# pylint:disable=too-many-lines, protected-access, redefined-outer-name, not-callable,
# pylint:disable=no-member
from __future__ import absolute_import, print_function
import sys
import os
import traceback
import signal as signalmodule
# pylint:disable=undefined-all-variable
__all__ = [
'get_version',
'get_header_version',
'supported_backends',
'recommended_backends',
'embeddable_backends',
'time',
'loop',
]
import gevent.libev._corecffi as _corecffi # pylint:disable=no-name-in-module
ffi = _corecffi.ffi # pylint:disable=no-member
libev = _corecffi.lib # pylint:disable=no-member
if hasattr(libev, 'vfd_open'):
# Must be on windows
assert sys.platform.startswith("win"), "vfd functions only needed on windows"
vfd_open = libev.vfd_open
vfd_free = libev.vfd_free
vfd_get = libev.vfd_get
else:
vfd_open = vfd_free = vfd_get = lambda fd: fd
#####
## NOTE on Windows:
# The C implementation does several things specially for Windows;
# a possibly incomplete list is:
#
# - the loop runs a periodic signal checker;
# - the io watcher constructor is different and it has a destructor;
# - the child watcher is not defined
#
# The CFFI implementation does none of these things, and so
# is possibly NOT FUNCTIONALLY CORRECT on Win32
#####
#####
## Note on CFFI objects, callbacks and the lifecycle of watcher objects
#
# Each subclass of `watcher` allocates a C structure of the
# appropriate type e.g., struct gevent_ev_io and holds this pointer in
# its `_gwatcher` attribute. When that watcher instance is garbage
# collected, then the C structure is also freed. The C structure is
# passed to libev from the watcher's start() method and then to the
# appropriate C callback function, e.g., _gevent_ev_io_callback, which
# passes it back to python's _python_callback where we need the
# watcher instance. Therefore, as long as that callback is active (the
# watcher is started), the watcher instance must not be allowed to get
# GC'd---any access at the C level or even the FFI level to the freed
# memory could crash the process.
#
# However, the typical idiom calls for writing something like this:
# loop.io(fd, python_cb).start()
# thus forgetting the newly created watcher subclass and allowing it to be immediately
# GC'd. To combat this, when the watcher is started, it places itself into the loop's
# `_keepaliveset`, and it only removes itself when the watcher's `stop()` method is called.
# Often, this is the *only* reference keeping the watcher object, and hence its C structure,
# alive.
#
# This is slightly complicated by the fact that the python-level
# callback, called from the C callback, could choose to manually stop
# the watcher. When we return to the C level callback, we now have an
# invalid pointer, and attempting to pass it back to Python (e.g., to
# handle an error) could crash. Hence, _python_callback,
# _gevent_io_callback, and _python_handle_error cooperate to make sure
# that the watcher instance stays in the loops `_keepaliveset` while
# the C code could be running---and if it gets removed, to not call back
# to Python again.
# See also https://github.com/gevent/gevent/issues/676
####
@ffi.callback("int(void* handle, int revents)")
def _python_callback(handle, revents):
"""
Returns an integer having one of three values:
- -1
An exception occurred during the callback and you must call
:func:`_python_handle_error` to deal with it. The Python watcher
object will have the exception tuple saved in ``_exc_info``.
- 0
Everything went according to plan. You should check to see if the libev
watcher is still active, and call :func:`_python_stop` if so. This will
clean up the memory.
- 1
Everything went according to plan, but the watcher has already
been stopped. Its memory may no longer be valid.
"""
try:
# Even dereferencing the handle needs to be inside the try/except;
# if we don't return normally (e.g., a signal) then we wind up going
# to the 'onerror' handler, which
# is not what we want; that can permanently wedge the loop depending
# on which callback was executing
the_watcher = ffi.from_handle(handle)
args = the_watcher.args
if args is None:
# Legacy behaviour from corecext: convert None into ()
# See test__core_watcher.py
args = _NOARGS
if args and args[0] == GEVENT_CORE_EVENTS:
args = (revents, ) + args[1:]
the_watcher.callback(*args)
except: # pylint:disable=bare-except
the_watcher._exc_info = sys.exc_info()
