You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
441 lines
16 KiB
Python
441 lines
16 KiB
Python
"""Base class for implementing servers"""
|
|
# Copyright (c) 2009-2012 Denis Bilenko. See LICENSE for details.
|
|
from __future__ import print_function
|
|
from __future__ import absolute_import
|
|
from __future__ import division
|
|
|
|
import sys
|
|
import _socket
|
|
import errno
|
|
|
|
from gevent.greenlet import Greenlet
|
|
from gevent.event import Event
|
|
from gevent.hub import get_hub
|
|
from gevent._compat import string_types
|
|
from gevent._compat import integer_types
|
|
from gevent._compat import xrange
|
|
|
|
|
|
|
|
__all__ = ['BaseServer']
|
|
|
|
|
|
# We define a helper function to handle closing the socket in
|
|
# do_handle; We'd like to bind it to a kwarg to avoid *any* lookups at
|
|
# all, but that's incompatible with the calling convention of
|
|
# do_handle. On CPython, this is ~20% faster than creating and calling
|
|
# a closure and ~10% faster than using a @staticmethod. (In theory, we
|
|
# could create a closure only once in set_handle, to wrap self._handle,
|
|
# but this is safer from a backwards compat standpoint.)
|
|
# we also avoid unpacking the *args tuple when calling/spawning this object
|
|
# for a tiny improvement (benchmark shows a wash)
|
|
def _handle_and_close_when_done(handle, close, args_tuple):
|
|
try:
|
|
return handle(*args_tuple)
|
|
finally:
|
|
close(*args_tuple)
|
|
|
|
|
|
class BaseServer(object):
|
|
"""
|
|
An abstract base class that implements some common functionality for the servers in gevent.
|
|
|
|
:param listener: Either be an address that the server should bind
|
|
on or a :class:`gevent.socket.socket` instance that is already
|
|
bound (and put into listening mode in case of TCP socket).
|
|
|
|
:keyword handle: If given, the request handler. The request
|
|
handler can be defined in a few ways. Most commonly,
|
|
subclasses will implement a ``handle`` method as an
|
|
instance method. Alternatively, a function can be passed
|
|
as the ``handle`` argument to the constructor. In either
|
|
case, the handler can later be changed by calling
|
|
:meth:`set_handle`.
|
|
|
|
When the request handler returns, the socket used for the
|
|
request will be closed. Therefore, the handler must not return if
|
|
the socket is still in use (for example, by manually spawned greenlets).
|
|
|
|
:keyword spawn: If provided, is called to create a new
|
|
greenlet to run the handler. By default,
|
|
:func:`gevent.spawn` is used (meaning there is no
|
|
artificial limit on the number of concurrent requests). Possible values for *spawn*:
|
|
|
|
- a :class:`gevent.pool.Pool` instance -- ``handle`` will be executed
|
|
using :meth:`gevent.pool.Pool.spawn` only if the pool is not full.
|
|
While it is full, no new connections are accepted;
|
|
- :func:`gevent.spawn_raw` -- ``handle`` will be executed in a raw
|
|
greenlet which has a little less overhead then :class:`gevent.Greenlet` instances spawned by default;
|
|
- ``None`` -- ``handle`` will be executed right away, in the :class:`Hub` greenlet.
|
|
``handle`` cannot use any blocking functions as it would mean switching to the :class:`Hub`.
|
|
- an integer -- a shortcut for ``gevent.pool.Pool(integer)``
|
|
|
|
.. versionchanged:: 1.1a1
|
|
When the *handle* function returns from processing a connection,
|
|
the client socket will be closed. This resolves the non-deterministic
|
|
closing of the socket, fixing ResourceWarnings under Python 3 and PyPy.
|
|
.. versionchanged:: 1.5
|
|
Now a context manager that returns itself and calls :meth:`stop` on exit.
|
|
|
|
"""
|
|
# pylint: disable=too-many-instance-attributes,bare-except,broad-except
|
|
|
|
#: the number of seconds to sleep in case there was an error in accept() call
|
|
#: for consecutive errors the delay will double until it reaches max_delay
|
|
#: when accept() finally succeeds the delay will be reset to min_delay again
|
|
min_delay = 0.01
|
|
max_delay = 1
|
|
|
|
#: Sets the maximum number of consecutive accepts that a process may perform on
|
|
#: a single wake up. High values give higher priority to high connection rates,
|
|
#: while lower values give higher priority to already established connections.
