Mercurial > sdl-ios-xcode

view docs/html/thread.html @ 1120:8e1fde455471

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Patch by me to fix crash described below. --ryan. To: sdl@libsdl.org From: Rainer Deyke <rainerd@eldwood.com> Date: Tue, 16 Aug 2005 01:08:18 -0600 Subject: [SDL] Bug report: SDL_CreateRGBSurface with SDL_HWSURFACE crashes If SDL is in full-screen mode with a hardware video surface on OS X, SDL_CreateRGBSurface with SDL_HWSURFACE crashes. The crash occurs on line 109 of SDL_Surface.c. This was tested on OS X 10.3.9 with both SDL 1.2.8 and the latest CVS. Here is a small C++ program that demonstrates the problem: #include "SDL.h" #include <stdio.h> namespace { void wait_for_key() { SDL_Event e; printf("%d\n", SDL_GetAppState()); while (SDL_WaitEvent(&e)) { if (e.type == SDL_KEYDOWN || e.type == SDL_QUIT) return; } } } int main(int, char *[]) { SDL_Init(SDL_INIT_VIDEO); SDL_Surface *screen = SDL_SetVideoMode(640, 480, 32, SDL_FULLSCREEN | SDL_HWSURFACE); SDL_Surface *s = SDL_CreateRGBSurface(SDL_HWSURFACE, 640, 480, 32, screen->format->Rmask, screen->format->Gmask, screen->format->Bmask, screen->format->Amask); wait_for_key(); if (s) SDL_FreeSurface(s); SDL_Quit(); printf("Success!\n"); return 0; }
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 18 Aug 2005 06:46:32 +0000
parents 355632dca928
children f12379c41042
line wrap: on
line source

<HTML
><HEAD
><TITLE
>Multi-threaded Programming</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="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
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="sdlcdtrack.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdlcreatethread.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><DIV
CLASS="CHAPTER"
><H1
><A
NAME="THREAD"
></A
>Chapter 12. Multi-threaded Programming</H1
><DIV
CLASS="TOC"
><DL
><DT
><B
>Table of Contents</B
></DT
><DT
><A
HREF="sdlcreatethread.html"
>SDL_CreateThread</A
>&nbsp;--&nbsp;Creates a new thread of execution that shares its parent's properties.</DT
><DT
><A
HREF="sdlthreadid.html"
>SDL_ThreadID</A
>&nbsp;--&nbsp;Get the 32-bit thread identifier for the current thread.</DT
><DT
><A
HREF="sdlgetthreadid.html"
>SDL_GetThreadID</A
>&nbsp;--&nbsp;Get the SDL thread ID of a SDL_Thread</DT
><DT
><A
HREF="sdlwaitthread.html"
>SDL_WaitThread</A
>&nbsp;--&nbsp;Wait for a thread to finish.</DT
><DT
><A
HREF="sdlkillthread.html"
>SDL_KillThread</A
>&nbsp;--&nbsp;Gracelessly terminates the thread.</DT
><DT
><A
HREF="sdlcreatemutex.html"
>SDL_CreateMutex</A
>&nbsp;--&nbsp;Create a mutex</DT
><DT
><A
HREF="sdldestroymutex.html"
>SDL_DestroyMutex</A
>&nbsp;--&nbsp;Destroy a mutex</DT
><DT
><A
HREF="sdlmutexp.html"
>SDL_mutexP</A
>&nbsp;--&nbsp;Lock a mutex</DT
><DT
><A
HREF="sdlmutexv.html"
>SDL_mutexV</A
>&nbsp;--&nbsp;Unlock a mutex</DT
><DT
><A
HREF="sdlcreatesemaphore.html"
>SDL_CreateSemaphore</A
>&nbsp;--&nbsp;Creates a new semaphore and assigns an initial value to it.</DT
><DT
><A
HREF="sdldestroysemaphore.html"
>SDL_DestroySemaphore</A
>&nbsp;--&nbsp;Destroys a semaphore that was created by <A
HREF="sdlcreatesemaphore.html"
>SDL_CreateSemaphore</A
>.</DT
><DT
><A
HREF="sdlsemwait.html"
>SDL_SemWait</A
>&nbsp;--&nbsp;Lock a semaphore and suspend the thread if the semaphore value is zero.</DT
><DT
><A
HREF="sdlsemtrywait.html"
>SDL_SemTryWait</A
>&nbsp;--&nbsp;Attempt to lock a semaphore but don't suspend the thread.</DT
><DT
><A
HREF="sdlsemwaittimeout.html"
>SDL_SemWaitTimeout</A
>&nbsp;--&nbsp;Lock a semaphore, but only wait up to a specified maximum time.</DT
><DT
><A
HREF="sdlsempost.html"
>SDL_SemPost</A
>&nbsp;--&nbsp;Unlock a semaphore.</DT
><DT
><A
HREF="sdlsemvalue.html"
>SDL_SemValue</A
>&nbsp;--&nbsp;Return the current value of a semaphore.</DT
><DT
><A
HREF="sdlcreatecond.html"
>SDL_CreateCond</A
>&nbsp;--&nbsp;Create a condition variable</DT
><DT
><A
HREF="sdldestroycond.html"
>SDL_DestroyCond</A
>&nbsp;--&nbsp;Destroy a condition variable</DT
><DT
><A
HREF="sdlcondsignal.html"
>SDL_CondSignal</A
>&nbsp;--&nbsp;Restart a thread wait on a condition variable</DT
><DT
><A
HREF="sdlcondbroadcast.html"
>SDL_CondBroadcast</A
>&nbsp;--&nbsp;Restart all threads waiting on a condition variable</DT
><DT
><A
HREF="sdlcondwait.html"
>SDL_CondWait</A
>&nbsp;--&nbsp;Wait on a condition variable</DT
><DT
><A
HREF="sdlcondwaittimeout.html"
>SDL_CondWaitTimeout</A
>&nbsp;--&nbsp;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
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="sdlcdtrack.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="sdlcreatethread.html"
ACCESSKEY="N"
>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"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>SDL_CreateThread</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>