245 lines
7.8 KiB
Python
245 lines
7.8 KiB
Python
# Copyright (c) 2009-2011 Denis Bilenko. See LICENSE for details.
|
|
"""
|
|
Waiting for I/O completion.
|
|
"""
|
|
from __future__ import absolute_import
|
|
|
|
import sys
|
|
|
|
from gevent.event import Event
|
|
from gevent.hub import get_hub
|
|
from gevent.hub import sleep as _g_sleep
|
|
from gevent._compat import integer_types
|
|
from gevent._compat import iteritems
|
|
from gevent._compat import itervalues
|
|
from gevent._util import copy_globals
|
|
from gevent._util import _NONE
|
|
|
|
from errno import EINTR
|
|
if sys.platform.startswith('win32'):
|
|
def _original_select(_r, _w, _x, _t):
|
|
# windows cant handle three empty lists, but we've always
|
|
# accepted that, so don't try the compliance check on windows
|
|
return ((), (), ())
|
|
else:
|
|
from select import select as _original_select
|
|
|
|
try:
|
|
from select import poll as original_poll
|
|
from select import POLLIN, POLLOUT, POLLNVAL
|
|
__implements__ = ['select', 'poll']
|
|
except ImportError:
|
|
original_poll = None
|
|
__implements__ = ['select']
|
|
|
|
__all__ = ['error'] + __implements__
|
|
|
|
import select as __select__
|
|
|
|
error = __select__.error
|
|
|
|
__imports__ = copy_globals(__select__, globals(),
|
|
names_to_ignore=__all__,
|
|
dunder_names_to_keep=())
|
|
|
|
_EV_READ = 1
|
|
_EV_WRITE = 2
|
|
|
|
def get_fileno(obj):
|
|
try:
|
|
fileno_f = obj.fileno
|
|
except AttributeError:
|
|
if not isinstance(obj, integer_types):
|
|
raise TypeError('argument must be an int, or have a fileno() method: %r' % (obj,))
|
|
return obj
|
|
else:
|
|
return fileno_f()
|
|
|
|
|
|
class SelectResult(object):
|
|
__slots__ = ('read', 'write', 'event')
|
|
|
|
def __init__(self):
|
|
self.read = []
|
|
self.write = []
|
|
self.event = Event()
|
|
|
|
def add_read(self, socket):
|
|
self.read.append(socket)
|
|
self.event.set()
|
|
|
|
add_read.event = _EV_READ
|
|
|
|
def add_write(self, socket):
|
|
self.write.append(socket)
|
|
self.event.set()
|
|
|
|
add_write.event = _EV_WRITE
|
|
|
|
def __add_watchers(self, watchers, fdlist, callback, io, pri):
|
|
for fd in fdlist:
|
|
watcher = io(get_fileno(fd), callback.event)
|
|
watcher.priority = pri
|
|
watchers.append(watcher)
|
|
watcher.start(callback, fd)
|
|
|
|
def _make_watchers(self, watchers, rlist, wlist):
|
|
loop = get_hub().loop
|
|
io = loop.io
|
|
MAXPRI = loop.MAXPRI
|
|
|
|
try:
|
|
self.__add_watchers(watchers, rlist, self.add_read, io, MAXPRI)
|
|
self.__add_watchers(watchers, wlist, self.add_write, io, MAXPRI)
|
|
except IOError as ex:
|
|
raise error(*ex.args)
|
|
|
|
def _closeall(self, watchers):
|
|
for watcher in watchers:
|
|
watcher.stop()
|
|
del watchers[:]
|
|
|
|
def select(self, rlist, wlist, timeout):
|
|
watchers = []
|
|
try:
|
|
self._make_watchers(watchers, rlist, wlist)
|
|
self.event.wait(timeout=timeout)
|
|
return self.read, self.write, []
|
|
finally:
|
|
self._closeall(watchers)
|
|
|
|
|
|
def select(rlist, wlist, xlist, timeout=None): # pylint:disable=unused-argument
|
|
"""An implementation of :meth:`select.select` that blocks only the current greenlet.
|
|
|
|
.. caution:: *xlist* is ignored.
|
|
|
|
.. versionchanged:: 1.2a1
|
|
Raise a :exc:`ValueError` if timeout is negative. This matches Python 3's
|
|
behaviour (Python 2 would raise a ``select.error``). Previously gevent had
|
|
undefined behaviour.
|
|
.. versionchanged:: 1.2a1
|
|
Raise an exception if any of the file descriptors are invalid.
