/**
* Allocate a new <tt>KThread</tt>. If this is the first <tt>KThread</tt>, create an idle thread
* as well.
*/
public KThread() {
if (currentThread != null) {
tcb = new TCB();
} else {
readyQueue = ThreadedKernel.scheduler.newThreadQueue(false);
readyQueue.acquire(this);
currentThread = this;
tcb = TCB.currentTCB();
name = "main";
restoreState();
createIdleThread();
}
}
/**
* Prepare this thread to be run. Set <tt>status</tt> to <tt>statusRunning</tt> and check
* <tt>toBeDestroyed</tt>.
*/
protected void restoreState() {
Lib.debug(dbgThread, "Running thread: " + currentThread.toString());
Lib.assertTrue(Machine.interrupt().disabled());
Lib.assertTrue(this == currentThread);
Lib.assertTrue(tcb == TCB.currentTCB());
Machine.autoGrader().runningThread(this);
status = statusRunning;
if (toBeDestroyed != null) {
toBeDestroyed.tcb.destroy();
toBeDestroyed.tcb = null;
toBeDestroyed = null;
}
}