# Depending on when the exception happened, the watcher
# may or may not have been stopped. We need to make sure its
# memory stays valid so we can stop it at the ev level if needed.
the_watcher.loop._keepaliveset.add(the_watcher)
return -1
else:
if the_watcher in the_watcher.loop._keepaliveset:
# It didn't stop itself
return 0
return 1 # It stopped itself
libev.python_callback = _python_callback
@ffi.callback("void(void* handle, int revents)")
def _python_handle_error(handle, revents):
try:
watcher = ffi.from_handle(handle)
exc_info = watcher._exc_info
del watcher._exc_info
watcher.loop.handle_error(watcher, *exc_info)
finally:
# XXX Since we're here on an error condition, and we
# made sure that the watcher object was put in loop._keepaliveset,
# what about not stopping the watcher? Looks like a possible
# memory leak?
if revents & (libev.EV_READ | libev.EV_WRITE):
try:
watcher.stop()
except: # pylint:disable=bare-except
watcher.loop.handle_error(watcher, *sys.exc_info())
return # pylint:disable=lost-exception
libev.python_handle_error = _python_handle_error
@ffi.callback("void(void* handle)")
def _python_stop(handle):
watcher = ffi.from_handle(handle)
watcher.stop()
libev.python_stop = _python_stop
UNDEF = libev.EV_UNDEF
NONE = libev.EV_NONE
READ = libev.EV_READ
WRITE = libev.EV_WRITE
TIMER = libev.EV_TIMER
PERIODIC = libev.EV_PERIODIC
SIGNAL = libev.EV_SIGNAL
CHILD = libev.EV_CHILD
STAT = libev.EV_STAT
IDLE = libev.EV_IDLE
PREPARE = libev.EV_PREPARE
CHECK = libev.EV_CHECK
EMBED = libev.EV_EMBED
FORK = libev.EV_FORK
CLEANUP = libev.EV_CLEANUP
ASYNC = libev.EV_ASYNC
CUSTOM = libev.EV_CUSTOM
ERROR = libev.EV_ERROR
READWRITE = libev.EV_READ | libev.EV_WRITE
MINPRI = libev.EV_MINPRI
MAXPRI = libev.EV_MAXPRI
BACKEND_PORT = libev.EVBACKEND_PORT
BACKEND_KQUEUE = libev.EVBACKEND_KQUEUE
BACKEND_EPOLL = libev.EVBACKEND_EPOLL
BACKEND_POLL = libev.EVBACKEND_POLL
BACKEND_SELECT = libev.EVBACKEND_SELECT
FORKCHECK = libev.EVFLAG_FORKCHECK
NOINOTIFY = libev.EVFLAG_NOINOTIFY
SIGNALFD = libev.EVFLAG_SIGNALFD
NOSIGMASK = libev.EVFLAG_NOSIGMASK
class _EVENTSType(object):
def __repr__(self):
return 'gevent.core.EVENTS'
EVENTS = GEVENT_CORE_EVENTS = _EVENTSType()
def get_version():
return 'libev-%d.%02d' % (libev.ev_version_major(), libev.ev_version_minor())
def get_header_version():
return 'libev-%d.%02d' % (libev.EV_VERSION_MAJOR, libev.EV_VERSION_MINOR)
_flags = [(libev.EVBACKEND_PORT, 'port'),
(libev.EVBACKEND_KQUEUE, 'kqueue'),
(libev.EVBACKEND_EPOLL, 'epoll'),
(libev.EVBACKEND_POLL, 'poll'),
(libev.EVBACKEND_SELECT, 'select'),
(libev.EVFLAG_NOENV, 'noenv'),
(libev.EVFLAG_FORKCHECK, 'forkcheck'),
(libev.EVFLAG_SIGNALFD, 'signalfd'),
(libev.EVFLAG_NOSIGMASK, 'nosigmask')]
_flags_str2int = dict((string, flag) for (flag, string) in _flags)
_events = [(libev.EV_READ, 'READ'),
(libev.EV_WRITE, 'WRITE'),
(libev.EV__IOFDSET, '_IOFDSET'),
(libev.EV_PERIODIC, 'PERIODIC'),
(libev.EV_SIGNAL, 'SIGNAL'),
(libev.EV_CHILD, 'CHILD'),
(libev.EV_STAT, 'STAT'),
(libev.EV_IDLE, 'IDLE'),
(libev.EV_PREPARE, 'PREPARE'),
(libev.EV_CHECK, 'CHECK'),
(libev.EV_EMBED, 'EMBED'),
(libev.EV_FORK, 'FORK'),
(libev.EV_CLEANUP, 'CLEANUP'),
(libev.EV_ASYNC, 'ASYNC'),
(libev.EV_CUSTOM, 'CUSTOM'),
(libev.EV_ERROR, 'ERROR')]
def _flags_to_list(flags):
result = []
for code, value in _flags:
if flags & code:
result.append(value)
flags &= ~code
if not flags:
break
if flags:
result.append(flags)
return result
if sys.version_info[0] >= 3:
basestring = (bytes, str)
integer_types = (int,)
else:
import __builtin__ # pylint:disable=import-error
basestring = __builtin__.basestring,
integer_types = (int, __builtin__.long)
def _flags_to_int(flags):
# Note, that order does not matter, libev has its own predefined order
if not flags:
return 0
