |
251 HREF="sdlsemvalue.html" | |
252 ><TT | |
253 CLASS="FUNCTION" | |
254 >SDL_SemValue</TT | |
255 ></A | |
256 ></P | |
257 ></DIV | |
258 ><DIV | |
259 CLASS="NAVFOOTER" | |
260 ><HR | |
261 ALIGN="LEFT" | |
262 WIDTH="100%"><TABLE | |
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263 SUMMARY="Footer navigation table" |
0 | 264 WIDTH="100%" |
265 BORDER="0" | |
266 CELLPADDING="0" | |
267 CELLSPACING="0" | |
268 ><TR | |
269 ><TD | |
270 WIDTH="33%" | |
271 ALIGN="left" | |
272 VALIGN="top" | |
273 ><A | |
274 HREF="sdlsemtrywait.html" | |
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275 ACCESSKEY="P" |
0 | 276 >Prev</A |
277 ></TD | |
278 ><TD | |
279 WIDTH="34%" | |
280 ALIGN="center" | |
281 VALIGN="top" | |
282 ><A | |
283 HREF="index.html" | |
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284 ACCESSKEY="H" |
0 | 285 >Home</A |
286 ></TD | |
287 ><TD | |
288 WIDTH="33%" | |
289 ALIGN="right" | |
290 VALIGN="top" | |
291 ><A | |
292 HREF="sdlsempost.html" | |
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293 ACCESSKEY="N" |
0 | 294 >Next</A |
295 ></TD | |
296 ></TR | |
297 ><TR | |
298 ><TD | |
299 WIDTH="33%" | |
300 ALIGN="left" | |
301 VALIGN="top" | |
302 >SDL_SemTryWait</TD | |
303 ><TD | |
304 WIDTH="34%" | |
305 ALIGN="center" | |
306 VALIGN="top" | |
307 ><A | |
308 HREF="thread.html" | |
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309 ACCESSKEY="U" |
0 | 310 >Up</A |
311 ></TD | |
312 ><TD | |
313 WIDTH="33%" | |
314 ALIGN="right" | |
315 VALIGN="top" | |
316 >SDL_SemPost</TD | |
317 ></TR | |
318 ></TABLE | |
319 ></DIV | |
320 ></BODY | |
321 ></HTML | |
322 > |