int gtthread_join(gtthread_t thread, void **status){
int i = 0;
steque_node_t* current;
//TODO: No need to block and unblock signals?
if (gtthread_equal(thread, gtthread_self())){
printf("cannot join same thread\n");
return -1;
}
//Searching for node with gtthread_t thread
current = q->front;
for (i = 0; (i < q->N); i++) {
if(gtthread_equal(thread, ((node_t*)current -> item) -> id)) {
break;
}
current = current -> next;
}
//Checking for canceled thread, blocking otherwise
while (1){
if (((node_t*)current -> item) -> canceled == 1){
if(status != NULL){
*status = ((node_t*)current -> item) -> returns;
}
break;
}
gtthread_yield();
}
return 0;
}
void *func4(void *arg) {
gtthread_t *t3_self = (gtthread_t*) arg;
gtthread_t gtt = gtthread_self();
int res = gtthread_equal(gtt, *t3_self);
printf("Fourth test is not equal: %s\n", !res ? "correct" : "incorrect");
return NULL;
}
/*
The gtthread_cancel() function is analogous to pthread_cancel,
allowing one thread to terminate another asynchronously.
*/
int gtthread_cancel(gtthread_t thread)
{
/* if a thread cancel itself */
if (gtthread_equal(current->tid, thread))
gtthread_exit(0);
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
thread_t* t = thread_get(thread);
if (t == NULL)
{
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
return -1;
}
if (t->state == GTTHREAD_DONE)
{
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
return -1;
}
if (t->state == GTTHREAD_CANCEL)
{
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
return -1;
}
else
t->state = GTTHREAD_CANCEL;
free(t->ucp->uc_stack.ss_sp);
free(t->ucp);
t->ucp = NULL;
t->joining = 0;
steque_enqueue(&zombie_queue, t);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
return 0;
}
void* thr2(void *in) {
if(gtthread_equal(gtthread_self(), t1)) {
printf("Failure.\n");
} else {
printf("Success\n");
}
return NULL;
}
void* thr(void *in) {
if(gtthread_equal(gtthread_self(), t)) {
printf("Success");
} else {
printf("Failure");
}
return NULL;
}
void *func2(void *arg) {
gtt_tuple *tuple = (gtt_tuple*) arg;
gtthread_yield(); // ensure that the tuple is set first
gtthread_yield();
gtthread_yield();
int res = gtthread_equal(tuple->gtt1, tuple->gtt2);
printf("Second test is not equal: %s\n", !res ? "correct" : "incorrect");
return NULL;
}
void *func1(void *arg) {
gtthread_t *gtt = (gtthread_t*) arg;
gtthread_yield(); // ensure that the global is set first
gtthread_yield();
gtthread_yield();
int res = gtthread_equal(g_gtt, *gtt);
printf("First test is equal: %s\n", res ? "correct" : "incorrect");
return NULL;
}
void* worker(void* arg)
{
gtthread_t tid = gtthread_self();
if(gtthread_equal(g_th2, tid))
printf("same\n");
else
printf("diff\n");
}
void *func3(void *arg) {
gtthread_t gtt = gtthread_self();
gtthread_yield(); // ensure that the global is set first
gtthread_yield();
gtthread_yield();
int res = gtthread_equal(g_gtt, gtt);
printf("Third test is equal: %s\n", res ? "correct" : "incorrect");
gtthread_t *ret = malloc(sizeof(gtt));
memcpy(ret, >t, sizeof(gtt));
return ret;
}
void thread2fn()
{
if(gtthread_equal(*thread1, gtthread_self()) != 0)
{
fprintf(stderr, "\nSame");
}
else
{
fprintf(stderr, "\nDiff");
}
}
int main() {
printf("test4b. Should print 'Success'.\n");
gtthread_init(50000L);
gtthread_t t;
gtthread_create( &t, thr, NULL);
if(gtthread_equal(gtthread_self(), t)) {
printf("Failure.");
} else {
printf("Success");
}
return EXIT_SUCCESS;
}
/*
The gtthread_cancel() function is analogous to pthread_cancel,
allowing one thread to terminate another asynchronously.
*/
int gtthread_cancel(gtthread_t thread){
int i = 0;
steque_node_t* current = q->front;
block_signal();
if (gtthread_equal(thread, gtthread_self())){
gtthread_exit((void*)GTTHREAD_CANCELED);
}
for (i = 0; (i < q->N); i++) {
if(gtthread_equal(thread, ((node_t*)current -> item) -> id)) {
if (((node_t*)current -> item) -> canceled == 1){
return ESRCH;
}
else{
((node_t*)current -> item) -> canceled = 1;
((node_t*)current -> item) -> returns = (void*)GTTHREAD_CANCELED;
break;
}
}
current = current -> next;
}
unblock_signal();
return 0;
}
/**
* Helper function for yield.