if isinstance(flags, integer_types):
return flags
result = 0
try:
if isinstance(flags, basestring):
flags = flags.split(',')
for value in flags:
value = value.strip().lower()
if value:
result |= _flags_str2int[value]
except KeyError as ex:
raise ValueError('Invalid backend or flag: %s\nPossible values: %s' % (ex, ', '.join(sorted(_flags_str2int.keys()))))
return result
def _str_hex(flag):
if isinstance(flag, integer_types):
return hex(flag)
return str(flag)
def _check_flags(flags):
as_list = []
flags &= libev.EVBACKEND_MASK
if not flags:
return
if not flags & libev.EVBACKEND_ALL:
raise ValueError('Invalid value for backend: 0x%x' % flags)
if not flags & libev.ev_supported_backends():
as_list = [_str_hex(x) for x in _flags_to_list(flags)]
raise ValueError('Unsupported backend: %s' % '|'.join(as_list))
def _events_to_str(events):
result = []
for (flag, string) in _events:
c_flag = flag
if events & c_flag:
result.append(string)
events = events & (~c_flag)
if not events:
break
if events:
result.append(hex(events))
return '|'.join(result)
def supported_backends():
return _flags_to_list(libev.ev_supported_backends())
def recommended_backends():
return _flags_to_list(libev.ev_recommended_backends())
def embeddable_backends():
return _flags_to_list(libev.ev_embeddable_backends())
def time():
return libev.ev_time()
_default_loop_destroyed = False
def _loop_callback(*args, **kwargs):
return ffi.callback(*args, **kwargs)
class loop(object):
# pylint:disable=too-many-public-methods
error_handler = None
def __init__(self, flags=None, default=None):
self._in_callback = False
self._callbacks = []
# self._check is a watcher that runs in each iteration of the
# mainloop, just after the blocking call
self._check = ffi.new("struct ev_check *")
self._check_callback_ffi = _loop_callback("void(*)(struct ev_loop *, void*, int)",
self._check_callback,
onerror=self._check_callback_handle_error)
libev.ev_check_init(self._check, self._check_callback_ffi)
# self._prepare is a watcher that runs in each iteration of the mainloop,
# just before the blocking call
self._prepare = ffi.new("struct ev_prepare *")
self._prepare_callback_ffi = _loop_callback("void(*)(struct ev_loop *, void*, int)",
self._run_callbacks,
onerror=self._check_callback_handle_error)
libev.ev_prepare_init(self._prepare, self._prepare_callback_ffi)
# A timer we start and stop on demand. If we have callbacks,
# too many to run in one iteration of _run_callbacks, we turn this
# on so as to have the next iteration of the run loop return to us
# as quickly as possible.
# TODO: There may be a more efficient way to do this using ev_timer_again;
# see the "ev_timer" section of the ev manpage (http://linux.die.net/man/3/ev)
self._timer0 = ffi.new("struct ev_timer *")
libev.ev_timer_init(self._timer0, libev.gevent_noop, 0.0, 0.0)
# TODO: We may be able to do something nicer and use the existing python_callback
# combined with onerror and the class check/timer/prepare to simplify things
# and unify our handling
c_flags = _flags_to_int(flags)
_check_flags(c_flags)
c_flags |= libev.EVFLAG_NOENV
c_flags |= libev.EVFLAG_FORKCHECK
if default is None:
default = True
if _default_loop_destroyed:
default = False
if default:
self._ptr = libev.gevent_ev_default_loop(c_flags)
if not self._ptr:
raise SystemError("ev_default_loop(%s) failed" % (c_flags, ))
else:
self._ptr = libev.ev_loop_new(c_flags)
if not self._ptr:
raise SystemError("ev_loop_new(%s) failed" % (c_flags, ))
if default or globals()["__SYSERR_CALLBACK"] is None:
set_syserr_cb(self._handle_syserr)
libev.ev_prepare_start(self._ptr, self._prepare)
self.unref()
libev.ev_check_start(self._ptr, self._check)
self.unref()
self._keepaliveset = set()
def _check_callback_handle_error(self, t, v, tb):
