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annotate docs/html/thread.html @ 1260:80f8c94b5199
Date: 10 Jun 2003 15:30:59 -0400
From: Mike Shal
Subject: [SDL] Bug in SDL_wave.c?
Hey everyone, I'm not sure if this is a bug in SDL, or if I just have
incorrect WAV files. The problem I'm having is loading multiple
concatenated WAVs from SDL_LoadWAV_RW. Some WAV files put comments at
the end of the file (which may be bad form), and SDL doesn't skip past
them when reading from the RWops. So the next WAV I try to load will
start at the comment section of the previous WAV, which obviously
doesn't work. If anyone else is having this problem, one quick fix you
can do is run sox on the bad WAVs, which strips out all of the comment
sections.
Eg:
$ sox sound.wav tmp.wav
$ mv -f tmp.wav sound.wav
The other fix is to patch SDL_wave.c, which is included with this email.
(Assuming I made the patch correctly :). All it does is calculate how
much remaining space there is in the WAV file after the data chunk, and
does SDL_RWseek to skip it. I don't think it should interfere with
anything else, but if someone could check it that would be nice :). If
the bug is really with SDL and not with my WAVs, can someone work this
into the next version of SDL? Thanks,
-Mike Shal
author | Sam Lantinga <slouken@libsdl.org> |
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date | Tue, 24 Jan 2006 07:20:18 +0000 |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >Multi-threaded Programming</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="SDL Reference" | |
14 HREF="reference.html"><LINK | |
15 REL="PREVIOUS" | |
16 TITLE="SDL_CDtrack" | |
17 HREF="sdlcdtrack.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_CreateThread" | |
20 HREF="sdlcreatethread.html"><META | |
21 NAME="KEYWORD" | |
22 CONTENT="threads"><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 | |
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35 SUMMARY="Header navigation table" |
0 | 36 WIDTH="100%" |
37 BORDER="0" | |
38 CELLPADDING="0" | |
39 CELLSPACING="0" | |
40 ><TR | |
41 ><TH | |
42 COLSPAN="3" | |
43 ALIGN="center" | |
44 >SDL Library Documentation</TH | |
45 ></TR | |
46 ><TR | |
47 ><TD | |
48 WIDTH="10%" | |
49 ALIGN="left" | |
50 VALIGN="bottom" | |
51 ><A | |
52 HREF="sdlcdtrack.html" | |
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53 ACCESSKEY="P" |
0 | 54 >Prev</A |
55 ></TD | |
56 ><TD | |
57 WIDTH="80%" | |
58 ALIGN="center" | |
59 VALIGN="bottom" | |
60 ></TD | |
61 ><TD | |
62 WIDTH="10%" | |
63 ALIGN="right" | |
64 VALIGN="bottom" | |
65 ><A | |
66 HREF="sdlcreatethread.html" | |
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67 ACCESSKEY="N" |
0 | 68 >Next</A |
69 ></TD | |
70 ></TR | |
71 ></TABLE | |
72 ><HR | |
73 ALIGN="LEFT" | |
74 WIDTH="100%"></DIV | |
75 ><DIV | |
76 CLASS="CHAPTER" | |
77 ><H1 | |
78 ><A | |
79 NAME="THREAD" | |
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80 ></A |
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81 >Chapter 12. Multi-threaded Programming</H1 |
0 | 82 ><DIV |
83 CLASS="TOC" | |
84 ><DL | |
85 ><DT | |
86 ><B | |
87 >Table of Contents</B | |
88 ></DT | |
89 ><DT | |
90 ><A | |
91 HREF="sdlcreatethread.html" | |
92 >SDL_CreateThread</A | |
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93 > -- Creates a new thread of execution that shares its parent's properties.</DT |
0 | 94 ><DT |
95 ><A | |
96 HREF="sdlthreadid.html" | |
97 >SDL_ThreadID</A | |
