samiandClaude Sonnet 5
ef816c21fb
DownloadTaskState::quiesce() (Engine shutdown / ~Engine, via quiesce_task()) cancelled every live worker's transfer, then immediately cleared `workers` on the calling thread. transfer.cancel() only *requests* the HttpClient worker thread stop the transfer -- it does not wait for that to happen. If that thread was mid write-callback (seg_data -> WriteBuffer::append -> SparseFile::write_at), clearing the map destroyed the SegWorker (and its ring buffer) it was still writing through: a heap-use-after-free, caught by ASan via tools/bench alloc-check, which by design drops its Engine while a download is still active mid-sample. Every other exit path (verify/fail/auto_pause/demote, via begin_drain_locked) already gets this right: cancel, then let each worker remove and flush itself through seg_finished once HttpClient actually confirms the transfer stopped, on the correct thread. quiesce() now does the same instead of tearing the map down itself -- wait on a condition variable, notified from seg_finished right after it erases, until `workers` is empty. Co-Authored-By: Claude Sonnet 5 <[email protected]> Claude-Session: https://claude.ai/code/session_01Q3QrF7rCt21bkAjt9BCDFQ
Owner: lane CORE. See ../docs/agents/AGENT-CORE.md and ../docs/04-engine-design.md. No JSON, no SQL, no Qt, no RPC in this tree.