test1.cpp

操作系统经典同步问题 消费者与生产者问题

#include <stdlib.h>
#include <stdio.h>
#include <windows.h>

typedef int buffer_item;
#define BUFFER_SIZE 5
buffer_item buffer[BUFFER_SIZE];
int count=0,in=0,out=0;
bool producer_done = 0;
HANDLE sem_full;		
HANDLE sem_empty;		
HANDLE sem_mutex;

DWORD WINAPI producer(LPVOID arg)
{
	buffer_item num;
	for(int p=0;p<=10;p++)
	{
		num=rand()%RAND_MAX;
		WaitForSingleObject(sem_empty,INFINITE);
        WaitForSingleObject(sem_mutex,INFINITE); 
        buffer[in]=num;
	    in=(in+1)%BUFFER_SIZE;
	    count++;
		printf("producer produced %d\n",num);
		ReleaseSemaphore(sem_mutex,1,NULL);
        ReleaseSemaphore(sem_full,1,NULL); 
	}
	WaitForSingleObject(sem_mutex,INFINITE);
    producer_done = 1;
    ReleaseSemaphore(sem_mutex,1,NULL);
	return 0;
}

DWORD WINAPI consumer(LPVOID arg)
{
	buffer_item num;
	for(int p=0;p<=10;p++)
	{
		WaitForSingleObject(sem_mutex,INFINITE);		
        if (count<=0 && producer_done)
	    {
	       ReleaseSemaphore(sem_mutex,1,NULL);
	       break;
	    }
        ReleaseSemaphore(sem_mutex,1,NULL);
	    WaitForSingleObject(sem_full,INFINITE);
        WaitForSingleObject(sem_mutex,INFINITE);		
        num=buffer[out];
		out=(out+1)%BUFFER_SIZE;
		count--;
		printf("consumer consumed %d\n",num);
		ReleaseSemaphore(sem_mutex,1,NULL);
		ReleaseSemaphore(sem_empty,1,NULL);
	}
	return num; 
}

int main()
{
	int i;
	sem_mutex=CreateSemaphore(NULL,1,1,NULL);
	sem_full=CreateSemaphore(NULL,0,5,NULL);
	sem_empty=CreateSemaphore(NULL,5,5,NULL);
	for( i=0;i<BUFFER_SIZE;i++)
	      buffer[i]=0;
	HANDLE pro,con;
	for( i=0;i<11;i++)
	{
		printf("This is No. %d producer\n",i);
	    pro=CreateThread(NULL,0,producer,NULL,0,NULL);
    }
	for( i=0;i<11;i++)
	{
		printf("This is No. %d consumer\n",i);
	    pro=CreateThread(NULL,0,consumer,NULL,0,NULL);
    }
	for( i=0;i<11;i++)
	   WaitForSingleObject(pro,INFINITE);
	for( i=0;i<11;i++)
	   WaitForSingleObject(con,INFINITE);
	return 0;
}