Multi thread updating value java

Question

We have 2 threads:

• they have no task scheduling

• they also have no synchronization mechanisms

Their task is:

• to read a value into a register

• increment the value in the register

• write the value back to location X

At start X contains value 0. Both threads modify value at same location.

Both threads start at the same time and do 1000 iterations.

Question: What is the smallest value X after both threads finish? (not 1000 and not 2000)

Answer 1

The smallest possible number is 2.

T1 reads the value 0.
T2 increments X 999 times to 999.
T1 writes the value 1
T2 reads the value 1
T1 increments X 999 times to 1000
T2 writes the value 2.