# None as the context argument causes the exception to be raised
# in the main greenlet.
self.handle_error(None, t, v, tb)
def _check_callback(self, *args):
# If we have the onerror callback, this is a no-op; all the real
# work to rethrow the exception is done by the onerror callback
pass
def _run_callbacks(self, _evloop, _, _revents):
count = 1000
libev.ev_timer_stop(self._ptr, self._timer0)
while self._callbacks and count > 0:
callbacks = self._callbacks
self._callbacks = []
for cb in callbacks:
self.unref()
callback = cb.callback
args = cb.args
if callback is None or args is None:
# it's been stopped
continue
cb.callback = None
try:
callback(*args)
except: # pylint:disable=bare-except
# If we allow an exception to escape this method (while we are running the ev callback),
# then CFFI will print the error and libev will continue executing.
# There are two problems with this. The first is that the code after
# the loop won't run. The second is that any remaining callbacks scheduled
# for this loop iteration will be silently dropped; they won't run, but they'll
# also not be *stopped* (which is not a huge deal unless you're looking for
# consistency or checking the boolean/pending status; the loop doesn't keep
# a reference to them like it does to watchers...*UNLESS* the callback itself had
# a reference to a watcher; then I don't know what would happen, it depends on
# the state of the watcher---a leak or crash is not totally inconceivable).
# The Cython implementation in core.ppyx uses gevent_call from callbacks.c
# to run the callback, which uses gevent_handle_error to handle any errors the
# Python callback raises...it unconditionally simply prints any error raised
# by loop.handle_error and clears it, so callback handling continues.
# We take a similar approach (but are extra careful about printing)
try:
self.handle_error(cb, *sys.exc_info())
except: # pylint:disable=bare-except
try:
print("Exception while handling another error", file=sys.stderr)
traceback.print_exc()
except: # pylint:disable=bare-except
pass # Nothing we can do here
finally:
# NOTE: this must be reset here, because cb.args is used as a flag in
# the callback class so that bool(cb) of a callback that has been run
# becomes False
cb.args = None
count -= 1
if self._callbacks:
libev.ev_timer_start(self._ptr, self._timer0)
def _stop_aux_watchers(self):
if libev.ev_is_active(self._prepare):
self.ref()
libev.ev_prepare_stop(self._ptr, self._prepare)
if libev.ev_is_active(self._check):
self.ref()
libev.ev_check_stop(self._ptr, self._check)
def destroy(self):
global _default_loop_destroyed
if self._ptr:
self._stop_aux_watchers()
if globals()["__SYSERR_CALLBACK"] == self._handle_syserr:
set_syserr_cb(None)
if libev.ev_is_default_loop(self._ptr):
_default_loop_destroyed = True
libev.ev_loop_destroy(self._ptr)
self._ptr = ffi.NULL
@property
def ptr(self):
return self._ptr
@property
def WatcherType(self):
return watcher
@property
def MAXPRI(self):
return libev.EV_MAXPRI
@property
def MINPRI(self):
return libev.EV_MINPRI
def _handle_syserr(self, message, errno):
try:
errno = os.strerror(errno)
except: # pylint:disable=bare-except
traceback.print_exc()
try:
message = '%s: %s' % (message, errno)
except: # pylint:disable=bare-except
traceback.print_exc()
self.handle_error(None, SystemError, SystemError(message), None)
def handle_error(self, context, type, value, tb):
handle_error = None
error_handler = self.error_handler
if error_handler is not None:
