X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=schedule.cc;h=915bbc90fb3daa8d5985decdf9e1641a93e59993;hp=d344fb1acdcf858db73d098b7341a8dae930125f;hb=f1ecfba94c7ceb77c071ffa906cd6d51f66f8ee3;hpb=6357baf85edec072a52c7ea18e9fdb087765f9cb

diff --git a/schedule.cc b/schedule.cc
index d344fb1..915bbc9 100644
--- a/schedule.cc
+++ b/schedule.cc
@@ -1,48 +1,255 @@
-#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
+ */
+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());
+}
+
+/**
+ * @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);
+}
+
+/**
+ * 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);
+}
+
+/**
+ * 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);
 }
 
-Thread *Scheduler::next_thread(void)
+/**
+ * Wake a Thread up that was previously waiting (see Scheduler::wait)
+ * @param t The Thread to wake up
+ */
+void Scheduler::wake(Thread *t)
 {
-	Thread *t = model->schedule_next_thread();
+	ASSERT(!t->is_model_thread());
+	set_enabled(t, THREAD_ENABLED);
+	t->set_state(THREAD_READY);
+}
 
-	if (t != NULL) {
-		current = t;
-		readyList.remove(t);
-	} else if (readyList.empty()) {
+/**
+ * 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 {
-		t = readyList.front();
-		current = t;
-		readyList.pop_front();
+		curr_thread_index = id_to_int(t->get_id());
 	}
 
-	print();
-
+	current = t;
+	if (DBG_ENABLED())
+		print();
 	return t;
 }
 
-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("# 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");
 }