Preparation for Recitation 6
Tuesday, February 23th
Before reading the Eraser paper, refresh your memory on what race
conditions are and the troubles that they can cause by revisiting sections
5.2.2, 5.2.3, and 5.2.4 of the class notes. Then, read the Eraser
paper, with the following questions in mind:
- According to the lockset algorithm, when does eraser signal a data
race? Why is this condition chosen?
- Under what conditions does Eraser report a false positive? What
conditions does it produce false negatives?
- Typically, instrumenting a program changes the intra-thread timing
(the paper calls it interleaving). This can cause bugs to disappear
when you start trying to find them. What aspect of the Eraser design
mitigates this problem?
- Writing serious multi-threaded code is generally reserved for
"wizard" programmers; is Eraser functional enough and easy enough to
use that non-wizards could use it to write safe code? Think it would
have helped the Therac-25?