On Thu, 27 Nov 2025 12:46:34 GMT, Daniel Fuchs <[email protected]> wrote:
>> 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 incrementally with four additional > commits since the last revision: > > - Update test/jdk/java/net/httpclient/PlainConnectionLockTest.java > > Co-authored-by: Volkan Yazıcı <[email protected]> > - Update test/jdk/java/net/httpclient/PlainConnectionLockTest.java > > Co-authored-by: Volkan Yazıcı <[email protected]> > - Update test/jdk/java/net/httpclient/PlainConnectionLockTest.java > > Co-authored-by: Volkan Yazıcı <[email protected]> > - Update test/jdk/java/net/httpclient/PlainConnectionLockTest.java > > Co-authored-by: Volkan Yazıcı <[email protected]> I haven't paid close attention to the test, but the source changes look good to me. ------------- Marked as reviewed by jpai (Reviewer). PR Review: https://git.openjdk.org/jdk/pull/28430#pullrequestreview-3516441878
