16 C++ 多线程

Android Ndk 学习笔记（目录）

#include <iostream>
#include <vector>
#include <unistd.h>
#include <thread>
#include <pthread.h> 
#include <queue>
using namespace std;


// 1 C++ 11 后 自带的Thread

void runAction(int number){
    for (int i = 0; i < 10; ++i) {
        cout << number << endl ;
        sleep(1);
    }
}

void useThread(){
    thread thread(runAction,100);
    thread.join();
}

void * customPthreadTask(void * pVoid){
    int * number = static_cast<int *>(pVoid);
    cout << "异步线程执行了:" << *number << endl;
    return 0 ;
}

void usePthread(){
    int number = 1123;
    pthread_t pthreadID;
    pthread_create(&pthreadID,0,customPthreadTask,&number);
    // 等待线程执行
    pthread_join(pthreadID,0);

}


queue<int> queueData;
pthread_mutex_t mutex ;


void * task(void * pVoid){
    pthread_mutex_lock(&mutex);

    cout << "异步线程-当前线程的标记是:" << *static_cast<int *>(pVoid) << "异步线程" << endl;

    if (!queueData.empty()){
        printf("异步线程-获取队列的数据：%d\n",queueData.front());
        queueData.pop();
    }else{
        printf("异步线程-队列中没有数据了\n");
    }

    pthread_mutex_unlock(&mutex);
    return  0 ;
}

void useTask(){

    pthread_mutex_init(&mutex,NULL);

    for (int i = 10000; i < 10011; ++i) {
        queueData.push(i);
    }

    pthread_t pthreadIDArray[10];
    for (int i = 0; i < 10; ++i) {
        pthread_create(&pthreadIDArray[i],0,task,&i);
    }

    sleep(12);

    pthread_mutex_destroy(&mutex);

}

#include "safe_queue_too2.h";

//
// Created by admin on 2021/8/2.
//

#ifndef C___SAFE_QUEUE_TOO2_H
#define C___SAFE_QUEUE_TOO2_H

#endif //C___SAFE_QUEUE_TOO2_H

#pragma once

#include <iostream>
#include <string>
#include <pthread.h>
#include <string>
#include <queue>

using namespace std;
template<typename T>
class SafeQueue2Class{


private:
    queue<T> queue;
    pthread_mutex_t mutex;
    pthread_cond_t cond ;

public:
    SafeQueue2Class(){
        pthread_mutex_init(&mutex,0);
        pthread_cond_init(&cond,0);
    }

    ~SafeQueue2Class(){
        pthread_mutex_destroy(&mutex);
        pthread_cond_destroy(&cond);
    }

    void add(T t){
        pthread_mutex_lock(&mutex);
        queue.push(t);
        pthread_cond_broadcast(&cond);
        pthread_mutex_unlock(&mutex);
    }

    void get(T & t){

        pthread_mutex_lock(&mutex);


        while (queue.empty()){
            pthread_cond_wait(&cond,&mutex);
        }

        t = queue.front();
        queue.pop();

        pthread_mutex_unlock(&mutex);

    }

};

SafeQueue2Class<int> sq;


void * getMethod(void *){
    while(true){
        int value ;
        sq.get(value);
        if (-1 == value){
            break;
        }
    }
    return 0 ;
}

void * setMethod(void *) {
    while (true) {
        int value;
        printf("请输入你要生成的信息:\n");
        cin >> value;
        // 你只要传入 -1 就结束当前循环
        if (-1 == value) {
            sq.add(value); // 为了让消费者 可以结束循环
            break;
        }
        sq.add(value);
    }
    return 0;
}

int main(){

    pthread_t pthreadGet;
    pthread_create(&pthreadGet, 0, getMethod, 0);
    // pthread_join(pthreadGet, 0); 不能这样写，否则，下面的代码，可能无法有机会执行

    pthread_t pthreadSet;
    pthread_create(&pthreadSet, 0, setMethod, 0);


    pthread_join(pthreadGet, 0);

    pthread_join(pthreadSet, 0);

    return 0 ;
}