KvGUreCr

1  struct mmap_file *mf;
2  mf = (struct mmap_file *)malloc(sizeof(struct mmap_file));
3  if(mf == NULL)
4    return MAP_FAILED;
5  mf->mid = t->mmap_files_num_ever;
6  t->mmap_files_num_ever++;
7  mf->file = file_to_map;
8  mf->upage = addr;
9
10  /* Fill in entries in supplementary table and page table */
11  offset = 0;
12  int pg_num = 0;
13  size_t read_bytes = PGSIZE;
14  uint32_t *pte;
15  uint32_t *pd = t->pagedir;
16  for (offset = 0; offset < len; offset += PGSIZE)
17  {
18    /* Fill in page table entry in pagedir, but do not allocate memory */
19    ASSERT (pagedir_get_page (pd, addr + offset) == NULL);
20    pte = lookup_page (pd, addr + offset, true);
21    ASSERT (pte != NULL);
22    ASSERT ((*pte & PTE_P) == 0);
23    *pte = PTE_U | PTE_M;
24    bool is_writable = file_is_writable(t->file_handlers[fd]);
25    *pte |= is_writable ? PTE_W : ~PTE_W;
26    /* Create suppl_pte */
27    if(offset + PGSIZE >= len)
28      read_bytes = len - offset;
29    if (!suppl_pt_insert_mmf (t, pte, is_writable, file_to_map, offset, read_bytes))
30      return MAP_FAILED;
31    pg_num ++;
32  }
33  mf->num_pages = pg_num;
34  if( hash_insert (&t->mmap_files, &mf->elem) != NULL)
35    return MAP_FAILED;
36
37  return mf->mid;
38}
39
40/* Unmap system call : unmap a file */
41static void
42_munmap(mapid_t mapping)
43{
44  struct thread *t = thread_current();
45  struct mmap_file mf;
46  struct hash_elem *h_elem_mf;
47  mf.mid = mapping;
48  h_elem_mf = hash_delete (&t->mmap_files,&mf.elem);
49  /* otherwise, such mapping not exists */
50  if(h_elem_mf)
51    mmap_free_file (h_elem_mf, NULL);
52}