Re: Reading Serial Port
"clinisbut" <clinisbut@gmail.com> wrote in message
news:418aa539-db6b-49a1-8d17-3343fcd65ef5@s37g2000prg.googlegroups.com...
My OnDestroy:
void CUart3DEMODlg::OnDestroy()
{
CDialog::OnDestroy();
TRACE("Closing port.\n");
pMySerial->PostThreadMessage( WM_MYSERIAL_CLOSE, 0, 0 );
WaitForSingleObject( pMySerial->m_hThread, INFINITE );
TRACE("Port closed.\n");
}
This code looks good....
Debugging, it enters into WM_MY_SERIAL_CLOSE handle (close()), and
reaches
SetEvent( ShutdownEvent );
WaitForSingleObject( pReaderThread->m_hThread, INFINITE );
OK, so it looks like pMySerial has another worker thread (pReaderThread)
that needs to be ended when pMySerial thread is ending? That's what the
above 2 lines say.
Set a breakpoint in pReaderThread that is waiting for ShutdownEvent. Does
it get it? Does it properly exit the thread function when it does get it?
When the thread function is exited, WFSO returns, and
pReaderThread->m_hThread is nomore. You should close its handle:
CloseHandle( pReaderThread->m_hThread);
NOTE: if pReaderThread has the auto-delete TRUE, then you can't access
pReaderThread->m_hThread at this time because it is gone. So you need to
create a temporary HANDLE to cache the thread handle that will be deleted:
// Cache the thread handle so we can call CloseHandle() on it. I'm not
sure if this is allowed,
// or we need to call DuplicateHandle() instead?
HTHREAD hThread = pReaderThread->m_hThread;
SetEvent( ShutdownEvent );
WaitForSingleObject( hThread, INFINITE );
CloseHandle(hThread);
Also, the WM_MY_SERIAL_CLOSE handler does not terminate the pMySerial
thread! You need to add this after pReaderThread has successfully
terminated:
PostThreadMessage (GetCurrentThreadId(), WM_QUIT, 0, 0);
This causes pMySerial thread's message pump to end, which causes the thread
handle (m_hThread) to be destroyed, which causes the WFSO in the "good" code
at the top of this post to return.
The whole handler function then is:
// Cache the thread handle so we can call CloseHandle() on it. I'm not
sure if this is allowed,
// or we need to call DuplicateHandle() instead?
HTHREAD hThread = pReaderThread->m_hThread;
SetEvent( ShutdownEvent );
WaitForSingleObject( hThread, INFINITE );
CloseHandle(hThread);
PostThreadMessage (GetCurrentThreadId(), WM_QUIT, 0, 0);
-- David