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Hi
I have the following...
<br />
vector<HANDLE> handles;<br />
handles.push_back(CreateMutex(NULL , FALSE , "A"));<br />
handles.push_back(CreateMutex(NULL , FALSE , "B"));<br />
<br />
WaitForMultipleObjects(handles.size() , (const HANDLE*)(&handles) , TRUE , INFINITE);<br />
Basically, the Wait doesn't. I replaced the vectors with an array of handles
<br />
HANDLE handles[2];<br />
handles[0] = CreateMutex(NULL , FALSE , "A");<br />
handles[1] = CreateMutex(NULL , FALSE , "B");<br />
<br />
WaitForMultipleObjects(2 , handles , TRUE , INFINITE);<br />
and it works a treat. It's obviously me, I'm new to STL - I reckon it's the cast to the second param of WaitForMultipleObjects.
Thanks for any input...
Cheers
Angel1058
*********************************************
The sooner you fall behind, the longer you have to catch up.
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Try:
WaitForMultipleObjects(handles.size() , &handles[0], TRUE , INFINITE);
My programming blahblahblah blog. If you ever find anything useful here, please let me know to remove it.
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 Many thanks. Easy when you know how....and now I do.
Angel1058
*********************************************
The sooner you fall behind, the longer you have to catch up.
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I have been tasked to update a WTL program. The program creates many modeless windows, the windows are created with style pop-up and the parent for the window is set to NULL in the create call. The main problem is the tabbing order on the modeless windows is not working. I have verified the VK_TAB message arrives in the main dialog(pretranslate message function) that created the modeless dialogs. How do I go about forwarding the message to the appropriate dialog, or is there a simpler solution to make the tabbing work? I have never had to work with the tabbing msgs before and it all seems a bit mysterious what is really going on.
TIA
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Try something like this:
virtual BOOL PreTranslateMessage(MSG* pMsg)
{
if (pMsg->message == WM_KEYDOWN && pMsg->wParam == VK_TAB)
return m_dlgChild.PreTranslateMessage(pMsg);
}
Then in your child dialog message handler you handle it.
Igor.
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Each modeless window (I assume they're all dialogs?) should derive from CMessageFilter and override the PreTranslateMessage() method. The PreTranslateMessage() would do:
BOOL CYourWindow::PreTranslateMessage ( MSG* pMsg )
{
return IsDialogMessage ( pMsg );
}In each window's OnInitDialog(), register for pre-translate calls with:
CMessageLoop* pLoop = _Module.GetMessageLoop();
ATLASSERT(pLoop != NULL);
pLoop->AddMessageFilter ( this ); Look at the wizard-generated CMainFrame::OnCreate() if this part is still unclear.
--
I'm Michael Dunn and I approve this post.
Vote Trogdor in oh-four!
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This is more of a visual studio problem than ATL/WTL, I suspect. I have a project that builds a COM client. When I try to open the .rc file, it tells me it can't open atlres.h, one of the include files. However, I can compile and build without any problem (the proper include directory is in the build path). Furthermore, if I edit the .rc file in the text editor and right-click atlres.h at the location of the include statement to try and open it, i get a error messagebox telling my it can't find the file and open it... BUT, it also displays the entire build path and that path includes the directory with atlres.h!!!!
Arg! What's going on? Why can't if find that file during editing, but it can during the compile?
Thanks for any thoughts,
Matt
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do u hav WTL installed and its path configured properly with VC++ IDE
-------------------------
Have a great day ahead!
Regards,
Sohail Kadiwala
(My COM Blog - http://lovecom.blogspot.com)
modified 21-Apr-21 21:01pm.
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Figured it out. I had all proper paths specified under the Project Properties, but not in the Options sections (Tools -> Options). Seems like it shouldn't matter and VS should have been able to find the file, but obviously is couldn't.
Matt
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Good
I was talking about the same "Options sections" settings for WTL.
