CreateThread示例

The CreateThread function creates a new thread for a process. The creating thread must specify the starting address of the code that the new thread is to execute. Typically, the starting address is the name of a function defined in the program code (for more information, see ThreadProc). This function takes a single parameter and returns a DWORD value. A process can have multiple threads simultaneously executing the same function.

CreateThread 函数从一个进程里面创建一个线程。这个开始的线程必须指定开始执行代码的地址，新线程执行。有代表性的，开始地址就是一个函数名。这个函数有一个参数，并且返回一个 DWORD 值。一个进程里面同时有多个线程在执行。

 

The following is a simple example that demonstrates how to create a new thread that executes the locally defined function, ThreadProc. The creating thread uses a dynamically allocated buffer to pass unique information to each instance of the thread function. It is the responsibility of the thread function to free the memory.

下面这个例子演示如何创建一个新线程，执行本地定义的函数。 ThreadProc. 建立的线程动态分配内存传递信息到每个线程的实例中。线程函数负责释放这些内存。

 

The calling thread uses the WaitForMultipleObjects function to persist until all worker threads have terminated. Note that if you were to close the handle to a worker thread before it terminated, this does not terminate the worker thread. However, the handle will be unavailable for use in subsequent function calls.

 

被调用的线程用 WaitForMultipleObjects 持续等待，知道所有的工作线程退出。在线程退出后，关掉线程函数的句柄。

#include <windows.h>
#include <strsafe.h> //win2003 SDK必须安装　要不无此头文件。此文件是为了实现StringCchPrintf，StringCchLength。


#define MAX_THREADS 3
#define BUF_SIZE 255

typedef struct _MyData {
    int val1;
    int val2;
} MYDATA, *PMYDATA;

DWORD WINAPI ThreadProc( LPVOID lpParam )
{
    HANDLE hStdout;
    PMYDATA pData;

    TCHAR msgBuf[BUF_SIZE];
    size_t cchStringSize;
    DWORD dwChars;

    hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
    if( hStdout == INVALID_HANDLE_VALUE )
        return 1;

    // Cast the parameter to the correct data type.


    pData = (PMYDATA)lpParam;

    // Print the parameter values using thread-safe functions.


    StringCchPrintf(msgBuf, BUF_SIZE, TEXT("Parameters = %d, %d\n"),
        pData->val1, pData->val2);
    StringCchLength(msgBuf, BUF_SIZE, &cchStringSize);
    WriteConsole(hStdout, msgBuf, cchStringSize, &dwChars, NULL);

    // Free the memory allocated by the caller for the thread

    // data structure.


    HeapFree(GetProcessHeap(), 0, pData);

    return 0;
}
 
void main()
{
    PMYDATA pData;
    DWORD dwThreadId[MAX_THREADS];
    HANDLE hThread[MAX_THREADS];
    int i;

    // Create MAX_THREADS worker threads.


    for( i=0; i<MAX_THREADS; i++ )
    {
        // Allocate memory for thread data.


        pData = (PMYDATA)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,
                sizeof(MYDATA));
    //5);


        if( pData == NULL )
            ExitProcess(2);

        // Generate unique data for each thread.


        pData->val1 = i;
        pData->val2 = i+100;

        hThread[i] = CreateThread(
            NULL, // default security attributes

            0, // use default stack size

            ThreadProc, // thread function

            pData, // argument to thread function

            0, // use default creation flags

            &dwThreadId[i]); // returns the thread identifier

 
        // Check the return value for success.

 
        if (hThread[i] == NULL)
        {
            ExitProcess(i);
        }
    }

    // Wait until all threads have terminated.


    WaitForMultipleObjects(MAX_THREADS, hThread, TRUE, INFINITE);

    // Close all thread handles upon completion.


    for(i=0; i<MAX_THREADS; i++)
    {
        CloseHandle(hThread[i]);
    }
}