私が直面している問題は、ファイルをコピーしようとすると、ファイルの一部のみがコピーされ、他の部分は読み取り不能な文字の束であるということです。これは、バリア同期を使用する必要がある学術的な課題のためのものであるため、open、write、および read を使用する必要があります。
スレッド関数を何度も作り直しましたが、それが問題である場合は再度変更できます。メインの for ループをまったく変更していないので、それが問題かもしれませんが、それが何であるかはわかりません。最後に、バリアをどうするかはよくわかりません。私の教授は非常にあいまいで、私は彼に質問することはできません.おそらく障壁は私が本当に欠けている部分です.
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <semaphore.h>
#include <pthread.h>
#include <unistd.h>
typedef struct args {
int fd;
int copy;
long int start;
long int size;
}threadarg;
int barrier = 0;
int main(int argc, char *argv[])
{
void usage(char *progname);
int chkdst(char **argv);
void die(char *why);
long int filesize(char *srcpath);
void buildpath(char *src, char *dst, char **dstpath);
int isvalid(char *path, char *dst);
void *dowork(void *arg);
if (argc < 4) usage("a8");
int workers, i;
char *check;
workers = strtol(argv[3], &check, 10);
if (!check) usage("a8");
else if (!chkdst(&argv[2])) die ("DST not valid!");
long int size = filesize(argv[1]);
if (size == -1) die ("Could not find file size");
char *dstpath; buildpath(argv[1], argv[2], &dstpath);
if (!isvalid(argv[1], dstpath)) die ("scr not valid!");
long int chunksize = size / workers;
long int remainder = size % workers;
int fd = open(argv[1], O_RDONLY);
int copy = open(dstpath, O_CREAT | O_RDWR, 0644);
if (fd < 0 || copy < 0) die("Fail to access or create files");
barrier = workers;
threadarg threadargs[workers];
pthread_t threads[workers];
for (i = 0; i < workers; i++)
{
threadargs[i].fd = fd;
threadargs[i].copy = copy;
threadargs[i].start = i * chunksize;
if (i == workers - 1)
threadargs[i].size = chunksize + remainder;
else
threadargs[i].size = chunksize;
if (pthread_create(&threads[i], NULL, dowork, (void *) &threadargs[i]))
die("Thread Creation Failure");
}
for (i = 0; i < workers; i++)
pthread_join(threads[i], NULL);
}
void usage(char *progname)
{
fprintf(stderr, "./%s srcpath dstpath workercount\n", progname);
exit(0);
}
void die(char *why)
{
fprintf(stderr, "Program Killed...\nReason: %s\n", why);
exit(1);
}
long int filesize(char *srcpath)
{
struct stat st;
if(stat(srcpath, &st) != 0) return 0;
return st.st_size;
}
/*
void domd5(char *path)
{
}
*/
void *dowork(void *arg)
{
threadarg *args = (threadarg *)arg;
int fd = args->fd,
copy = args->copy, rd;
long int start = args->start,
size = args->size;
char bufs[2048], *remains;
lseek(fd, start, SEEK_SET);
lseek(copy, start, SEEK_SET);
printf("%d thread with offset %ldKB, reached barrier\n", (int) pthread_self(), start);
barrier--;
while (barrier > 0);
long int count = 0, remainder = 0, i;
for (i = 0; i < size; i += 2048)
{
if (i + 2048 > size)
{
remainder = size - count;
remains = malloc(remainder * sizeof(char));
rd = read (fd, remains, sizeof(remains));
if (write(copy, remains, rd) != rd)
die("Error accessing files during copy");
count += remainder;
}
else
{
rd = read(fd, bufs, sizeof(bufs));
if (write(copy, bufs, rd) != rd)
die("Error accessing files during copy");
count += 2048;
}
}
pthread_exit(NULL);
}
/* Takes a single pointer, *argv, and passes it to isdir()
to check if the directory exists. If isdir returns a 1 a
1 is returned from this module. Otherwise, an error message
is printed and a 0 is returned.
Calls isdir().
Called by main().
*/
int chkdst(char **argv)
{
int isdir(char *path);
if (isdir(*argv)) return 1;
return 0;
}
/* Uses the Stat struct to construct a struct, sbuf,
and uses stat() to obtain information from the file and
write it to sbuf. Uses S_ISDIR() on sbuf.st_mode to see
the mode of the file. A 1 is returned if the file is a
directory otherwise a 0 is returned.
Called by isvalid().
*/
int isdir(char *path)
{
struct stat sbuf;
if (stat(path, &sbuf)) return 0;
return S_ISDIR(sbuf.st_mode);
}
/* Uses the Stat struct to construct a struct, sbuf,
and uses stat() to obtain information from the file and
write it to sbuf. Uses S_ISREG on sbuf.st_mode to see if
the file is regular. A 1 is returned if the S_ISREG is true
otherwise a 0 is returned.
Called by isvalid().
*/
int isregular(char *path)
{
struct stat sbuf;
if (stat(path, &sbuf)) return 0;
return S_ISREG(sbuf.st_mode);
}
/* Checks if the source path is a directory first, then if its
a regular file return 0 if it is dir and if it isn't a regular
file, then checks if the destionation path was created or if
the file exist at the destination if either return 0, if none
of these return 1.
Calls isdir() and isregular().
Called by copyfiles().
*/
int isvalid(char *path, char *dst)
{
if (isdir(path))
{
return 0;
}
else if (!isregular(path))
{
return 0;
}
else if (dst == NULL)
{
return 0;
}
else if (isregular(dst))
{
return 0;
}
return 1;
}
/* Builds destination-path using strrchr() function from library,
dstpath is null on error and defined otherwise. The src file has
its original destination removed and replaced with the new one if
it has a original destination on it otherwise it is just added to
the end of the existing name of the file.
Called by copyfiles().
*/
void buildpath(char *src, char *dst, char **dstpath)
{
char *ptr;
int n;
ptr = strrchr(src, '/');
if (ptr) n = strlen(dst) + strlen(ptr) + 2;
else n = strlen(dst) + strlen(src) + 2;
*dstpath = malloc(n);
if (!dstpath) return;
if (ptr)
{
strcpy(*dstpath, dst);
strcat(*dstpath, ptr);
}
else
{
strcpy(*dstpath, dst);
strcat(*dstpath, "/");
strcat(*dstpath, src);
}
}