/**
* Convert the XML input to INFO output.
*/
int process(FILE* is, FILE* os)
{
struct state_t state;
char buf[4096];
state.parser = XML_ParserCreate(NULL);
if (!state.parser) {
fprintf(stderr, "Couldn't allocate memory for parser\n");
return -1;
}
state.depth = -1;
state.os = os;
state.error = 0;
container_alloc(&state.game_map, &state.game_mac, &state.game_max);
container_alloc(&state.reference_map, &state.reference_mac, &state.reference_max);
XML_SetUserData(state.parser, &state);
XML_SetElementHandler(state.parser, start_handler, end_handler);
XML_SetCharacterDataHandler(state.parser, data_handler);
while (1) {
int done;
int len;
len = fread(buf, 1, sizeof(buf), is);
if (ferror(is)) {
process_error(&state, "", "read error");
break;
}
done = feof(is);
if (XML_Parse(state.parser, buf, len, done) == XML_STATUS_ERROR) {
process_error(&state, "", XML_ErrorString(XML_GetErrorCode(state.parser)));
break;
}
if (done)
break;
}
XML_ParserFree(state.parser);
if (state.error) {
return -1;
}
if (check(&state) != 0) {
return -1;
}
container_free(&state.game_map, &state.game_mac, &state.game_max);
container_free(&state.reference_map, &state.reference_mac, &state.reference_max);
return 0;
}
/**
* This function will be called when there's no mapping found in the page structure
* for the given virtual address [vaddr], e.g., by the page fault handler when
* a page fault happened because the user process accessed a virtual address
* that is not mapped yet.
* The task of this function is to allocate a physical page and use it to register
* the mapping for the virtual address with given permission.
* It should return the physical page index registered in the page directory, i.e., the
* return value from map_page.
* In the case of error, it should return the MagicNumber.
*/
unsigned int alloc_page (unsigned int proc_index, unsigned int vaddr, unsigned int perm)
{
unsigned int page_id;
if (page_id = container_alloc(proc_index))
{
return map_page(proc_index, vaddr, page_id, perm);
}
return MagicNumber;
}
/**
* Allocates a page (with container_alloc) for the page table,
* and registers it in page directory for the given virtual address,
* and clears (set to 0) the whole page table entries for this newly mapped page table.
* It returns the page index of the newly allocated physical page.
* In the case when there's no physical page available, it returns 0.
*/
unsigned int alloc_ptbl(unsigned int proc_index, unsigned int vadr)
{
// TODO
unsigned int i;
unsigned int pi;
unsigned int pde_index;
pi = container_alloc(proc_index);
if (pi != 0)
{
set_pdir_entry_by_va(proc_index, vadr, pi);
pde_index = vadr / (4096 * 1024);
i = 0;
while (i < 1024)
{
rmv_ptbl_entry(proc_index, pde_index, i);
i ++;
}
}
return pi;
}