# we do want to do getattr every time so that setting Hub.handle_error property just works
handle_error = getattr(error_handler, 'handle_error', error_handler)
handle_error(context, type, value, tb)
else:
self._default_handle_error(context, type, value, tb)
def _default_handle_error(self, context, type, value, tb): # pylint:disable=unused-argument
# note: Hub sets its own error handler so this is not used by gevent
# this is here to make core.loop usable without the rest of gevent
traceback.print_exception(type, value, tb)
libev.ev_break(self._ptr, libev.EVBREAK_ONE)
def run(self, nowait=False, once=False):
flags = 0
if nowait:
flags |= libev.EVRUN_NOWAIT
if once:
flags |= libev.EVRUN_ONCE
libev.ev_run(self._ptr, flags)
def reinit(self):
libev.ev_loop_fork(self._ptr)
def ref(self):
libev.ev_ref(self._ptr)
def unref(self):
libev.ev_unref(self._ptr)
def break_(self, how=libev.EVBREAK_ONE):
libev.ev_break(self._ptr, how)
def verify(self):
libev.ev_verify(self._ptr)
def now(self):
return libev.ev_now(self._ptr)
def update(self):
libev.ev_now_update(self._ptr)
def __repr__(self):
return '<%s at 0x%x %s>' % (self.__class__.__name__, id(self), self._format())
@property
def default(self):
return True if libev.ev_is_default_loop(self._ptr) else False
@property
def iteration(self):
return libev.ev_iteration(self._ptr)
@property
def depth(self):
return libev.ev_depth(self._ptr)
@property
def backend_int(self):
return libev.ev_backend(self._ptr)
@property
def backend(self):
backend = libev.ev_backend(self._ptr)
for key, value in _flags:
if key == backend:
return value
return backend
@property
def pendingcnt(self):
return libev.ev_pending_count(self._ptr)
def io(self, fd, events, ref=True, priority=None):
return io(self, fd, events, ref, priority)
def timer(self, after, repeat=0.0, ref=True, priority=None):
return timer(self, after, repeat, ref, priority)
def signal(self, signum, ref=True, priority=None):
return signal(self, signum, ref, priority)
def idle(self, ref=True, priority=None):
return idle(self, ref, priority)
def prepare(self, ref=True, priority=None):
return prepare(self, ref, priority)
def check(self, ref=True, priority=None):
return check(self, ref, priority)
def fork(self, ref=True, priority=None):
return fork(self, ref, priority)
def async(self, ref=True, priority=None):
return async(self, ref, priority)
if sys.platform != "win32":
def child(self, pid, trace=0, ref=True):
return child(self, pid, trace, ref)
def install_sigchld(self):
libev.gevent_install_sigchld_handler()
def reset_sigchld(self):
libev.gevent_reset_sigchld_handler()
def stat(self, path, interval=0.0, ref=True, priority=None):
return stat(self, path, interval, ref, priority)
def callback(self, priority=None):
return callback(self, priority)
def run_callback(self, func, *args):
cb = callback(func, args)
self._callbacks.append(cb)
self.ref()
return cb
def _format(self):
if not self._ptr:
return 'destroyed'
msg = self.backend
if self.default:
msg += ' default'
msg += ' pending=%s' % self.pendingcnt
msg += self._format_details()
return msg
def _format_details(self):
msg = ''
fileno = self.fileno()
try:
activecnt = self.activecnt
except AttributeError:
activecnt = None
if activecnt is not None:
msg += ' ref=' + repr(activecnt)
if fileno is not None:
msg += ' fileno=' + repr(fileno)
#if sigfd is not None and sigfd != -1:
# msg += ' sigfd=' + repr(sigfd)
return msg
def fileno(self):
if self._ptr:
fd = self._ptr.backend_fd
if fd >= 0:
return fd
@property
def activecnt(self):
if not self._ptr:
raise ValueError('operation on destroyed loop')
