多线程信号量的使用

使用信号量实现了多个生产者，多个消费者，多个缓冲区的消费者和生产者的解决方案。

模拟场景： 15个生产者，10个消费者，5个缓冲区，缓冲区数据结构包含数据、生产线程tid、写入时间。

编译时使用： 

gcc -o kk kk.c -lpthread

#include <stdlib.h>
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>  //getpid()
#include <semaphore.h> 
#include <fcntl.h>
#include <errno.h>
#include <sys/syscall.h>   //gettid() thread
#include<time.h>
#include <string.h>      //for memset
//创建模式权限
#define FILE_MODE  (S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH)
#define BUFFER 5 // 缓冲区数量
#define PRO_NO 30 // PRODUCING NO
#define OVER ( - 1)
#define PSLEEP 10000  // 
#define CSLEEP 10000  // 

#define PRODUCER 15  // 生产者线程数量
#define CONSUMER 10  // 消费者线程数量
#define gettid() syscall(SYS_gettid)   //获取线程ID

    sem_t empty,full;//同步信号量
    pthread_mutex_t mutex;//互斥信号量

struct prodcons
{// 缓冲区相关数据结构
    int buf[BUFFER]; /* 实际数据存放的数组*/
    int tid[BUFFER];            //生产进程PID   getpid() 头文件
    char *time[BUFFER];         //写入时间
    int readpos, writepos; /* 读写指针*/
};
struct prodcons buffer;

/* 初始化缓冲区结构 */
void init(struct prodcons *b)
{
    b->readpos = 0;
    b->writepos = 0;
}
int producer_id=0,consumer_id=0;//生产者消费者ID


void *Producer()//生产者函数
{
int n=0;
time_t timep;
time(&timep);
char *tem;
int nn=PRO_NO;
   while(nn--)
   {

     sleep(3);
     sem_wait(&empty);
     pthread_mutex_lock(&mutex);
     
    buffer.buf[buffer.writepos] = n;
    buffer.tid[buffer.writepos] = gettid();  //threadid
    tem = asctime(gmtime(&timep));
    buffer.time[buffer.writepos] = tem; //time
    printf("data:%d ,tid: %ld ,time_in: %s --->\n", n,gettid(),tem);
        
    buffer.writepos++;
    if (buffer.writepos >= BUFFER)
        buffer.writepos = 0;
     pthread_mutex_unlock(&mutex);
     sem_post(&full);
     n++;
   }
   
}
void *Consumer()//消费者函数
{
    int d;
int gettid;
char *tt;
   while(1)
   {
     sleep(3);
     sem_wait(&full);
     pthread_mutex_lock(&mutex);
    /* 读数据,移动读指针*/
    d = buffer.buf[buffer.readpos];
    gettid = buffer.tid[buffer.readpos];
    tt = buffer.time[buffer.readpos];
    //usleep(CSLEEP);
    buffer.readpos++;
    if (buffer.readpos >= BUFFER)
        buffer.readpos = 0;
    printf("--->data:%d ,tid: %d ,time_in: %s \n", d,gettid,tt);
    if (d == OVER)
        break;
     
     pthread_mutex_unlock(&mutex);
     sem_post(&empty);
   }
}

int main()
{
init(&buffer);
   int rthread[18],i;
   pthread_t producer[PRODUCER];//生产者
   pthread_t consumer[CONSUMER];//消费者

   int sinit1=sem_init(&empty,0,BUFFER);//初始化同步信号量
   int sinit2=sem_init(&full,0,0);
   int minit =pthread_mutex_init(&mutex,NULL);//初始化互斥信号量
   if(sinit1 && sinit2)
   {
     printf("sem initialize failed /n");
     exit(1);
   }
   if(minit)
   {
     printf("sem initialize failed /n");
     exit(1);
   }
   for(i=0;i<PRODUCER;i++)//创建生产者线程
   {
      rthread[i]=pthread_create(&producer[i], NULL, Producer, NULL);
      if(rthread[i])
      {
          printf("producer %d create failed /n", i);
          exit(1);
      }
   }
   for(i=0;i<CONSUMER;i++)//创建消费者线程
   {
      rthread[i]=pthread_create(&consumer[i], NULL, Consumer,NULL);
      if(rthread[i])
      {
          printf("consumer %d create failed /n", i);
          exit(1);
      }
   }
   for(i=0;i<PRODUCER;i++)//销毁生产者线程
   {
      pthread_join(producer[i],NULL);
   }
   for(i=0;i<CONSUMER;i++)//销毁生产者线程
   {
      pthread_join(consumer[i],NULL);
   }
   exit(0);
}