X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=schedule.cc;h=915bbc90fb3daa8d5985decdf9e1641a93e59993;hp=abb3e4b3975f34c3cbaf876ead0af680699864d9;hb=f1ecfba94c7ceb77c071ffa906cd6d51f66f8ee3;hpb=3e3ba08b7f8483430946ac7db0cc3bdbaa6f8a90 diff --git a/schedule.cc b/schedule.cc index abb3e4b..915bbc9 100644 --- a/schedule.cc +++ b/schedule.cc @@ -1,26 +1,255 @@ -#include "libthreads.h" +#include +#include + +#include "threads-model.h" #include "schedule.h" #include "common.h" #include "model.h" +#include "nodestack.h" -void Scheduler::add_thread(struct thread *t) +/** + * Format an "enabled_type_t" for printing + * @param e The type to format + * @param str The output character array + */ +static void enabled_type_to_string(enabled_type_t e, char *str) { - DEBUG("thread %d\n", t->id); - queue.push(t); + const char *res; + switch (e) { + case THREAD_DISABLED: + res = "disabled"; + break; + case THREAD_ENABLED: + res = "enabled"; + break; + case THREAD_SLEEP_SET: + res = "sleep"; + break; + default: + ASSERT(0); + res = NULL; + break; + } + strcpy(str, res); } -struct thread *Scheduler::next_thread(void) +/** Constructor */ +Scheduler::Scheduler() : + enabled(NULL), + enabled_len(0), + curr_thread_index(0), + current(NULL) { - if (queue.empty()) - return NULL; +} - current = queue.front(); - queue.pop(); +void Scheduler::set_enabled(Thread *t, enabled_type_t enabled_status) { + int threadid = id_to_int(t->get_id()); + if (threadid >= enabled_len) { + enabled_type_t *new_enabled = (enabled_type_t *)snapshot_malloc(sizeof(enabled_type_t) * (threadid + 1)); + memset(&new_enabled[enabled_len], 0, (threadid + 1 - enabled_len) * sizeof(enabled_type_t)); + if (enabled != NULL) { + memcpy(new_enabled, enabled, enabled_len * sizeof(enabled_type_t)); + snapshot_free(enabled); + } + enabled = new_enabled; + enabled_len = threadid + 1; + } + enabled[threadid] = enabled_status; + if (enabled_status == THREAD_DISABLED) + model->check_promises_thread_disabled(); +} - return current; +/** + * @brief Check if a Thread is currently enabled + * + * Check if a Thread is currently enabled. "Enabled" includes both + * THREAD_ENABLED and THREAD_SLEEP_SET. + * @param t The Thread to check + * @return True if the Thread is currently enabled + */ +bool Scheduler::is_enabled(const Thread *t) const +{ + return is_enabled(t->get_id()); +} + +/** + * @brief Check if a Thread is currently enabled + * + * Check if a Thread is currently enabled. "Enabled" includes both + * THREAD_ENABLED and THREAD_SLEEP_SET. + * @param tid The ID of the Thread to check + * @return True if the Thread is currently enabled + */ +bool Scheduler::is_enabled(thread_id_t tid) const +{ + int i = id_to_int(tid); + return (i >= enabled_len) ? false : (enabled[i] != THREAD_DISABLED); +} + +/** + * @brief Check if a Thread is currently in the sleep set + * @param t The Thread to check + * @return True if the Thread is currently enabled + */ +bool Scheduler::is_sleep_set(const Thread *t) const +{ + return get_enabled(t) == THREAD_SLEEP_SET; +} + +enabled_type_t Scheduler::get_enabled(const Thread *t) const +{ + int id = id_to_int(t->get_id()); + ASSERT(id < enabled_len); + return enabled[id]; +} + +void Scheduler::update_sleep_set(Node *n) { + enabled_type_t *enabled_array = n->get_enabled_array(); + for (int i = 0; i < enabled_len; i++) { + if (enabled_array[i] == THREAD_SLEEP_SET) { + enabled[i] = THREAD_SLEEP_SET; + } + } +} + +/** + * Add a Thread