Output Debug String

As we know, we can use API OutputDebugString to show string on output window, like,

OutputDebugString(" This is debug message. ");
OutputDebugStringW(L" This is debug message. ");

You also can attach some variable to the output string.

wchar_t* world = L"world";
wchar_t* szBuffer = new wchar_t[512];
wsprintf(szBuffer, _T(" Hello %s \n"),  world);
OutputDebugString(szBuffer);
delete[] szBuffer;

or

wchar_t* message = L"world !";

wchar_t* str = L" Hello ";
wchar_t* buffer = new wchar_t[sizeof(str)+sizeof(message)+1];
wcscpy(buffer, str);
wcscat(buffer, message);
OutputDebugStringW(buffer);


or

float value = 100;
wchar_t* szBuffer = new wchar_t[512];
wsprintf(szBuffer, L" My math grade is %d \n",   (int)value);
OutputDebugString(szBuffer);
delete[] szBuffer;

or

float value = 100;
char* szBuffer = new char[512];
sprintf(szBuffer, L" My math grade is %f \n",  value);
OutputDebugStringA(szBuffer);
delete[] szBuffer;

[C++] Threading Sample

This is a simple sample for understanding of thread create in C++.

#include "stdafx.h" #include <windows.h> #include <process.h> #include <stdio.h> void myfunc(int n); int _tmain(int argc, _TCHAR* argv[]) {     HANDLE thd[2];     DWORD tid;     printf("Thead Start.\n");     for (int i=0; i<2; i++)     {         thd[i] = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)myfunc, (void*)i, 0, &tid);         printf("Thread %d is start \n",tid);     }     Sleep(1000);     printf("main is end \n");     system("pause"); } void myfunc(int n) {     int i;     for(int i=0;i<5;i++){         printf("Thread %d, index=%d\n", n, i);         Sleep(1000);     }     printf("Thread %d is over \n", getpid()); }

Reference:
http://wuminfajoy.blogspot.tw/2010/10/c.html

Watch Virtual / Physical Memory Usage

With previous article http://twnin.blogspot.com/2012/05/watch-process-memory-usage.html
There is another way to watch memory usage in program with win32 api.

    MEMORYSTATUS ms;
    ms.dwLength = sizeof(ms);
    GlobalMemoryStatus(&ms);

    const int nBufSize = 512;
    TCHAR chBuf[nBufSize];
    ::ZeroMemory(chBuf,nBufSize);

    // Process-specific info (for calling process)
    wsprintf(chBuf,_T("TotalVirtual: %ld\n"), ms.dwTotalVirtual);
    OutputDebugString(chBuf);
    wsprintf(chBuf,_T("AvailVirtual: %ld\n"), ms.dwAvailVirtual);
    OutputDebugString(chBuf);

    // Process virtual memory usage (reserved + commit)
    wsprintf(chBuf,_T("UsageVirtual: %ld\n"), ms.dwTotalVirtual - ms.dwAvailVirtual);
    OutputDebugString(chBuf);

    // System info
    wsprintf(chBuf,_T("MemoryLoad: %ld\n"), ms.dwMemoryLoad);
    OutputDebugString(chBuf);
    wsprintf(chBuf,_T("TotalPhys: %ld\n"), ms.dwTotalPhys);
    OutputDebugString(chBuf);
    wsprintf(chBuf,_T("AvailPhys: %ld\n"), ms.dwAvailPhys);
    OutputDebugString(chBuf);

    // System usage
    wsprintf(chBuf,_T("UsagePhys: %ld\n"), ms.dwTotalPhys - ms.dwAvailPhys);
    OutputDebugString(chBuf);

    // Unused/unsupported
    wsprintf(chBuf,_T("TotalPageFile: %lu\n"), ms.dwTotalPageFile);
    OutputDebugString(chBuf);
    wsprintf(chBuf,_T("AvailPageFile: %lu\n"), ms.dwAvailPageFile);
    OutputDebugString(chBuf);

Watch Process Memory Usage

To watch current process memory usage, we can use GetProcessMemoryInfo to get paging information.
It is sample code below.

