Linux--生产者消费者模型，信号量和条件信号量

生产者和消费者

一个生产者，三个消费者模型，利用

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

#define PRO 1
#define CON 3

int ready = 0; // 生产的产品编号

pthread_cond_t cond;
pthread_mutex_t mutex;
pthread_t tids[PRO+CON] ;

void *pro(void *arg) {
int id = *(int*)arg;
free(arg);
while ( 1 ) { 
sleep(1);
pthread_mutex_lock(&mutex);
printf("%d生产者线程开始生产产品，产品编号为%d\n", id, ready+1);
ready++;
sleep(rand()%3);
printf("%d生产者线程结束生产产品, 产品编号%d\n", id, ready);
pthread_cond_signal(&cond); // 通知消费者进行消费
pthread_mutex_unlock(&mutex);
sleep(rand()%3);
}
}
void *con(void *arg) {
int id = *(int*)arg;
free(arg);

while ( 1 ) {
pthread_mutex_lock(&mutex);
while ( ready <= 0 ) {
printf("%d消费者线程等待产品\n", id);
pthread_cond_wait(&cond, &mutex);
printf("%d消费者线程等到产品，返回\n", id);
}
printf("%d消费者线程开始消费产品,%d\n",id, ready);
ready--;
sleep(rand()%3);
printf("%d消费者线程消费完毕,%d\n", id, ready+1);
pthread_mutex_unlock(&mutex);
sleep(rand()%2);
}
}

int main( void ) {
int i;

srand(getpid());
pthread_cond_init(&cond, NULL);
pthread_mutex_init(&mutex, NULL);
for (i=0; i<PRO; i++) {
int *p = malloc(sizeof(int));
*p = i;
pthread_create(&tids[i], NULL, pro, (void*)p);
}
for (i=0; i<CON; i++) {
int *p = malloc(sizeof(int));
*p = i;
pthread_create(&tids[PRO+i], NULL, con, (void*)p);
}

for (i=0; i<PRO+CON; i++) {
pthread_join(tids[i], NULL);
}

pthread_mutex_destroy(&mutex);
pthread_cond_destroy(&cond);
}