-------------------------
Have a great day ahead!
Regards,
Sohail Kadiwala
(My COM Blog - http://lovecom.blogspot.com)
modified 21-Apr-21 21:01pm.
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Is it possible to make a list view single selection at runtime or does LVS_SINGLESEL have to be set when you create the control?
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Use CWindow::ModifyStyle():
CWindow wndList = GetDlgItem ( IDC_YOUR_LIST );
wndList.ModifyStyle ( LVS_SINGLESEL, 0 );
--
I'm Michael Dunn and I approve this post.
Vote Trogdor in oh-four!
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Hi,
I am writing a very simple ATL in-proc server to experience the STA mechanism.
My code is like that:
1) I defined an interface called IEcho, which has only one function called Echo(DWORD).
2) I implemeted this interface in coclass CoEcho,
which has a data member named "m_nNumber" with type "long" and which implements Echo(DWORD) as the following:
///------------------------------------------
ATLTRACE("%ld enter\n", GetCurrentThreadId());
this->m_nNumber = number;
Sleep(1000);
//!!!!! NOTICE THIS STAEMENT
//MessageBox(NULL, _T("WAIT"), _T("WAIT"), 0);
//!!!!!
ATLTRACE("the number passed in: %ld\n",
this->m_nNumber);
ATLTRACE("%ld leave\n", GetCurrentThreadId());
return S_OK;
///----------------------------------------------
3) Then, I create a STA Client, which creates a IEcho instance, marshals it and passes it to two threads sharing the same thread function.
the STA Client is like:
//------------------THREAD FUNCTION-----
//it is very simple
DWORD WINAPI ThreadFunc(LPVOID lpara){
CoInitialize(NULL);
IStream * pStream =(IStream*)lpara;
IEcho *pEcho;
CoGetInterfaceAndReleaseStream(pStream,
IID_IEcho,
(LPVOID*)&pEcho);
pEcho->Echo(GetCurrentThreadId());
pEcho->Release();
CoUninitialize();
return 0;
}
int _tmain(int argc, _TCHAR* argv[])
{
CoInitialize(NULL);
IEcho * pEcho = NULL;
CoCreateInstance(CLSID_CoEcho, NULL,
CLSCTX_ALL, IID_IEcho,
(void **)&pEcho);
IStream * t1stream;
IStream * t2stream;
CoMarshalInterThreadInterfaceInStream(IID_IEcho,
pEcho, &t1stream);
HANDLE hThread1 = CreateThread(NULL, 0,
ThreadFunc, t1stream, 0, NULL);
CoMarshalInterThreadInterfaceInStream(IID_IEcho,
pEcho, &t2stream);
HANDLE hThread2 = CreateThread(NULL, 0,
ThreadFunc, t2stream, 0, NULL);
//message pump
MSG ms;
while(GetMessage(&ms, 0, 0, 0)){
TranslateMessage(&ms);
DispatchMessage(&ms);
}
WaitForSingleObject(hThread1, INFINITE);
WaitForSingleObject(hThread2, INFINITE);
CloseHandle(hThread1);
CloseHandle(hThread2);
pEcho->Release();
CoUninitialize();
return 0;
}
///
What I am expecting is that though two threads may call IEcho simultaneously with different thread ids, the data member "m_nNumber" of CoEcho should be well protected by COM STA since only one thread can enter IEcho::Echo function.
for examle, if main thread id is 3, the first thread's id is 1 and the second 2, the ECHO should output:
3 enter
the number passed in 1
3 leave
3 enter
the number passed in 2
3 leave
It works well
But if I have the statement
MessageBox(NULL, _T("WAIT"), _T("WAIT"), 0);
added, m_nNumber is damaged.
the output is something like:
//thread 1 in
3 enter
//thread 2 in?
3 enter <--- it should not be that, only one
thread can be here!!!
the number passed in 2 // thread 1's id is lost
....
I am very confused by that.
Any explaination?
