Mercurial > sdl-ios-xcode
annotate docs/html/sdlcreatesemaphore.html @ 1585:980d2a0dc2a3
Date: Tue, 4 Mar 2003 15:05:31 -0800
From: "Jim"
Subject: [SDL] Frame Buffer patches...
Okay I'm new at patch generation - so please tell me if there's a better way
I could have done this.
Attached are two patch files generated with 'cvs diff -u'
SDL-fb-open-lock.patch applies to SDL_fbvideo.c
Modifies the open loop to check /dev/fb/0 found on devfs...
Modifies the lock code to return failure if the current virtual terminal
is not the one opened for frame buffer writing...
Lock would hang forever if switched away (ctrl-alt-F1) ...
SDL-fb-mousedrv-screensave.patch applies to SDL_fbevents.c
Switches default mouse mode based on SDL_MOUSEDRV - currently only
accepts PS2 - otherwise default is MS Mouse.
When the screen is switched - exisiting code (wrapped in ifdef
SAVE_SCREEN_COTENTS) would save the wrong bit of the screen....
( I run frame buffer 1600x1200, the size I requested was 800x600 - the
save would save the top 800 lines (non biased) and restore them... Adding
screen->offset fixed that )
However, if that option is not set, then a call to SDL_UpdateRect (full
screen) is made. (which may have had it's contents changed since the screen
is not entirely locked because of lock-failure patch)
Jim
[patches slightly tweaked for SDL 1.2.10]
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 22 Mar 2006 07:48:22 +0000 |
parents | 355632dca928 |
children |
rev | line source |
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0 | 1 <HTML |
2 ><HEAD | |
3 ><TITLE | |
4 >SDL_CreateSemaphore</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_mutexV" | |
17 HREF="sdlmutexv.html"><LINK | |
18 REL="NEXT" | |
19 TITLE="SDL_DestroySemaphore" | |
20 HREF="sdldestroysemaphore.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="sdlmutexv.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="sdldestroysemaphore.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="SDLCREATESEMAPHORE" | |
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74 ></A |
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75 >SDL_CreateSemaphore</H1 |
0 | 76 ><DIV |
77 CLASS="REFNAMEDIV" | |
78 ><A | |
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79 NAME="AEN7936" |
0 | 80 ></A |
81 ><H2 | |
82 >Name</H2 | |
83 >SDL_CreateSemaphore -- Creates a new semaphore and assigns an initial value to it.</DIV | |
84 ><DIV | |
85 CLASS="REFSYNOPSISDIV" | |
86 ><A | |
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87 NAME="AEN7939" |
0 | 88 ></A |
89 ><H2 | |
90 >Synopsis</H2 | |
91 ><DIV | |
92 CLASS="FUNCSYNOPSIS" | |
93 ><A | |
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94 NAME="AEN7940" |
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 >SDL_sem *<B | |
107 CLASS="FSFUNC" | |
108 >SDL_CreateSemaphore</B | |
109 ></CODE | |
110 >(Uint32 initial_value);</CODE | |
111 ></P | |
112 ><P | |
113 ></P | |
114 ></DIV | |
115 ></DIV | |
116 ><DIV | |
117 CLASS="REFSECT1" | |
118 ><A | |
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119 NAME="AEN7946" |
0 | 120 ></A |
121 ><H2 | |
122 >Description</H2 | |
123 ><P | |
124 ><TT | |
125 CLASS="FUNCTION" | |
126 >SDL_CreateSemaphore()</TT | |
127 > creates a new semaphore and | |
128 initializes it with the value <TT | |
129 CLASS="PARAMETER" | |
130 ><I | |
131 >initial_value</I | |
132 ></TT | |
133 >. | |
134 Each locking operation on the semaphore by | |
135 <A | |
136 HREF="sdlsemwait.html" | |
137 >SDL_SemWait</A | |
138 >, | |
139 <A | |
140 HREF="sdlsemtrywait.html" | |
141 >SDL_SemTryWait</A | |
142 > or | |
143 <A | |
144 HREF="sdlsemwaittimeout.html" | |
145 >SDL_SemWaitTimeout</A | |
