Mercurial > sdl-ios-xcode
view docs/html/sdlsemwait.html @ 2320:166400aa33d7
Deleted a call to X__PumpEvents at the end of X11_GL_InitExtensions(). This function is being called from SDL_RecreateWindow at a point when the numwindows value in
is incorrect. The result is that an illegal access is being made in X_PumpEvents when it tries to look up the windows ID of the source of an event. Taking out that
call does not seem to have any effect on the testgl. But, I would be happy if someone else took a look at this problem and found a fix higher up the stack.
author | Bob Pendleton <bob@pendleton.com> |
---|---|
date | Sat, 01 Mar 2008 20:34:36 +0000 |
parents | 355632dca928 |
children |
line wrap: on
line source
<HTML ><HEAD ><TITLE >SDL_SemWait</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="Multi-threaded Programming" HREF="thread.html"><LINK REL="PREVIOUS" TITLE="SDL_DestroySemaphore" HREF="sdldestroysemaphore.html"><LINK REL="NEXT" TITLE="SDL_SemTryWait" HREF="sdlsemtrywait.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >SDL Library Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="sdldestroysemaphore.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlsemtrywait.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="SDLSEMWAIT" ></A >SDL_SemWait</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN8023" ></A ><H2 >Name</H2 >SDL_SemWait -- Lock a semaphore and suspend the thread if the semaphore value is zero.</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN8026" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><A NAME="AEN8027" ></A ><P ></P ><PRE CLASS="FUNCSYNOPSISINFO" >#include "SDL.h" #include "SDL_thread.h"</PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int <B CLASS="FSFUNC" >SDL_SemWait</B ></CODE >(SDL_sem *sem);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8033" ></A ><H2 >Description</H2 ><P ><TT CLASS="FUNCTION" >SDL_SemWait()</TT > suspends the calling thread until either the semaphore pointed to by <TT CLASS="PARAMETER" ><I >sem</I ></TT > has a positive value, the call is interrupted by a signal or error. If the call is successful it will atomically decrement the semaphore value.</P ><P >After <TT CLASS="FUNCTION" >SDL_SemWait()</TT > is successful, the semaphore can be released and its count atomically incremented by a successful call to <A HREF="sdlsempost.html" >SDL_SemPost</A >.</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8041" ></A ><H2 >Return Value</H2 ><P >Returns <SPAN CLASS="RETURNVALUE" >0</SPAN > if successful or <SPAN CLASS="RETURNVALUE" >-1</SPAN > if there was an error (leaving the semaphore unchanged).</P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8046" ></A ><H2 >Examples</H2 ><P ><PRE CLASS="PROGRAMLISTING" >if (SDL_SemWait(my_sem) == -1) { return WAIT_FAILED; } ... SDL_SemPost(my_sem);</PRE ></P ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN8050" ></A ><H2 >See Also</H2 ><P ><A HREF="sdlcreatesemaphore.html" ><TT CLASS="FUNCTION" >SDL_CreateSemaphore</TT ></A >, <A HREF="sdldestroysemaphore.html" ><TT CLASS="FUNCTION" >SDL_DestroySemaphore</TT ></A >, <A HREF="sdlsemtrywait.html" ><TT CLASS="FUNCTION" >SDL_SemTryWait</TT ></A >, <A HREF="sdlsemwaittimeout.html" ><TT CLASS="FUNCTION" >SDL_SemWaitTimeout</TT ></A >, <A HREF="sdlsempost.html" ><TT CLASS="FUNCTION" >SDL_SemPost</TT ></A >, <A HREF="sdlsemvalue.html" ><TT CLASS="FUNCTION" >SDL_SemValue</TT ></A ></P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdldestroysemaphore.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlsemtrywait.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_DestroySemaphore</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="thread.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_SemTryWait</TD ></TR ></TABLE ></DIV ></BODY ></HTML >