Amazon Interview Question for SDE1s

Country: United States

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This question is based on thread scheduling. Normally, if you were designing a thread scheduler and had access to the internals, you would change the priority of each thread such that Thread 1 would have the highest priority, Thread 2 would have a lower priority and Thread 3 would have the lowest priority. And if the scheduler dispatched the threads according to the priorities, then T1, T2, T3 would be executed in that order.
However, in most systems, since you can only treat the Thread Scheduler as a black box, you can only use the join() method to control the execution of the threads. One simple way would be to have thread1 call join() and when it finishes, thread2 calls join() and so forth. In essence, calling join() will make the other thread wait. I have implemented my solution in Python below.

My solution:

import threading
import time

def worker():
    print(threading.currentThread().getName(), 'Starting')
    print(threading.currentThread().getName(), 'Exiting')

t1 = threading.Thread(name='Thread 1', target=worker)
t2 = threading.Thread(name='Thread 2', target=worker)
t3 = threading.Thread(name='Thread 3', target=worker)


- prudent_programmer March 05, 2018 | Flag Reply

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