146 > | |
147 will atomically decrement the semaphore value. The locking operation will be blocked | |
148 if the semaphore value is not positive (greater than zero). Each unlock operation by | |
149 <A | |
150 HREF="sdlsempost.html" | |
151 >SDL_SemPost</A | |
152 > | |
153 will atomically increment the semaphore value.</P | |
154 ></DIV | |
155 ><DIV | |
156 CLASS="REFSECT1" | |
157 ><A | |
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158 NAME="AEN7955" |
0 | 159 ></A |
160 ><H2 | |
161 >Return Value</H2 | |
162 ><P | |
163 >Returns a pointer to an initialized semaphore or | |
164 <SPAN | |
165 CLASS="RETURNVALUE" | |
166 >NULL</SPAN | |
167 > if there was an error.</P | |
168 ></DIV | |
169 ><DIV | |
170 CLASS="REFSECT1" | |
171 ><A | |
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172 NAME="AEN7959" |
0 | 173 ></A |
174 ><H2 | |
175 >Examples</H2 | |
176 ><P | |
177 ><PRE | |
178 CLASS="PROGRAMLISTING" | |
179 >SDL_sem *my_sem; | |
180 | |
181 my_sem = SDL_CreateSemaphore(INITIAL_SEM_VALUE); | |
182 | |
183 if (my_sem == NULL) { | |
184 return CREATE_SEM_FAILED; | |
185 }</PRE | |
186 ></P | |
187 ></DIV | |
188 ><DIV | |
189 CLASS="REFSECT1" | |
190 ><A | |
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191 NAME="AEN7963" |
0 | 192 ></A |
193 ><H2 | |
194 >See Also</H2 | |
195 ><P | |
196 ><A | |
197 HREF="sdldestroysemaphore.html" | |
198 ><TT | |
199 CLASS="FUNCTION" | |
200 >SDL_DestroySemaphore</TT | |
201 ></A | |
202 >, | |
203 <A | |
204 HREF="sdlsemwait.html" | |
205 ><TT | |
206 CLASS="FUNCTION" | |
207 >SDL_SemWait</TT | |
208 ></A | |
209 >, | |
210 <A | |
211 HREF="sdlsemtrywait.html" | |
212 ><TT | |
213 CLASS="FUNCTION" | |
214 >SDL_SemTryWait</TT | |
215 ></A | |
216 >, | |
217 <A | |
218 HREF="sdlsemwaittimeout.html" | |
219 ><TT | |
220 CLASS="FUNCTION" | |
221 >SDL_SemWaitTimeout</TT | |
222 ></A | |
223 >, | |
224 <A | |
225 HREF="sdlsempost.html" | |
226 ><TT | |
227 CLASS="FUNCTION" | |
228 >SDL_SemPost</TT | |
229 ></A | |
230 >, | |
231 <A | |
232 HREF="sdlsemvalue.html" | |
233 ><TT | |
234 CLASS="FUNCTION" | |
235 >SDL_SemValue</TT | |
236 ></A | |
237 ></P | |
238 ></DIV | |
239 ><DIV | |
240 CLASS="NAVFOOTER" | |
241 ><HR | |
242 ALIGN="LEFT" | |
243 WIDTH="100%"><TABLE | |
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244 SUMMARY="Footer navigation table" |
0 | 245 WIDTH="100%" |
246 BORDER="0" | |
247 CELLPADDING="0" | |
248 CELLSPACING="0" | |
249 ><TR | |
250 ><TD | |
251 WIDTH="33%" | |
252 ALIGN="left" | |
253 VALIGN="top" | |
254 ><A | |
255 HREF="sdlmutexv.html" | |
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256 ACCESSKEY="P" |
0 | 257 >Prev</A |
258 ></TD | |
259 ><TD | |
260 WIDTH="34%" | |
261 ALIGN="center" | |
262 VALIGN="top" | |
263 ><A | |
264 HREF="index.html" | |
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265 ACCESSKEY="H" |
0 | 266 >Home</A |
267 ></TD | |
268 ><TD | |
269 WIDTH="33%" | |
270 ALIGN="right" | |
271 VALIGN="top" | |
272 ><A | |
273 HREF="sdldestroysemaphore.html" | |
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274 ACCESSKEY="N" |
0 | 275 >Next</A |
276 ></TD | |
277 ></TR | |
278 ><TR | |
279 ><TD | |
280 WIDTH="33%" | |
281 ALIGN="left" | |
282 VALIGN="top" | |
283 >SDL_mutexV</TD | |
284 ><TD | |
285 WIDTH="34%" | |
286 ALIGN="center" | |
287 VALIGN="top" | |
288 ><A | |
289 HREF="thread.html" | |
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290 ACCESSKEY="U" |
0 | 291 >Up</A |
292 ></TD | |
293 ><TD | |
294 WIDTH="33%" | |
295 ALIGN="right" | |
296 VALIGN="top" | |
297 >SDL_DestroySemaphore</TD | |
298 ></TR | |
299 ></TABLE | |
300 ></DIV | |
301 ></BODY | |
302 ></HTML | |
303 > |