UA-.NETStandard/ComIOP/Wrapper/Common/COpcThread.cpp

/* ========================================================================
 * Copyright (c) 2005-2019 The OPC Foundation, Inc. All rights reserved.
 *
 * OPC Foundation MIT License 1.00
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 * The complete license agreement can be found here:
 * http://opcfoundation.org/License/MIT/1.00/
 * ======================================================================*/

#include "StdAfx.h"
#include "COpcThread.h"

//==============================================================================
// Local Functions

static DWORD WINAPI ThreadProc(LPVOID lpParameter)
{
    return ((COpcThread*)lpParameter)->Run();
}

//==============================================================================
// COpcThread

// Constructor
COpcThread::COpcThread()
{
    m_dwID            = NULL;
    m_hThread         = NULL;
    m_hEvent          = NULL;
    m_pfnControl      = NULL;
    m_pData           = NULL;
    m_bWaitingForStop = false;
}

// Destructor
COpcThread::~COpcThread() 
{
    if (m_hThread != NULL) CloseHandle(m_hThread);
    if (m_hEvent != NULL)  CloseHandle(m_hEvent);
}

//==============================================================================
// Public Methods

// Start
bool COpcThread::Start(
    PfnOpcThreadControl pfnControl, 
    void*               pData, 
    DWORD               dwTimeout,
	int                 iPriority)
{
    m_pfnControl = pfnControl;
    m_pData      = pData;

    // no control procedure specified.
    if (m_pfnControl == NULL)
    {
        return false;
    }

    // thread already running.
    if (m_hThread != NULL)
    {
        return false;
    }

    // create thread started event.
    m_hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

    if (m_hEvent == NULL)
    {
        return false;
    }

    // start thread.
    m_hThread = CreateThread(
        NULL,
        NULL,
        ThreadProc,
        (void*)this,
        NULL,
        &m_dwID);

    if (m_hThread == NULL)
    {
        return false;
    }

	// set thread priority.
	SetThreadPriority(m_hThread, iPriority);

    // wait for thread start.
    DWORD dwResult = WaitForSingleObject(m_hEvent, dwTimeout);

    if (dwResult != WAIT_OBJECT_0)
    {
        return false;
    }

    // reset thread event.
    ResetEvent(m_hEvent);

    return true;
}

// Stop
void COpcThread::Stop(DWORD dwTimeout)
{
    // check if thread is not stopping itself and if thread is running.
    if (m_dwID != GetCurrentThreadId() && m_hThread != NULL)
    {
        m_bWaitingForStop = true;

        // post quit message.
        PostThreadMessage(m_dwID, WM_QUIT, 0, 0);

        // call thread procedure for user defined stop message.
        m_pfnControl(NULL, true);

        // wait for thread stopped event.
        WaitForSingleObject(m_hEvent, dwTimeout);
    }

    // close handles.
    if (m_hThread != NULL) CloseHandle(m_hThread);
    if (m_hEvent != NULL)  CloseHandle(m_hEvent);

    // intialize state.
    m_dwID            = NULL;
    m_hThread         = NULL;
    m_hEvent          = NULL;
    m_pfnControl      = NULL;
    m_pData           = NULL;
    m_bWaitingForStop = false;
}

// Run
DWORD COpcThread::Run()
{
    // initialize message queue.
    MSG cMsg; memset(&cMsg, 0, sizeof(cMsg));
    PeekMessage(&cMsg, NULL, 0, 0, PM_NOREMOVE);

    // signal that the thread started.
    SetEvent(m_hEvent);

    // call thread procedure.
    m_pfnControl(m_pData, false);

    // signal that the thread stopped.
    CloseHandle(m_hThread);
    InterlockedExchange((LONG*)&m_hThread, NULL);

    SetEvent(m_hEvent);

    return 0;
}

// PostMessage
bool COpcThread::PostMessage(UINT uMsgID, WPARAM wParam, LPARAM lParam)
{
    return (PostThreadMessage(m_dwID, uMsgID, wParam, lParam) != 0);
}