to the sleep set. + * @param t The Thread to add + */ +void Scheduler::add_sleep(Thread *t) +{ + DEBUG("thread %d\n", id_to_int(t->get_id())); + set_enabled(t, THREAD_SLEEP_SET); +} + +/** + * Remove a Thread from the sleep set. + * @param t The Thread to remove + */ +void Scheduler::remove_sleep(Thread *t) +{ + DEBUG("thread %d\n", id_to_int(t->get_id())); + set_enabled(t, THREAD_ENABLED); } -struct thread *Scheduler::get_current_thread(void) +/** + * Add a Thread to the scheduler's ready list. + * @param t The Thread to add + */ +void Scheduler::add_thread(Thread *t) { + DEBUG("thread %d\n", id_to_int(t->get_id())); + ASSERT(!t->is_model_thread()); + set_enabled(t, THREAD_ENABLED); +} + +/** + * Remove a given Thread from the scheduler. + * @param t The Thread to remove + */ +void Scheduler::remove_thread(Thread *t) +{ + if (current == t) + current = NULL; + set_enabled(t, THREAD_DISABLED); +} + +/** + * Prevent a Thread from being scheduled. The sleeping Thread should be + * re-awoken via Scheduler::wake. + * @param thread The Thread that should sleep + */ +void Scheduler::sleep(Thread *t) +{ + set_enabled(t, THREAD_DISABLED); + t->set_state(THREAD_BLOCKED); +} + +/** + * Wake a Thread up that was previously waiting (see Scheduler::wait) + * @param t The Thread to wake up + */ +void Scheduler::wake(Thread *t) +{ + ASSERT(!t->is_model_thread()); + set_enabled(t, THREAD_ENABLED); + t->set_state(THREAD_READY); +} + +/** + * Select a Thread. This implementation defaults to round-robin, if a + * thread is not already provided. + * + * @param t Thread to run, if chosen by an external entity (e.g., + * ModelChecker). May be NULL to indicate no external choice. + * @return The next Thread to run + */ +Thread * Scheduler::next_thread(Thread *t) +{ + if (t == NULL) { + int old_curr_thread = curr_thread_index; + bool have_enabled_thread_with_priority = false; + Node *n = model->get_curr_node(); + + for (int i = 0; i < enabled_len; i++) { + thread_id_t tid = int_to_id(i); + if (n->has_priority(tid)) { + DEBUG("Node (tid %d) has priority\n", i); + //Have a thread with priority + if (enabled[i] != THREAD_DISABLED) + have_enabled_thread_with_priority = true; + } + } + + while (true) { + curr_thread_index = (curr_thread_index + 1) % enabled_len; + thread_id_t curr_tid = int_to_id(curr_thread_index); + if (enabled[curr_thread_index] == THREAD_ENABLED && + (!have_enabled_thread_with_priority || n->has_priority(curr_tid))) { + t = model->get_thread(curr_tid); + break; + } + if (curr_thread_index == old_curr_thread) { + if (DBG_ENABLED()) + print(); + return NULL; + } + } + } else if (t->is_model_thread()) { + /* model-checker threads never run */ + t = NULL; + } else { + curr_thread_index = id_to_int(t->get_id()); + } + + current = t; + if (DBG_ENABLED()) + print(); + return t; +} + +/** + * @return The currently-running Thread + */ +Thread * Scheduler::get_current_thread() const +{ + ASSERT(!current || !current->is_model_thread()); return current; } + +/** + * Print debugging information about the current state of the scheduler. Only + * prints something if debugging is enabled. + */ +void Scheduler::print() const +{ + int curr_id = current ? id_to_int(current->get_id()) : -1; + + model_print("Scheduler: "); + for (int i = 0; i < enabled_len; i++) { + char str[20]; + enabled_type_to_string(enabled[i], str); + model_print("[%i: %s%s]", i, i == curr_id ? "current, " : "", str); + } + model_print("\n"); +}