view docs/html/thread.html @ 4324:1496aa09e41e SDL-1.2

Steven Noonan to sdl While trying to build the SDLMain.m included with SDL 1.2.14, with #define SDL_USE_NIB_FILE 1: /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m: In function '-[SDLMain fixMenu:withAppName:]': /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m:122: warning: 'sizeToFit' is deprecated (declared at /Developer/SDKs/MacOSX10.6.sdk/System/Library/Frameworks/AppKit.framework/Headers/NSMenu.h:281) /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m: In function 'main': /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m:376: warning: 'poseAsClass:' is deprecated (declared at /Developer/SDKs/MacOSX10.6.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:127) /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m:376: error: 'poseAsClass:' is unavailable (declared at /Developer/SDKs/MacOSX10.6.sdk/System/Library/Frameworks/Foundation.framework/Headers/NSObject.h:127) /Users/steven/Development/darwinia/targets/macosx/Darwinia/SDLMain.m:377: warning: passing argument 2 of 'NSApplicationMain' from incompatible pointer type Eric Wing to Sam I don't have time today to look at this in detail, but the problem is definitely the poseAsClass: method. This was deprecated in Obj-C 2.0 and not retained in 64-bit. I've never used this method and it has always been limited to esoteric uses. I think this is why Apple wanted to dump it (among complicating some other things they do). I have read about others getting bit by this when migrating. Long story short, there really isn't a migration path for this method. The question that then must be asked is why are we using it (what does it accomplish), and then figure out the 'proper' way of accomplishing that. Glancing at SDLMain.m, it's not obvious to me why it is there or what it is really accomplishing. My only speculation is that NSApplicationMain hardcodes something to look for NSApplication and a subclass (SDLApplication) fails for some reason (assuming that the original coder did this for good reason). Three thoughts come to mind. 1) The Info.plist has properties to control things related to the startup class and nib. NSPrincipalClass, NSMainNibFile Maybe principle class needs to be SDLApplication and we can delete the poseAs 2) I was told that 10.6 introduced new APIs to make programatic NIB wrangling and avoidance easier. Unfortunately, I don't know the specifics. 3) Instead of subclassing NSApplication in SDLMain.m, maybe we can just add a category. It looks like the following is the only thing that is done (quick glance): @interface SDLApplication : NSApplication @end @implementation SDLApplication /* Invoked from the Quit menu item */ - (void)terminate:(id)sender { /* Post a SDL_QUIT event */ SDL_Event event; event.type = SDL_QUIT; SDL_PushEvent(&event); } @end So instead, we change this to: (warning written in mail and untested) @interface NSApplication (SDLApplication) - (void) terminate:(id)sender; @end @implementation NSApplication (SDLApplication) /* Invoked from the Quit menu item */ - (void)terminate:(id)sender { /* Post a SDL_QUIT event */ SDL_Event event; event.type = SDL_QUIT; SDL_PushEvent(&event); } @end Then everywhere SDLApplication is used, we change it to NSApplication (and remove the poseAsClass line). Perhaps you could ask the bug reporter to try this solution (#3). And if that fails, maybe try #1. -Eric Steven Noonan to Sam The suggested change (diff below) seems to work fine. - Steven
author Sam Lantinga <slouken@libsdl.org>
date Mon, 12 Oct 2009 21:07:12 +0000
parents f12379c41042
children
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>Chapter 12. Multi-threaded Programming</H1
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>Table of Contents</B
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><DT
><A
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>SDL_CreateThread</A
>&nbsp;--&nbsp;Creates a new thread of execution that shares its parent's properties.</DT
><DT
><A
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>SDL_ThreadID</A
>&nbsp;--&nbsp;Get the 32-bit thread identifier for the current thread.</DT
><DT
><A
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>SDL_GetThreadID</A
>&nbsp;--&nbsp;Get the SDL thread ID of a SDL_Thread</DT
><DT
><A
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>SDL_WaitThread</A
>&nbsp;--&nbsp;Wait for a thread to finish.</DT
><DT
><A
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>SDL_KillThread</A
>&nbsp;--&nbsp;Gracelessly terminates the thread.</DT
><DT
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>SDL_CreateMutex</A
>&nbsp;--&nbsp;Create a mutex</DT
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>SDL_DestroyMutex</A
>&nbsp;--&nbsp;Destroy a mutex</DT
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>SDL_mutexP</A
>&nbsp;--&nbsp;Lock a mutex</DT
><DT
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>SDL_mutexV</A
>&nbsp;--&nbsp;Unlock a mutex</DT
><DT
><A
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>SDL_CreateSemaphore</A
>&nbsp;--&nbsp;Creates a new semaphore and assigns an initial value to it.</DT
><DT
><A
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>SDL_DestroySemaphore</A
>&nbsp;--&nbsp;Destroys a semaphore that was created by <A
HREF="sdlcreatesemaphore.html"
>SDL_CreateSemaphore</A
>.</DT
><DT
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>SDL_SemWait</A
>&nbsp;--&nbsp;Lock a semaphore and suspend the thread if the semaphore value is zero.</DT
><DT
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>SDL_SemTryWait</A
>&nbsp;--&nbsp;Attempt to lock a semaphore but don't suspend the thread.</DT
><DT
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>SDL_SemWaitTimeout</A
>&nbsp;--&nbsp;Lock a semaphore, but only wait up to a specified maximum time.</DT
><DT
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>SDL_SemPost</A
>&nbsp;--&nbsp;Unlock a semaphore.</DT
><DT
><A
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>SDL_SemValue</A
>&nbsp;--&nbsp;Return the current value of a semaphore.</DT
><DT
><A
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>SDL_CreateCond</A
>&nbsp;--&nbsp;Create a condition variable</DT
><DT
><A
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>SDL_DestroyCond</A
>&nbsp;--&nbsp;Destroy a condition variable</DT
><DT
><A
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>SDL_CondSignal</A
>&nbsp;--&nbsp;Restart a thread wait on a condition variable</DT
><DT
><A
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>SDL_CondBroadcast</A
>&nbsp;--&nbsp;Restart all threads waiting on a condition variable</DT
><DT
><A
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>SDL_CondWait</A
>&nbsp;--&nbsp;Wait on a condition variable</DT
><DT
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>SDL_CondWaitTimeout</A
>&nbsp;--&nbsp;Wait on a condition variable, with timeout</DT
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><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
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>Don't call SDL video/event functions from separate threads</P
></LI
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>Don't use any library functions in separate threads</P
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>Don't perform any memory management in separate threads</P
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><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
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>Think very carefully about all possible ways your code may interact</P
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>Note: </B
>SDL's threading is not implemented on MacOS, due to that lack of preemptive thread support (Mac OS X dos nt suffer from this problem)</P
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