view docs/html/thread.html @ 571:8e3ce997621c

Date: Thu, 16 Jan 2003 13:48:31 +0200 From: "Mike Gorchak" Subject: All QNX patches whole patches concerning QNX. Almost all code has been rewritten by Julian and me. Added initial support for hw overlays in QNX and many many others fixes. P.S. This patches has been reviewed by Dave Rempel from QSSL and included in SDL 1.2.5 distribution, which coming on 3rd party CD for newest 6.2.1 version of QNX, which will be available soon.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 20 Jan 2003 01:38:37 +0000
parents e5bc29de3f0a
children 355632dca928
line wrap: on
line source

<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
> &#8212; Creates a new thread of execution that shares its parent's properties.</DT
><DT
><A
HREF="sdlthreadid.html"
>SDL_ThreadID</A
> &#8212; Get the 32-bit thread identifier for the current thread.</DT
><DT
><A
HREF="sdlgetthreadid.html"
>SDL_GetThreadID</A
> &#8212; Get the SDL thread ID of a SDL_Thread</DT
><DT
><A
HREF="sdlwaitthread.html"
>SDL_WaitThread</A
> &#8212; Wait for a thread to finish.</DT
><DT
><A
HREF="sdlkillthread.html"
>SDL_KillThread</A
> &#8212; Gracelessly terminates the thread.</DT
><DT
><A
HREF="sdlcreatemutex.html"
>SDL_CreateMutex</A
> &#8212; Create a mutex</DT
><DT
><A
HREF="sdldestroymutex.html"
>SDL_DestroyMutex</A
> &#8212; Destroy a mutex</DT
><DT
><A
HREF="sdlmutexp.html"
>SDL_mutexP</A
> &#8212; Lock a mutex</DT
><DT
><A
HREF="sdlmutexv.html"
>SDL_mutexV</A
> &#8212; Unlock a mutex</DT
><DT
><A
HREF="sdlcreatesemaphore.html"
>SDL_CreateSemaphore</A
> &#8212; Creates a new semaphore and assigns an initial value to it.</DT
><DT
><A
HREF="sdldestroysemaphore.html"
>SDL_DestroySemaphore</A
> &#8212; Destroys a semaphore that was created by <A
HREF="sdlcreatesemaphore.html"
>SDL_CreateSemaphore</A
>.</DT
><DT
><A
HREF="sdlsemwait.html"
>SDL_SemWait</A
> &#8212; Lock a semaphore and suspend the thread if the semaphore value is zero.</DT
><DT
><A
HREF="sdlsemtrywait.html"
>SDL_SemTryWait</A
> &#8212; Attempt to lock a semaphore but don't suspend the thread.</DT
><DT
><A
HREF="sdlsemwaittimeout.html"
>SDL_SemWaitTimeout</A
> &#8212; Lock a semaphore, but only wait up to a specified maximum time.</DT
><DT
><A
HREF="sdlsempost.html"
>SDL_SemPost</A
> &#8212; Unlock a semaphore.</DT
><DT
><A
HREF="sdlsemvalue.html"
>SDL_SemValue</A
> &#8212; Return the current value of a semaphore.</DT
><DT
><A
HREF="sdlcreatecond.html"
>SDL_CreateCond</A
> &#8212; Create a condition variable</DT
><DT
><A
HREF="sdldestroycond.html"
>SDL_DestroyCond</A
> &#8212; Destroy a condition variable</DT
><DT
><A
HREF="sdlcondsignal.html"
>SDL_CondSignal</A
> &#8212; Restart a thread wait on a condition variable</DT
><DT
><A
HREF="sdlcondbroadcast.html"
>SDL_CondBroadcast</A
> &#8212; Restart all threads waiting on a condition variable</DT
><DT
><A
HREF="sdlcondwait.html"
>SDL_CondWait</A
> &#8212; Wait on a condition variable</DT
><DT
><A
HREF="sdlcondwaittimeout.html"
>SDL_CondWaitTimeout</A
> &#8212; 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
>