D:/opendownloadmanager/ODM-1.x/fsMutex.cpp

Go to the documentation of this file.

/*
  Free Download Manager Copyright (c) 2003-2007 FreeDownloadManager.ORG
  Open Download Manager Copyright (c) 2008-2010 OpenDownloadManager.ORG
*/        

#include "stdafx.h"
#include "fsMutex.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif        

fsMutex::fsMutex()
{
        m_mx = CreateMutex (NULL, FALSE, NULL);
        m_cLocks = 0;
}

fsMutex::~fsMutex()
{
        if (m_mx)
                CloseHandle (m_mx);
}

void fsMutex::Lock()
{
        ASSERT (m_mx != NULL);

        if (m_mx == NULL)
                return;

        const int WAIT_TIME             = 10000;
        const int WAIT_INTERVAL = 50;

        for (int i = 0; i < WAIT_TIME/WAIT_INTERVAL; i++)
        {
                DWORD dwRet = WaitForSingleObject (m_mx, WAIT_INTERVAL);
                if (dwRet == WAIT_TIMEOUT)
                {
                        MSG msg;
                        while (PeekMessage (&msg, 0, 0, 0, PM_REMOVE))
                        {
                                TranslateMessage (&msg);
                                DispatchMessage (&msg);
                        }
                }
                else
                {
                        
                        m_cLocks++;
                        break;
                }
        }
        
        if (i == WAIT_TIME/WAIT_INTERVAL)
        {
                ASSERT (FALSE);
                HANDLE h = m_mx;
                m_mx = CreateMutex (NULL, FALSE, NULL);
                CloseHandle (h);
        }
}

void fsMutex::Unlock()
{
        if (m_mx == NULL || m_cLocks == 0)
                return;
        
        m_cLocks--;
        ReleaseMutex (m_mx);
}

---