|
|
#: Default is 100.
|
|
#:
|
|
#: Note that, in case of multiple working processes on the same
|
|
#: listening socket, it should be set to a lower value. (pywsgi.WSGIServer sets it
|
|
#: to 1 when ``environ["wsgi.multiprocess"]`` is true)
|
|
#:
|
|
#: This is equivalent to libuv's `uv_tcp_simultaneous_accepts
|
|
#: <http://docs.libuv.org/en/v1.x/tcp.html#c.uv_tcp_simultaneous_accepts>`_
|
|
#: value. Setting the environment variable UV_TCP_SINGLE_ACCEPT to a true value
|
|
#: (usually 1) changes the default to 1.
|
|
max_accept = 100
|
|
|
|
_spawn = Greenlet.spawn
|
|
|
|
#: the default timeout that we wait for the client connections to close in stop()
|
|
stop_timeout = 1
|
|
|
|
fatal_errors = (errno.EBADF, errno.EINVAL, errno.ENOTSOCK)
|
|
|
|
def __init__(self, listener, handle=None, spawn='default'):
|
|
self._stop_event = Event()
|
|
self._stop_event.set()
|
|
self._watcher = None
|
|
self._timer = None
|
|
self._handle = None
|
|
# XXX: FIXME: Subclasses rely on the presence or absence of the
|
|
# `socket` attribute to determine whether we are open/should be opened.
|
|
# Instead, have it be None.
|
|
# XXX: In general, the state management here is confusing. Lots of stuff is
|
|
# deferred until the various ``set_`` methods are called, and it's not documented
|
|
# when it's safe to call those
|
|
self.pool = None # can be set from ``spawn``; overrides self.full()
|
|
try:
|
|
self.set_listener(listener)
|
|
self.set_spawn(spawn)
|
|
self.set_handle(handle)
|
|
self.delay = self.min_delay
|
|
self.loop = get_hub().loop
|
|
if self.max_accept < 1:
|
|
raise ValueError('max_accept must be positive int: %r' % (self.max_accept, ))
|
|
except:
|
|
self.close()
|
|
raise
|
|
|
|
def __enter__(self):
|
|
return self
|
|
|
|
def __exit__(self, *args):
|
|
self.stop()
|
|
|
|
def set_listener(self, listener):
|
|
if hasattr(listener, 'accept'):
|
|
if hasattr(listener, 'do_handshake'):
|
|
raise TypeError('Expected a regular socket, not SSLSocket: %r' % (listener, ))
|
|
self.family = listener.family
|
|
self.address = listener.getsockname()
|
|
self.socket = listener
|
|
else:
|
|
self.family, self.address = parse_address(listener)
|
|
|
|
def set_spawn(self, spawn):
|
|
if spawn == 'default':
|
|
self.pool = None
|
|
self._spawn = self._spawn
|
|
elif hasattr(spawn, 'spawn'):
|
|
self.pool = spawn
|
|
self._spawn = spawn.spawn
|
|
elif isinstance(spawn, integer_types):
|
|
from gevent.pool import Pool
|
|
self.pool = Pool(spawn)
|
|
self._spawn = self.pool.spawn
|
|
else:
|
|
self.pool = None
|
|
self._spawn = spawn
|
|
if hasattr(self.pool, 'full'):
|
|
self.full = self.pool.full
|
|
if self.pool is not None:
|
|
self.pool._semaphore.rawlink(self._start_accepting_if_started)
|
|
|
|
def set_handle(self, handle):
|
|
if handle is not None:
|
|
self.handle = handle
|
|
if hasattr(self, 'handle'):
|
|
self._handle = self.handle
|
|
else:
|
|
raise TypeError("'handle' must be provided")
|
|
|
|
def _start_accepting_if_started(self, _event=None):
|
|
if self.started:
|
|
self.start_accepting()
|
|
|
|
def start_accepting(self):
|
|
if self._watcher is None:
