+#include <string.h>
#include <stdlib.h>
-#include "libthreads.h"
+#include "threads-model.h"
#include "schedule.h"
#include "common.h"
#include "model.h"
+#include "nodestack.h"
-struct thread_list_node {
- struct thread *t;
- struct thread_list_node *next;
- int live;
-};
+/**
+ * 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)
+{
+ 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);
+}
+
+/** Constructor */
+Scheduler::Scheduler() :
+ enabled(NULL),
+ enabled_len(0),
+ curr_thread_index(0),
+ current(NULL)
+{
+}
+
+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();
+}
+
+/**
+ * @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());
+}
-#define NUM_LIST_NODES 32
+/**
+ * @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);
+}
-struct thread_list_node *head, *tail;
-struct thread_list_node nodes[NUM_LIST_NODES];
-struct thread *current;
+/**
+ * @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;
+}
-static void enqueue_thread(struct thread *t)
+enabled_type_t Scheduler::get_enabled(const Thread *t) const
{
- int i;
- struct thread_list_node *node;
+ int id = id_to_int(t->get_id());
+ ASSERT(id < enabled_len);
+ return enabled[id];
+}
- for (node = nodes, i = 0; node->live && i < NUM_LIST_NODES; i++, node++);
- if (i >= NUM_LIST_NODES) {
- printf("ran out of nodes\n");
- exit(1);
+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;
+ }
}
- node->t = t;
- node->next = NULL;
- node->live = 1;
+}
- if (tail)
- tail->next = node;
- else
- head = node;
- tail = node;
+/**
+ * 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);
}
-static struct thread *dequeue_thread(void)
+/**
+ * Remove a Thread from the sleep set.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_sleep(Thread *t)
{
- struct thread *pop;
+ DEBUG("thread %d\n", id_to_int(t->get_id()));
+ set_enabled(t, THREAD_ENABLED);
+}
- if (!head)
- return NULL;
+/**
+ * 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);
+}
- pop = head->t;
- head->live = 0;
- if (head == tail)
- tail = NULL;
- head = head->next;
+/**
+ * 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);
+}
- /* Set new current thread */
- current = pop;
+/**
+ * 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);
+}
- return pop;
+/**
+ * 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);
}
-void DefaultScheduler::add_thread(struct thread *t)
+/**
+ * @brief Select a Thread to run via round-robin
+ * @return The next Thread to run
+ */
+Thread * Scheduler::select_next_thread()
{
- DEBUG("thread %d\n", t->id);
- enqueue_thread(t);
+ 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);
+ if (enabled[i] != THREAD_DISABLED)
+ have_enabled_thread_with_priority = true;
+ }
+ }
+
+ for (int i = 0; i < enabled_len; i++) {
+ curr_thread_index = (old_curr_thread + i + 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))) {
+ return model->get_thread(curr_tid);
+ }
+ }
+ /* No thread was enabled */
+ return NULL;
+}
+
+void Scheduler::set_scheduler_thread(thread_id_t tid) {
+ curr_thread_index=id_to_int(tid);
}
-struct thread *DefaultScheduler::next_thread(void)
+/**
+ * @brief Set the current "running" Thread
+ * @param t Thread to run
+ */
+void Scheduler::set_current_thread(Thread *t)
{
- return dequeue_thread();
+ ASSERT(t && !t->is_model_thread());
+
+ //curr_thread_index = id_to_int(t->get_id());
+
+ current = t;
+ if (DBG_ENABLED())
+ print();
}
-struct thread *DefaultScheduler::get_current_thread(void)
+/**
+ * @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");
+}