|
|
"""
|
|
if timeout is not None and timeout < 0:
|
|
# Raise an error like the real implementation; which error
|
|
# depends on the version. Python 3, where select.error is OSError,
|
|
# raises a ValueError (which makes sense). Older pythons raise
|
|
# the error from the select syscall...but we don't actually get there.
|
|
# We choose to just raise the ValueError as it makes more sense and is
|
|
# forward compatible
|
|
raise ValueError("timeout must be non-negative")
|
|
|
|
# First, do a poll with the original select system call. This
|
|
# is the most efficient way to check to see if any of the file descriptors
|
|
# have previously been closed and raise the correct corresponding exception.
|
|
# (Because libev tends to just return them as ready...)
|
|
# We accept the *xlist* here even though we can't below because this is all about
|
|
# error handling.
|
|
sel_results = ((), (), ())
|
|
try:
|
|
sel_results = _original_select(rlist, wlist, xlist, 0)
|
|
except error as e:
|
|
enumber = getattr(e, 'errno', None) or e.args[0]
|
|
if enumber != EINTR:
|
|
# Ignore interrupted syscalls
|
|
raise
|
|
|
|
if sel_results[0] or sel_results[1] or sel_results[2]:
|
|
# If we actually had stuff ready, go ahead and return it. No need
|
|
# to go through the trouble of doing our own stuff.
|
|
# However, because this is typically a place where scheduling switches
|
|
# can occur, we need to make sure that's still the case; otherwise a single
|
|
# consumer could monopolize the thread. (shows up in test_ftplib.)
|
|
_g_sleep()
|
|
return sel_results
|
|
|
|
result = SelectResult()
|
|
return result.select(rlist, wlist, timeout)
|
|
|
|
|
|
if original_poll is not None:
|
|
class PollResult(object):
|
|
__slots__ = ('events', 'event')
|
|
|
|
def __init__(self):
|
|
self.events = set()
|
|
self.event = Event()
|
|
|
|
def add_event(self, events, fd):
|
|
if events < 0:
|
|
result_flags = POLLNVAL
|
|
else:
|
|
result_flags = 0
|
|
if events & _EV_READ:
|
|
result_flags = POLLIN
|
|
if events & _EV_WRITE:
|
|
result_flags |= POLLOUT
|
|
|
|
self.events.add((fd, result_flags))
|
|
self.event.set()
|
|
|
|
class poll(object):
|
|
"""
|
|
An implementation of :class:`select.poll` that blocks only the current greenlet.
|
|
|
|
.. caution:: ``POLLPRI`` data is not supported.
|
|
|
|
.. versionadded:: 1.1b1
|
|
"""
|
|
def __init__(self):
|
|
self.fds = {} # {int -> watcher}
|
|
self.loop = get_hub().loop
|
|
|
|
def register(self, fd, eventmask=_NONE):
|
|
if eventmask is _NONE:
|
|
flags = _EV_READ | _EV_WRITE
|
|
else:
|
|
flags = 0
|
|
if eventmask & POLLIN:
|
|
flags = _EV_READ
|
|
if eventmask & POLLOUT:
|
|
flags |= _EV_WRITE
|
|
# If they ask for POLLPRI, we can't support
|
|
# that. Should we raise an error?
|
|
|
|
fileno = get_fileno(fd)
|
|
watcher = self.loop.io(fileno, flags)
|
|
watcher.priority = self.loop.MAXPRI
|
|
self.fds[fileno] = watcher
|
|
|
|
def modify(self, fd, eventmask):
|
|
self.register(fd, eventmask)
|
|
|
|
def poll(self, timeout=None):
|
|
"""
|
|
poll the registered fds.
|
|
|
|
.. versionchanged:: 1.2a1
|
|
File descriptors that are closed are reported with POLLNVAL.
|
|
"""
|
|
result = PollResult()
|
|
try:
|
|
for fd, watcher in iteritems(self.fds):
|
|
watcher.start(result.add_event, fd, pass_events=True)
|
|
if timeout is not None and timeout > -1:
|
|
timeout /= 1000.0
|
|
result.event.wait(timeout=timeout)
|
|
return list(result.events)
|
|
finally:
|
|
for awatcher in itervalues(self.fds):
|
|
awatcher.stop()
|
|
|
|
def unregister(self, fd):
|
|
"""
|
|
Unregister the *fd*.
|
|
|
|
.. versionchanged:: 1.2a1
|
|
Raise a `KeyError` if *fd* was not registered, like the standard
|
|
library. Previously gevent did nothing.
|
|
"""
|
|
fileno = get_fileno(fd)
|
|
del self.fds[fileno]
|
|
|
|
del original_poll
|