#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)
+{
+ 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)
{
- Thread *t = model->schedule_next_thread();
+ 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);
} else if (readyList.empty()) {
t = NULL;
return t;
}
-Thread *Scheduler::get_current_thread(void)
+/**
+ * @return The currently-running Thread
+ */
+Thread * Scheduler::get_current_thread() const
{
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());
+ DEBUG("Current thread: %d\n", current->get_id());
else
- printf("No current thread\n");
- printf("# Threads in ready list: %ld\n", readyList.size());
+ DEBUG("No current thread\n");
+ DEBUG("Num. threads in ready list: %zu\n", readyList.size());
- std::list<Thread *>::iterator it;
+ std::list<Thread *, MyAlloc< Thread * > >::const_iterator it;
for (it = readyList.begin(); it != readyList.end(); it++)
- printf("In ready list: thread %d\n", (*it)->get_id());
+ DEBUG("In ready list: thread %d\n", (*it)->get_id());
}