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Date: 28 Jun 2003 22:42:52 +0100
From: Alan Swanson
Subject: Re: [SDL] New XFree 4.3 Video Mode Patch
I have a wee amendment that moves the qsort in set_best_resolution
to only occur after failing to find an exact match only. This would
make absolutely sure we get a user set mode.
While I've never had any problems for my normal resolutions (1280x1024,
1024x768, 800x600 & 640,480) while closely examining the output from
qsort I've noticed it doesn't seem to sort the modes fully. These is
one definite wrong at 1152x768 and a few that just look wrong to me.
From a program (attached) I made to examine this more easily. X has
sorted its mode list using the same method as ours (plus frequency),
and our user modes get inserted without any other movement.
On the patch I've made I've also changed cmpmodes to sort on vertical
resolution and then horizontal. Ie vertical is now most significant
bit.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Sat, 28 Jun 2003 21:52:26 +0000 |
parents | e5bc29de3f0a |
children | 355632dca928 |
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<HTML ><HEAD ><TITLE >Multi-threaded Programming</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.64 "><LINK REL="HOME" TITLE="SDL Library Documentation" HREF="index.html"><LINK REL="UP" TITLE="SDL Reference" HREF="reference.html"><LINK REL="PREVIOUS" TITLE="SDL_CDtrack" HREF="sdlcdtrack.html"><LINK REL="NEXT" TITLE="SDL_CreateThread" HREF="sdlcreatethread.html"><META NAME="KEYWORD" CONTENT="threads"><META NAME="KEYWORD" CONTENT="function"></HEAD ><BODY CLASS="CHAPTER" BGCOLOR="#FFF8DC" TEXT="#000000" LINK="#0000ee" VLINK="#551a8b" ALINK="#ff0000" ><DIV CLASS="NAVHEADER" ><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="sdlcdtrack.html" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="sdlcreatethread.html" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="CHAPTER" ><H1 ><A NAME="THREAD" >Chapter 12. Multi-threaded Programming</A ></H1 ><DIV CLASS="TOC" ><DL ><DT ><B >Table of Contents</B ></DT ><DT ><A HREF="sdlcreatethread.html" >SDL_CreateThread</A > — Creates a new thread of execution that shares its parent's properties.</DT ><DT ><A HREF="sdlthreadid.html" >SDL_ThreadID</A > — Get the 32-bit thread identifier for the current thread.</DT ><DT ><A HREF="sdlgetthreadid.html" >SDL_GetThreadID</A > — Get the SDL thread ID of a SDL_Thread</DT ><DT ><A HREF="sdlwaitthread.html" >SDL_WaitThread</A > — Wait for a thread to finish.</DT ><DT ><A HREF="sdlkillthread.html" >SDL_KillThread</A > — Gracelessly terminates the thread.</DT ><DT ><A HREF="sdlcreatemutex.html" >SDL_CreateMutex</A > — Create a mutex</DT ><DT ><A HREF="sdldestroymutex.html" >SDL_DestroyMutex</A > — Destroy a mutex</DT ><DT ><A HREF="sdlmutexp.html" >SDL_mutexP</A > — Lock a mutex</DT ><DT ><A HREF="sdlmutexv.html" >SDL_mutexV</A > — Unlock a mutex</DT ><DT ><A HREF="sdlcreatesemaphore.html" >SDL_CreateSemaphore</A > — Creates a new semaphore and assigns an initial value to it.</DT ><DT ><A HREF="sdldestroysemaphore.html" >SDL_DestroySemaphore</A > — Destroys a semaphore that was created by <A HREF="sdlcreatesemaphore.html" >SDL_CreateSemaphore</A >.</DT ><DT ><A HREF="sdlsemwait.html" >SDL_SemWait</A > — Lock a semaphore and suspend the thread if the semaphore value is zero.</DT ><DT ><A HREF="sdlsemtrywait.html" >SDL_SemTryWait</A > — Attempt to lock a semaphore but don't suspend the thread.</DT ><DT ><A HREF="sdlsemwaittimeout.html" >SDL_SemWaitTimeout</A > — Lock a semaphore, but only wait up to a specified maximum time.</DT ><DT ><A HREF="sdlsempost.html" >SDL_SemPost</A > — Unlock a semaphore.</DT ><DT ><A HREF="sdlsemvalue.html" >SDL_SemValue</A > — Return the current value of a semaphore.</DT ><DT ><A HREF="sdlcreatecond.html" >SDL_CreateCond</A > — Create a condition variable</DT ><DT ><A HREF="sdldestroycond.html" >SDL_DestroyCond</A > — Destroy a condition variable</DT ><DT ><A HREF="sdlcondsignal.html" >SDL_CondSignal</A > — Restart a thread wait on a condition variable</DT ><DT ><A HREF="sdlcondbroadcast.html" >SDL_CondBroadcast</A > — Restart all threads waiting on a condition variable</DT ><DT ><A HREF="sdlcondwait.html" >SDL_CondWait</A > — Wait on a condition variable</DT ><DT ><A HREF="sdlcondwaittimeout.html" >SDL_CondWaitTimeout</A > — Wait on a condition variable, with timeout</DT ></DL ></DIV ><P >SDL provides functions for creating threads, mutexes, semphores and condition variables.</P ><P >In general, you must be very aware of concurrency and data integrity issues when writing multi-threaded programs. Some good guidelines include: <P ></P ><UL ><LI ><P >Don't call SDL video/event functions from separate threads</P ></LI ><LI ><P >Don't use any library functions in separate threads</P ></LI ><LI ><P >Don't perform any memory management in separate threads</P ></LI ><LI ><P >Lock global variables which may be accessed by multiple threads</P ></LI ><LI ><P >Never terminate threads, always set a flag and wait for them to quit</P ></LI ><LI ><P >Think very carefully about all possible ways your code may interact</P ></LI ></UL ></P ><DIV CLASS="NOTE" ><BLOCKQUOTE CLASS="NOTE" ><P ><B >Note: </B >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 ></BLOCKQUOTE ></DIV ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="sdlcdtrack.html" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="sdlcreatethread.html" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >SDL_CDtrack</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="reference.html" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >SDL_CreateThread</TD ></TR ></TABLE ></DIV ></BODY ></HTML >