from __future__ import absolute_import, division, print_function
import logging
import os
import signal
import subprocess
import sys
from tornado.httpclient import HTTPClient, HTTPError
from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop
from tornado.log import gen_log
from tornado.process import fork_processes, task_id, Subprocess
from tornado.simple_httpclient import SimpleAsyncHTTPClient
from tornado.testing import bind_unused_port, ExpectLog, AsyncTestCase, gen_test
from tornado.test.util import unittest, skipIfNonUnix
from tornado.web import RequestHandler, Application
try:
import asyncio
except ImportError:
asyncio = None
def skip_if_twisted():
if IOLoop.configured_class().__name__.endswith('TwistedIOLoop'):
raise unittest.SkipTest("Process tests not compatible with TwistedIOLoop")
# Not using AsyncHTTPTestCase because we need control over the IOLoop.
@skipIfNonUnix
class ProcessTest(unittest.TestCase):
def get_app(self):
class ProcessHandler(RequestHandler):
def get(self):
if self.get_argument("exit", None):
# must use os._exit instead of sys.exit so unittest's
# exception handler doesn't catch it
os._exit(int(self.get_argument("exit")))
if self.get_argument("signal", None):
os.kill(os.getpid(),
int(self.get_argument("signal")))
self.write(str(os.getpid()))
return Application([("/", ProcessHandler)])
def tearDown(self):
if task_id() is not None:
# We're in a child process, and probably got to this point
# via an uncaught exception. If we return now, both
# processes will continue with the rest of the test suite.
# Exit now so the parent process will restart the child
# (since we don't have a clean way to signal failure to
# the parent that won't restart)
logging.error("aborting child process from tearDown")
logging.shutdown()
os._exit(1)
# In the surviving process, clear the alarm we set earlier
signal.alarm(0)
super(ProcessTest, self).tearDown()
def test_multi_process(self):
# This test doesn't work on twisted because we use the global
# reactor and don't restore it to a sane state after the fork
# (asyncio has the same issue, but we have a special case in
# place for it).
skip_if_twisted()
with ExpectLog(gen_log, "(Starting .* processes|child .* exited|uncaught exception)"):
sock, port = bind_unused_port()
def get_url(path):
return "http://127.0.0.1:%d%s" % (port, path)
# ensure that none of these processes live too long
signal.alarm(5) # master process
try:
id = fork_processes(3, max_restarts=3)
self.assertTrue(id is not None)
signal.alarm(5) # child processes
except SystemExit as e:
# if we exit cleanly from fork_processes, all the child processes
# finished with status 0
self.assertEqual(e.code, 0)
self.assertTrue(task_id() is None)
sock.close()
return
try:
if asyncio is not None:
# Reset the global asyncio event loop, which was put into
# a broken state by the fork.
asyncio.set_event_loop(asyncio.new_event_loop())
if id in (0, 1):
self.assertEqual(id, task_id())
server = HTTPServer(self.get_app())
server.add_sockets([sock])
IOLoop.current().start()
elif id == 2:
self.assertEqual(id, task_id())
sock.close()
# Always use SimpleAsyncHTTPClient here; the curl
# version appears to get confused sometimes if the
# connection gets closed before it's had a chance to
# switch from writing mode to reading mode.
client = HTTPClient(SimpleAsyncHTTPClient)
def fetch(url, fail_ok=False):
try:
return client.fetch(get_url(url))
except HTTPError as e:
if not (fail_ok and e.code == 599):
raise
# Make two processes exit abnormally
fetch("/?exit=2", fail_ok=True)
fetch("/?exit=3", fail_ok=True)
# They've been restarted, so a new fetch will work
int(fetch("/").body)
# Now the same with signals
# Disabled because on the mac a process dying with a signal
# can trigger an "Application exited abnormally; send error
# report to Apple?" prompt.
# fetch("/?signal=%d" % signal.SIGTERM, fail_ok=True)
# fetch("/?signal=%d" % signal.SIGABRT, fail_ok=True)
# int(fetch("/").body)
# Now kill them normally so they won't be restarted
fetch("/?exit=0", fail_ok=True)
# One process left; watch it's pid change
pid = int(fetch("/").body)
fetch("/?exit=4", fail_ok=True)
pid2 = int(fetch("/").body)
self.assertNotEqual(pid, pid2)
# Kill the last one so we shut down cleanly
fetch("/?exit=0", fail_ok=True)
os._exit(0)
except Exception:
logging.error("exception in child process %d", id, exc_info=True)
raise
@skipIfNonUnix
class SubprocessTest(AsyncTestCase):
@gen_test
def test_subprocess(self):
if IOLoop.configured_class().__name__.endswith('LayeredTwistedIOLoop'):
