ostree/src/ostbuild/pyostbuild/mainloop.py

97 lines
3.0 KiB
Python

#
# Copyright (C) 2011 Colin Walters <walters@verbum.org>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
import os
import sys
import select
import time
class Mainloop(object):
DEFAULT = None
def __init__(self):
self._running = True
self.poll = None
self._timeouts = []
self._pid_watches = {}
self._fd_callbacks = {}
@classmethod
def get(cls, context):
if context is None:
if cls.DEFAULT is None:
cls.DEFAULT = cls()
return cls.DEFAULT
raise NotImplementedError("Unknown context %r" % (context, ))
def _ensure_poll(self):
if self.poll is None:
self.poll = select.poll()
def watch_fd(self, fd, callback):
self._ensure_poll()
self.poll.register(fd)
self._fd_callbacks[fd] = callback
def unwatch_fd(self, fd):
self.poll.unregister(fd)
del self._fd_callbacks[fd]
def watch_pid(self, pid, callback):
self._pid_watches[pid] = callback
def timeout_add(self, ms, callback):
self._timeouts.append((ms, callback))
def quit(self):
self._running = False
def run_once(self):
min_timeout = None
if len(self._pid_watches) > 0:
min_timeout = 500
for (ms, callback) in self._timeouts:
if (min_timeout is None) or (ms < min_timeout):
min_timeout = ms
origtime = time.time() * 1000
self._ensure_poll()
fds = self.poll.poll(min_timeout)
for fd in fds:
self._fd_callbacks[fd]()
to_delete_pids = []
for pid in self._pid_watches:
(opid, status) = os.waitpid(pid, os.WNOHANG)
if opid == pid:
to_delete_pids.append(pid)
self._pid_watches[pid](pid, status)
for pid in to_delete_pids:
del self._pid_watches[pid]
newtime = time.time() * 1000
diff = int(newtime - origtime)
if diff < 0: diff = 0
for i,(ms, callback) in enumerate(self._timeouts):
remaining_ms = ms - diff
if remaining_ms <= 0:
callback()
else:
self._timeouts[i] = (remaining_ms, callback)
def run(self):
self._running = True
while self._running:
self.run_once()