// Block and wait for the next debug event from the debuggee process.
BOOL DbgTransportPipeline::WaitForDebugEvent(DEBUG_EVENT * pEvent, DWORD dwTimeout, CordbProcess * pProcess)
{
    if (!IsTransportRunning())
    {
        return FALSE;
    }

    // We need to wait for a debug event from the transport and the process termination event.
    // On Windows, process termination is communicated via a debug event as well, but that's not true for
    // the Mac debugging transport.
    DWORD cWaitSet = 2;
    HANDLE rghWaitSet[2];
    rghWaitSet[0] = m_pTransport->GetDebugEventReadyEvent();
    rghWaitSet[1] = m_hProcess;

    DWORD dwRet = ::WaitForMultipleObjectsEx(cWaitSet, rghWaitSet, FALSE, dwTimeout, FALSE);

    if (dwRet == WAIT_OBJECT_0)
    {
        // The Mac debugging transport actually transmits IPC events and not debug events.
        // We need to convert the IPC event to a debug event and pass it back to the caller.
        m_pTransport->GetNextEvent(m_pIPCEvent, CorDBIPC_BUFFER_SIZE);

        pEvent->dwProcessId = m_pIPCEvent->processId;
        _ASSERTE(m_dwProcessId == m_pIPCEvent->processId);

        // We are supposed to return a thread ID in the DEBUG_EVENT back to our caller.  
        // However, we don't actually store the thread ID in the DebuggerIPCEvent anymore.  Instead, 
        // we just get a VMPTR_Thread, and so we need to find the thread ID associated with the VMPTR_Thread.
        pEvent->dwThreadId = 0;
        HRESULT hr = S_OK;
        EX_TRY
        {
            if (!m_pIPCEvent->vmThread.IsNull())
            {
                pEvent->dwThreadId = pProcess->GetDAC()->TryGetVolatileOSThreadID(m_pIPCEvent->vmThread);
            }
        }
        EX_CATCH_HRESULT(hr);
        if (FAILED(hr))
        {
            return FALSE;
        }

        // The Windows implementation stores the target address of the IPC event in the debug event.
        // We can do that for Mac debugging, but that would require the caller to do another cross-machine
        // ReadProcessMemory().  Since we have all the data in-proc already, we just store a local address.
        // 
        // @dbgtodo  Mac - We are using -1 as a dummy base address right now.  
        // Currently Mac remote debugging doesn't really support multi-instance.
        InitEventForDebuggerNotification(pEvent, PTR_TO_CORDB_ADDRESS(reinterpret_cast<LPVOID>(-1)), m_pIPCEvent);

        return TRUE;
    }
// Get the reply from the LS for a previously sent IPC event.
//
// virtual 
HRESULT RemoteEventChannel::GetReplyFromLeftSide(DebuggerIPCEvent * pReplyEvent, SIZE_T eventSize)
{
    // Delegate to the transport.
    m_pTransport->GetNextEvent(pReplyEvent, (DWORD)eventSize);
    return S_OK;
}