X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=schedule.cc;h=cbb4957a3e4a3865730679e8e816dfb51f636324;hp=691c6f43088595300ac198783328d4b102c8b0f4;hb=1bc8782b55cab0503f1b64529f993f0b9e3a1846;hpb=517d8ce6cc880bb523ee55005afdcad1ec551e64

diff --git a/schedule.cc b/schedule.cc
index 691c6f4..cbb4957 100644
--- a/schedule.cc
+++ b/schedule.cc
@@ -3,24 +3,102 @@
 #include "common.h"
 #include "model.h"
 
+/** Constructor */
+Scheduler::Scheduler() :
+	current(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", t->get_id());
-	queue.push(t);
+	readyList.push_back(t);
 }
 
-Thread *Scheduler::next_thread(void)
+/**
+ * Remove a given Thread from the scheduler.
+ * @param t The Thread to remove
+ */
+void Scheduler::remove_thread(Thread *t)
 {
-	if (queue.empty())
-		return NULL;
+	if (current == t)
+		current = NULL;
+	else
+		readyList.remove(t);
+}
 
-	current = queue.front();
-	queue.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)
+{
+	remove_thread(t);
+	t->set_state(THREAD_BLOCKED);
+}
 
-	return current;
+/**
+ * Wake a Thread up that was previously waiting (see Scheduler::wait)
+ * @param t The Thread to wake up
+ */
+void Scheduler::wake(Thread *t)
+{
+	add_thread(t);
+	t->set_state(THREAD_READY);
 }
 
-Thread *Scheduler::get_current_thread(void)
+/**
+ * Remove one Thread from the scheduler. This implementation defaults to FIFO,
+ * 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) {
+		current = t;
+		readyList.remove(t);
+	} else if (readyList.empty()) {
+		t = NULL;
+	} else {
+		t = readyList.front();
+		current = t;
+		readyList.pop_front();
+	}
+
+	print();
+
+	return t;
+}
+
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
 {
 	return current;
 }
+
+/**
+ * Print debugging information about the current state of the scheduler. Only
+ * prints something if debugging is enabled.
+ */
+void Scheduler::print() const
+{
+	if (current)
+		DEBUG("Current thread: %d\n", current->get_id());
+	else
+		DEBUG("No current thread\n");
+	DEBUG("Num. threads in ready list: %zu\n", readyList.size());
+
+	std::list<Thread *, MyAlloc< Thread * > >::const_iterator it;
+	for (it = readyList.begin(); it != readyList.end(); it++)
+		DEBUG("In ready list: thread %d\n", (*it)->get_id());
+}