artiq/artiq/master/worker.py

96 lines
3.1 KiB
Python

import sys
import asyncio
import subprocess
import signal
import traceback
from artiq.management import pyon
class WorkerFailed(Exception):
pass
class RunFailed(Exception):
pass
class Worker:
def __init__(self, handlers,
send_timeout=0.5, start_reply_timeout=1.0, term_timeout=1.0):
self.handlers = handlers
self.send_timeout = send_timeout
self.start_reply_timeout = start_reply_timeout
self.term_timeout = term_timeout
@asyncio.coroutine
def create_process(self):
self.process = yield from asyncio.create_subprocess_exec(
sys.executable, "-m", "artiq.master.worker_impl",
stdout=subprocess.PIPE, stdin=subprocess.PIPE)
@asyncio.coroutine
def _send(self, obj, timeout):
line = pyon.encode(obj)
self.process.stdin.write(line.encode())
self.process.stdin.write("\n".encode())
try:
fut = self.process.stdin.drain()
if fut is not (): # FIXME: why does Python return this?
yield from asyncio.wait_for(fut, timeout=timeout)
except asyncio.TimeoutError:
raise WorkerFailed("Timeout sending data from worker")
except:
raise WorkerFailed("Failed to send data to worker")
@asyncio.coroutine
def _recv(self, timeout):
try:
line = yield from asyncio.wait_for(
self.process.stdout.readline(), timeout=timeout)
except asyncio.TimeoutError:
raise WorkerFailed("Timeout receiving data from worker")
if not line:
raise WorkerFailed(
"Worker ended unexpectedly while trying to receive data")
try:
obj = pyon.decode(line.decode())
except:
raise WorkerFailed("Worker sent invalid PYON data")
return obj
@asyncio.coroutine
def run(self, run_params, result_timeout):
yield from self._send(run_params, self.send_timeout)
obj = yield from self._recv(self.start_reply_timeout)
if obj != "ack":
raise WorkerFailed("Incorrect acknowledgement")
while True:
obj = yield from self._recv(result_timeout)
action = obj["action"]
if action == "report_completed":
if obj["status"] != "ok":
raise RunFailed(obj["message"])
else:
return
else:
del obj["action"]
try:
data = self.handlers[action](**obj)
reply = {"status": "ok", "data": data}
except:
reply = {"status": "failed",
"message": traceback.format_exc()}
yield from self._send(reply, self.send_timeout)
@asyncio.coroutine
def end_process(self):
if self.process.returncode is not None:
return
self.process.send_signal(signal.SIGTERM)
try:
yield from asyncio.wait_for(
self.process.wait(), timeout=self.term_timeout)
except asyncio.TimeoutError:
self.process.send_signal(signal.SIGKILL)