DWORD WINAPI producer(LPVOID) { for (int i = 0; i < 10; i++) { cout << "put " << i << "\t"; bool ok = b.put(i); if (ok) cout << "ok"; else cout << "failed"; cout << endl; } return 0; }什么意思

这段代码是一个生产者线程的实现，其中：

- DWORD WINAPI 是 Windows API 中线程函数的类型定义；
- LPVOID 是指向任意类型数据的指针类型；
- for 循环的循环次数为 10；
- cout 语句用于输出信息，put i 表示将 i 放入某个缓冲区；
- b.put(i) 是一个函数调用，表示将 i 放入缓冲区 b 中，并返回一个 bool 类型的值，表示成功或失败；
- if-else 语句用于根据返回值输出相应的信息；
- 最后返回值为 0。

这段代码实现了一个生产者线程，可以将数据放入一个缓冲区中。

相关问题

#include<iostream> #include<Windows.h> #include <iomanip> #include <math.h> using namespace std; float x=0; DWORD WINAPI Thread1(LPVOID lpParameter); DWORD WINAPI Thread2(LPVOID lpParameter); void f1() { int i=10; while(i--) cout<<"i="<<i<<endl; } void f2() { int j=20; while(j--) cout<<"j="<<j<<endl; } int main() { cout<<"主线程已启动"<<endl; //f1(); //f2(); HANDLE hThread1=CreateThread(NULL,0,Thread1,NULL,0,NULL);//启动线程1 HANDLE hThread2=CreateThread(NULL,0,Thread2,NULL,0,NULL);//启动线程2 CloseHandle(hThread1);//关闭线程1 CloseHandle(hThread2);//关闭线程2 int i=25; while(i--) { cout<<"主线程运行中"<<endl; Sleep(100);//延时0.1s } //CloseHandle(hThread1);//关闭线程1 //CloseHandle(hThread2);//关闭线程2 system("pause");//暂停防止程序退出 return 0; } DWORD WINAPI Thread1(LPVOID lpParameter) { // cout<<"线程1已启动"<<endl; // //int i=5; // //while(i--) // //{ // //cout<<"线程1运行中"<<endl; //cout<<"i1="<<i<<endl; //Sleep(100);//延时0.1s // //} int i=0; while(i<101) { x=x+0.02; i++; Sleep(100);//延时0.1s } return 0; } DWORD WINAPI Thread2(LPVOID lpParameter) { // cout<<"线程2已启动"<<endl; // //int i=100; // //while(i--) // //{ // //cout<<"线程2运行中"<<endl; ////cout<<setw(i*10)<<"*"<<endl; //cout<<"i2="<<i<<endl; //Sleep(100);//延时0.1s // //} int i=0; while(x<=2.0) { //cout<<setw(30*sin(x))<<"*"<<endl; cout<<x<<endl; Sleep(100);//延时0.1s } return 0; }在所给线程代码的基础上，修改： (1)一个线程负责数的变化，从0变到4*3.14159，步长为0.02； (2)一个线程负责读取系统时间； (3)一个线程负责将数的正弦、余弦与正要值计算并显示，同时显示系统时间； (4)步长停顿100ms。 要求：用console程序。

好的，你的要求是让我修改所给的多线程代码。根据你的要求，我对代码进行了如下修改：

#include<iostream>
#include<Windows.h>
#include <iomanip>
#include <math.h>
using namespace std;

float x = 0;
SYSTEMTIME st;

DWORD WINAPI Thread1(LPVOID lpParameter);
DWORD WINAPI Thread2(LPVOID lpParameter);
DWORD WINAPI Thread3(LPVOID lpParameter);

int main()
{
    cout << "主线程已启动" << endl;

    HANDLE hThread1 = CreateThread(NULL, 0, Thread1, NULL, 0, NULL);//启动线程1
    HANDLE hThread2 = CreateThread(NULL, 0, Thread2, NULL, 0, NULL);//启动线程2
    HANDLE hThread3 = CreateThread(NULL, 0, Thread3, NULL, 0, NULL);//启动线程3

    CloseHandle(hThread1);//关闭线程1
    CloseHandle(hThread2);//关闭线程2
    CloseHandle(hThread3);//关闭线程3

    int i = 25;
    while (i--)
    {
        cout << "主线程运行中" << endl;
        Sleep(100);//延时0.1s
    }

    system("pause");//暂停防止程序退出
    return 0;
}

DWORD WINAPI Thread1(LPVOID lpParameter)
{
    while (x <= 4 * 3.14159)
    {
        x += 0.02;
        Sleep(100);//延时0.1s
    }
    return 0;
}

DWORD WINAPI Thread2(LPVOID lpParameter)
{
    while (1)
    {
        GetLocalTime(&st);
        Sleep(1000);//延时1s
    }
}

DWORD WINAPI Thread3(LPVOID lpParameter)
{
    while (1)
    {
        float s = sin(x);
        float c = cos(x);
        float t = tan(x);

        cout << "sin(x)=" << s << ", cos(x)=" << c << ", tan(x)=" << t << endl;
        cout << "System Time: " << st.wHour << ":" << st.wMinute << ":" << st.wSecond << endl;
        cout << endl;

        Sleep(100);//延时0.1s
    }
    return 0;
}

我添加了一个新的线程Thread3，负责计算sin(x)、cos(x)和tan(x)的值，并输出系统时间。同时，Thread2负责获取系统时间。Thread1则负责将x的值从0逐渐增加到4*3.14159，步长为0.02。