    HANDLE hProcess = ::GetCurrentProcess();
    PROCESS_MEMORY_COUNTERS pmc;
    pmc.cb = sizeof(PROCESS_MEMORY_COUNTERS);
    ::GetProcessMemoryInfo(hProcess, &pmc, sizeof(pmc));

    const int nBufSize = 512;
    TCHAR chBuf[nBufSize];
    ::ZeroMemory(chBuf,nBufSize);

    wsprintf(chBuf,_T("PageFaultCount: 0x%08X\n"), pmc.PageFaultCount );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("PeakWorkingSetSize: 0x%08X\n"),
    pmc.PeakWorkingSetSize );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("WorkingSetSize: 0x%08X\n"), pmc.WorkingSetSize );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("QuotaPeakPagedPoolUsage: 0x%08X\n"),
    pmc.QuotaPeakPagedPoolUsage );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("QuotaPagedPoolUsage: 0x%08X\n"),
    pmc.QuotaPagedPoolUsage );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("QuotaPeakNonPagedPoolUsage: 0x%08X\n"),
    pmc.QuotaPeakNonPagedPoolUsage );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("QuotaNonPagedPoolUsage: 0x%08X\n"),
    pmc.QuotaNonPagedPoolUsage );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("PagefileUsage: 0x%08X\n"), pmc.PagefileUsage );
    OutputDebugString(chBuf);

    wsprintf(chBuf,_T("PeakPagefileUsage: 0x%08X\n"),
    pmc.PeakPagefileUsage );
    OutputDebugString(chBuf);

    CloseHandle(hProcess);

Reference:
http://msdn.microsoft.com/en-us/library/ms682050(v=VS.85).aspx
http://blog.csdn.net/caimouse/article/details/1947575

Work around link error:
error lnk2019: unresolved external symbol _getprocessmemoryinfo@12 referenced in function
http://lanvu.wordpress.com/tag/error-lnk2019-unresolved-external-symbol-_getprocessmemoryinfo12-referenced-in-function/

It seems doesn't work on windows ce.
https://groups.google.com/group/microsoft.public.pocketpc.developer/browse_thread/thread/22c685d1df9ec17d/e05ad892433d56aa?lnk=raot&pli=1

Structure of PROCESS_MEMORY_COUNTERS
http://blog.csdn.net/zhsp1029/article/details/3162048

[Win API] Get Tick Count and Output Debug String

This is a sample to output string to debugger.


DWORD dwTickCount = GetTickCount();
LPWSTR szBuffer;
wsprintf(szBuffer, _T(" [Debug] The computer has ran %ld ms."),  dwTickCount);
OutputDebugString(szBuffer);



GetTickCount() :  Retrieves the number of milliseconds that have elapsed since the system was started, up to 49.7 days.
OutputDebugString() : Sends a string to the debugger for display.

[Win API] Check directory or file exist

This is a example for check file or directory is exist or not before you access it.

    WIN32_FIND_DATA fileInfo;
    HANDLE hFind = FindFirstFile(unicodestr, &fileInfo);
    if (hFind == INVALID_HANDLE_VALUE)
    {
        bala...bala....
    }
    FindClose(hFind);


Reference:
http://blog.yam.com/csylvia/article/7026165

[Win API] Sample of reading txt file

It is just a simple example for reading text from .txt file using win32 api.


HANDLE hFile = CreateFile(dataFilePath, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, 0);
if (hFile == INVALID_HANDLE_VALUE)
{
    return;
}

// read all characters from file.
DWORD bufferSize = GetFileSize(hFile, 0);
char* buffer = new char[bufferSize];
memset(buffer, '\0', bufferSize);

bool result = false;
DWORD bytesRead = 0;
result = !!ReadFile(hFile, &buffer, bufferSize, &bytesRead, 0);

delete[]  buffer;
CloseHandle(hFile);

Then, you can follow the example below to get file path.
http://twnin.blogspot.com/2012/03/get-current-directory-and-convert-to.html