/*Ubuntu 14.04平台下* 利用多线程 mmap文件内存共享* 实现文件拷贝*//*more thread copy files* 默认情况下开启5个线程*/#include <stdio.h>#include <sys/stat.h>#include <sys/mman.h>#include <stdlib.h>#include <fcntl.h>#include <unistd.h>#include <string.h>#include <pthread.h>#include <errno.h>#include <sys/types.h>/*thread number*/#define T_NUM 5#define ITEMS 50typedef struct{ /*off size,file size,thread identifier */ int off,size,t_no;}arg_t;void err_sys(void *str){ perror(str); exit(1);}void err_usr(char *str){ fputs(str,stderr); exit(1);}char *pch_sour_file,*pch_des_file;int *pi_has_done;int pnum=T_NUM;/*arg {off,size,t_no}*/void *pt_cp(void *arg){ if(NULL==arg) return NULL; arg_t *arg_p;int i; char *pch,*qch; arg_p=(arg_t *)arg; pch=pch_sour_file+arg_p->off,qch=pch_des_file+arg_p->off; for(i=0;i<arg_p->size;i++) { *qch++=*pch++; pi_has_done[arg_p->t_no]++; /*usleep function is like to sleep*/ usleep(5000); } return NULL;}void *display_pro(void * arg){ int size,draw=0,sum,i,j,interval; size=(int)arg; interval=size/ITEMS; while(draw<ITEMS) { for(i=0,sum=0;i<pnum;i++) sum+=pi_has_done[i]; j=sum/interval+1; for(;j>draw;draw++) putchar('=');fflush(stdout); } printf("\n"); return NULL;}int main(int argc,char *argv[]){ int src,dst,i,len,off; struct stat statbuff; pthread_t *tid; arg_t *arg_arr; if(argc!=3 && argc!=4) err_usr("usage：cp src dst [pthread_no]\n"); /*修改线程数*/ if(argc==4) pnum=atoi(argv[3]); src=open(argv[1],O_RDONLY); if(src<0) {printf("fail to open %s\n",argv[1]);return -1;} dst=open(argv[2],O_RDWR | O_CREAT | O_TRUNC,0644); if(dst<-1) {printf("fail to open %s\n",argv[2]);return -1;} if(fstat(src,&statbuff)==-1) { err_sys("fail to stat"); return -1; } /*创建同样的大小文件*/ lseek(dst,statbuff.st_size-1,SEEK_SET); write(dst,"a",1); pch_sour_file=(char *)mmap(NULL,statbuff.st_size,PROT_READ,MAP_SHARED,src,0); if(pch_sour_file==MAP_FAILED) { err_sys("fail to mmap"); return -1; } pch_des_file=(char *)mmap(NULL,statbuff.st_size,PROT_WRITE,MAP_SHARED,dst,0); if(pch_des_file==MAP_FAILED) { err_sys("fail to mmap"); return -1; } /*close file discription*/ close(src);close(dst); /*crate pthread tid[n+1]*/ tid=(pthread_t *)malloc(sizeof(pthread_t)*(pnum+1)); if(NULL==tid) { err_sys("fail to malloc"); return -1; } /*per thread copy bite*/ /*每个线程需要的拷贝的字节数*/ pi_has_done=(int *)calloc(sizeof(int),pnum); if(NULL==pi_has_done) { err_sys("fail to calloc"); return -1; } /*arg_arr[n] per thread task*/ arg_arr=(arg_t *)malloc(sizeof(arg_t)*pnum); if(NULL==arg_arr) { err_sys("fail to malloc"); return -1; } /*allocating task*/ len=statbuff.st_size/pnum,off=0; for(i=0;i<pnum;i++,off+=len) arg_arr[i].off=off,arg_arr[i].size=len,arg_arr[i].t_no=i; /*reminder byte add last struct arg_t*/ arg_arr[pnum-1].size+=statbuff.st_size%pnum; /*create pthread to do*/ for(i=0;i<pnum;i++) pthread_create((tid+i),NULL,pt_cp,(void *)(arg_arr+i)); /*专门显示进度的线程*/ pthread_create((tid+pnum),NULL,display_pro,(void *)statbuff.st_size); for(i=0;i<pnum;i++) pthread_join(tid[i],NULL); /*关闭文件共享*/ munmap(pch_sour_file,statbuff.st_size); munmap(pch_des_file,statbuff.st_size); /*回收内存*/ free(tid); free(arg_arr); free(pi_has_done); return 0;}效果图如下所示：
，还深深埋在心底，要除去，怕是不能活命。
