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annotate docs/html/sdlmutexp.html @ 968:4675910b0b7b
Date: Mon, 11 Oct 2004 15:17:27 +0300 (EEST)
From: Hannu Savolainen
Subject: Re: SDL uses obsolete OSS features
I did some work on getting OSS to work better with SDL. There have been
some problems with select which should be fixed now.
I'm having some problems in understanding what is the purpose of the
DSP_WaitAudio() routine. I added a return to the very beginning of this
routine and commendted out the define for USE_BLOCKING_WRITES. At least
lbreakout2 seems to work as well as earlier. The latencies are the same.
An ordinary blocking write does exactly the same thing than DSP_WaitAudio
does. So I would recommend using the USE_BLOCKING_WRITES approach and
removing everything from the DSP_WaitAudio routine. Also enabling
USE_BLOCKING_WRITES makes it possible to simplify DSP_PlayAudio() because
you don't need to handle the partial writes (the do-while loop).
Attached is a patch against SDL-1.2.7. After these changes SDL will use
OSS as it's designed to be used (make it as simple as possible). This code
should work with all OSS implementations because it uses only the very
fundamental features that have been there since the jurassic times.
author | Sam Lantinga <slouken@libsdl.org> |
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date | Fri, 12 Nov 2004 21:39:04 +0000 |
parents | 355632dca928 |
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rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_mutexP</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_DestroyMutex" | |
17 HREF="sdldestroymutex.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_mutexV" | |
20 HREF="sdlmutexv.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="sdldestroymutex.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="sdlmutexv.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="SDLMUTEXP" | |
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74 ></A |
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75 >SDL_mutexP</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN7872" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_mutexP -- Lock a mutex</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN7875" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN7876" |
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_mutexP</B | |
109 ></CODE | |
110 >(SDL_mutex *mutex);</CODE | |
111 ></P | |
112 ><P | |
113 ></P | |
114 ></DIV | |
115 ></DIV | |
116 ><DIV | |
117 CLASS="REFSECT1" | |
118 ><A | |
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119 NAME="AEN7882" |
0 | 120 ></A |
121 ><H2 | |
122 >Description</H2 | |
123 ><P | |
124 >Locks the <TT | |
125 CLASS="PARAMETER" | |
126 ><I | |
127 >mutex</I | |
128 ></TT | |
129 >, which was previously created with <A | |
130 HREF="sdlcreatemutex.html" | |
131 ><TT | |
132 CLASS="FUNCTION" | |
133 >SDL_CreateMutex</TT | |
134 ></A | |
135 >. If the mutex is already locked then <TT | |
136 CLASS="FUNCTION" | |
137 >SDL_mutexP</TT | |
138 > will not return until it is <A | |
139 HREF="sdlmutexv.html" | |
140 >unlocked</A | |
141 >. Returns <SPAN | |
142 CLASS="RETURNVALUE" | |
143 >0</SPAN | |
144 > on success, or <SPAN | |
145 CLASS="RETURNVALUE" | |
146 >-1</SPAN | |
147 > on an error.</P | |
148 ><P | |
149 >SDL also defines a macro <TT | |
150 CLASS="LITERAL" | |
151 >#define SDL_LockMutex(m) SDL_mutexP(m)</TT | |
152 >.</P | |
153 ></DIV | |
154 ><DIV | |
155 CLASS="REFSECT1" | |
156 ><A | |
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157 NAME="AEN7894" |
0 | 158 ></A |
159 ><H2 | |
160 >See Also</H2 | |
161 ><P | |
162 ><A | |
163 HREF="sdlcreatemutex.html" | |
164 ><TT | |
165 CLASS="FUNCTION" | |
166 >SDL_CreateMutex</TT | |
167 ></A | |
168 >, | |
169 <A | |
170 HREF="sdlmutexv.html" | |
171 ><TT | |
172 CLASS="FUNCTION" | |
173 >SDL_mutexV</TT | |
174 ></A | |
175 ></P | |
176 ></DIV | |
177 ><DIV | |
178 CLASS="NAVFOOTER" | |
179 ><HR | |
180 ALIGN="LEFT" | |
181 WIDTH="100%"><TABLE | |
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182 SUMMARY="Footer navigation table" |
0 | 183 WIDTH="100%" |
184 BORDER="0" | |
185 CELLPADDING="0" | |
186 CELLSPACING="0" | |
187 ><TR | |
188 ><TD | |
189 WIDTH="33%" | |
190 ALIGN="left" | |
191 VALIGN="top" | |
192 ><A | |
193 HREF="sdldestroymutex.html" | |
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194 ACCESSKEY="P" |
0 | 195 >Prev</A |
196 ></TD | |
197 ><TD | |
198 WIDTH="34%" | |
199 ALIGN="center" | |
200 VALIGN="top" | |
201 ><A | |
202 HREF="index.html" | |
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203 ACCESSKEY="H" |
0 | 204 >Home</A |
205 ></TD | |
206 ><TD | |
207 WIDTH="33%" | |
208 ALIGN="right" | |
209 VALIGN="top" | |
210 ><A | |
211 HREF="sdlmutexv.html" | |
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212 ACCESSKEY="N" |
0 | 213 >Next</A |
214 ></TD | |
215 ></TR | |
216 ><TR | |
217 ><TD | |
218 WIDTH="33%" | |
219 ALIGN="left" | |
220 VALIGN="top" | |
221 >SDL_DestroyMutex</TD | |
222 ><TD | |
223 WIDTH="34%" | |
224 ALIGN="center" | |
225 VALIGN="top" | |
226 ><A | |
227 HREF="thread.html" | |
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228 ACCESSKEY="U" |
0 | 229 >Up</A |
230 ></TD | |
231 ><TD | |
232 WIDTH="33%" | |
233 ALIGN="right" | |
234 VALIGN="top" | |
235 >SDL_mutexV</TD | |
236 ></TR | |
237 ></TABLE | |
238 ></DIV | |
239 ></BODY | |
240 ></HTML | |
241 > |