[PATCH] user32: Add a timeout when sending WM_WINE_DESTROYWINDOW

[Andrew Eikum]

On Fri, Feb 23, 2018 at 10:11:06AM +0100, Alexandre Julliard wrote:
> Andrew Eikum <aeikum at codeweavers.com> writes:
> 
> > Without this change, the test will deadlock in DestroyWindow waiting
> > for the other thread to process the WM_WINE_DESTROYWINDOW message.
> >
> > Note that this adds about 1 second of runtime to the test, waiting for
> > the SendMessage to time out. Windows does not time out like this.
> > Another option would be to use PostMessage, but that seems like a
> > larger change.
> 
> Your test doesn't deadlock here, and I'm not sure I see why it should,
> since the thread is processing messages. Do you have a backtrace of the
> deadlock?
> 

Backtraces of the two threads below. My understanding is the
DestroyWindow is waiting for the second thread to handle the
WM_WINE_DESTROYWINDOW, while the second thread is waiting for the
first thread to call SetEvent.

Windows doesn't send WM_WINE_DESTROYWINDOW, so DestroyWindow exits and
the test calls SetEvent.

There might be a race condition in the test, if the first thread sends
WM_WINE_DESTROYWINDOW before the PostQuitMessage's WM_QUIT causes the
second thread's event loop to exit. However, it deadlocks every time
for me.

Andrew


Backtracing for thread 002d in process 0008 (Z:\home\aeikum\src\wine\dlls\user32\tests\user32_test.exe):
Backtrace:
=>0 0xf7f9bdb7 __kernel_vsyscall+0x7() in [vdso].so (0x0046f9d8)
  1 0xf7d6383b __libc_read+0x5a() in libpthread.so.0 (0x0046f9d8)
  2 0x7bc7fa27 wait_select_reply+0x66(cookie=0x46fa28) [/home/aeikum/src/wine/dlls/ntdll/server.c:359] in ntdll (0x0046f9d8)
  3 0x7bc81233 server_select+0x252(select_op=0x46fb38, size=0x8, flags=0x2, timeout=(nil)) [/home/aeikum/src/wine/dlls/ntdll/server.c:618] in ntdll (0x0046fb08)
  4 0x7bc888f4 wait_objects+0x83(count=<is not available>, handles=<is not available>, wait_any=<is not available>, alertable=0, timeout=(nil)) [/home/aeikum/src/wine/dlls/ntdll/sync.c:1031] in ntdll (0x0046f
  5 0x7bc8ae77 NtWaitForMultipleObjects+0x36(count=<couldn't compute location>, handles=<couldn't compute location>, wait_any=<couldn't compute location>, alertable=<couldn't compute location>, timeout=<could
  6 0x7b4767dc WaitForMultipleObjectsEx.part+0xcb() in kernel32 (0x0046fde8)
  7 0x7b476ac0 WaitForMultipleObjectsEx+0x3f() in kernel32 (0x0046fe38)
  8 0x7b476b29 WaitForSingleObject+0x38(handle=<couldn't compute location>, timeout=<couldn't compute location>) [/home/aeikum/src/wine/dlls/kernel32/sync.c:128] in kernel32 (0x0046fe78)
  9 0x7eab926e destroy_thread+0x11d() in user32_test (0x0046fed8)
  10 0x7bc8264c call_thread_func_wrapper+0xb() in ntdll (0x0046feec)
  11 0x7bc85c23 call_thread_func+0x102(entry=0x7eab9150, arg=0x0(nil)) [/home/aeikum/src/wine/dlls/ntdll/signal_i386.c:2623] in ntdll (0x0046ffdc)
  12 0x7bc8263e call_thread_entry+0x9() in ntdll (0x0046ffec)

