static void
syscall_handler (struct intr_frame *f)
{
uint32_t *esp = f->esp;
if (not_valid(esp))
exit (-1);
switch (*esp)
{
case SYS_HALT:
halt ();
break;
case SYS_EXIT:
if (not_valid(esp+1)) exit(-1);
exit ((int) ARG0);
break;
case SYS_EXEC:
f->eax = exec ((const char *) ARG0);
break;
case SYS_WAIT:
f->eax = wait ((pid_t) ARG0);
break;
case SYS_CREATE:
f->eax = create ((const char *) ARG0, (unsigned) ARG1);
break;
case SYS_REMOVE:
f->eax = remove ((const char *) ARG0);
break;
case SYS_OPEN:
f->eax = open ((const char *) ARG0);
break;
case SYS_FILESIZE:
f->eax = filesize ((int) ARG0);
break;
case SYS_READ:
f->eax = read ((int) ARG0, (void *) ARG1, (unsigned) ARG2);
break;
case SYS_WRITE:
f->eax = write ((int) ARG0, (void *) ARG1, (unsigned) ARG2);
break;
case SYS_SEEK:
seek ((int) ARG0, (unsigned) ARG1);
break;
case SYS_TELL:
f->eax = tell ((int) ARG0);
break;
case SYS_CLOSE:
close ((int) ARG0);
break;
default:
printf ("Invalid syscall!\n");
thread_exit();
}
}
int main()
{
char inp[35];
fgets(inp,33,stdin);
int l;
int i;
if((l=strlen(inp)) != strlen(f)) {
return not_valid();
}
for(i=0;i<l;i++) {
if(inp[i] != f[l-1-i])
return not_valid();
}
return valid();
}
bool
create(const char *file, unsigned initial_size)
{
if (not_valid(file))
exit (-1);
lock_acquire(&file_lock);
bool result = filesys_create (file, initial_size);
lock_release(&file_lock);
return result;
}
int
write (int fd, const void *buffer, unsigned size)
{
if (not_valid(buffer) || not_valid(buffer+size) || fd == STDIN_FILENO)
exit (-1);
lock_acquire(&file_lock);
int result = 0;
if (fd == STDOUT_FILENO)
{
putbuf (buffer, size);
result = size;
}
else
{
struct file *file = get_file(fd);
result = file? file_write(file, buffer, size) : -1;
}
lock_release(&file_lock);
return result;
}
int g3_fastMove(const struct connect4 *game, int *movesToExplore) {
const char me = game->whoseTurn;
struct connect4 tempGame;
// Clear space for wins
int wins[NUM_COLS];
memset(wins, 0, sizeof(wins));
int i, count;
for (i = 0; i < NUM_COLS; i++) {
if (movesToExplore[i] == 0)
continue;
// Run a bunch of sims for this column
for (count = 0; count < g3_FAST_SIMULATIONS; count++) {
memcpy(&tempGame, game, sizeof(struct connect4));
// Play a move in the ith column
tempGame.board[get_row(&tempGame, i)][i] = tempGame.whoseTurn;
tempGame.whoseTurn = other(tempGame.whoseTurn);
char winner = 0;
while (winner == 0 && g3_movesAvailable(&tempGame)) {
int nextMove = g3_has3Wins(&tempGame);
// Try again if move is invalid
while (not_valid(&tempGame, nextMove))
nextMove = rand() % NUM_COLS; // Try again
// If the move would result in a winner or the game is CATS, break the loop
int validRow = get_row(&tempGame, nextMove);
if (g3_is3Win(&tempGame, validRow, nextMove, tempGame.whoseTurn)) {
winner = tempGame.whoseTurn;
} else {
// Otherwise, play the move and keep playing
move(&tempGame, nextMove, tempGame.whoseTurn);
tempGame.whoseTurn = other(tempGame.whoseTurn);
}
}
wins[i] += (winner == me);
}
}
int greatest = -1, greatestMove = -1;
for (i = 0; i < NUM_COLS; i++) {
if (wins[i] > greatest) {
greatest = wins[i];
greatestMove = i;
}
}
return greatestMove;
}
int
read (int fd, void *buffer, unsigned size)
{
if (not_valid(buffer) || not_valid(buffer+size) || fd == STDOUT_FILENO)
exit (-1);
lock_acquire(&file_lock);
int count = 0, result = 0;
if (fd == STDIN_FILENO)
{
while (count < size)
{
*((uint8_t *) (buffer + count)) = input_getc ();
count++;
}
result = size;
}
else
{
struct file *file = get_file(fd);