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98 > -- Get the 32-bit thread identifier for the current thread.</DT |
0 | 99 ><DT |
100 ><A | |
101 HREF="sdlgetthreadid.html" | |
102 >SDL_GetThreadID</A | |
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103 > -- Get the SDL thread ID of a SDL_Thread</DT |
0 | 104 ><DT |
105 ><A | |
106 HREF="sdlwaitthread.html" | |
107 >SDL_WaitThread</A | |
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108 > -- Wait for a thread to finish.</DT |
0 | 109 ><DT |
110 ><A | |
111 HREF="sdlkillthread.html" | |
112 >SDL_KillThread</A | |
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113 > -- Gracelessly terminates the thread.</DT |
0 | 114 ><DT |
115 ><A | |
116 HREF="sdlcreatemutex.html" | |
117 >SDL_CreateMutex</A | |
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118 > -- Create a mutex</DT |
0 | 119 ><DT |
120 ><A | |
121 HREF="sdldestroymutex.html" | |
122 >SDL_DestroyMutex</A | |
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123 > -- Destroy a mutex</DT |
0 | 124 ><DT |
125 ><A | |
126 HREF="sdlmutexp.html" | |
127 >SDL_mutexP</A | |
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128 > -- Lock a mutex</DT |
0 | 129 ><DT |
130 ><A | |
131 HREF="sdlmutexv.html" | |
132 >SDL_mutexV</A | |
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133 > -- Unlock a mutex</DT |
0 | 134 ><DT |
135 ><A | |
136 HREF="sdlcreatesemaphore.html" | |
137 >SDL_CreateSemaphore</A | |
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138 > -- Creates a new semaphore and assigns an initial value to it.</DT |
0 | 139 ><DT |
140 ><A | |
141 HREF="sdldestroysemaphore.html" | |
142 >SDL_DestroySemaphore</A | |
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143 > -- Destroys a semaphore that was created by <A |
0 | 144 HREF="sdlcreatesemaphore.html" |
145 >SDL_CreateSemaphore</A | |
146 >.</DT | |
147 ><DT | |
148 ><A | |
149 HREF="sdlsemwait.html" | |
150 >SDL_SemWait</A | |
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151 > -- Lock a semaphore and suspend the thread if the semaphore value is zero.</DT |
0 | 152 ><DT |
153 ><A | |
154 HREF="sdlsemtrywait.html" | |
155 >SDL_SemTryWait</A | |
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156 > -- Attempt to lock a semaphore but don't suspend the thread.</DT |
0 | 157 ><DT |
158 ><A | |
159 HREF="sdlsemwaittimeout.html" | |
160 >SDL_SemWaitTimeout</A | |
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161 > -- Lock a semaphore, but only wait up to a specified maximum time.</DT |
0 | 162 ><DT |
163 ><A | |
164 HREF="sdlsempost.html" | |
165 >SDL_SemPost</A | |
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166 > -- Unlock a semaphore.</DT |
0 | 167 ><DT |
168 ><A | |
169 HREF="sdlsemvalue.html" | |
170 >SDL_SemValue</A | |
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171 > -- Return the current value of a semaphore.</DT |
0 | 172 ><DT |
173 ><A | |
174 HREF="sdlcreatecond.html" | |
175 >SDL_CreateCond</A | |
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176 > -- Create a condition variable</DT |
0 | 177 ><DT |
178 ><A | |
179 HREF="sdldestroycond.html" | |
180 >SDL_DestroyCond</A | |
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181 > -- Destroy a condition variable</DT |
0 | 182 ><DT |
183 ><A | |
184 HREF="sdlcondsignal.html" | |
185 >SDL_CondSignal</A | |
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186 > -- Restart a thread wait on a condition variable</DT |
0 | 187 ><DT |
188 ><A | |
