On Sat, 31 Aug 2024 00:04:57 GMT, Chris Plummer <cjplum...@openjdk.org> wrote:
>> Only allocate the cmdQueueLock once rather than allocate each time there is >> a new connection (and destroy when the connection is terminated). >> >> Currently each time there is a new debug agent connection established, the >> cmdQueueLock is allocated. It is then destroyed when the connection is >> dropped, only to be recreated on the next connection. I looked closely at >> the use of this lock, and what happens when the connection is dropped, and I >> can't see any reason to create and then dispose of cmdQueueLock for each >> connection. Of the 18 debug agent raw monitors, this is the only one that >> gets destroyed and recreated. The other 17 stick around for the next >> connection. I'd like to get rid of this reallocation in order to support >> static initialization of all the debug agent raw monitors on startup. This >> will be done as part of the ranked monitor support >> ([JDK-8328866](https://bugs.openjdk.org/browse/JDK-8328866)). >> >> As part of the testing for this change, I put an assert in place when we try >> to create cmdQueueLock for the 2nd time. I ran all our debugger tests, and >> unfortunately none of them failed. This means we don't currently test >> attaching to the debug agent more than once in any of our tests, so I did >> two things to better test out this change. The first was to write a test >> that attaches numerous times in sequence, and the 2nd was to manually attach >> and reattach using jdb. At the same time I stepped through the debug agent >> code in gdb just to help better understand the setup and use of >> cmdQueueLock. I didn't see anything that gave me concern about making this >> change. >> >> Tested by running all jdi, jdwp, and jdb tests on all supported platforms. > > Chris Plummer has updated the pull request incrementally with one additional > commit since the last revision: > > Get rid of extra space char Marked as reviewed by amenkov (Reviewer). ------------- PR Review: https://git.openjdk.org/jdk/pull/20755#pullrequestreview-2273684804
