线程编程练习2



子线程循环 3 次，接着主线程循环 6 次，接着又回到子线程循环 3 次，接着再回到主线程又循环6 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 50

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 < 3; 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 < 6; k++)
printf(" %d", k);

printf("\n");

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

pthread_join(tid, &tret);

return 0;
}