189 HREF="sdlcondbroadcast.html" | |
190 >SDL_CondBroadcast</A | |
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191 > -- Restart all threads waiting on a condition variable</DT |
0 | 192 ><DT |
193 ><A | |
194 HREF="sdlcondwait.html" | |
195 >SDL_CondWait</A | |
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196 > -- Wait on a condition variable</DT |
0 | 197 ><DT |
198 ><A | |
199 HREF="sdlcondwaittimeout.html" | |
200 >SDL_CondWaitTimeout</A | |
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201 > -- Wait on a condition variable, with timeout</DT |
0 | 202 ></DL |
203 ></DIV | |
204 ><P | |
205 >SDL provides functions for creating threads, mutexes, semphores and condition variables.</P | |
206 ><P | |
207 >In general, you must be very aware of concurrency and data integrity issues | |
208 when writing multi-threaded programs. Some good guidelines include: | |
209 <P | |
210 ></P | |
211 ><UL | |
212 ><LI | |
213 ><P | |
214 >Don't call SDL video/event functions from separate threads</P | |
215 ></LI | |
216 ><LI | |
217 ><P | |
218 >Don't use any library functions in separate threads</P | |
219 ></LI | |
220 ><LI | |
221 ><P | |
222 >Don't perform any memory management in separate threads</P | |
223 ></LI | |
224 ><LI | |
225 ><P | |
226 >Lock global variables which may be accessed by multiple threads</P | |
227 ></LI | |
228 ><LI | |
229 ><P | |
230 >Never terminate threads, always set a flag and wait for them to quit</P | |
231 ></LI | |
232 ><LI | |
233 ><P | |
234 >Think very carefully about all possible ways your code may interact</P | |
235 ></LI | |
236 ></UL | |
237 ></P | |
238 ><DIV | |
239 CLASS="NOTE" | |
240 ><BLOCKQUOTE | |
241 CLASS="NOTE" | |
242 ><P | |
243 ><B | |
244 >Note: </B | |
181
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245 >SDL's threading is not implemented on MacOS, due to that lack of preemptive thread support (MacOS X dos nt suffer from this problem)</P |
0 | 246 ></BLOCKQUOTE |
247 ></DIV | |
248 ></DIV | |
249 ><DIV | |
250 CLASS="NAVFOOTER" | |
251 ><HR | |
252 ALIGN="LEFT" | |
253 WIDTH="100%"><TABLE | |
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254 SUMMARY="Footer navigation table" |
0 | 255 WIDTH="100%" |
256 BORDER="0" | |
257 CELLPADDING="0" | |
258 CELLSPACING="0" | |
259 ><TR | |
260 ><TD | |
261 WIDTH="33%" | |
262 ALIGN="left" | |
263 VALIGN="top" | |
264 ><A | |
265 HREF="sdlcdtrack.html" | |
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266 ACCESSKEY="P" |
0 | 267 >Prev</A |
268 ></TD | |
269 ><TD | |
270 WIDTH="34%" | |
271 ALIGN="center" | |
272 VALIGN="top" | |
273 ><A | |
274 HREF="index.html" | |
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275 ACCESSKEY="H" |
0 | 276 >Home</A |
277 ></TD | |
278 ><TD | |
279 WIDTH="33%" | |
280 ALIGN="right" | |
281 VALIGN="top" | |
282 ><A | |
283 HREF="sdlcreatethread.html" | |
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284 ACCESSKEY="N" |
0 | 285 >Next</A |
286 ></TD | |
287 ></TR | |
288 ><TR | |
289 ><TD | |
290 WIDTH="33%" | |
291 ALIGN="left" | |
292 VALIGN="top" | |
293 >SDL_CDtrack</TD | |
294 ><TD | |
295 WIDTH="34%" | |
296 ALIGN="center" | |
297 VALIGN="top" | |
298 ><A | |
299 HREF="reference.html" | |
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300 ACCESSKEY="U" |
0 | 301 >Up</A |
302 ></TD | |
303 ><TD | |
304 WIDTH="33%" | |
305 ALIGN="right" | |
306 VALIGN="top" | |
307 >SDL_CreateThread</TD | |
308 ></TR | |
309 ></TABLE | |
310 ></DIV | |
311 ></BODY | |
312 ></HTML | |
313 > |