子线程循环 10 次，接着主线程循环 100 次

子线程循环 10 次，接着主线程循环 100 次，接着又回到子线程循环 10 次，接着再回到主线程又循环 100 次，如此循环50次，试写出代码。

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>

#define LOOP 5

int num = 0;
int parm_0 = 0;
int parm_1 = 1;

pthread_mutex_t mylock = PTHREAD_MUTEX_INITIALIZER;
pthread_cond_t qready=PTHREAD_COND_INITIALIZER;

void* thread_func(void *arg)
{
    int i, j;
    for(i = 0; i < LOOP; i++)
    {
        pthread_mutex_lock(&mylock);
        while(parm_0 != num)
            pthread_cond_wait(&qready, &mylock);

        printf("thread: \n");
        for(j = 0; j < 10; j++)
            printf(" %d ", j);
        printf("\n");

        num = (num + 1) % 2;
        pthread_mutex_unlock(&mylock);
        pthread_cond_signal(&qready);
    }

    return (void*) 0;
}

int main()
{
    int i, k;
    pthread_t tid;
    void *tret;


    pthread_create(&tid, NULL, thread_func, NULL);

    for(i = 0; i < LOOP; i++)
    {
        pthread_mutex_lock(&mylock);

        while(parm_1 != num)
            pthread_cond_wait(&qready, &mylock);

        printf("main: \n");
        for(k = 0; k < 10; k++)
            printf(" %d", k + 100);
        printf("\n");

        num = (num + 1) % 2;
        pthread_mutex_unlock(&mylock);
        pthread_cond_signal(&qready);
    }

    pthread_join(tid, &tret);
}