Ken Giusti created DISPATCH-1330:
------------------------------------
Summary: Q2 stall due to incorrect msg buffer ref count decrement
on link detach
Key: DISPATCH-1330
URL: https://issues.apache.org/jira/browse/DISPATCH-1330
Project: Qpid Dispatch
Issue Type: Bug
Components: Routing Engine
Affects Versions: 1.6.0, 1.7.0
Reporter: Ken Giusti
Assignee: Ken Giusti
Fix For: 1.8.0
Very rarely the test_40_drop_rx_client_multicast_large_message
(system_tests_edge_router.RouterTest) will hang.
On examination it turns out that very large mcast message is stuck in the Q2
holdoff=true state.
The message buffers are supposed to be discarded as the senders advance.
However in this case all senders are at the end of the buffer list having sent
all data.
The refcounts of the preceding buffers are all stuck at 1 - this is incorrect
as the refcount should've hit 0 and the buffers should be freed.
It turns out that a sender was detached *after* the buffer refcounts were
incremented for it, but *before* the msg's cursor was set. This prevented the
cleanup code from walking the list of unsent buffers decrement the refcounts on
detach.
Kudos to Fernando Giorgetti for finding this issue.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