# This test fails non-deterministically with LayeredTwistedIOLoop.
# (the read_until('\n') returns '\n' instead of 'hello\n')
# This probably indicates a problem with either TornadoReactor
# or TwistedIOLoop, but I haven't been able to track it down
# and for now this is just causing spurious travis-ci failures.
raise unittest.SkipTest("Subprocess tests not compatible with "
"LayeredTwistedIOLoop")
subproc = Subprocess([sys.executable, '-u', '-i'],
stdin=Subprocess.STREAM,
stdout=Subprocess.STREAM, stderr=subprocess.STDOUT)
self.addCleanup(lambda: (subproc.proc.terminate(), subproc.proc.wait()))
self.addCleanup(subproc.stdout.close)
self.addCleanup(subproc.stdin.close)
yield subproc.stdout.read_until(b'>>> ')
subproc.stdin.write(b"print('hello')\n")
data = yield subproc.stdout.read_until(b'\n')
self.assertEqual(data, b"hello\n")
yield subproc.stdout.read_until(b">>> ")
subproc.stdin.write(b"raise SystemExit\n")
data = yield subproc.stdout.read_until_close()
self.assertEqual(data, b"")
@gen_test
def test_close_stdin(self):
# Close the parent's stdin handle and see that the child recognizes it.
subproc = Subprocess([sys.executable, '-u', '-i'],
stdin=Subprocess.STREAM,
stdout=Subprocess.STREAM, stderr=subprocess.STDOUT)
self.addCleanup(lambda: (subproc.proc.terminate(), subproc.proc.wait()))
yield subproc.stdout.read_until(b'>>> ')
subproc.stdin.close()
data = yield subproc.stdout.read_until_close()
self.assertEqual(data, b"\n")
@gen_test
def test_stderr(self):
# This test is mysteriously flaky on twisted: it succeeds, but logs
# an error of EBADF on closing a file descriptor.
skip_if_twisted()
subproc = Subprocess([sys.executable, '-u', '-c',
r"import sys; sys.stderr.write('hello\n')"],
stderr=Subprocess.STREAM)
self.addCleanup(lambda: (subproc.proc.terminate(), subproc.proc.wait()))
data = yield subproc.stderr.read_until(b'\n')
self.assertEqual(data, b'hello\n')
# More mysterious EBADF: This fails if done with self.addCleanup instead of here.
subproc.stderr.close()
def test_sigchild(self):
# Twisted's SIGCHLD handler and Subprocess's conflict with each other.
skip_if_twisted()
Subprocess.initialize()
self.addCleanup(Subprocess.uninitialize)
subproc = Subprocess([sys.executable, '-c', 'pass'])
subproc.set_exit_callback(self.stop)
ret = self.wait()
self.assertEqual(ret, 0)
self.assertEqual(subproc.returncode, ret)
@gen_test
def test_sigchild_future(self):
skip_if_twisted()
Subprocess.initialize()
self.addCleanup(Subprocess.uninitialize)
subproc = Subprocess([sys.executable, '-c', 'pass'])
ret = yield subproc.wait_for_exit()
self.assertEqual(ret, 0)
self.assertEqual(subproc.returncode, ret)
def test_sigchild_signal(self):
skip_if_twisted()
Subprocess.initialize()
self.addCleanup(Subprocess.uninitialize)
subproc = Subprocess([sys.executable, '-c',
'import time; time.sleep(30)'],
stdout=Subprocess.STREAM)
self.addCleanup(subproc.stdout.close)
subproc.set_exit_callback(self.stop)
os.kill(subproc.pid, signal.SIGTERM)
try:
ret = self.wait(timeout=1.0)
except AssertionError:
# We failed to get the termination signal. This test is
# occasionally flaky on pypy, so try to get a little more
# information: did the process close its stdout
# (indicating that the problem is in the parent process's
# signal handling) or did the child process somehow fail
# to terminate?
subproc.stdout.read_until_close(callback=self.stop)
try:
self.wait(timeout=1.0)
except AssertionError:
raise AssertionError("subprocess failed to terminate")
else:
raise AssertionError("subprocess closed stdout but failed to "
"get termination signal")
self.assertEqual(subproc.returncode, ret)
self.assertEqual(ret, -signal.SIGTERM)
@gen_test
def test_wait_for_exit_raise(self):
skip_if_twisted()
Subprocess.initialize()
self.addCleanup(Subprocess.uninitialize)
subproc = Subprocess([sys.executable, '-c', 'import sys; sys.exit(1)'])
with self.assertRaises(subprocess.CalledProcessError) as cm:
yield subproc.wait_for_exit()
self.assertEqual(cm.exception.returncode, 1)
@gen_test
def test_wait_for_exit_raise_disabled(self):
skip_if_twisted()
Subprocess.initialize()
self.addCleanup(Subprocess.uninitialize)
subproc = Subprocess([sys.executable, '-c', 'import sys; sys.exit(1)'])
ret = yield subproc.wait_for_exit(raise_error=False)
self.assertEqual(ret, 1)