fix: prevent deadlock on concurrent push and disconnect (CP: 23.7) (#24229) (CP: 23.6)#24236
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vaadin-bot merged 1 commit into23.6from May 1, 2026
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…24229) The previous `AtomicBoolean` guard in `AtmospherePushConnection` closed only the disconnect-vs-disconnect race. A push thread that reads `disconnecting` as false before a concurrent `disconnect()` flips it can still proceed into `synchronized(lock)` behind the disconnect thread, which is itself blocked inside `resource.close()` waiting for the servlet container's HTTP session lock held by the push thread — a two-lock cycle. Move `resource.close()` out of the monitor: inside `synchronized(lock)` capture the resource into a local and call `connectionLost()` to transition the state, then release the monitor before invoking `close()` on the stashed reference. Add a matching re-check of `isConnected()` at the top of the `synchronized` block in `push()` so a push that waited for the monitor observes the late disconnect and defers via `PUSH_PENDING`/`RESPONSE_PENDING` instead of NPEing on the cleared resource. The `disconnecting` flag stays set until `close()` returns so subsequent pushes take the fast path and no new `disconnect()` re-enters while `close()` is still in flight. Related-to #24192
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This PR is eligible for auto-merging policy, so it has been approved automatically. If there are pending conditions, auto merge (with 'squash' method) has been enabled for this PR[Message is sent from bot] |
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May 1, 2026
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This ticket/PR has been released with Vaadin 23.6.10. |
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This PR cherry-picks changes from the original PR #24229 to branch 23.6.
Original PR description