信号量与双缓冲

双缓冲

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <pthread.h>
#include <semaphore.h>
#include <vector>
#include <iostream>
using namespace std;

vector<int> v1;
vector<int> v2;

sem_t semaphore;
unsigned int vectorSize = 5;
bool pushV1=true,pushV2=false;

pthread_mutex_t mutexV1,mutexV2;

void *producer(void */*arg*/)
{
    int i=1,j=11;
    while(1)
    {
        if(pushV1)
        {
            pthread_mutex_lock(&mutexV1);
            v1.push_back(i);
            cout << "push back vector1:" << i << ",size:" <<v1.size() << endl;
            i++;
            if(v1.size()>=vectorSize)
            {
                pushV1 = false;
                pushV2 = true;
                i = 1;
                sem_post(&semaphore);
            }
            pthread_mutex_unlock(&mutexV1);
        }else if(pushV2)
        {
            pthread_mutex_lock(&mutexV2);
            v2.push_back(j);
            cout << "push back vector2:" << j << ",size:" <<v2.size() << endl;
            j++;
            if(v2.size()>=vectorSize)
            {
                pushV2 = false;
                pushV1 = true;
                j = 11;
                sem_post(&semaphore);
            }
            pthread_mutex_unlock(&mutexV2);
        }
        usleep(200*1000);
    }
    return 0;
}

void *consumer(void */*arg*/)
{
    while (1)
    {
        sem_wait(&semaphore);
        if(pushV2)
        {
            pthread_mutex_lock(&mutexV1);
            if(v1.size()>0)
            {
                while(v1.size()>0)
                {
                    int i = *v1.begin();
                    v1.erase(v1.begin());
                    cout << "vector1 pop:" << i <<",size:" << v1.size() << endl;
                    usleep(100*1000);
                }
            }
            pthread_mutex_unlock(&mutexV1);
        }else if(pushV1)
        {
            pthread_mutex_lock(&mutexV2);
            if(v2.size()>0)
            {
                while(v2.size()>0)
                {
                    int i = *v2.begin();
                    v2.erase(v2.begin());
                    cout << "vector2 pop:" << i <<",size:" << v2.size() << endl;
                    usleep(100*1000);
                }
            }
            pthread_mutex_unlock(&mutexV2);
        }
        usleep(5*1000);
    }
    return 0;
}

int main()
{
    pthread_t consumerThread,producerThread;

    if(pthread_mutex_init(&mutexV1,NULL)!=0)
    {
        pthread_mutex_destroy(&mutexV1);
        perror("init mutex fail");
    }
    if(pthread_mutex_init(&mutexV2,NULL)!=0)
    {
        pthread_mutex_destroy(&mutexV2);
        perror("init mutex fail");
    }
    int res = sem_init(&semaphore, 0, 0);
    if (res != 0)
    {
        perror("Semaphore initialization failed");
    }
    res = pthread_create(&consumerThread, NULL, consumer, NULL);
    if (res != 0)
    {
        perror("Thread creation failure");
    }
    res = pthread_create(&producerThread, NULL, producer, NULL);
    if (res != 0)
    {
        perror("Thread creation failure");
    }
    while (1)
    {
        sleep(5);
    }
    sem_destroy(&semaphore);
}



}

那些usleep请自己动态调整,我只是为了测试生产者生产快或消费者消费更快而写的