|
#include<stdio.h>
#include<pthread.h>
#include<sys/types.h>
#include<sys/stat.h>
#include<fcntl.h>
#include<unistd.h>
#include<stdlib.h>
#include<sys/mman.h>
#include<string.h>
#include<strings.h>
#define MAXFILESIZE 128
#define MAXTHERAD 10
static int file_size;
static int new_file_size; //其实只用设置前面一个就好了，这里是开始写这段代码拿来测试文件空洞有没有形成
static char *file_point;
static char *new_file_point;
static int threadNum = 0;
//这些静态变量不赋初值默认都是0
void *pthFunc(void *args)
{
int i = threadNum++;
int srcpoint = (file_size/10)*i; //获取对应线程的拷贝起始点
int destpoint = srcpoint;
if(i!=9)
{
memcpy(new_file_point+destpoint,file_point+srcpoint,file_size/10);
}
else
{ //考虑最后一个线程拷贝的可能不足一块
memcpy(new_file_point+destpoint,file_point+srcpoint,file_size-srcpoint);
}
pthread_exit(NULL);
}
|
int main(int argc,char **argv)
{
if(2!=argc)
{
printf("error args\n");
return -1;
}
int fdr = open(argv[1],O_RDONLY,0666);
if(-1==fdr)
{
printf("fdr open error\n");
return -1;
}
char new_file_name[MAXFILESIZE];
sprintf(new_file_name,"%s%s","new_",argv[1]);
int fdw = open(new_file_name,O_CREAT|O_RDWR,0666);
if(-1==fdw)
{
printf("fdw open error\n");
return -1;
}
struct stat buf1,buf2;
bzero(&buf1,sizeof(buf1));
bzero(&buf2,sizeof(buf2));
fstat(fdr,&buf1);
file_size = buf1.st_size;
ftruncate(fdw,file_size);
fstat(fdw,&buf2);
new_file_size = buf2.st_size;
file_point = (char*)mmap(NULL,file_size,PROT_READ,MAP_SHARED,fdr,0);
//prot只是读权限，则文件描述符要有可读权限
new_file_point = (char*)mmap(NULL,new_file_size,PROT_WRITE,MAP_SHARED,fdw,0); //prot是写权限，则文件描述符要有可读可写权限
pthread_t pth[MAXTHERAD];
for(int i = 0;i<10;i++)
{
pthread_create(&pth[i],NULL,pthFunc,NULL);
}
printf("start copying\n");
for(int i = 0;i<10;i++)
{
pthread_join(pth[i],NULL);
}
printf("Done!\n"); //没有解除映射，不过进程结束自动解除
return 0;
}
|
