Files
multi-agent-mux/.agents/skills/lib_py/atomic_yaml.py
T
GodopuandClaude Fable 5.1 7844ae2c5f fix(create): one pane claim at a time per herdr server; a create keeps the pane the monitor registered for it
Three `create --onboard` at once into one folder (the control root, so no
control-plane prefix reaches the pane and the shim reuses an idle pane):
the shim's new-session chooses a pane - an idle one in a workspace on the
same cwd, a split, a fresh workspace's root pane - and then claims it with
`agent start`; two shims could choose the pane one of them had just made,
and the later start failed with agent_pane_busy (one create in three).

mam_herdr now runs every new-session call holding one lock per server: a
flock on fd 9, opened for the block and taken by lib_py.pane_lock, which
also bounds the wait (MAM_PANE_CLAIM_WAIT_S, default 120). It is released
with the block or with the process, however it ends. The shim heredoc is
unchanged (S11). Other servers' creates are not held.

Serialising the claims exposed a second race: a create's end-of-run
`reconcile.sh --once` adopted the pane of another create that had not yet
written its row, and that create refused its own name as already running
(exit 4). Such a row - registered by the monitor, no job, for a pane
created after this create began - is now replaced, not refused.

Tests: real herdr - shim-level and create-level three-way races into one
folder (the real herdr's pane-creating replies held back so the window is
hit on every run; both fail on the base with the orchestrator's error),
the different-folder test kept; pane_lock unit tests (per-server file,
timeout, kill -9 holder, handover, knob); the adoption rule and its three
refusals; shim contract h26 (held lock: no pane calls). The herdr box gets
a ~/.zshrc: without it every first `agent start` typed into zsh's first-run
menu and timed out at 30 s.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2026-10-11 06:05:52 +00:00

