view docs/html/thread.html @ 4393:9afe12fb4c41 SDL-1.2

Fixed bug #901 Tim Angus 2009-12-11 11:45:46 PST Disable mouse event generation when state is not SDL_APPMOUSEFOCUS If a Windows SDL application is minimised by using alt-tab, SDL_APPMOUSEFOCUS is lost as part of the minimisation. Unfortunately, the directx driver doesn't pay any attention to this state when generating mouse button events, so clicking on the Desktop can cause mouse clicks in the SDL application, while it's still minimised. The attached patch fixes this. It looks much more complicated than it actually is due to indentation; here it is ignoring whitespace: tma@abraxas:~/sources/SDL-1.2-svn$ svn diff -x -b Index: src/video/windx5/SDL_dx5events.c =================================================================== --- src/video/windx5/SDL_dx5events.c (revision 5376) +++ src/video/windx5/SDL_dx5events.c (working copy) @@ -374,10 +374,9 @@ if ( !(SDL_GetAppState() & SDL_APPMOUSEFOCUS) ) { mouse_lost = 1; ClipCursor(NULL); - } - + } else { /* If the mouse was lost, regain some sense of mouse state */ - if ( mouse_lost && (SDL_GetAppState() & SDL_APPMOUSEFOCUS) ) { + if ( mouse_lost ) { POINT mouse_pos; Uint8 old_state; Uint8 new_state; @@ -548,6 +547,7 @@ if ( xrel || yrel ) { post_mouse_motion(1, xrel, yrel); } + } } /* The main Win32 event handler */
author Sam Lantinga <slouken@libsdl.org>
date Mon, 14 Dec 2009 22:41:31 +0000
parents f12379c41042
children
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>Multi-threaded Programming</TITLE
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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
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>SDL_KillThread</A
>&nbsp;--&nbsp;Gracelessly terminates the thread.</DT
><DT
><A
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>SDL_CreateMutex</A
>&nbsp;--&nbsp;Create a mutex</DT
><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
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>SDL_CreateSemaphore</A
>&nbsp;--&nbsp;Creates a new semaphore and assigns an initial value to it.</DT
><DT
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>SDL_DestroySemaphore</A
>&nbsp;--&nbsp;Destroys a semaphore that was created by <A
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>SDL_CreateSemaphore</A
>.</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
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>SDL_SemWaitTimeout</A
>&nbsp;--&nbsp;Lock a semaphore, but only wait up to a specified maximum time.</DT
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>SDL_SemPost</A
>&nbsp;--&nbsp;Unlock a semaphore.</DT
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>SDL_SemValue</A
>&nbsp;--&nbsp;Return the current value of a semaphore.</DT
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>SDL_CreateCond</A
>&nbsp;--&nbsp;Create a condition variable</DT
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>SDL_DestroyCond</A
>&nbsp;--&nbsp;Destroy a condition variable</DT
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>SDL_CondSignal</A
>&nbsp;--&nbsp;Restart a thread wait on a condition variable</DT
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>SDL_CondBroadcast</A
>&nbsp;--&nbsp;Restart all threads waiting on a condition variable</DT
><DT
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>SDL_CondWait</A
>&nbsp;--&nbsp;Wait on a condition variable</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
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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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>Lock global variables which may be accessed by multiple threads</P
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>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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