Update README.md

README.md

@@ -1,2 +1,60 @@
 # ThreadPrograming
+#include <stdio.h>   
+#include <stdlib.h>//for exit()
+#include <pthread.h>//for pthread()   
+#include <unistd.h> //for fork()and execl()
+#include <sys/types.h>  
+#include <semaphore.h>//for sem_wait()and sem_post()
 
+int n=10,in=0,out=0,buffer[10];         //global variables:buffer   sem_t defines signal and two signal inited in main
+//n用作取模，in和out分别当作生产者的放和消费者的取,buffer[10]代表十个缓冲区，可同时读和写
+sem_t empty,full;	//当库存为空时，消费者不再拿。当库存为满时，生产者不再生产。
+
+void* producer(void*arg)
+{
+    int tag=pthread_self()%100;		//线程id的模，可重复
+	int nextPro;		//用作输出当前线程产品名
+	srand(time(NULL)+tag);		//pthread_self(): thread number 	Srand: rand seed;
+	// one producer produces constantly
+	while(1)
+	{
+		nextPro=rand()%97;
+		sem_wait(&empty);
+		buffer[in]=nextPro;
+		printf("production:%d %d\n",nextPro,buffer[in]);	//buffer[in]可能在多线程中发生冲突而改变
+		usleep(1000*1000/20);	//sleep: unit is weimiao;	1 seconds = 1000*1000 weimiao,except 20 equal to 0.05 seconds;	
+		in=(in+1)%n;
+		sem_post(&full);	//wait and signal of signmount
+		usleep(1000*1000/2); 
+	}
+}
+//consumer process
+void* consumer(void *arg)
+{
+	int item;
+	while(1)
+	{
+		sem_wait(&full);
+		item = buffer[out];
+		sem_post(&empty);
+		printf("consume:%d\n",buffer[out]);
+		out=(out+1)%n;
+		usleep(1000*1000/2);
+	}
+}
+
+int main()
+{
+	pthread_t tid[2];
+	//初始有10个缓冲区
+	//线程号数组：根据需要，有多少线程，就定位多大
+	sem_init(&empty,0,10);	//整形信号量初始化函数：第3个参数表示信号量的初始值，第2个参数可暂时不管
+	sem_init(&full,0,0);
+	pthread_create(&tid[0],NULL,producer,NULL);			//create thread
+	pthread_create(&tid[1],NULL,consumer,NULL);
+	for(int i=0;i<2;i++)
+	{
+		pthread_join(tid[i],NULL);	//等待所有线程结束，若不然，main结束后其他线程将被终止
+	}
+	printf("main is over\n");
+}