return self._ptr.activecnt
# For times when *args is captured but often not passed (empty),
# we can avoid keeping the new tuple that was created for *args
# around by using a constant.
_NOARGS = ()
class callback(object):
__slots__ = ('callback', 'args')
def __init__(self, callback, args):
self.callback = callback
self.args = args or _NOARGS
def stop(self):
self.callback = None
self.args = None
# Note that __nonzero__ and pending are different
# bool() is used in contexts where we need to know whether to schedule another callback,
# so it's true if it's pending or currently running
# 'pending' has the same meaning as libev watchers: it is cleared before actually
# running the callback
def __nonzero__(self):
# it's nonzero if it's pending or currently executing
# NOTE: This depends on loop._run_callbacks setting the args property
# to None.
return self.args is not None
__bool__ = __nonzero__
@property
def pending(self):
return self.callback is not None
def _format(self):
return ''
def __repr__(self):
result = "<%s at 0x%x" % (self.__class__.__name__, id(self))
if self.pending:
result += " pending"
if self.callback is not None:
result += " callback=%r" % (self.callback, )
if self.args is not None:
result += " args=%r" % (self.args, )
if self.callback is None and self.args is None:
result += " stopped"
return result + ">"
class watcher(object):
def __init__(self, _loop, ref=True, priority=None, args=_NOARGS):
self.loop = _loop
if ref:
self._flags = 0
else:
self._flags = 4
self._args = None
self._callback = None
self._handle = ffi.new_handle(self)
self._watcher = ffi.new(self._watcher_struct_pointer_type)
self._watcher.data = self._handle
if priority is not None:
libev.ev_set_priority(self._watcher, priority)
self._watcher_init(self._watcher,
self._watcher_callback,
*args)
# A string identifying the type of libev object we watch, e.g., 'ev_io'
# This should be a class attribute.
_watcher_type = None
# A class attribute that is the callback on the libev object that init's the C struct,
# e.g., libev.ev_io_init. If None, will be set by _init_subclasses.
_watcher_init = None
# A class attribute that is the callback on the libev object that starts the C watcher,
# e.g., libev.ev_io_start. If None, will be set by _init_subclasses.
_watcher_start = None
# A class attribute that is the callback on the libev object that stops the C watcher,
# e.g., libev.ev_io_stop. If None, will be set by _init_subclasses.
_watcher_stop = None
# A cffi ctype object identifying the struct pointer we create.
# This is a class attribute set based on the _watcher_type
_watcher_struct_pointer_type = None
# The attribute of the libev object identifying the custom
# callback function for this type of watcher. This is a class
# attribute set based on the _watcher_type in _init_subclasses.
_watcher_callback = None
@classmethod
def _init_subclasses(cls):
for subclass in cls.__subclasses__(): # pylint:disable=no-member
watcher_type = subclass._watcher_type
subclass._watcher_struct_pointer_type = ffi.typeof('struct ' + watcher_type + '*')
subclass._watcher_callback = ffi.addressof(libev,
'_gevent_generic_callback')
for name in 'start', 'stop', 'init':
ev_name = watcher_type + '_' + name
watcher_name = '_watcher' + '_' + name
if getattr(subclass, watcher_name) is None:
setattr(subclass, watcher_name,
getattr(libev, ev_name))
# this is not needed, since we keep alive the watcher while it's started
#def __del__(self):
# self._watcher_stop(self.loop._ptr, self._watcher)
def __repr__(self):
formats = self._format()
result = "<%s at 0x%x%s" % (self.__class__.__name__, id(self), formats)
if self.pending:
result += " pending"
if self.callback is not None:
result += " callback=%r" % (self.callback, )
if self.args is not None:
result += " args=%r" % (self.args, )
if self.callback is None and self.args is None:
result += " stopped"
result += " handle=%s" % (self._watcher.data)
return result + ">"
def _format(self):
return ''
def _libev_unref(self):
if self._flags & 6 == 4:
self.loop.unref()
self._flags |= 2
def _get_ref(self):