|
|
# just stop watcher without creating a new one?
|
|
self._watcher = self.loop.io(self.socket.fileno(), 1)
|
|
self._watcher.start(self._do_read)
|
|
|
|
def stop_accepting(self):
|
|
if self._watcher is not None:
|
|
self._watcher.stop()
|
|
self._watcher.close()
|
|
self._watcher = None
|
|
if self._timer is not None:
|
|
self._timer.stop()
|
|
self._timer.close()
|
|
self._timer = None
|
|
|
|
def do_handle(self, *args):
|
|
spawn = self._spawn
|
|
handle = self._handle
|
|
close = self.do_close
|
|
|
|
try:
|
|
if spawn is None:
|
|
_handle_and_close_when_done(handle, close, args)
|
|
else:
|
|
spawn(_handle_and_close_when_done, handle, close, args)
|
|
except:
|
|
close(*args)
|
|
raise
|
|
|
|
def do_close(self, *args):
|
|
pass
|
|
|
|
def do_read(self):
|
|
raise NotImplementedError()
|
|
|
|
def _do_read(self):
|
|
for _ in xrange(self.max_accept):
|
|
if self.full():
|
|
self.stop_accepting()
|
|
if self.pool is not None:
|
|
self.pool._semaphore.rawlink(self._start_accepting_if_started)
|
|
return
|
|
try:
|
|
args = self.do_read()
|
|
self.delay = self.min_delay
|
|
if not args:
|
|
return
|
|
except:
|
|
self.loop.handle_error(self, *sys.exc_info())
|
|
ex = sys.exc_info()[1]
|
|
if self.is_fatal_error(ex):
|
|
self.close()
|
|
sys.stderr.write('ERROR: %s failed with %s\n' % (self, str(ex) or repr(ex)))
|
|
return
|
|
if self.delay >= 0:
|
|
self.stop_accepting()
|
|
self._timer = self.loop.timer(self.delay)
|
|
self._timer.start(self._start_accepting_if_started)
|
|
self.delay = min(self.max_delay, self.delay * 2)
|
|
break
|
|
else:
|
|
try:
|
|
self.do_handle(*args)
|
|
except:
|
|
self.loop.handle_error((args[1:], self), *sys.exc_info())
|
|
if self.delay >= 0:
|
|
self.stop_accepting()
|
|
self._timer = self.loop.timer(self.delay)
|
|
self._timer.start(self._start_accepting_if_started)
|
|
self.delay = min(self.max_delay, self.delay * 2)
|
|
break
|
|
|
|
def full(self): # pylint: disable=method-hidden
|
|
# If a Pool is given for to ``set_spawn`` (the *spawn* argument
|
|
# of the constructor) it will replace this method.
|
|
return False
|
|
|
|
def __repr__(self):
|
|
return '<%s at %s %s>' % (type(self).__name__, hex(id(self)), self._formatinfo())
|
|
|
|
def __str__(self):
|
|
return '<%s %s>' % (type(self).__name__, self._formatinfo())
|
|
|
|
def _formatinfo(self):
|
|
if hasattr(self, 'socket'):
|
|
try:
|
|
fileno = self.socket.fileno()
|
|
except Exception as ex:
|
|
fileno = str(ex)
|
|
result = 'fileno=%s ' % fileno
|
|
else:
|
|
result = ''
|
|
try:
|
|
if isinstance(self.address, tuple) and len(self.address) == 2:
|
|
result += 'address=%s:%s' % self.address
|
|
else:
|
|
result += 'address=%s' % (self.address, )
|
|
except Exception as ex:
|
|
result += str(ex) or '<error>'
|
|
|
|
handle = self.__dict__.get('handle')
|
|
if handle is not None:
|
|
fself = getattr(handle, '__self__', None)
|
|
try:
|
|
if fself is self:
|
|
# Checks the __self__ of the handle in case it is a bound
|
|
# method of self to prevent recursively defined reprs.
|
|
handle_repr = '<bound method %s.%s of self>' % (
|
|
self.__class__.__name__,
|
|
handle.__name__,
|
|
)
|
|
else:
|
|
handle_repr = repr(handle)
|
|
|
|
result += ' handle=' + handle_repr
|
|
except Exception as ex:
|
|
result += str(ex) or '<error>'
|
|
|
|
return result
|
|
|
|
@property
|
|
def server_host(self):
|
|
"""IP address that the server is bound to (string)."""
|
|
if isinstance(self.address, tuple):
|
|
return self.address[0]
|
|
|
|
@property
|
|
def server_port(self):
|
|
"""Port that the server is bound to (an integer)."""
|
|
if isinstance(self.address, tuple):
|
|
return self.address[1]
|
|
|
|
def init_socket(self):
|
|
"""
|
|
If the user initialized the server with an address rather than
|
|
socket, then this function must create a socket, bind it, and
|
|
put it into listening mode.
