Bug report: unrar.exe kept running after closing the launcher during a
game install. The orphaned process kept extracting in the background and
held file handles on the staging directory.
Root cause (regular install path): run_unrar_sidecar ran the unrar
sidecar via tauri-plugin-shell's Command::output(). That helper spawns
the process on a detached SharedChild OS thread and immediately drops the
CommandChild; there is no Drop impl that kills the process. On app exit
only shutdown_peer_runtime ran, and Windows does not cascade-kill child
processes, so closing the launcher left unrar running.
Fix:
- run_unrar_sidecar now uses .spawn() instead of .output(), keeping a
killable CommandChild. It registers the child in a new
LanSpreadState.active_unrar_children registry and an RAII
UnrarChildGuard deregisters it on every return path. The CommandEvent
stream is drained to reproduce the exact stdout/stderr (NEWLINE_BYTE
is b'\n'), status code, success flag, and UnpackLogEntry the old
.output() produced, so logging behavior is unchanged.
- kill_active_unrar_children() runs in the RunEvent::Exit handler before
shutdown_peer_runtime, killing every in-progress unrar. Killing first
also lets the install task unwind so the runtime stops promptly.
Two concurrency hazards were closed in the registry design:
- Children are keyed by a monotonic id, not pid. A pid key let a
finishing install's guard deregister a different install's child after
the OS recycled the pid, which could re-orphan a live child.
- A shutting_down latch lives in the registry under the same mutex as
the kill sweep. The sweep is a one-shot drain, so a child registered
after it (a task caught between spawn() and registration, or a later
archive in a multi-archive install -- unpack_archives does not observe
the shutdown token) would be missed. Registration now checks the latch
under that mutex and kills the child immediately instead of inserting
it. Since registration and the sweep serialize on one mutex, every
interleaving kills the child.
Also hardened the streamed-install sender path (ExternalUnrarStream
Provider) with kill_on_drop(true) on its tokio unrar spawns, so a
dropped or aborted producer task cannot orphan unrar there either.
Known limitation: a hard force-kill or crash of the launcher (e.g. Task
Manager -> End Task) bypasses RunEvent::Exit and is not covered. Making
that bulletproof would require a Windows Job Object with
JOB_OBJECT_LIMIT_KILL_ON_JOB_CLOSE; the reported "close the launcher"
case is fully fixed.
Test Plan:
- just clippy (pedantic, -D warnings): clean.
- just fmt: no changes.
- just test: all suites pass (incl. the 20 Tauri-lib unit tests).
- Manual (Windows): start a game install, close the launcher mid-extract,
confirm no unrar.exe remains in Task Manager. Repeat with two
concurrent installs and with a multi-archive game.
ddidderr
d376983296