Thanks a lot in advanced!
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duckpond wrote:
Any explaination?
COM uses a hidden window's message queue to synchronize the calls towards the objects of an STA. It seems that when it hits MessageBox(NULL, ...), the hidden window's procedure must retreive and dispatch messages by itself; this makes it reentrant and thus the main apartment - which holds pEcho - unblocks, allowing the second call of Echo to execute.
It is, in essence, equivalent with a cross-apartment call.
"though nothing
will keep us together
we can beat them
for ever and ever"
rechi
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Thanks Rechi  I got it.
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May I recommend the book Essential COM by Don Box? IIRC, this reentrancy behaviour is described in it. To summarize: objects living in an STA need not prepare itself for concurrency, but it should prepare itself for reentrancy, as your example shows.
Essential COM is a really good read, and a must for COM developers IMHO.
--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.
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Since we don't have OLE DB forum I think ATL is pretty close.
So!
I got a prob. I'm using a recordset with CDynamicAccessor.
when I close it it crashes in here:
in ATLDBCLI.H
<br />
class CAccessorBase<br />
.....<br />
HRESULT ReleaseAccessors(IUnknown* pUnk)<br />
{<br />
ATLASSERT(pUnk != NULL);<br />
HRESULT hr = S_OK;<br />
if (m_nAccessors > 0)<br />
{<br />
CComPtr<IAccessor> spAccessor;<br />
hr = pUnk->QueryInterface(IID_IAccessor, (void**)&spAccessor);<br />
if (SUCCEEDED(hr))<br />
{<br />
ATLASSERT(m_pAccessorInfo != NULL);<br />
for (ULONG i = 0; i < m_nAccessors; i++)<br />
spAccessor->ReleaseAccessor(m_pAccessorInfo[i].hAccessor, NULL);<br />
}<br />
m_nAccessors = 0;<br />
delete [] m_pAccessorInfo;
m_pAccessorInfo = NULL;<br />
}<br />
return hr;<br />
}<br />
Why that delete fails? I mean this code allocates it why can't it delete?
The only other note is that I put my code that uses this in a regular windows DLL. Could that be a prob?
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inner wrote:
The only other note is that I put my code that uses this in a regular windows DLL. Could that be a prob?
Yes that could be the problem. Make sure your app and DLL links against the same C runtime library. If they don't, then they will get separate heaps. The heap is where memory is allocated from by using new, and returned to when deallocated using delete. If you allocate memory in the DLL, and delete it in the app, then errors will occur if they do not share the same heap.
--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.
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Need suggestions for the problem preferrably in VC6:
There are two machines A and B. A telnet(or SSH) to B.On logged in to B, B should give it's own window in Machine A. That is, B should be the owner of window in A.
If it is something to do with XWindows or Xterm, I am not clear how exactly to hit the problem.
I hate that lazy Java
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i am working on a project which needs vc7 specific dlls ( atl71.dll msvcr71.dll etc) which i need to ship to the client thro the setup.
Since these dlls are not registered where should my setup register / copy these dlls so that my code uses them. if these are not COM dlls then how do they get referenced when any piece of code uses them?
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Same directory as the binary or a directory which is in the PATH environment variable, C:\Windows[\system32]. I'd opt for same directory as binary, just to make sure no other app replaces your dll's.
--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.
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Installing anything into windows and/or system32 is discouraged these days, because it leads to DLL Hell™. Installing into the app dir, and creating a APPNAME.exe.local file is the way to go on Win2K+.
--
I'm Michael Dunn and I approve this post.
Vote Trogdor in oh-four!
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What's the .local file for? 
--
Weiter, weiter, ins verderben.
Wir müssen leben bis wir sterben.
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In short, it tells the OS to load DLLs from the EXE's directory if they exist there, before searching the normal path for DLLs. More info here[^]
--
I'm Michael Dunn and I approve this post.
Vote Trogdor in oh-four!
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