On Wed, 9 Jun 2021 11:31:52 GMT, Maurizio Cimadamore <mcimadam...@openjdk.org> wrote:
>> This tests fails intermittently but very rarely, on Windows it seems. The >> subtest in question is `testLockSharedMultiThread`. This test is spawning a >> number of threads, each of which: >> >> * increments a counter atomically >> * acquire scope >> * waits some time >> * release scope >> * decrement counter (in finally block) >> >> The main test thread tries (while the counter value is > 0) to repeatedly >> close the scope, and asserts that if the scope closes successfully, then the >> counter value should be exactly zero. >> >> Looking at the test closely, I realized there's an issue: the order in which >> counter is incremented and scope is acquired is wrong. As such it is >> possible for counter to be increased, but then for subsequent acquire to >> fail (e.g. if segment is already closed). This would lead to the main test >> thread to fail, as it would appear as if the segment has been closed >> successfully, but the counter value is not zero. >> >> The fix is to only increment the counter after a successful acquire. I have >> also tweaked the test so that it keeps trying closing the scope, even if the >> counter value reaches zero permanently (e.g. all other threads have >> completed). > > Maurizio Cimadamore has updated the pull request incrementally with one > additional commit since the last revision: > > Update wrong copyright date Marked as reviewed by dfuchs (Reviewer). ------------- PR: https://git.openjdk.java.net/jdk/pull/4427