result = file ? file_read(file, buffer, size) : -1;
}
lock_release(&file_lock);
return result;
}
bool
remove (const char *file)
{
if (not_valid(file))
exit (-1);
lock_acquire(&file_lock);
/* In case the file is opened. First check its existence. */
struct file *f = filesys_open (file);
bool result;
if (f == NULL)
result = false;
else
{
file_close (f);
result = filesys_remove (file);
}
lock_release(&file_lock);
return result;
}
// Convert dheluks data package to encoded string
// has_msg = false: package contains bare minimum (header + pubkey)
// has_msg = true: package contains a message (header + pubkey + nonce + cphtxt)
int pkg_to_str(dheluks_pkg_t *pkg, unsigned char *str, bool has_msg) {
size_t datalen; //length of package data
size_t max_datalen; //max length of pkg data
uint8_t *data; //stores data
size_t codelen; //length of encoded data
unsigned char *code;//stores code
datalen = KEY_SIZE; //min length
max_datalen = KEY_SIZE + NONCE_SIZE + DIGEST_SIZE + pkg->csize; //max length
data = malloc(max_datalen); //allocate max length
memcpy(data, pkg->pubkey, KEY_SIZE); //put the public key in first
if (has_msg == true) { //if there is supposed to be a message
if(not_valid(pkg->cphtxt)) { //but there actually isn't one
err(ERR_NUL, "has_msg is true, but there is no ciphertext.");
return -1; //raise an error
} //else,
datalen += (NONCE_SIZE + DIGEST_SIZE + pkg->csize); //increase datalen for nonce/cphtxt
memcpy(data + KEY_SIZE, pkg->nonce, NONCE_SIZE); //add nonce to data
memcpy(data + KEY_SIZE + NONCE_SIZE, pkg->digest, DIGEST_SIZE);
memcpy(data + KEY_SIZE + NONCE_SIZE + DIGEST_SIZE, pkg->cphtxt, pkg->csize); //add ctxt
}
codelen = B64_ENCODE_LEN(datalen); //size of encoded data
code = malloc(codelen); //allocate memory for code
uint8_to_str(data, code, datalen); //convert data to code
memcpy(str, HEADER, HEADER_LEN); //place the header
memcpy(str+HEADER_LEN, code, codelen); //place the encoded data
free(data); //clean up
return 0; //there were no errors
}
int
open (const char *file)
{
if (not_valid(file))
exit (-1);
lock_acquire(&file_lock);
struct file_descriptor *file_d = malloc(sizeof(struct file_descriptor));
struct file *f = filesys_open(file);
struct thread *cur = thread_current();
if (f == NULL)
{
lock_release(&file_lock);
return -1;
}
file_d->file = f;
file_d->fd = cur->fd;
cur->fd = cur->fd + 1;
list_push_back(&thread_current()->files,&file_d->elem);
lock_release(&file_lock);
return file_d->fd;
}
// Frees a pointer whose value is not null
void free_mem(void *ptr) {
if(not_valid(ptr) == false) //if ptr is not null,
free(ptr); //free it
}
pid_t exec (const char *cmd_line)
{
if (not_valid(cmd_line))
exit (-1);
return process_execute(cmd_line);
}
int g3_handleSpecialCase(const struct connect4 *game) {
// Play the center if there are no other moves
if (!not_valid(game, g3_CENTER)) {
//isCrazy checks if there are moves in other columns;
if (!g3_isCrazy(game)) return g3_CENTER;
}
//Continue to checking for 3wins and 2wins if you shouldn't play the center
int col;
int didTheyWin = -1;
//determines who is who for each of the pieces based on whose turn it is
char us = game->whoseTurn;
//they have to be the opposite of our piece, so set them to the opposite of us
char them = other(us);
//Check all of the columns for if we win by playing in the column or if we block their win
for (col = 0; col < NUM_COLS; col++) {
//finds the row you will be playing in if you select that column
int validRow = get_row(game, col);
//If you can win there, play there!
