多线程编程示例（结合实例）

#pragma once

#include<cstdio>
#include<Windows.h>
#include<crtdbg.h>
#include<process.h>

//子线程函数
DWORD WINAPI ThreadFun1(LPVOID pM)
{
    printf("子线程的线程ID号为：%d\nHello world!\n",GetCurrentThreadId());
    return 0;
}

void fun1()
{
    printf("简单多线程实例！\n\n");

    /*
       CreateThread参数解析
       1:线程内核安全属性
       2：线程栈空间大小
       3：线程执行函数地址
       4：传给线程执行函数参数
       5：线程创建控制参数(CREATE_SUSPENDED)
       6：线程ID号
    */
    HANDLE handle = CreateThread(NULL, 0, ThreadFun1, NULL, 0, NULL);
    WaitForSingleObject(handle, INFINITE);
    CloseHandle(handle);
}

//设置计数全局变量
int COUNT = 0;

//子线程函数
unsigned int _stdcall ThreadFun2(PVOID pM)
{
    ++COUNT;
    printf("子线程的线程ID号为：%d，报数为%d\nHello world!\n", GetCurrentThreadId(),COUNT);
    return 0;
}

void fun2()
{
    printf("简单多线程实例！\n\n");

    const int THREAD_NUM = 5;
    HANDLE handle[THREAD_NUM];

    for (size_t i = 0; i < THREAD_NUM; i++)
    {
        handle[i] = (HANDLE)_beginthreadex(NULL, 0, ThreadFun2, NULL, 0, NULL);
    }
    WaitForMultipleObjects(THREAD_NUM, handle, TRUE, INFINITE);
}

int main(void)
{
    //使用CreateThread
    //fun1();

    //使用_beginthreadex
    //推荐使用原因为：使用标准C运行库函数时，易发生race condition
    //使用_beginthreadex可以避免数据被其他线程篡改
    //更加合理的解释可以参考Win32多线程编程
    fun2();

    //检测内存泄漏
    _CrtDumpMemoryLeaks();
    return 0;
}

#pragma once

#include<cstdio>
#include<Windows.h>
#include<crtdbg.h>
#include<process.h>

volatile long COUNT = 0;
const int THREAD_NUM = 500;

unsigned int _stdcall ThreadFun(LPVOID pM)
{
    Sleep(50);
    //++COUNT;
    InterlockedIncrement((LPLONG)&COUNT); //使用原子锁替换
    Sleep(50);
    return 0;
}

void fun1()
{
    HANDLE handle[THREAD_NUM];

    for (size_t i = 0; i < THREAD_NUM; i++)
    {
        handle[i] = (HANDLE)_beginthreadex(NULL, 0, ThreadFun, NULL, 0, NULL);
    }
    WaitForMultipleObjects(THREAD_NUM, handle, TRUE, INFINITE);
    printf("有%d个线程启动,记录结果为%d", THREAD_NUM, COUNT);
}

int main()
{
    //test1
    fun1(); //易发现线程启动数和计数不匹配

    //检测内存泄漏
    _CrtDumpMemoryLeaks();
    return 0;
}