Homework 4

This assignment is intended to help you study for the final exam. It will not be graded (i.e., you need not turn anything in).

Assumption: all variables originally hold the value 0.

1. Consider the following sequence of operations:

P1: W(x)1 W(x)3

P2: W(x)2

P3: R(x)3 R(x)2

P4: R(x)2 R(x)3

Is this execution causally consistent? Add or modify an event to change the answer.

2. Consider the following sequence of operations:

P1: W(x)1 W(x)3

P2: R(x)1 W(x)2 R(x)1

Is this execution sequentially consistent? Add or modify an event to change the answer.

3. Consider the following sequence of operations:

P1: W(x)1 W(x)3

P2: R(x)1 R(x)1 R(x)3

Is this execution strictly consistent? Add or modify an event to change the answer.

4. Consider the following sequence of operations:

P1: W(x)1 W(x)3

P2: R(x)1 W(x)2 R(x)3

P3: R(x)3 R(x)1

Is this execution causally consistent? Add or modify an event to change the answer.

5. Consider the following sequence of operations:

P1: W(x)1 W(x)3 S S R(x)3

P2: S R(x)3 W(x)2 S

Is this execution weakly consistent? Add or modify an event to change the answer.

6. Consider the following sequence of operations:

P1: W(x)1 W(x)3 S

P2: R(x)3 S R(x)1

Is this execution weakly consistent? Add or modify an event to change the answer.

7. Consider the following sequence of operations:

P1: W(x)1 W(x)3

P2: R(x)1 W(x)2 R(x)3

Is this execution sequentially consistent? Add or modify an event to change the answer.

8. Consider the following sequence of operations:

P1: W(x)1 R(x)2 W(x)3

P2: W(x)2 R(x)1 W(x)4 R(x)4 R(x)3

P3: R(x)3 R(x)2

Is this execution causally consistent? Add or modify an event to change the answer.

9. Consider the following sequence of operations:

P1: L W(x)1 W(x)3 U

P2: L R(x)3 U R(x)1

Is this execution release consistent? Add or modify an event to change the answer.

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