Host — the two remaining app-wide stall mechanisms plus main-thread pins found by mining all nine hang reports: - LinuxProcess.startStdinRelay wrote to a BLOCKING stdin fd on a width-limited cooperative-pool thread, non-cancellably; wedged guests starved the whole concurrency runtime (decode loops, watchdogs — an app-wide freeze surviving the reconcile fix). Writes now offload to a per-process GCD queue (vendored patch #18). - TranscriptWriter (actor) did blocking write/fsync on the cooperative pool; it now runs on its own DispatchSerialQueue executor. - UserMessageBubble's truncation probe typeset entire pasted-log-sized messages through CoreText per layout pass (100% main-thread pins in the 07-21 hang reports); certainly-long messages now skip the probe and render a prefix while collapsed. - toolGroupSignature JSON-encoded every tool input in the transcript up to 12.5x/s on the MainActor; now a structural hash. The summary pass is trailing-throttled to 0.4s, and flatItems joins streaming chunks once instead of re-copying the prefix per delta. - StatusFeedFetcher.parseDate allocated three formatters per call (86% of a pool thread in the 07-26 report); now shared statics. Guest (vminitd) — teardown data loss and epoll registration hazards: - IOPair no longer closes on a bare EPOLLHUP with a backpressure flush in flight (dropped the CLI's final output line); EPOLLOUT finishes the flush, then EOF closes loss-free. ManagedProcess.setExit closes only stdin, letting stdout/stderr self-close on EOF, with an 8s grace pass (patch #16). - Epoll events carry a registration generation; the supervisor ignores stale events for recycled fd numbers. registerFd refuses EEXIST instead of clobbering the existing handler. TerminalIO's stdin relay writes a dup of the terminal fd so its backpressure registration can't collide with the stdout relay's (patch #17). - VsockProxy flushes bytes parked toward the surviving peer on hangup, closes the dialing socket on a failed backend connect, and StandardIO/TerminalIO clean up partially-created pairs on setup failure (patch #16). Full suite: 1451+292+74+20 tests, two failures — both pre-existing environmental (MacVM base image absent on this machine; a load-flaky liveness test that passes 3/3 in isolation). Co-Authored-By: Claude Fable 5 <[email protected]>
OS
This target contains general useful OS related definitions or wrappers.