> An experimental change to SelectorManager::shutdown unveiled a potential > deadlock between the SelectorManager thread trying to stop the > HttpClientImpl, and an executor thread concurrently trying to return a > connection to the pool. > > The issue seems to be caused by the ConnectionPool::returnToPool trying to > close the returned connection when stopping, while holding the ConnectionPool > state lock, and the SelectorManager thread trying to close a pooled > connection, holding the connection stateLock and trying to close the channel, > which caused the CleanupTrigger to fire and attempt to remove the connection > from the pool. > > This problem was observed once with the > java/net/httpclient/ThrowingSubscribersAsLimitingAsync.java test. > > To avoid the problem, the proposed fix is to wait until the > ConnectionPool::stateLock has been released before actually closing the > connection, and to wait until the PlainHttpConnection::stateLock has been > released before actually closing the channel. Indeed, there should be no need > to close those while holding the lock. > > This PR was recreated due to a bad merge pushed to > https://github.com/openjdk/jdk/pull/28421
Daniel Fuchs has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains seven commits: - Merge master - 8372198: Avoid closing PlainHttpConnection while holding a lock - Merge branch 'master' into SelectorManagerVT-8372159 - Copyright years - Review feedback on test - Revert changes to SelectorManager::shutdown - 8372159: HttpClient SelectorManager thread could be a VirtualThread ------------- Changes: https://git.openjdk.org/jdk/pull/28430/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=28430&range=02 Stats: 48 lines in 3 files changed: 23 ins; 9 del; 16 mod Patch: https://git.openjdk.org/jdk/pull/28430.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/28430/head:pull/28430 PR: https://git.openjdk.org/jdk/pull/28430
