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Performance meter and memory leaks detector

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5 Dec 2001 1  
This article describes how to monitor program heap for memory leaks

Introduction

While working in QA team I got a task "Measure product-components performance, i.e. CPU/Memory usage during their work and detect possible memory leaks". Detecting of memory leaks isn't a simple procedure. At first because there is no any definite technique for making it. The first idea was viewing the process memory space at the page level. But this method is rough enough ( I guess), and  Windows doesn't always free allocated blocks immediately. So I decided to calculate PROCESS_HEAP_ENTRY_BUSY nodes in program heap before using all components (loading dll's) and after it.

Details

About CPU usage - the first idea wasn't so bright again :) I've tried to measure CPU usage by Windows NT Pdh-functions, but then there is the necessity of loading pdh.lib. So I used NtQuerySystemInformation technique (unfortunately I don't know the author 's name, because I get sources through third person).

Well now, to detect memory leaks in the components of your application and to get system resources info during work, you can define a monitoring thread function like this:

#define PERFORMANCE_FILENAME "DocProcPerf.log"

typedef struct EVENTS
{
    HANDLE StartEvent;
    HANDLE StopEvent;
};

DWORD WINAPI UserThreadProc(LPVOID lpParameter)
{
    EVENTS* hWait = (EVENTS *)lpParameter;
    DWORD  dwStartTime = GetTickCount();

    CCompInfo* hInfo = new CCompInfo(PERFORMANCE_FILENAME);

    hInfo->HeapMakeSnapShot();
    hInfo->HeapStoreDumpToFile();

    SetEvent((HANDLE)hWait->StartEvent);

    hInfo->m_log->print( "DocProcTest started at %s\n", 
        hInfo->GetTimeString() );

    while (1)
    {
        if(WaitForSingleObject(
            (HANDLE)hWait->StopEvent,0) == WAIT_OBJECT_0)
            break;
        hInfo->m_log->print(
            "%s CPU[%d%%] Memory[%dKb]\n", 
            hInfo->GetTimeString(), 
            hInfo->GetCPUInfo(),
            hInfo->HeapCommitedBytes()/1024);
        Sleep(1000);
    };

    hInfo->m_log->print( "%s CPU[%d%%] Memory[%dKb]\n",
        hInfo->GetTimeString(), 
        hInfo->GetCPUInfo(),
        hInfo->HeapCommitedBytes()/1024);

    hInfo->m_log->print( "DocProcTest finished at %s\n",
        hInfo->GetTimeString() );
    hInfo->m_log->print( "Elapsed time %d sec\n",
        (GetTickCount() - dwStartTime)/1000 );
    hInfo->m_log->print( 
        "Total memory difference: %dKb\n\n",
        hInfo->HeapCompareSnapShots()/1024 );

    CloseHandle((HANDLE)hWait->StopEvent);
    CloseHandle((HANDLE)hWait->StartEvent);

    if (NULL != hWait)
        delete hWait;

    hInfo->HeapCompareDumpWithFile(FALSE); // basic report

    hInfo->HeapCompareDumpWithFile(TRUE);  // extended report


    if (NULL != hInfo)
        delete hInfo;

    return 0;
}

Thus we just have to add our keep-an-eye-thread initialization lines in the main application function like this:

printf(  "\nTest started.\n");
EVENTS *hEvent = new EVENTS;
hEvent->StartEvent = CreateEvent(NULL,TRUE,FALSE,NULL);
hEvent->StopEvent = CreateEvent(NULL,TRUE,FALSE,NULL);

HANDLE hTread = CreateThread( NULL,
                             NULL,
                             UserThreadProc,
                             hEvent,
                             NULL,
                             NULL); 
WaitForSingleObject((HANDLE)hEvent->StartEvent,15000);

...
//program body goes here

...

if (NULL != hEvent)
SetEvent((HANDLE)hEvent->StopEvent);
while (WaitForSingleObject(hTread,1000) != WAIT_OBJECT_0)
Sleep(1000);
printf(  "\nTest finished.\n");

In conclusion I want to add that this method is under research now so feel free to ask me for new stuff or modifications of it. I'll be grateful for your comments and suggestions.

License

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