Backtracing for thread 0009 in process 0008 (Z:\home\aeikum\src\wine\dlls\user32\tests\user32_test.exe):
Backtrace:
=>0 0xf7f9bdb7 __kernel_vsyscall+0x7() in [vdso].so (0x0033f4a8)
  1 0xf7d6383b __libc_read+0x5a() in libpthread.so.0 (0x0033f4a8)
  2 0x7bc7fa27 wait_select_reply+0x66(cookie=0x33f4f8) [/home/aeikum/src/wine/dlls/ntdll/server.c:359] in ntdll (0x0033f4a8)
  3 0x7bc81233 server_select+0x252(select_op=0x33f608, size=0x8, flags=0x2, timeout=(nil)) [/home/aeikum/src/wine/dlls/ntdll/server.c:618] in ntdll (0x0033f5d8)
  4 0x7bc888f4 wait_objects+0x83(count=<is not available>, handles=<is not available>, wait_any=<is not available>, alertable=0, timeout=(nil)) [/home/aeikum/src/wine/dlls/ntdll/sync.c:1031] in ntdll (0x0033f
  5 0x7bc8ae77 NtWaitForMultipleObjects+0x36(count=<couldn't compute location>, handles=<couldn't compute location>, wait_any=<couldn't compute location>, alertable=<couldn't compute location>, timeout=<could
  6 0x7b4767dc WaitForMultipleObjectsEx.part+0xcb() in kernel32 (0x0033f8b8)
  7 0x7b476ac0 WaitForMultipleObjectsEx+0x3f() in kernel32 (0x0033f908)
  8 0x7e12b0fb X11DRV_MsgWaitForMultipleObjectsEx+0x9a(count=<couldn't compute location>, handles=<couldn't compute location>, timeout=<couldn't compute location>, mask=<couldn't compute location>, flags=<cou
  9 0x7e8c76eb wait_message+0x3a() in user32 (0x0033f9c8)
  10 0x7e89000f wait_message_reply+0xbe(flags=<is not available>) [/home/aeikum/src/wine/dlls/user32/message.c:3035] in user32 (0x0033fab8)
  11 0x7e8903ac send_inter_thread_message+0x6b(info=0x33fb60, res_ptr=0x33fb28) [/home/aeikum/src/wine/dlls/user32/message.c:3213] in user32 (0x0033faf8)
  12 0x7e8906b2 send_message+0x161(info=0x33fb60, res_ptr=0x33fb5c, unicode=<is not available>) [/home/aeikum/src/wine/dlls/user32/message.c:3281] in user32 (0x0033fb48)
  13 0x7e8909cd SendMessageW+0x6c(hwnd=<couldn't compute location>, msg=<couldn't compute location>, wparam=<couldn't compute location>, lparam=<couldn't compute location>) [/home/aeikum/src/wine/dlls/user32/
  14 0x7e8bad2e WIN_DestroyWindow+0xbd(hwnd=0x30056) [/home/aeikum/src/wine/dlls/user32/win.c:974] in user32 (0x0033fc68)
  15 0x7e8bab84 DestroyWindow+0x263(hwnd=<couldn't compute location>) [/home/aeikum/src/wine/dlls/user32/win.c:1911] in user32 (0x0033fca8)
  16 0x7eabc669 func_win+0x2888() [/home/aeikum/src/wine/dlls/user32/tests/win.c:10520] in user32_test (0x0033fdb8)
  17 0x7ea0cfee main+0x2fd(argc=<is not available>, argv=<is not available>) [/home/aeikum/src/wine/dlls/user32/tests/../../../include/wine/test.h:603] in user32_test (0x0033fe78)
  18 0x7eac3211 __wine_spec_exe_entry+0x70(peb=<couldn't compute location>) [/home/aeikum/src/wine/dlls/winecrt0/exe_entry.c:36] in user32_test (0x0033feb8)
  19 0x7b463a9c call_process_entry+0xb() in kernel32 (0x0033fed8)
  20 0x7b465578 start_process+0x1c7(entry=<couldn't compute location>, peb=<couldn't compute location>) [/home/aeikum/src/wine/dlls/kernel32/process.c:1098] in kernel32 (0x0033ffd8)
  21 0x7b463aaa start_process_wrapper+0x9() in kernel32 (0x0033ffec)
0xf7f70db7 __kernel_vsyscall+0x7 in [vdso].so: int»·····$0x80