Import AITURK IDE 1.0.0-beta.1 from Hermes 63279301; preserve MIT license

gateway/cgroup_cleanup.py

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+"""SIGKILL any process left in this systemd unit's cgroup.
+
+Runs as ``ExecStopPost=`` so it only fires after the gateway's main process
+has exited. The gateway already reaps its own tool subprocesses on a clean
+shutdown; this is the safety net for long-lived helpers it doesn't track
+(``adb``, platform bridges, etc.) that would otherwise be orphaned in the
+cgroup and block ``Restart=always`` — issue #37454.
+
+We deliberately iterate ``cgroup.procs`` and send per-PID SIGKILLs instead
+of writing ``1`` to ``cgroup.kill``: the original failure mode in #37454
+was the kernel returning ``EINVAL`` on the cgroup-wide kill, while per-PID
+signal delivery uses a separate code path that still works.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+import signal
+import sys
+from pathlib import Path
+
+
+def _own_cgroup_path() -> str | None:
+    """Return the cgroup v2 path for the calling process, or None."""
+    try:
+        text = Path("/proc/self/cgroup").read_text(encoding="utf-8")
+    except OSError:
+        return None
+    match = re.search(r"^0::(.+)$", text, re.MULTILINE)
+    if not match:
+        return None
+    return match.group(1).strip()
+
+
+def _read_cgroup_pids(cgroup_path: str) -> list[int]:
+    procs_file = Path(f"/sys/fs/cgroup{cgroup_path}/cgroup.procs")
+    try:
+        raw = procs_file.read_text(encoding="utf-8")
+    except OSError:
+        return []
+    pids: list[int] = []
+    for line in raw.splitlines():
+        line = line.strip()
+        if not line:
+            continue
+        try:
+            pids.append(int(line))
+        except ValueError:
+            continue
+    return pids
+
+
+def reap_cgroup(cgroup_path: str | None = None) -> int:
+    """SIGKILL every PID in the cgroup other than the caller. Returns the count killed."""
+    if cgroup_path is None:
+        cgroup_path = _own_cgroup_path()
+    if not cgroup_path:
+        return 0
+    own = os.getpid()
+    killed = 0
+    for pid in _read_cgroup_pids(cgroup_path):
+        if pid == own:
+            continue
+        try:
+            os.kill(pid, signal.SIGKILL)  # windows-footgun: ok — Linux-only (reads /proc, /sys/fs/cgroup; runs from a systemd unit)
+            killed += 1
+        except ProcessLookupError:
+            continue
+        except PermissionError:
+            continue
+    return killed
+
+
+def main() -> int:
+    reap_cgroup()
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())