File

from pathlib import Path

import ctypes,hashlib,os,subprocess,sys,time

ROOT=Path(__file__).resolve().parents[1]; PROJECTS=ROOT/'projects'; WRAPPER=PROJECTS/'low_latency_relay_v4diag.py'; OLD_PID=9848; EXPECTED_SHA='f7771f74edab5f7194c8076346af4e5c339ae5f2a9d29213adea71f14e6496f1'; LOCK=ROOT/'bridge-data'/'sheet-relay'/'ll4d-switch-20260830.lock'

LOCK.parent.mkdir(parents=True,exist_ok=True)

try: fd=os.open(str(LOCK),os.O_CREAT|os.O_EXCL|os.O_WRONLY)

except FileExistsError: print('SWITCH_ALREADY_CLAIMED'); raise SystemExit(0)

with os.fdopen(fd,'w') as f:f.write(str(time.time()))

if hashlib.sha256(WRAPPER.read_bytes()).hexdigest()!=EXPECTED_SHA: raise SystemExit('SHA_MISMATCH')

compile(WRAPPER.read_text(encoding='utf-8'),str(WRAPPER),'exec')

p=subprocess.run(['powershell','-NoProfile','-Command',f"$p=Get-CimInstance Win32_Process -Filter 'ProcessId={OLD_PID}' -ErrorAction SilentlyContinue; if($p){{$p.CommandLine}}"],capture_output=True,text=True); old=p.stdout.strip(); print('OLD_CMD='+old)

if 'low_latency_relay_v3test.py' not in old: raise SystemExit('OLD_PID_GUARD_FAILED')

k=subprocess.run(['taskkill','/PID',str(OLD_PID),'/F'],capture_output=True,text=True); print('TASKKILL_RC='+str(k.returncode));

if k.returncode!=0: raise SystemExit('KILL_FAILED')

flags=getattr(subprocess,'CREATE_NO_WINDOW',0); new=subprocess.Popen([sys.executable,str(WRAPPER)],cwd=str(ROOT),stdin=subprocess.DEVNULL,stdout=subprocess.DEVNULL,stderr=subprocess.DEVNULL,creationflags=flags); time.sleep(2)

if new.poll() is not None: raise SystemExit('START_FAILED')

try: ok=bool(ctypes.windll.kernel32.SetPriorityClass(int(new._handle),0x00008000))

except Exception: ok=False

print('SWITCH_OK'); print('NEW_PID='+str(new.pid)); print('REVISION=20260830-107-LL4D'); print('PRIORITY_ABOVE_NORMAL='+str(ok))