|
|
|
|
It is not supposed to be called by the user, it is called by :meth:`start` before starting
|
|
the accept loop.
|
|
"""
|
|
|
|
@property
|
|
def started(self):
|
|
return not self._stop_event.is_set()
|
|
|
|
def start(self):
|
|
"""Start accepting the connections.
|
|
|
|
If an address was provided in the constructor, then also create a socket,
|
|
bind it and put it into the listening mode.
|
|
"""
|
|
self.init_socket()
|
|
self._stop_event.clear()
|
|
try:
|
|
self.start_accepting()
|
|
except:
|
|
self.close()
|
|
raise
|
|
|
|
def close(self):
|
|
"""Close the listener socket and stop accepting."""
|
|
self._stop_event.set()
|
|
try:
|
|
self.stop_accepting()
|
|
finally:
|
|
try:
|
|
self.socket.close()
|
|
except Exception:
|
|
pass
|
|
finally:
|
|
self.__dict__.pop('socket', None)
|
|
self.__dict__.pop('handle', None)
|
|
self.__dict__.pop('_handle', None)
|
|
self.__dict__.pop('_spawn', None)
|
|
self.__dict__.pop('full', None)
|
|
if self.pool is not None:
|
|
self.pool._semaphore.unlink(self._start_accepting_if_started)
|
|
# If the pool's semaphore had a notifier already started,
|
|
# there's a reference cycle we're a part of
|
|
# (self->pool->semaphere-hub callback->semaphore)
|
|
# But we can't destroy self.pool, because self.stop()
|
|
# calls this method, and then wants to join self.pool()
|
|
|
|
@property
|
|
def closed(self):
|
|
return not hasattr(self, 'socket')
|
|
|
|
def stop(self, timeout=None):
|
|
"""
|
|
Stop accepting the connections and close the listening socket.
|
|
|
|
If the server uses a pool to spawn the requests, then
|
|
:meth:`stop` also waits for all the handlers to exit. If there
|
|
are still handlers executing after *timeout* has expired
|
|
(default 1 second, :attr:`stop_timeout`), then the currently
|
|
running handlers in the pool are killed.
|
|
|
|
If the server does not use a pool, then this merely stops accepting connections;
|
|
any spawned greenlets that are handling requests continue running until
|
|
they naturally complete.
|
|
"""
|
|
self.close()
|
|
if timeout is None:
|
|
timeout = self.stop_timeout
|
|
if self.pool:
|
|
self.pool.join(timeout=timeout)
|
|
self.pool.kill(block=True, timeout=1)
|
|
|
|
|
|
def serve_forever(self, stop_timeout=None):
|
|
"""Start the server if it hasn't been already started and wait until it's stopped."""
|
|
# add test that serve_forever exists on stop()
|
|
if not self.started:
|
|
self.start()
|
|
try:
|
|
self._stop_event.wait()
|
|
finally:
|
|
Greenlet.spawn(self.stop, timeout=stop_timeout).join()
|
|
|
|
def is_fatal_error(self, ex):
|
|
return isinstance(ex, _socket.error) and ex.args[0] in self.fatal_errors
|
|
|
|
|
|
def _extract_family(host):
|
|
if host.startswith('[') and host.endswith(']'):
|
|
host = host[1:-1]
|
|
return _socket.AF_INET6, host
|
|
return _socket.AF_INET, host
|
|
|
|
|
|
def _parse_address(address):
|
|
if isinstance(address, tuple):
|
|
if not address[0] or ':' in address[0]:
|
|
return _socket.AF_INET6, address
|
|
return _socket.AF_INET, address
|
|
|
|
if ((isinstance(address, string_types) and ':' not in address)
|
|
or isinstance(address, integer_types)): # noqa (pep8 E129)
|
|
# Just a port
|
|
return _socket.AF_INET6, ('', int(address))
|
|
|
|
if not isinstance(address, string_types):
|
|
raise TypeError('Expected tuple or string, got %s' % type(address))
|
|
|
|
host, port = address.rsplit(':', 1)
|
|
family, host = _extract_family(host)
|
|
if host == '*':
|
|
host = ''
|
|
return family, (host, int(port))
|
|
|
|
|
|
def parse_address(address):
|
|
try:
|
|
return _parse_address(address)
|
|
except ValueError as ex: # pylint:disable=try-except-raise
|
|
raise ValueError('Failed to parse address %r: %s' % (address, ex))
|