sanic/sanic/reloader_helpers.py
2018-10-17 21:20:16 -07:00

159 lines
4.5 KiB
Python

import os
import signal
import subprocess
import sys
from multiprocessing import Process
from time import sleep
def _iter_module_files():
"""This iterates over all relevant Python files.
It goes through all
loaded files from modules, all files in folders of already loaded modules
as well as all files reachable through a package.
"""
# The list call is necessary on Python 3 in case the module
# dictionary modifies during iteration.
for module in list(sys.modules.values()):
if module is None:
continue
filename = getattr(module, "__file__", None)
if filename:
old = None
while not os.path.isfile(filename):
old = filename
filename = os.path.dirname(filename)
if filename == old:
break
else:
if filename[-4:] in (".pyc", ".pyo"):
filename = filename[:-1]
yield filename
def _get_args_for_reloading():
"""Returns the executable."""
rv = [sys.executable]
rv.extend(sys.argv)
return rv
def restart_with_reloader():
"""Create a new process and a subprocess in it with the same arguments as
this one.
"""
args = _get_args_for_reloading()
new_environ = os.environ.copy()
new_environ["SANIC_SERVER_RUNNING"] = "true"
cmd = " ".join(args)
worker_process = Process(
target=subprocess.call,
args=(cmd,),
kwargs=dict(shell=True, env=new_environ),
)
worker_process.start()
return worker_process
def kill_process_children_unix(pid):
"""Find and kill child processes of a process (maximum two level).
:param pid: PID of parent process (process ID)
:return: Nothing
"""
root_process_path = "/proc/{pid}/task/{pid}/children".format(pid=pid)
if not os.path.isfile(root_process_path):
return
with open(root_process_path) as children_list_file:
children_list_pid = children_list_file.read().split()
for child_pid in children_list_pid:
children_proc_path = "/proc/%s/task/%s/children" % (
child_pid,
child_pid,
)
if not os.path.isfile(children_proc_path):
continue
with open(children_proc_path) as children_list_file_2:
children_list_pid_2 = children_list_file_2.read().split()
for _pid in children_list_pid_2:
try:
os.kill(int(_pid), signal.SIGTERM)
except ProcessLookupError:
continue
try:
os.kill(int(child_pid), signal.SIGTERM)
except ProcessLookupError:
continue
def kill_process_children_osx(pid):
"""Find and kill child processes of a process.
:param pid: PID of parent process (process ID)
:return: Nothing
"""
subprocess.run(["pkill", "-P", str(pid)])
def kill_process_children(pid):
"""Find and kill child processes of a process.
:param pid: PID of parent process (process ID)
:return: Nothing
"""
if sys.platform == "darwin":
kill_process_children_osx(pid)
elif sys.platform == "linux":
kill_process_children_unix(pid)
else:
pass # should signal error here
def kill_program_completly(proc):
"""Kill worker and it's child processes and exit.
:param proc: worker process (process ID)
:return: Nothing
"""
kill_process_children(proc.pid)
proc.terminate()
os._exit(0)
def watchdog(sleep_interval):
"""Watch project files, restart worker process if a change happened.
:param sleep_interval: interval in second.
:return: Nothing
"""
mtimes = {}
worker_process = restart_with_reloader()
signal.signal(
signal.SIGTERM, lambda *args: kill_program_completly(worker_process)
)
signal.signal(
signal.SIGINT, lambda *args: kill_program_completly(worker_process)
)
while True:
for filename in _iter_module_files():
try:
mtime = os.stat(filename).st_mtime
except OSError:
continue
old_time = mtimes.get(filename)
if old_time is None:
mtimes[filename] = mtime
continue
elif mtime > old_time:
kill_process_children(worker_process.pid)
worker_process.terminate()
worker_process = restart_with_reloader()
mtimes[filename] = mtime
break
sleep(sleep_interval)