pthread producer-consumer

producer-consumer.cpp

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

bool bEnd = false;
pthread_cond_t cv;
pthread_mutex_t mp;
bool bDataReady = false;
bool bProcessed = false;

void* perform_work(void* argument) {

    std::cout << "perform_work: thread started" << std::endl;

    while(!bEnd){
        std::cout << "perform_work: waiting for data" << std::endl;
        while(!bDataReady){
            pthread_mutex_lock(&mp);
            pthread_cond_wait(&cv, &mp);
            if(bEnd){
                std::cout << "perform_work: exiting" << std::endl;
                break;
            }
        }
        pthread_mutex_unlock(&mp);
        if(bEnd){
            std::cout << "perform_work: exiting function" << std::endl;
            return 0;
        }

        std::cout << "perform_work: processing data" << std::endl;
        getchar();
        bProcessed = true;
        bDataReady = false;

        //signal main thread
        pthread_cond_signal(&cv);
    }

    return NULL;
}

int main(int argc, char *argv[])
{
    pthread_t threadProcess;
    std::string data;

    int result_code = pthread_cond_init(&cv, NULL);
    if(result_code != 0){
        std::cout << "main: failed to create condition variable" << std::endl;
        return 1;
    }

    result_code = pthread_create(&threadProcess, NULL, perform_work, NULL);
    if(result_code != 0){
        std::cout << "main: failed to create thread" << std::endl;
        return 1;
    }

    while(true){
        std::cout << "main: get processed data" << std::endl;
        std::cout << "Enter data or quit: ";
        std::cin >> data;
        if(data == "q"){
            bEnd = true;
            pthread_cond_signal(&cv); //signal thread and exit
            break;
        }
        std::cout << "main: waking up processing thread" << std::endl;
        bDataReady = true;
        pthread_cond_signal(&cv);

        std::cout << "main: waiting for data to be processed" << std::endl;
        while(!bProcessed){
            pthread_mutex_lock(&mp);
            pthread_cond_wait(&cv, &mp);
        }
        //reset all data
        bDataReady = false;
        bProcessed = false;
        pthread_mutex_unlock(&mp);
    }


    //wait for everyone
    result_code = pthread_join(threadProcess, NULL);
    pthread_cond_destroy(&cv);

    return 0;
}