请注意，因为Thread3和Thread2都是无限循环的线程，所以程序需要手动结束。

#include <windows.h> #include <iostream> using namespace std; const int N = 5; // 进程数 int count = 0; // 计数器 HANDLE mutex = CreateMutex(NULL, FALSE, NULL); // 互斥量 HANDLE barrier = CreateEvent(NULL, TRUE, FALSE, NULL); // 屏障 DWORD WINAPI Process(LPVOID lpParam) { int id = ((int)lpParam); cout << "Process " << id << " arrived at barrier." << endl; WaitForSingleObject(mutex, INFINITE); count++; ReleaseMutex(mutex); if (count == N) { cout << "All processes arrived at barrier, releasing barrier." << endl; SetEvent(barrier); } WaitForSingleObject(barrier, INFINITE); cout << "Process " << id << " starts the next phase of work." << endl; return 0; } DWORD WINAPI Broadcast(LPVOID lpParam) { WaitForSingleObject(mutex, INFINITE); cout << "Broadcast process started." << endl; ReleaseMutex(mutex); SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST); WaitForSingleObject(barrier, INFINITE); cout << "Broadcast process releasing all processes." << endl; ReleaseMutex(mutex); for (int i = 0; i < N; i++) { ReleaseSemaphore((HANDLE)lpParam, 1, NULL); } return 0; } int main() { HANDLE threads[N]; DWORD threadIds[N]; HANDLE sem = CreateSemaphore(NULL, 0, N, NULL); int ids[N]; for (int i = 0; i < N; i++) { ids[i] = i; threads[i] = CreateThread(NULL, 0, Process, &ids[i], 0, &threadIds[i]); if (threads[i] == NULL) { return 1; } } HANDLE broadcastThread = CreateThread(NULL, 0, Broadcast, sem, 0, NULL); if (broadcastThread == NULL) { return 1; } WaitForMultipleObjects(N, threads, TRUE, INFINITE); WaitForSingleObject(mutex, INFINITE); cout << "All processes completed." << endl; ReleaseMutex(mutex); return 0; }将此代码中的线程替换成进程

将线程替换成进程需要进行如下修改：

1. 需要将代码中的线程函数 Process 改为进程函数 ProcessProc，并修改其参数类型为 LPVOID。

2. 需要将代码中的 Broadcast 线程函数改为进程函数 BroadcastProc，并修改其参数类型为 LPVOID。

3. 需要使用 CreateProcess 函数创建进程，而不是使用 CreateThread 函数创建线程。

4. 进程间通信需要使用共享内存、命名管道或信号量等机制，而不是使用互斥量和事件等线程同步机制。

下面是修改后的代码示例：

#include <windows.h>
#include <iostream>
using namespace std;

const int N = 5; // 进程数
int count = 0; // 计数器
HANDLE mutex; // 互斥量
HANDLE barrier; // 屏障
HANDLE sem; // 信号量

DWORD WINAPI ProcessProc(LPVOID lpParam) {
int id = *((int*)lpParam);
cout << "Process " << id << " arrived at barrier." << endl;
WaitForSingleObject(mutex, INFINITE);
count++;
ReleaseMutex(mutex);
if (count == N) {
cout << "All processes arrived at barrier, releasing barrier." << endl;
SetEvent(barrier);
}
WaitForSingleObject(barrier, INFINITE);
cout << "Process " << id << " starts the next phase of work." << endl;
ReleaseSemaphore(sem, 1, NULL);
return 0;
}

DWORD WINAPI BroadcastProc(LPVOID lpParam) {
cout << "Broadcast process started." << endl;
WaitForSingleObject(barrier, INFINITE);
cout << "Broadcast process releasing all processes." << endl;
for (int i = 0; i < N; i++) {
ReleaseSemaphore(sem, 1, NULL);
}
return 0;
}

int main() {
mutex = CreateMutex(NULL, FALSE, NULL);
barrier = CreateEvent(NULL, TRUE, FALSE, NULL);
sem = CreateSemaphore(NULL, 0, N, NULL);

HANDLE processes[N];
int ids[N];
for (int i = 0; i < N; i++) {
ids[i] = i;
STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
if (!CreateProcess(NULL, "Process.exe", NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)) {
return 1;
}
processes[i] = pi.hProcess;
CloseHandle(pi.hThread);
}

STARTUPINFO si;
PROCESS_INFORMATION pi;
ZeroMemory(&si, sizeof(si));
si.cb = sizeof(si);
ZeroMemory(&pi, sizeof(pi));
if (!CreateProcess(NULL, "Broadcast.exe", NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)) {
return 1;
}
HANDLE broadcastProcess = pi.hProcess;
CloseHandle(pi.hThread);

WaitForMultipleObjects(N, processes, TRUE, INFINITE);
cout << "All processes completed." << endl;

CloseHandle(mutex);
CloseHandle(barrier);
CloseHandle(sem);
for (int i = 0; i < N; i++) {
CloseHandle(processes[i]);
}
CloseHandle(broadcastProcess);
return 0;
}

注意：上述代码中的 Process.exe 和 Broadcast.exe 是需要单独编译生成的进程可执行文件。在 Process.exe 中运行 ProcessProc 函数，在 Broadcast.exe 中运行 BroadcastProc 函数。可以使用 Visual Studio 或者其它 C++ 编译器进行编译。