------------------ Original ------------------
Date: Sat, Dec 13, 2014 11:32 PM
To: "Changhui Liu"<liuchanghui@linuxdeepin.com>;
Cc: "wine-devel"<wine-devel@winehq.org>;
Subject: Re: ole32:fix CoWaitForMultipleHandles cause RPC hang
Hi,
On 13.12.2014 16:15, Changhui Liu wrote:
> Hi Sebastian,
>
>
> I tested your current work-in-progress patch:
> https://github.com/wine-compholio/wine-staging/blob/master/patches/ole32-CoWaitForMultipleHandles/0001-ole32-tests-Add-additional-tests-for-CoWaitForMultip.patch
>
> I have two puzzles about these code:
>> index = 0xdeadbeef;
>> PostMessageA(hWnd, WM_DDE_FIRST, 0, 0);
>> PostQuitMessage(44);
>> thread = CreateThread(NULL, 0, post_message_thread, hWnd, 0, &tid);
>> ok(thread != NULL, "CreateThread failed, error %u\n", GetLastError());
>> hr = CoWaitForMultipleHandles(0, 100, 2, handles, &index);
>> ok(hr == RPC_S_CALLPENDING, "expected RPC_S_CALLPENDING, got 0x%08x\n", hr);
>> ok(index == 0 || broken(index == 0xdeadbeef) /* Win 8 */, "expected index 0, got %u\n", index);
>> success = PeekMessageA(&msg, hWnd, WM_DDE_FIRST, WM_DDE_FIRST, PM_REMOVE);
>> ok(success, "PeekMessageA failed, error %u\n", GetLastError());
>
>
> The first, why use the PeekMessage to check if received a WM_DDE_FIRST message?
> Is there an real application do like that way?
Of course there are multiple ways to test for window messages in the message queue, I just picked PeekMessageA because it doesn't require setting up a Wndproc.
>
>
> In fact CoWaitForMultipleHandles has a message loop, the WM_DDE_FIRST message has been
> dispatched to the window's WNDPROC. So the PeekMessageA certainly failed.
No, it doesn't. Feel free to run the tests yourself on a Windows machine, I have tested them with the Wine testbot and all tests pass on 2000/XP/Vista/8/2008/... - which means that Windows does not process all WM_DDE_FIRST messages.
This is also why I am unsure about how to fix it. When changing the behaviour in order to fix one of the tests which fails in Wine (marked with todo_wine), it breaks other tests which were working well before.
>
>
> I think the correct test should be this:
> 1, Define a custom WNDPROC function named cowait_test_wnd_proc .
> 2, Define a global int variable named g_count_of_wm_dde_first.
> 3, Set the value of g_count_of_wm_dde_first to zero before call CoWaitForMultipleHandles.
> 4, Increase the value of g_count_of_wm_dde_first by one, once received a WM_DDE_FIRST message in cowait_test_wnd_proc.
> 5, Check if the value of g_count_of_wm_dde_first is equal to 2 after CoWaitForMultipleHandles returned.
>
This testing method would also be fine, but you would get 1 instead of 2. My patch doesn't show any test failures on Windows, which means that one of the WM_DDE_FIRST messages is still in the queue.
>
> The second is why use todo_wine ?
> todo_wine
> ok(!success, "PeekMessageA succeeded\n");
> why not just write?
> ok(!success, "PeekMessageA succeeded\n");
>
The Wine coding guideline does not allow to add new test failures, instead all tests which do not pass yet have to be marked with "todo_wine". This makes easily visible which tests need further work just by looking at the source code, moreover it avoids introducing regressions (breaking tests which were working well before). Take a look at some of the other Wine tests, this is not the only place where its used.
>
>
>
> Thank you.
Regards,
Sebastian