if (g3_is3Win(game, validRow, col, us)) {
return col;
}
//Otherwise, keep track of where to block the opponent if they have a 3win
if (g3_is3Win(game, validRow, col, them)) didTheyWin = col;
}
//If you found a column you have to block, block it.
if (didTheyWin != -1) return didTheyWin;
//If there are no 3wins, check for 2wins
int enemy2Wins[NUM_COLS];
memset(enemy2Wins, 0, sizeof(enemy2Wins));
//Check in each col if there is a 2win
for (col = 0; col < NUM_COLS; col++) {
int validRow = get_row(game, col);
//if you have a 2win and you don't cause a 3win for the opponent, you should play there
if (g3_is2Win(game, validRow, col, us)) {
if (g3_isSafe(game, validRow, col, us)) {
return col;
}
}
/*
//If your opponent has a 2win and its safe to block them, do it
if (g3_is2Win(game, validRow, col, them) && g3_isSafe(game, validRow, col, us)) {
enemy2Wins[col] = 1;
}
*/
}
/*
for (col = 0; col < NUM_COLS; col++) {
if (enemy2Wins[col] == 1)
return g3_fastMove(game, enemy2Wins);
}
*/
return -1;
}
// Perform a Monte-Carlo Tree Search
void g3_mcts(const struct connect4 *game, g3_MCnode *root) {
// For concision
const char me = game->whoseTurn;
//const int winCondition = me == PLAYERONE ? X_WINS : O_WINS;
// Memory to do scratch-work in
struct connect4 tempGame;
g3_MCnode *nodeStack[g3_NUM_MOVES];
int moveStack[g3_NUM_MOVES];
int s = 0; // Stack pointer
static int runs = 0;
int numSims = g3_max(g3_SIMULATIONS / 26 * (26 - runs), g3_FAST_SIMULATIONS);
runs++;
//puts("g");
//printf("Running %d simulations\n", numSims);
int t; // current number of simulations
for (t = 0; t < numSims; t++) {
// Make a fresh copy of the game
memcpy(&tempGame, game, sizeof(struct connect4));
// Temp pointer to the current node in the tree
g3_MCnode *current = root;
// Reset stack pointer
s = 0;
// Play moves until the hypothetical game ends
char winner = 0;
while (winner == 0 && g3_movesAvailable(&tempGame)) {
if (s >= 26)
puts("Something's gone horribly wrong.");
double probabilities[NUM_COLS];
//const char currPlayer = tempGame.whoseTurn;
// Assume both players will go for special cases
int nextMove = g3_handleSpecialCase(&tempGame);
if (nextMove == -1) {
// Weight current player's path based on past success
if (tempGame.whoseTurn == me)
g3_computeWeightedProbs(probabilities, current->scores, t);
// If there was no immediate win, give all opponent paths an equal chance
else
g3_computeUniformProbs(probabilities);
// Use probabilities to select the next node
while (not_valid(&tempGame, nextMove))
nextMove = g3_chooseMove(probabilities);
}
// Push the move onto the stack if this is our move
if (tempGame.whoseTurn == me) {
//printf("Stack pointer at %d\n", s);
//print_board(&tempGame);
moveStack[s] = nextMove;
nodeStack[s++] = current;
}
// If the move would result in a winner or the game is CATS, break the loop
int validRow = get_row(&tempGame, nextMove);
if (g3_is3Win(&tempGame, validRow, nextMove, tempGame.whoseTurn)) {
winner = tempGame.whoseTurn;
} else {
// Otherwise, play the move and keep playing
tempGame.board[get_row(&tempGame, nextMove)][nextMove] = tempGame.whoseTurn;
tempGame.whoseTurn = other(tempGame.whoseTurn);
current = g3_getNextNode(current, nextMove);
}
}
// Determine if we won
int w = (winner == me);
// Backprop the result of the game
g3_backpropogate(nodeStack, moveStack, s - 1, w);
}
return;
}