Linux下多线程编程简介（六）

2021-09-30 03:05:17

本篇将根据前面所学的知识，设计一个简单的生产者/消费者模式。

有一个缓冲区和两个线程：生产者和消费者。生产者把产品放入缓冲区，而消费者从缓冲区中拿走。当缓冲区满时，生产者必须等待；另外，当缓冲区空时，消费者必须等待，并且缓冲区不能同时进行生产者和消费者的操作。

#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <errno.h>
#include <semaphore.h>

#define return_if_fail(p) \
if(!p) { printf("[%s]:func error!", __func__); return; }

typedef struct _PrivInfo {
          sem_t empty;
          sem_t full;
          char buf[50];
          time_t end_time;
}PrivInfo;

void info_init(PrivInfo *thiz);
void info_destroy(PrivInfo *thiz);
void *productor(void *paramthiz);
void *consumer(void *paramthiz);

int main (int argc, char** argv) {
pthread_t pt_1 = 0;
pthread_t pt_2 = 0;

int ret = 0;

PrivInfo *thiz = NULL;

thiz = (PrivInfo*)malloc(sizeof(PrivInfo));

          if(NULL == thiz) {
                    return -1;
          }

info_init(thiz);

ret = pthread_create(&pt_1, NULL, productor, (void*)thiz);

          if(0 != ret) {
                    perror("pthread1 creation failed!");
          }

          ret = pthread_create(&pt_2, NULL, consumer,(void*)thiz);

          if(0 != ret) {
                    perror("pthread2 creation failed!");
          }

pthread_join(pt_1, NULL);
pthread_join(pt_2, NULL);

          info_destroy(thiz);

          free(thiz);
          thiz = NULL;

          return 0;
}

void info_init(PrivInfo *thiz) {
return_if_fail(&thiz != NULL);

thiz->end_time = time(NULL) + 10;

          sem_init(&thiz->empty, 0, 1);
          sem_init(&thiz->full, 0, 0);

          memset(thiz->buf, 0, sizeof(thiz->buf));

          return;
}

void info_destroy(PrivInfo *thiz) {
return_if_fail(&thiz != NULL);

          sem_destroy(&thiz->empty);
          sem_destroy(&thiz->full);

          return;
}

void *productor(void *paramthiz) {
int i = 0;

PrivInfo *thiz = (PrivInfo *)paramthiz;

          while(time(NULL) < thiz->end_time) {
                    sem_wait(&thiz->empty);

                    for(; i<4; i++) {
                              thiz->buf[i] = 0x41 + i;
                    }

                    sem_post(&thiz->full);

sleep(1);
}

pthread_exit(NULL);
}

void *consumer(void *paramthiz) {
int numread = 0;

PrivInfo *thiz = (PrivInfo *)paramthiz;

while(time(NULL) < thiz->end_time) {
sem_wait(&thiz->full);

printf("get the string from buffer is: %s\n", thiz->buf);

sem_post(&thiz->empty);

                    sleep(1);
          }

          pthread_exit(NULL);
}

本文转自jazka 51CTO博客，原文链接：http://blog.51cto.com/jazka/234728，如需转载请自行联系原作者

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