X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=schedule.cc;h=be4a92f739a1129bb2aa4bee50bb23ba0a3f8556;hb=c5b57f3d98d1d14b4546995a0882753cf71a1c4b;hp=13b640cd8e832b2cca826e5a4b68d66143bb854c;hpb=94c12b28e9afeed050f40c3d2d625fa0e22f0387;p=model-checker.git

diff --git a/schedule.cc b/schedule.cc
index 13b640c..be4a92f 100644
--- a/schedule.cc
+++ b/schedule.cc
@@ -3,30 +3,105 @@
 #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());
 	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)
 {
-	Thread *t = model->schedule_next_thread();
+	if (current == t)
+		current = NULL;
+	else
+		readyList.remove(t);
+}
 
+/**
+ * Force one Thread to wait on another Thread. The "join" Thread should
+ * eventually wake up the waiting Thread via Scheduler::wake.
+ * @param wait The Thread that should wait
+ * @param join The Thread on which we are waiting.
+ */
+void Scheduler::wait(Thread *wait, Thread *join)
+{
+	ASSERT(!join->is_complete());
+	remove_thread(wait);
+	join->push_wait_list(wait);
+	wait->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)
+{
+	add_thread(t);
+	t->set_state(THREAD_READY);
+}
+
+/**
+ * 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);
-		return t;
+	} else if (readyList.empty()) {
+		t = NULL;
+	} else {
+		t = readyList.front();
+		current = t;
+		readyList.pop_front();
 	}
-	if (readyList.empty())
-		return NULL;
 
-	current = readyList.front();
-	readyList.pop_front();
+	print();
 
-	return current;
+	return t;
 }
 
-Thread *Scheduler::get_current_thread(void)
+/**
+ * @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());
+}