《操作系统》的实验代码。
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2.4 KiB

#include <defs.h>
#include <kmalloc.h>
#include <sem.h>
#include <vfs.h>
#include <dev.h>
#include <file.h>
#include <sfs.h>
#include <inode.h>
#include <assert.h>
//called when init_main proc start
void
fs_init(void) {
vfs_init();
dev_init();
sfs_init();
}
void
fs_cleanup(void) {
vfs_cleanup();
}
void
lock_files(struct files_struct *filesp) {
down(&(filesp->files_sem));
}
void
unlock_files(struct files_struct *filesp) {
up(&(filesp->files_sem));
}
//Called when a new proc init
struct files_struct *
files_create(void) {
//cprintf("[files_create]\n");
static_assert((int)FILES_STRUCT_NENTRY > 128);
struct files_struct *filesp;
if ((filesp = kmalloc(sizeof(struct files_struct) + FILES_STRUCT_BUFSIZE)) != NULL) {
filesp->pwd = NULL;
filesp->fd_array = (void *)(filesp + 1);
filesp->files_count = 0;
sem_init(&(filesp->files_sem), 1);
fd_array_init(filesp->fd_array);
}
return filesp;
}
//Called when a proc exit
void
files_destroy(struct files_struct *filesp) {
// cprintf("[files_destroy]\n");
assert(filesp != NULL && files_count(filesp) == 0);
if (filesp->pwd != NULL) {
vop_ref_dec(filesp->pwd);
}
int i;
struct file *file = filesp->fd_array;
for (i = 0; i < FILES_STRUCT_NENTRY; i ++, file ++) {
if (file->status == FD_OPENED) {
fd_array_close(file);
}
assert(file->status == FD_NONE);
}
kfree(filesp);
}
void
files_closeall(struct files_struct *filesp) {
// cprintf("[files_closeall]\n");
assert(filesp != NULL && files_count(filesp) > 0);
int i;
struct file *file = filesp->fd_array;
//skip the stdin & stdout
for (i = 2, file += 2; i < FILES_STRUCT_NENTRY; i ++, file ++) {
if (file->status == FD_OPENED) {
fd_array_close(file);
}
}
}
int
dup_files(struct files_struct *to, struct files_struct *from) {
// cprintf("[dup_fs]\n");
assert(to != NULL && from != NULL);
assert(files_count(to) == 0 && files_count(from) > 0);
if ((to->pwd = from->pwd) != NULL) {
vop_ref_inc(to->pwd);
}
int i;
struct file *to_file = to->fd_array, *from_file = from->fd_array;
for (i = 0; i < FILES_STRUCT_NENTRY; i ++, to_file ++, from_file ++) {
if (from_file->status == FD_OPENED) {
/* alloc_fd first */
to_file->status = FD_INIT;
fd_array_dup(to_file, from_file);
}
}
return 0;
}