To answer this question, let's go through each option to understand why it is correct or incorrect:
Option A) The output may be "r1 = 6, r2 = 14" - This option is true. In the given code, the doTransfer
method is called three times, each time transferring a certain amount from one Record
object to another. As the transfer
method in the Clerk
class is synchronized, only one thread can execute the transfer at a time. In the first transfer (doTransfer(r1, r2, 5)
), the value of r1
is decreased by 5 and the value of r2
is increased by 5. Therefore, after the first transfer, the value of r1
will be 5 and the value of r2
will be 15. In the subsequent transfers, the values will be updated accordingly, resulting in "r1 = 6, r2 = 14" as a possible output.
Option B) The output may be "r1 = 5, r2 = 15" - This option is true. As explained in option A, after the first transfer, the value of r1
will be 5 and the value of r2
will be 15. Therefore, "r1 = 5, r2 = 15" is a possible output.
Option C) The output may be "r1 = 8, r2 = 12" - This option is false. The given code does not involve any transfers or operations that would result in r1
becoming 8 and r2
becoming 12.
Option D) The code may run (and complete) with no output - This option is true. The code may execute without any errors and complete without printing any output.
Option E) The code may deadlock (without completing) with no output - This option is true. Deadlock can occur in a multi-threaded program when two or more threads are waiting for each other to release a resource. In this code, there are multiple synchronized blocks and multiple threads running concurrently. If a deadlock occurs, the code may get stuck and not complete, resulting in no output.
Option F) IllegalStateException or InterruptedException may be thrown - This option is false. There are no specific conditions in the given code that would cause an IllegalStateException
or InterruptedException
to be thrown.
Therefore, the correct answers are A, B, and E.