return False if self._flags & 4 else True
def _set_ref(self, value):
if value:
if not self._flags & 4:
return # ref is already True
if self._flags & 2: # ev_unref was called, undo
self.loop.ref()
self._flags &= ~6 # do not want unref, no outstanding unref
else:
if self._flags & 4:
return # ref is already False
self._flags |= 4
if not self._flags & 2 and libev.ev_is_active(self._watcher):
self.loop.unref()
self._flags |= 2
ref = property(_get_ref, _set_ref)
def _get_callback(self):
return self._callback
def _set_callback(self, cb):
if not callable(cb) and cb is not None:
raise TypeError("Expected callable, not %r" % (cb, ))
self._callback = cb
callback = property(_get_callback, _set_callback)
def _get_args(self):
return self._args
def _set_args(self, args):
if not isinstance(args, tuple) and args is not None:
raise TypeError("args must be a tuple or None")
self._args = args
args = property(_get_args, _set_args)
def start(self, callback, *args):
if callback is None:
raise TypeError('callback must be callable, not None')
self.callback = callback
self.args = args or _NOARGS
self._libev_unref()
self.loop._keepaliveset.add(self)
self._watcher_start(self.loop._ptr, self._watcher)
def stop(self):
if self._flags & 2:
self.loop.ref()
self._flags &= ~2
self._watcher_stop(self.loop._ptr, self._watcher)
self.loop._keepaliveset.discard(self)
self._callback = None
self.args = None
def _get_priority(self):
return libev.ev_priority(self._watcher)
def _set_priority(self, priority):
if libev.ev_is_active(self._watcher):
raise AttributeError("Cannot set priority of an active watcher")
libev.ev_set_priority(self._watcher, priority)
priority = property(_get_priority, _set_priority)
def feed(self, revents, callback, *args):
self.callback = callback
self.args = args or _NOARGS
if self._flags & 6 == 4:
self.loop.unref()
self._flags |= 2
libev.ev_feed_event(self.loop._ptr, self._watcher, revents)
if not self._flags & 1:
# Py_INCREF(<PyObjectPtr>self)
self._flags |= 1
@property
def active(self):
return True if libev.ev_is_active(self._watcher) else False
@property
def pending(self):
return True if libev.ev_is_pending(self._watcher) else False
class io(watcher):
_watcher_type = 'ev_io'
def __init__(self, loop, fd, events, ref=True, priority=None):
# XXX: Win32: Need to vfd_open the fd and free the old one?
# XXX: Win32: Need a destructor to free the old fd?
if fd < 0:
raise ValueError('fd must be non-negative: %r' % fd)
if events & ~(libev.EV__IOFDSET | libev.EV_READ | libev.EV_WRITE):
raise ValueError('illegal event mask: %r' % events)
watcher.__init__(self, loop, ref=ref, priority=priority, args=(fd, events))
def start(self, callback, *args, **kwargs):
# pylint:disable=arguments-differ
args = args or _NOARGS
if kwargs.get('pass_events'):
args = (GEVENT_CORE_EVENTS, ) + args
watcher.start(self, callback, *args)
def _get_fd(self):
return vfd_get(self._watcher.fd)
def _set_fd(self, fd):
if libev.ev_is_active(self._watcher):
raise AttributeError("'io' watcher attribute 'fd' is read-only while watcher is active")
vfd = vfd_open(fd)
vfd_free(self._watcher.fd)
self._watcher_init(self._watcher, self._watcher_callback, vfd, self._watcher.events)
fd = property(_get_fd, _set_fd)
def _get_events(self):
return self._watcher.events
def _set_events(self, events):
if libev.ev_is_active(self._watcher):
raise AttributeError("'io' watcher attribute 'events' is read-only while watcher is active")
self._watcher_init(self._watcher, self._watcher_callback, self._watcher.fd, events)
events = property(_get_events, _set_events)
@property
def events_str(self):
return _events_to_str(self._watcher.events)
def _format(self):
return ' fd=%s events=%s' % (self.fd, self.events_str)
class timer(watcher):
_watcher_type = 'ev_timer'
def __init__(self, loop, after=0.0, repeat=0.0, ref=True, priority=None):
if repeat < 0.0:
raise ValueError("repeat must be positive or zero: %r" % repeat)
watcher.__init__(self, loop, ref=ref, priority=priority, args=(after, repeat))
def start(self, callback, *args, **kw):
# pylint:disable=arguments-differ
update = kw.get("update", True)
if update:
