-#include "threads.h"
+#include <string.h>
+#include <stdlib.h>
+
+#include "threads-model.h"
#include "schedule.h"
#include "common.h"
#include "model.h"
+#include "nodestack.h"
+
+/**
+ * Format an "enabled_type_t" for printing
+ * @param e The type to format
+ * @param str The output character array
+ */
+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());
+}
+
+/**
+ * @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;
+}
+
+/**
+ * @brief Check if execution is stuck with no enabled threads and some sleeping
+ * thread
+ * @return True if no threads are enabled an some thread is in the sleep set;
+ * false otherwise
+ */
+bool Scheduler::all_threads_sleeping() const
+{
+ bool sleeping = false;
+ for (int i = 0; i < enabled_len; i++)
+ if (enabled[i] == THREAD_ENABLED)
+ return false;
+ else if (enabled[i] == THREAD_SLEEP_SET)
+ sleeping = true;
+ return sleeping;
+}
+
+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);
+}
+
+/**
+ * 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", t->get_id());
- readyList.push_back(t);
+ DEBUG("thread %d\n", id_to_int(t->get_id()));
+ ASSERT(!t->is_model_thread());
+ set_enabled(t, THREAD_ENABLED);
}
-Thread *Scheduler::next_thread(void)
+/**
+ * Remove a given Thread from the scheduler.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_thread(Thread *t)
{
- Thread *t = model->schedule_next_thread();
+ if (current == t)
+ current = NULL;
+ set_enabled(t, THREAD_DISABLED);
+}
- if (t != NULL) {
- current = t;
- readyList.remove(t);
- } else if (readyList.empty()) {
- t = NULL;
- } else {
- t = readyList.front();
- current = t;
- readyList.pop_front();
+/**
+ * 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);
+}
+
+/**
+ * @brief Select a Thread to run via round-robin
+ * @return The next Thread to run
+ */
+Thread * Scheduler::select_next_thread()
+{
+ int old_curr_thread = curr_thread_index;
+ Node *n = model->get_curr_node();
+
+ bool have_enabled_thread_with_priority = false;
+ if (model->params.fairwindow != 0) {
+ 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 (model->params.yieldon) {
+ bool bad_thread = false;
+ for (int j = 0; j < enabled_len; j++) {
+ thread_id_t tother = int_to_id(j);
+ if ((enabled[j] != THREAD_DISABLED) && n->has_priority_over(curr_tid, tother)) {
+ bad_thread=true;
+ break;
+ }
+ }
+ if (bad_thread)
+ continue;
+ }
+
+ 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);
+}
- print();
+/**
+ * @brief Set the current "running" Thread
+ * @param t Thread to run
+ */
+void Scheduler::set_current_thread(Thread *t)
+{
+ ASSERT(!t || !t->is_model_thread());
- return t;
+ current = t;
+ if (DBG_ENABLED())
+ print();
}
-Thread *Scheduler::get_current_thread(void)
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
{
+ ASSERT(!current || !current->is_model_thread());
return current;
}
-void Scheduler::print()
+/**
+ * Print debugging information about the current state of the scheduler. Only
+ * prints something if debugging is enabled.
+ */
+void Scheduler::print() const
{
- if (current)
- printf("Current thread: %d\n", current->get_id());
- else
- printf("No current thread\n");
- printf("Num. threads in ready list: %ld\n", readyList.size());
+ int curr_id = current ? id_to_int(current->get_id()) : -1;
- std::list<Thread *>::iterator it;
- for (it = readyList.begin(); it != readyList.end(); it++)
- printf("In ready list: thread %d\n", (*it)->get_id());
+ 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");
}