*/
static void yield_helper(int is_alarm_safe) {
if(is_alarm_safe)
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
// Don't need to do anything if there's just one thread in the queue.
if(steque_size(&g_threads_steque) == 1)
return;
gtthread_t *old_thread = steque_pop(&g_threads_steque);
gtthread_t *new_thread = NULL;
/* Find an eligible new thread - i.e., a thread that isn't queued for cancelation. */
if(!is_alarm_safe)
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
while(steque_size(&g_threads_steque) > 0) {
new_thread = steque_front(&g_threads_steque);
/* Cancels threads when it's their turn to run */
int i;
int canceled=0;
for(i=0; i < steque_size(&g_cancelatorium); i++) {
if((long) steque_front(&g_cancelatorium) == new_thread->id) {
new_thread->is_finished = 1;
new_thread->retval = (void *) -1;
steque_pop(&g_cancelatorium);
steque_pop(&g_threads_steque);
steque_enqueue(&g_dead_threads_steque, new_thread);
canceled=1;
joininator(new_thread); // Attempt to join the thread you just canceled.
break;
}
if(steque_size(&g_cancelatorium) > 0)
steque_cycle(&g_cancelatorium);
}
if(!canceled)
break;
}
/* If the thread that yielded finsihed executing, put it in the finished steque. */
if(old_thread->is_finished) {
steque_enqueue(&g_dead_threads_steque, old_thread);
joininator(old_thread);
} else {
steque_enqueue(&g_threads_steque, old_thread);
}
if(!is_alarm_safe)
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
// All threads have finished running. Is this necessary?
if(steque_size(&g_threads_steque) == 0)
exit(0);
// Don't context switch if the original thread is the only one left in the queue.
if(gtthread_equal(*((gtthread_t *) steque_front(&g_threads_steque)), *old_thread))
return;
if(is_alarm_safe) {
T.it_value.tv_usec = global_period; // Reset timer so that the next period can start immediately.
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
}
swapcontext(old_thread->context, new_thread->context);
}
/*
The gtthread_cancel() function is analogous to pthread_cancel,
allowing one thread to terminate another asynchronously.
*/
int gtthread_cancel(gtthread_t thread) {
steque_enqueue(&g_cancelatorium, (void *) thread.id);
if(gtthread_equal(thread, gtthread_self()))
alarm_safe_yield();
return 0;
}
/*
The gtthread_join() function is analogous to pthread_join.
All gtthreads are joinable.
*/
int gtthread_join(gtthread_t thread, void **status) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
gtthread_t *self = steque_front(&g_threads_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
/* The range [0, g_thread_id) indicates the range of thread ids that have ever belonged to valid threads.
Also can't join with self. */
if(thread.id >= g_thread_id || thread.id == self->id)
return 1;
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
self->is_joined = 0;
self->wait_tid = thread.id;
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
int found_among_dead = 0;
/* First look for joinee among threads that have already terminated. */
int i;
for(i=0; i<steque_size(&g_dead_threads_steque); i++) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
gtthread_t *curr = steque_front(&g_dead_threads_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
if(curr->id == self->wait_tid) {
found_among_dead = 1;
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
self->joinee = curr;
self->is_joined = 1;
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
break;
}
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
steque_cycle(&g_dead_threads_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
}
/* If we haven't found it, wait until it terminates. */
if(!found_among_dead) {
// First check to see that the thread I am waiting on is not already waiting on me.
for(i=0; i<steque_size(&g_join_steque); i++) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
gtthread_t *curr = steque_front(&g_join_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
if(curr->wait_tid == self->id && curr->id == self->wait_tid) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
self->is_joined = -1;
self->wait_tid = -1L;
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
return 1;
}
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
steque_cycle(&g_join_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
}
// If joinee isn't already waiting on me, enqueue myself in the join queue...
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
steque_enqueue(&g_join_steque, self);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
// ... and wait until joinee terminates.
while(!self->is_joined)
alarm_safe_yield();
}
if(status)
*status = self->joinee->retval;
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
self->joinee = NULL;
self->wait_tid = -1L;
self->is_joined = -1;
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
/* Remove yourself from the join steque, if you put yourself there. */
if(!found_among_dead) {
for(i=0; i<steque_size(&g_join_steque); i++) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
gtthread_t *curr = steque_front(&g_join_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
if(gtthread_equal(*self, *curr)) {
steque_pop(&g_join_steque);
break;
}
if(steque_size(&g_join_steque) > 0) {
sigprocmask(SIG_BLOCK, &vtalrm, NULL);
steque_cycle(&g_join_steque);
sigprocmask(SIG_UNBLOCK, &vtalrm, NULL);
}
}
}
return 0;
}