213 lines
8.8 KiB
Python

# atomic_yaml.py — atomic YAML/DB update logic
# Extracted from lib.sh atomic_dump_yaml PYEOF block
import os, sys, tempfile, shutil, glob, subprocess, json, sqlite3, fcntl
from datetime import datetime, timezone
import yaml
def atomic_dump_yaml_main():
yaml_path = os.environ['YAML_PATH']
db_path = os.path.splitext(yaml_path)[0] + '.db'
def _validate(d):
if not isinstance(d, dict):
raise SystemExit("VALIDATE: top-level is not a mapping")
sessions = d.get('herdr_sessions', [])
if not isinstance(sessions, list):
raise SystemExit("VALIDATE: herdr_sessions is not a list")
valid = {'running', 'terminated', 'archived', 'stopped'}
for i, s in enumerate(sessions):
if not isinstance(s, dict):
raise SystemExit(f"VALIDATE: herdr_sessions[{i}] not a mapping")
if not s.get('name') or not s.get('status'):
raise SystemExit(f"VALIDATE: herdr_sessions[{i}] missing name/status")
if s.get('role') is not None and (not isinstance(s['role'], str) or not s['role'].strip()):
raise SystemExit(f"VALIDATE: herdr_sessions[{i}] {s.get('name')!r} role must be a non-empty string")
if s['status'] not in valid:
raise SystemExit(f"VALIDATE: herdr_sessions[{i}] {s.get('name')!r} bad status {s['status']!r}")
if not isinstance(s.get('pane'), dict):
raise SystemExit(f"VALIDATE: herdr_sessions[{i}] {s.get('name')!r} missing pane")
orc_uuids = d.get('orchestrator_uuids')
if orc_uuids is not None:
if not isinstance(orc_uuids, list):
raise SystemExit("VALIDATE: orchestrator_uuids is not a list")
seen_orc = set()
for u in orc_uuids:
if not isinstance(u, str) or not u.strip():
raise SystemExit("VALIDATE: orchestrator_uuids items must be non-empty strings")
if u in seen_orc:
raise SystemExit("VALIDATE: orchestrator_uuids contains duplicate item")
seen_orc.add(u)
def get_terminal_set(d):
return {s.get('name'): s.get('status') for s in d.get('herdr_sessions', []) if s.get('status') in ('stopped', 'terminated', 'archived')}
def get_all_sessions_status(d):
import hashlib
res = {}
for s in d.get('herdr_sessions', []):
name = s.get('name')
ser = json.dumps(s, sort_keys=True)
res[name] = hashlib.sha256(ser.encode('utf-8')).hexdigest()
orc_uuids = d.get('orchestrator_uuids')
if orc_uuids is not None:
ser_orc = json.dumps(orc_uuids, sort_keys=True)
res['__orchestrator_uuids__'] = hashlib.sha256(ser_orc.encode('utf-8')).hexdigest()
return res
os.makedirs(os.path.dirname(db_path) or '.', exist_ok=True)
_flock_f = open(db_path + '.lock', 'w')
fcntl.flock(_flock_f, fcntl.LOCK_EX)
conn = sqlite3.connect(db_path, timeout=60.0)
conn.execute('PRAGMA busy_timeout = 60000')
for f in [db_path, db_path + '-wal', db_path + '-shm']:
if os.path.exists(f):
try:
os.chmod(f, 0o600)
except Exception:
pass
is_nfs = os.environ.get('MAM_IS_NFS') == 'true'
if is_nfs:
conn.execute('PRAGMA journal_mode=DELETE')
else:
conn.execute('PRAGMA journal_mode=WAL')
try:
for _beg_attempt in range(300):
try:
conn.execute('BEGIN IMMEDIATE')
break
except sqlite3.OperationalError:
import time
time.sleep(0.1)
else:
conn.execute('BEGIN IMMEDIATE')
conn.execute('CREATE TABLE IF NOT EXISTS state (id INTEGER PRIMARY KEY, data TEXT)')
conn.execute('CREATE TABLE IF NOT EXISTS sessions (name TEXT PRIMARY KEY, status TEXT, pane_cwd TEXT, data JSON)')
conn.execute('CREATE INDEX IF NOT EXISTS idx_sessions_pane_cwd ON sessions(pane_cwd)')
row = conn.execute('SELECT data FROM state WHERE id=1').fetchone()
if row:
d = json.loads(row[0])
else:
if os.path.exists(yaml_path):
with open(yaml_path) as f:
d = yaml.safe_load(f) or {}
else:
d = {}
db_sessions = []
cursor = conn.execute('SELECT name, status, pane_cwd, data FROM sessions')
for s_row in cursor.fetchall():
s_data = json.loads(s_row[3])
s_data['name'] = s_row[0]
s_data['status'] = s_row[1]
if 'pane' not in s_data:
s_data['pane'] = {}
s_data['pane']['cwd'] = s_row[2]
db_sessions.append(s_data)
if db_sessions:
d['herdr_sessions'] = db_sessions
elif 'herdr_sessions' not in d:
d['herdr_sessions'] = []
old_sessions = get_all_sessions_status(d)
# a mutation that replaces a row the monitor registered for a pane it
# created itself (create_session.sh) drops that name from old_roles
old_roles = {s.get('name'): s.get('role') for s in db_sessions if s.get('role')}
# --- caller mutation (module scope: sees d, yaml, os, glob, subprocess) ---
mutation_ns = dict(globals())
mutation_ns.update(locals())
exec(compile(os.environ['AGENT_SESSIONS_MUTATION'], '<mutation>', 'exec'), mutation_ns)
if 'd' in mutation_ns:
d = mutation_ns['d']
for s in d.get('herdr_sessions', []):
name = s.get('name')
if name in old_roles and s.get('role') != old_roles[name]:
raise SystemExit(f"VALIDATE: role of session {name!r} cannot be modified from {old_roles[name]!r} to {s.get('role')!r}")
running_keys = ['claude_session_id_own', 'agy_conversation_id_own', 'hermes_conversation_id_own', 'grok_session_id_own', 'opencode_session_id_own', 'codex_session_id_own']
id_to_session = {}
for s in d.get('herdr_sessions', []):
if s.get('status') == 'running':
s_name = s.get('name')
for k in running_keys:
v = s.get(k)
if v:
if v in id_to_session and id_to_session[v] != s_name:
raise SystemExit(f"VALIDATE: Duplicate running conversation ID {v!r} detected between {id_to_session[v]!r} and {s_name!r}")
id_to_session[v] = s_name
_validate(d)
d_state = {k: v for k, v in d.items() if k != 'herdr_sessions'}
conn.execute('REPLACE INTO state (id, data) VALUES (1, ?)', (json.dumps(d_state),))
current_names = []
for s in d.get('herdr_sessions', []):
name = s.get('name')
status = s.get('status')
pane_cwd = (s.get('pane') or {}).get('cwd', '')
conn.execute('REPLACE INTO sessions (name, status, pane_cwd, data) VALUES (?, ?, ?, ?)',
(name, status, pane_cwd, json.dumps(s)))
current_names.append(name)
if current_names:
placeholders = ','.join('?' for _ in current_names)
conn.execute(f'DELETE FROM sessions WHERE name NOT IN ({placeholders})', current_names)
else:
conn.execute('DELETE FROM sessions')
new_sessions = get_all_sessions_status(d)
conn.commit()
if new_sessions != old_sessions:
if os.path.exists(yaml_path):
try:
shutil.copy2(yaml_path, yaml_path + '.bak')
except Exception:
pass
dir_ = os.path.dirname(yaml_path) or '.'
fd, tmp = tempfile.mkstemp(dir=dir_, prefix='.agent-sessions.', suffix='.tmp')
try:
with os.fdopen(fd, 'w') as f:
yaml.safe_dump(d, f, default_flow_style=False, sort_keys=False,
allow_unicode=True, width=4096)
os.replace(tmp, yaml_path)
except Exception:
if os.path.exists(tmp):
os.remove(tmp)
raise
try:
conn.execute('PRAGMA wal_checkpoint(TRUNCATE)')
except Exception:
pass
except Exception:
conn.rollback()
raise
finally:
conn.close()
try:
os.chmod(db_path, 0o600)
wal = db_path + '-wal'
if os.path.exists(wal): os.chmod(wal, 0o600)
shm = db_path + '-shm'
if os.path.exists(shm): os.chmod(shm, 0o600)
except Exception:
pass
try:
fcntl.flock(_flock_f, fcntl.LOCK_UN)
_flock_f.close()
except Exception:
pass
if __name__ == '__main__':
atomic_dump_yaml_main()