class Scheduler {
  private:
    Queue readyList;
    SpinLock schedulerSpinLock;
  public:
    void suspend(SpinLock *lock);
    void makeReady(Thread *thread);
}

void
Scheduler::suspend(SpinLock *lock) {
    TCB *chosenTCB;

    disableInterrupts();  
    schedulerSpinLock.acquire();
    lock->release();    
    runningThread->state = #\waitingThreadState#;
    chosenTCB = readyList.getNextThread(); 
    thread_switch(runningThread, 
                  chosenTCB);    
    runningThread->state = #\runningThreadState#;
    schedulerSpinLock.release();
    enableInterrupts();
}

void
Scheduler::makeReady(TCB *thread) {
    disableInterrupts();  
    schedulerSpinLock.acquire();
    readyList.add(thread);
    thread->state = #\readyThreadState#;
    schedulerSpinLock.release();
    enableInterrupts(); 
}