* fix(context): take the lock in ContextGraph.to_dict()
to_dict() iterated self.nodes.values() and self.edges without holding
self._lock, so a concurrent writer raised "RuntimeError: dictionary changed
size during iteration". It was the only reader on the class that did not take
the lock -- stats(), density(), find_nodes(), find_edges(), get_neighbors(),
get_nodes_by_label(), state_at() and save_to_file() all hold it.
Commit 1d1ae398 introduced the RLock and added 26 "with self._lock:" blocks;
to_dict already existed and was not among them. save_to_file is safe only
incidentally -- it holds the lock and builds its payload inline rather than
delegating to to_dict, so it never reaches the unguarded loops.
Beyond the RuntimeError, the unguarded body could also return a torn snapshot:
the statistics block reads len(self.nodes)/len(self.edges) after building the
node and edge lists, so a write landing in between yields counts that
contradict the payload they describe.
self._lock is an RLock, so this composes with the callers that already hold it
(build_from_conversation and build_from_documents both return self.to_dict()
from inside a locked block). Neither external caller -- agent_context's
_capture_checkpoint_state nor triplet_store's knowledge-graph conversion --
defines a lock of its own, so there is no ordering inversion.
Add tests/context/test_context_graph_thread_safety.py: a deterministic check
that to_dict() blocks while another thread holds _lock (no race window
needed), a reentrancy check, and three checks under concurrent writes covering
the RuntimeError, statistics/payload agreement, and duplicate node ids. Four
of the five fail against the unfixed method.
Closes#923
* test(context): make to_dict lock tests deterministic and hang-proof
Wait for the worker thread to actually start before asserting to_dict()
blocks on _lock, and run the reentrancy check in a joined worker so a
non-reentrant lock fails the test instead of hanging CI.
* test(context): assert worker threads actually stopped after timed joins
A join(timeout=...) on a daemon thread returns even if the thread is
still running, so a deadlock would leak a live thread into subsequent
tests instead of failing. Assert not is_alive() after each timed join.
---------
Co-authored-by: Pravit Ampapathini <pravitampapathini@Pravits-MacBook-Air-3.local>
Co-authored-by: Zohaib Hassnain <109234410+ZohaibHassan16@users.noreply.github.com>
