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IDvoid *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);}