1 <HTML 2 ><HEAD 3 ><TITLE 4 >SDL_SemPost</TITLE 5 ><META 6 NAME="GENERATOR" 7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ 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_SemWaitTimeout" 17 HREF="sdlsemwaittimeout.html"><LINK 18 REL="NEXT" 19 TITLE="SDL_SemValue" 20 HREF="sdlsemvalue.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 SUMMARY="Header navigation table" 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="sdlsemwaittimeout.html" 49 ACCESSKEY="P" 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="sdlsemvalue.html" 63 ACCESSKEY="N" 64 >Next</A 65 ></TD 66 ></TR 67 ></TABLE 68 ><HR 69 ALIGN="LEFT" 70 WIDTH="100%"></DIV 71 ><H1 72 ><A 73 NAME="SDLSEMPOST" 74 ></A 75 >SDL_SemPost</H1 76 ><DIV 77 CLASS="REFNAMEDIV" 78 ><A 79 NAME="AEN8170" 80 ></A 81 ><H2 82 >Name</H2 83 >SDL_SemPost -- Unlock a semaphore.</DIV 84 ><DIV 85 CLASS="REFSYNOPSISDIV" 86 ><A 87 NAME="AEN8173" 88 ></A 89 ><H2 90 >Synopsis</H2 91 ><DIV 92 CLASS="FUNCSYNOPSIS" 93 ><A 94 NAME="AEN8174" 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_SemPost</B 109 ></CODE 110 >(SDL_sem *sem);</CODE 111 ></P 112 ><P 113 ></P 114 ></DIV 115 ></DIV 116 ><DIV 117 CLASS="REFSECT1" 118 ><A 119 NAME="AEN8180" 120 ></A 121 ><H2 122 >Description</H2 123 ><P 124 ><TT 125 CLASS="FUNCTION" 126 >SDL_SemPost</TT 127 > unlocks the semaphore pointed to by 128 <TT 129 CLASS="PARAMETER" 130 ><I 131 >sem</I 132 ></TT 133 > and atomically increments the semaphores value. 134 Threads that were blocking on the semaphore may be scheduled after this call 135 succeeds.</P 136 ><P 137 ><TT 138 CLASS="FUNCTION" 139 >SDL_SemPost</TT 140 > should be called after a semaphore is locked by a successful call to 141 <A 142 HREF="sdlsemwait.html" 143 >SDL_SemWait</A 144 >, 145 <A 146 HREF="sdlsemtrywait.html" 147 >SDL_SemTryWait</A 148 > or 149 <A 150 HREF="sdlsemwaittimeout.html" 151 >SDL_SemWaitTimeout</A 152 >.</P 153 ></DIV 154 ><DIV 155 CLASS="REFSECT1" 156 ><A 157 NAME="AEN8190" 158 ></A 159 ><H2 160 >Return Value</H2 161 ><P 162 >Returns <SPAN 163 CLASS="RETURNVALUE" 164 >0</SPAN 165 > if successful or 166 <SPAN 167 CLASS="RETURNVALUE" 168 >-1</SPAN 169 > if there was an error (leaving the semaphore unchanged).</P 170 ></DIV 171 ><DIV 172 CLASS="REFSECT1" 173 ><A 174 NAME="AEN8195" 175 ></A 176 ><H2 177 >Examples</H2 178 ><P 179 ><PRE 180 CLASS="PROGRAMLISTING" 181 >SDL_SemPost(my_sem);</PRE 182 ></P 183 ></DIV 184 ><DIV 185 CLASS="REFSECT1" 186 ><A 187 NAME="AEN8199" 188 ></A 189 ><H2 190 >See Also</H2 191 ><P 192 ><A 193 HREF="sdlcreatesemaphore.html" 194 ><TT 195 CLASS="FUNCTION" 196 >SDL_CreateSemaphore</TT 197 ></A 198 >, 199 <A 200 HREF="sdldestroysemaphore.html" 201 ><TT 202 CLASS="FUNCTION" 203 >SDL_DestroySemaphore</TT 204 ></A 205 >, 206 <A 207 HREF="sdlsemwait.html" 208 ><TT 209 CLASS="FUNCTION" 210 >SDL_SemWait</TT 211 ></A 212 >, 213 <A 214 HREF="sdlsemtrywait.html" 215 ><TT 216 CLASS="FUNCTION" 217 >SDL_SemTryWait</TT 218 ></A 219 >, 220 <A 221 HREF="sdlsemwaittimeout.html" 222 ><TT 223 CLASS="FUNCTION" 224 >SDL_SemWaitTimeout</TT 225 ></A 226 >, 227 <A 228 HREF="sdlsemvalue.html" 229 ><TT 230 CLASS="FUNCTION" 231 >SDL_SemValue</TT 232 ></A 233 ></P 234 ></DIV 235 ><DIV 236 CLASS="NAVFOOTER" 237 ><HR 238 ALIGN="LEFT" 239 WIDTH="100%"><TABLE 240 SUMMARY="Footer navigation table" 241 WIDTH="100%" 242 BORDER="0" 243 CELLPADDING="0" 244 CELLSPACING="0" 245 ><TR 246 ><TD 247 WIDTH="33%" 248 ALIGN="left" 249 VALIGN="top" 250 ><A 251 HREF="sdlsemwaittimeout.html" 252 ACCESSKEY="P" 253 >Prev</A 254 ></TD 255 ><TD 256 WIDTH="34%" 257 ALIGN="center" 258 VALIGN="top" 259 ><A 260 HREF="index.html" 261 ACCESSKEY="H" 262 >Home</A 263 ></TD 264 ><TD 265 WIDTH="33%" 266 ALIGN="right" 267 VALIGN="top" 268 ><A 269 HREF="sdlsemvalue.html" 270 ACCESSKEY="N" 271 >Next</A 272 ></TD 273 ></TR 274 ><TR 275 ><TD 276 WIDTH="33%" 277 ALIGN="left" 278 VALIGN="top" 279 >SDL_SemWaitTimeout</TD 280 ><TD 281 WIDTH="34%" 282 ALIGN="center" 283 VALIGN="top" 284 ><A 285 HREF="thread.html" 286 ACCESSKEY="U" 287 >Up</A 288 ></TD 289 ><TD 290 WIDTH="33%" 291 ALIGN="right" 292 VALIGN="top" 293 >SDL_SemValue</TD 294 ></TR 295 ></TABLE 296 ></DIV 297 ></BODY 298 ></HTML 299 >
