#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <pthread.h>
#include <sys/types.h>
#include <sys/stat.h>

#define READMAX 200
#define WRITEMAX 50

int num = 0;

void* read_num(void* arg);
void* write_num(void* arg);

pthread_rwlock_t rwlock;

int main(int argc, char const *argv[])
{
    pthread_t t1[5], t2[3];

    pthread_rwlock_init(&rwlock, NULL);

    // 创建5个读线程
    for (size_t i = 0; i < 5; i++)
    {
        pthread_create(&t1[i], NULL, read_num, NULL);
    }
    
    // 创建3个写线程
    for (size_t i = 0; i < 3; i++)
    {
        pthread_create(&t2[i], NULL, write_num, NULL);
    }

    // 线程回收
    for (size_t i = 0; i < 5; i++)
    {
        pthread_join(t1[i], NULL);
    }

    for (size_t i = 0; i < 3; i++)
    {
        pthread_join(t2[i], NULL);
    }
    
    pthread_rwlock_destroy(&rwlock);

    return 0;
}

void* read_num(void* arg){
    int count = 0;
    for (size_t i = 0; i < READMAX; i++)
    {
        pthread_rwlock_rdlock(&rwlock);
        printf("Read Thread id = %lu, num = %d ...... %d\n", pthread_self(), num, count++);
        pthread_rwlock_unlock(&rwlock);
        usleep(rand()%5);
    }

    return NULL;
}

void* write_num(void* arg){

    int count = 0;
    for (size_t i = 0; i < WRITEMAX; i++)
    {
        pthread_rwlock_wrlock(&rwlock);
        int cur = num;
        cur++;
        num = cur;
        printf("Write Thread id = %lu, num=%d ...... %d\n", pthread_self(), num, count++);
        pthread_rwlock_unlock(&rwlock);
        usleep(500);
    }

    return NULL;
}