from pathlib import Path
import json,subprocess,time,os,signal,socket,selectors
root=Path('/tmp/work');spec=json.loads((root/'launch.json').read_text());p=None
unix=socket.socket(socket.AF_UNIX,socket.SOCK_DGRAM);unix.bind(str(root/'inner.sock'))
udp=socket.socket(socket.AF_INET,socket.SOCK_DGRAM);udp.bind(('127.0.0.1',0));udp.connect(('127.0.0.1',2001))
sel=selectors.DefaultSelector();sel.register(unix,selectors.EVENT_READ);sel.register(udp,selectors.EVENT_READ)
try:
 with (root/'server-stdout.log').open('w') as log:
  p=subprocess.Popen(spec['server'],cwd='/tmp/runtime',stdout=log,stderr=subprocess.STDOUT,start_new_session=True)
  while p.poll() is None and not (root/'stop').exists():
   for key,_ in sel.select(.2):
    if key.fileobj is unix:
     packet,_=unix.recvfrom(65535);udp.send(packet)
    else:
     packet=udp.recv(65535);unix.sendto(packet,str(root/'outer.sock'))
finally:
 if p and p.poll() is None:
  os.killpg(p.pid,signal.SIGTERM)
  try:p.wait(timeout=8)
  except subprocess.TimeoutExpired:os.killpg(p.pid,signal.SIGKILL);p.wait(timeout=5)
 (root/'server-result.json').write_text(json.dumps({'exit':p.returncode if p else None}))