At 07:55 AM 5/10/00 -0500, you wrote:
>Interesting, I did try this with some debug messages. Although I was using
>+toolbar,+menus,+tab,+win at the time. And also have run in managed mode
>with the debug messages. I did worry that the patch may cause the program to
>deadlock but saw no sign of it from my testing.
>
>The specific problem the patch address is that during window destruction it
>is possible for a ConfigureNotify event to come in. If that messages is
>timed right then the HWND pointer points to a valid window when ProcessEvent
>is called. Then the thread destroying the window proceeds in deleting the
>WND structure for the HWND. In the event processing loop, ConfigureNotify is
>called and then EVENT_QueryZOrder.
>
>In QueryZOrder we get the WND pointer for the HWND but because the HWND is
>now invalid we receive NULL. When we try to do X11DRV_WND_GetXWindow with
>that we get null and then X dumps out with an error message.
>
>Placing the event processing inside the critical section seemed like a
>logical fix., but maybe another one needs to be found.
>
Maybe.
Here is a trace generated; it starts in a call to MessageBox
I have added a few trace to better understand what is happening.
I am not sure at all, but my guess is that your change don't take
in account it's possible to explicitly release the locks by
WIN_SuspendWndLocks
Gerard
trace:win:ShowWindow hwnd=012c, cmd=1
trace:relay:WINPROC_CallWndProc
(wndproc=0x4018b87c,hwnd=0000012c,msg=WM_SHOWWINDOW,wp=00000001,lp=00000000)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:relay:WINPROC_CallWndProc
(wndproc=0x401a148c,hwnd=0000012c,msg=WM_SHOWWINDOW,wp=00000001,lp=00000000)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:SetWindowPos hwnd 012c, swp (0,0)-(0,0) flags 00000063
trace:win:SetWindowPos current (200,130)-(628,218), style 84c80082
trace:win:SetWindowPos before winposchanging for thread 807ba38 bChangePos = 1
trace:relay:WINPROC_CallWndProc
(wndproc=0x4018b87c,hwnd=0000012c,msg=WM_WINDOWPOSCHANGING,wp=00000000,lp=40bd637c)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:relay:WINPROC_CallWndProc
(wndproc=0x401a148c,hwnd=0000012c,msg=WM_WINDOWPOSCHANGING,wp=00000000,lp=40bd637c)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:SetWindowPos after winposchaning for thread 807ba38, bChangePos=1
warn:win:SWP_DoOwnedPopups (012c) hInsertAfter = 0000
trace:relay:WINPROC_CallWndProc
(wndproc=0x4018b87c,hwnd=0000012c,msg=WM_NCCALCSIZE,wp=00000001,lp=40bd6224)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:relay:WINPROC_CallWndProc
(wndproc=0x401a148c,hwnd=0000012c,msg=WM_NCCALCSIZE,wp=00000001,lp=40bd6224)
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:WIN_RestoreWndsLock thread=807ba38
trace:win:WINPOS_SendNCCalcSize 200,130-628,218
trace:x11:TSXReconfigureWMWindow Call XReconfigureWMWindow
Here the service thread is coming to play.
trace:timer:SERVICE_Loop Wait returned: 2, thread=80784b8
trace:event:EVENT_ProcessAllEvents called (thread 80784b8).
trace:timer:SERVICE_Loop Waiting for 3 objects
Return to the main thread.
trace:x11:TSXReconfigureWMWindow Ret XReconfigureWMWindow
trace:x11:TSXMapWindow Call XMapWindow
trace:x11:TSXMapWindow Ret XMapWindow
trace:win:WIN_SuspendWndsLock thread=807ba38
trace:event:X11DRV_EVENT_Synchronize called (thread 807ba38).
trace:x11:TSXSync Call XSync
Service thread again.
trace:timer:SERVICE_Loop Wait returned: 2, thread=80784b8
trace:event:EVENT_ProcessAllEvents called (thread 80784b8).
trace:event:EVENT_ProcessEvent called thread=80784b8.
trace:event:EVENT_ProcessEvent returns.
trace:event:EVENT_ProcessEvent called thread=80784b8.
trace:x11:TSXFindContext Call XFindContext
trace:x11:TSXFindContext Ret XFindContext
trace:event:EVENT_ProcessEvent Got event ConfigureNotify for hwnd 012c
trace:win:EVENT_ConfigureNotify 012c moving from (200,130) to (367,437)
This is the special call to SetWindowPos for the 'flying windows' (flag 80000000)
trace:win:SetWindowPos hwnd 012c, swp (367,437)-(795,525) flags 80000015
trace:win:SetWindowPos current (200,130)-(628,218), style 94c80082
trace:win:SetWindowPos before winposchanging for thread 80784b8 bChangePos = 0
Note that I have added a trace after this SetWindowPos; it is not called
so this SetWindowPos don't return before the crash.
trace:win:WIN_SuspendWndsLock thread=80784b8
trace:x11:TSXSync Ret XSync
The main thread comes back.
trace:event:X11DRV_EVENT_Synchronize after XSync (thread 807ba38).
trace:event:EVENT_ProcessAllEvents called (thread 807ba38).
trace:event:EVENT_ProcessEvent called thread=807ba38.
trace:x11:TSXFindContext Call XFindContext
trace:x11:TSXFindContext Ret XFindContext
trace:event:EVENT_ProcessEvent Got event MapNotify for hwnd 012c
trace:event:EVENT_ProcessEvent returns.
trace:event:EVENT_ProcessEvent called thread=807ba38.
trace:x11:TSXFindContext Call XFindContext
trace:x11:TSXFindContext Ret XFindContext
trace:event:EVENT_ProcessEvent Got event Expose for hwnd 012c
Call user32.426: RedrawWindow(0000012c,40bd60f8,00000000,00000685) ret=40729007 fs=0247
err:win32:SYSLEVEL_CheckNotLevel (2): Holding lock of level 2!
Bang...
