多线程文件拷贝

多线程文件拷贝

#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <unistd.h>
pthread_mutex_t mutex;
char *src_addr=NULL;
char *new_addr=NULL;
int count;
void *pth_work(void *arg)
{
	int i=*(int *)arg;
	pthread_mutex_lock(&mutex);//上锁
	printf("%ld子线程开始拷贝.....\n",pthread_self());
	memcpy(new_addr+i*count,src_addr+i*count,count);
	pthread_mutex_unlock(&mutex);//解锁
}
int main(int argc, char **argv)
{
	int fp=open(argv[1],0);
	if(fp<0)
	{
		printf("文件打开失败\n");
		return 0;
	}
	int new_fp=open(argv[2],O_RDWR|O_CREAT,0666);
	if(new_fp<0)
	{
		printf("新文件打开失败\n");
		return 0;
	}
	//获取文件大小
	struct stat statbuf;
	fstat(fp,&statbuf);
	//设置新文件大小
	ftruncate(new_fp,statbuf.st_size);
	//内存映射
	src_addr=mmap(NULL,statbuf.st_size,PROT_READ,MAP_PRIVATE,fp,0);
	new_addr=mmap(NULL,statbuf.st_size,PROT_READ|PROT_WRITE,MAP_SHARED,new_fp,0);
	close(fp);
	close(new_fp);
	//内存拷贝
	count=statbuf.st_size/5;
	int remain=statbuf.st_size%5;
	//创建普通锁
	pthread_mutex_init(&mutex,NULL);
	pthread_t pthid;
	int i=0;
	for(i=0;i<5;i++)
	{
		pthread_create(&pthid,NULL,pth_work,(void *)&i);
		sleep(1);
	}
	while(1)
	{
		pthread_mutex_lock(&mutex);//上锁
		memcpy(new_addr+i*count,src_addr+i*count,remain);
		pthread_mutex_unlock(&mutex);//解锁
		//取消映射
		munmap(src_addr,statbuf.st_size);
		munmap(new_addr,statbuf.st_size);
		exit(0);//结束进程
	}
}