To better understand this question, refer to my earlier question:
C++ MSAPI 5: SetNotifyCallbackFunction not working
In Microsoft SAPI, in order to deliver the text-to-speech events when you are using the SetNotifyCallbackFunction
you need to create a message pump, below is the code.
Now my problem is that I need the message pump to be done asynchronously. I have tried the std::thread, pthread and the boost library. But whenever I put the message pump in another thread. The pump failed. It is also the case whenever I tried calling the Speak
in another thread. How can I solve this? Again my goal is to make the MSAPI speak asynchronously with events.
to call the message pump:
HANDLE hWait = pV->SpeakCompleteEvent();
WaitAndPumpMessagesWithTimeout(hWait, INFINITE);
the actual message pump code:
HRESULT WaitAndPumpMessagesWithTimeout(HANDLE hWaitHandle, DWORD dwMilliseconds)
{
HRESULT hr = S_OK;
BOOL fContinue = TRUE;
while (fContinue)
{
DWORD dwWaitId = ::MsgWaitForMultipleObjectsEx(1, &hWaitHandle, dwMilliseconds, QS_ALLINPUT, MWMO_INPUTAVAILABLE);
switch (dwWaitId)
{
case WAIT_OBJECT_0:
{
fContinue = FALSE;
}
break;
case WAIT_OBJECT_0 + 1:
{
MSG Msg;
while (::PeekMessage(&Msg, NULL, 0, 0, PM_REMOVE))
{
::TranslateMessage(&Msg);
::DispatchMessage(&Msg);
}
}
break;
case WAIT_TIMEOUT:
{
hr = S_FALSE;
fContinue = FALSE;
}
break;
default:// Unexpected error
{
fContinue = FALSE;
hr = E_FAIL;
}
break;
}
}
return hr;
}
I forgot to answer my own question yesterday. But I'll give credit to Eric Brow
First off, my purpose in doing the asynch event is it will be used as a library for other language.
What I have researched yesterday was like what Eric said, all SAPI interaction must occur on the same thread. Therefore, I solve this by creating a class that is derive from CWinThread which also has the SAPI functionalities. Then I let the wrapper functions interact with the derived CWinThread class.
Source: http://www.codeproject.com/Articles/551/Using-User-Interface-Threads