# Quoth the libev doc: "This is a costly operation and is
# usually done automatically within ev_run(). This
# function is rarely useful, but when some event callback
# runs for a very long time without entering the event
# loop, updating libev's idea of the current time is a
# good idea."
# So do we really need to default to true?
libev.ev_now_update(self.loop._ptr)
watcher.start(self, callback, *args)
@property
def at(self):
return self._watcher.at
def again(self, callback, *args, **kw):
# Exactly the same as start(), just with a different initializer
# function
self._watcher_start = libev.ev_timer_again
try:
self.start(callback, *args, **kw)
finally:
del self._watcher_start
class signal(watcher):
_watcher_type = 'ev_signal'
def __init__(self, loop, signalnum, ref=True, priority=None):
if signalnum < 1 or signalnum >= signalmodule.NSIG:
raise ValueError('illegal signal number: %r' % signalnum)
# still possible to crash on one of libev's asserts:
# 1) "libev: ev_signal_start called with illegal signal number"
# EV_NSIG might be different from signal.NSIG on some platforms
# 2) "libev: a signal must not be attached to two different loops"
# we probably could check that in LIBEV_EMBED mode, but not in general
watcher.__init__(self, loop, ref=ref, priority=priority, args=(signalnum, ))
class idle(watcher):
_watcher_type = 'ev_idle'
class prepare(watcher):
_watcher_type = 'ev_prepare'
class check(watcher):
_watcher_type = 'ev_check'
class fork(watcher):
_watcher_type = 'ev_fork'
class async(watcher):
_watcher_type = 'ev_async'
def send(self):
libev.ev_async_send(self.loop._ptr, self._watcher)
@property
def pending(self):
return True if libev.ev_async_pending(self._watcher) else False
class child(watcher):
_watcher_type = 'ev_child'
def __init__(self, loop, pid, trace=0, ref=True):
if not loop.default:
raise TypeError('child watchers are only available on the default loop')
loop.install_sigchld()
watcher.__init__(self, loop, ref=ref, args=(pid, trace))
def _format(self):
return ' pid=%r rstatus=%r' % (self.pid, self.rstatus)
@property
def pid(self):
return self._watcher.pid
@property
def rpid(self, ):
return self._watcher.rpid
@rpid.setter
def rpid(self, value):
self._watcher.rpid = value
@property
def rstatus(self):
return self._watcher.rstatus
@rstatus.setter
def rstatus(self, value):
self._watcher.rstatus = value
class stat(watcher):
_watcher_type = 'ev_stat'
@staticmethod
def _encode_path(path):
if isinstance(path, bytes):
return path
# encode for the filesystem. Not all systems (e.g., Unix)
# will have an encoding specified
encoding = sys.getfilesystemencoding() or 'utf-8'
try:
path = path.encode(encoding, 'surrogateescape')
except LookupError:
# Can't encode it, and the error handler doesn't
# exist. Probably on Python 2 with an astral character.
# Not sure how to handle this.
raise UnicodeEncodeError("Can't encode path to filesystem encoding")
return path
def __init__(self, _loop, path, interval=0.0, ref=True, priority=None):
# Store the encoded path in the same attribute that corecext does
self._paths = self._encode_path(path)
# Keep the original path to avoid re-encoding, especially on Python 3
self._path = path
# Although CFFI would automatically convert a bytes object into a char* when
# calling ev_stat_init(..., char*, ...), on PyPy the char* pointer is not
# guaranteed to live past the function call. On CPython, only with a constant/interned
# bytes object is the pointer guaranteed to last path the function call. (And since
# Python 3 is pretty much guaranteed to produce a newly-encoded bytes object above, thats
# rarely the case). Therefore, we must keep a reference to the produced cdata object
# so that the struct ev_stat_watcher's `path` pointer doesn't become invalid/deallocated
self._cpath = ffi.new('char[]', self._paths)
watcher.__init__(self, _loop, ref=ref, priority=priority,
args=(self._cpath,
interval))
@property
def path(self):
return self._path
@property
def attr(self):
if not self._watcher.attr.st_nlink:
return
return self._watcher.attr
@property
def prev(self):
if not self._watcher.prev.st_nlink:
return
return self._watcher.prev
@property
def interval(self):
return self._watcher.interval
# All watcher subclasses must be declared above. Now we do some
# initialization; this is not only a minor optimization, it protects
# against later runtime typos and attribute errors
watcher._init_subclasses()
def _syserr_cb(msg):
try:
msg = ffi.string(msg)
__SYSERR_CALLBACK(msg, ffi.errno)
except:
set_syserr_cb(None)
raise # let cffi print the traceback
_syserr_cb._cb = ffi.callback("void(*)(char *msg)", _syserr_cb)
def set_syserr_cb(callback):
global __SYSERR_CALLBACK
if callback is None:
libev.ev_set_syserr_cb(ffi.NULL)
__SYSERR_CALLBACK = None
elif callable(callback):
libev.ev_set_syserr_cb(_syserr_cb._cb)
__SYSERR_CALLBACK = callback
else:
raise TypeError('Expected callable or None, got %r' % (callback, ))
__SYSERR_CALLBACK = None
LIBEV_EMBED = True