twisted.internet.posixbase.PosixReactorBase : API documentation

Known subclasses: twisted.internet._glibbase.GlibReactorBase, twisted.internet._threadedselect.ThreadedSelectReactor, twisted.internet.asyncioreactor.AsyncioSelectorReactor, twisted.internet.cfreactor.CFReactor, twisted.internet.epollreactor.EPollReactor, twisted.internet.kqreactor.KQueueReactor, twisted.internet.pollreactor.PollReactor, twisted.internet.selectreactor.SelectReactor, twisted.internet.win32eventreactor.Win32Reactor

Implements interfaces: twisted.internet.interfaces.IReactorMulticast, twisted.internet.interfaces.IReactorProcess, twisted.internet.interfaces.IReactorSocket, twisted.internet.interfaces.IReactorSSL, twisted.internet.interfaces.IReactorTCP, twisted.internet.interfaces.IReactorUDP, twisted.internet.interfaces.IReactorUNIX, twisted.internet.interfaces.IReactorUNIXDatagram

A basis for reactors that use file descriptors.

Method	installWaker	Install a `waker' to allow threads and signals to wake up the IO thread.
Method	spawnProcess	Spawn a process, with a process protocol.
Method	listenUDP	Connects a given `DatagramProtocol` to the given numeric UDP port.
Method	listenMulticast	Connects a given DatagramProtocol to the given numeric UDP port.
Method	connectUNIX	Connect a client protocol to a UNIX socket.
Method	listenUNIX	Listen on a UNIX socket.
Method	listenUNIXDatagram	Connects a given `DatagramProtocol` to the given path.
Method	connectUNIXDatagram	Connects a `ConnectedDatagramProtocol` instance to a path.
Method	adoptStreamPort	Create a new `IListeningPort` from an already-initialized socket.
Method	adoptStreamConnection
Method	adoptDatagramPort	Add an existing listening SOCK_DGRAM socket to the reactor to monitor for read and write readiness.
Method	listenTCP	Connects a given protocol factory to the given numeric TCP/IP port.
Method	connectTCP	Connect a TCP client.
Method	connectSSL	Connect a client Protocol to a remote SSL socket.
Method	listenSSL	Connects a given protocol factory to the given numeric TCP/IP port. The connection is a SSL one, using contexts created by the context factory.
Instance Variable	_childWaker	`None` or a reference to the `_SIGCHLDWaker` which is used to properly notice child process termination.
Method	_handleSignals	Extend the basic signal handling logic to also support handling SIGCHLD to know when to try to reap child processes.
Method	_uninstallHandler	If a child waker was created and installed, uninstall it now.
Method	_removeAll	Remove all readers and writers, and list of removed `IReadDescriptor`s and `IWriteDescriptor`s.

Inherited from ReactorBase:

Instance Variable	running	See `IReactorCore.running`
Method	__init__	Undocumented
Method	installResolver	See `IReactorPluggableResolver`.
Method	installNameResolver	See `IReactorPluggableNameResolver`.
Method	nameResolver	Implementation of read-only `IReactorPluggableNameResolver.nameResolver`.
Method	wakeUp	Wake up the event loop.
Method	doIteration	Do one iteration over the readers and writers which have been added.
Method	addReader	Undocumented
Method	addWriter	Undocumented
Method	removeReader	Undocumented
Method	removeWriter	Undocumented
Method	removeAll	Undocumented
Method	getReaders	Undocumented
Method	getWriters	Undocumented
Method	resolve	Return a Deferred that will resolve a hostname.
Method	stop	See twisted.internet.interfaces.IReactorCore.stop.
Method	crash	See twisted.internet.interfaces.IReactorCore.crash.
Method	sigInt	Handle a SIGINT interrupt.
Method	sigBreak	Handle a SIGBREAK interrupt.
Method	sigTerm	Handle a SIGTERM interrupt.
Method	disconnectAll	Disconnect every reader, and writer in the system.
Method	iterate	See twisted.internet.interfaces.IReactorCore.iterate.
Method	fireSystemEvent	See twisted.internet.interfaces.IReactorCore.fireSystemEvent.
Method	addSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.addSystemEventTrigger.
Method	removeSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.removeSystemEventTrigger.
Method	callWhenRunning	See twisted.internet.interfaces.IReactorCore.callWhenRunning.
Method	startRunning	Method called when reactor starts: do some initialization and fire startup events.
Method	callLater	See twisted.internet.interfaces.IReactorTime.callLater.
Method	getDelayedCalls	No summary
Method	timeout	Determine the longest time the reactor may sleep (waiting on I/O notification, perhaps) before it must wake up to service a time-related event.
Method	runUntilCurrent	Run all pending timed calls.
Method	callFromThread 0	See `twisted.internet.interfaces.IReactorFromThreads.callFromThread`.
Method	getThreadPool	See `twisted.internet.interfaces.IReactorThreads.getThreadPool`.
Method	callInThread	See `twisted.internet.interfaces.IReactorInThreads.callInThread`.
Method	suggestThreadPoolSize	See `twisted.internet.interfaces.IReactorThreads.suggestThreadPoolSize`.
Method	callFromThread	Cause a function to be executed by the reactor thread.
Instance Variable	_stopped	A flag which is true between paired calls to `reactor.run` and `reactor.stop`. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_justStopped	A flag which is true between the time `reactor.stop` is called and the time the shutdown system event is fired. This is used to determine whether that event should be fired after each iteration through the mainloop. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_started	A flag which is true from the time `reactor.run` is called until the time `reactor.run` returns. This is used to prevent calls to `reactor.run` on a running reactor. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_registerAsIOThread	A flag controlling whether the reactor will register the thread it is running in as the I/O thread when it starts. If `True`, registration will be done, otherwise it will not be.
Method	_reallyStartRunning	Method called to transition to the running state. This should happen in the during startup event trigger phase.
Method	_moveCallLaterSooner	Undocumented
Method	_cancelCallLater	Undocumented
Method	_insertNewDelayedCalls	Undocumented
Method	_checkProcessArgs	Check for valid arguments and environment to spawnProcess.
Method	_initThreads	Undocumented
Method	_initThreadPool	Create the threadpool accessible with callFromThread.
Method	_stopThreadPool	No summary

Inherited from ReactorBase:

Instance Variable	running	See `IReactorCore.running`
Method	__init__	Undocumented
Method	installResolver	See `IReactorPluggableResolver`.
Method	installNameResolver	See `IReactorPluggableNameResolver`.
Method	nameResolver	Implementation of read-only `IReactorPluggableNameResolver.nameResolver`.
Method	wakeUp	Wake up the event loop.
Method	doIteration	Do one iteration over the readers and writers which have been added.
Method	addReader	Undocumented
Method	addWriter	Undocumented
Method	removeReader	Undocumented
Method	removeWriter	Undocumented
Method	removeAll	Undocumented
Method	getReaders	Undocumented
Method	getWriters	Undocumented
Method	resolve	Return a Deferred that will resolve a hostname.
Method	stop	See twisted.internet.interfaces.IReactorCore.stop.
Method	crash	See twisted.internet.interfaces.IReactorCore.crash.
Method	sigInt	Handle a SIGINT interrupt.
Method	sigBreak	Handle a SIGBREAK interrupt.
Method	sigTerm	Handle a SIGTERM interrupt.
Method	disconnectAll	Disconnect every reader, and writer in the system.
Method	iterate	See twisted.internet.interfaces.IReactorCore.iterate.
Method	fireSystemEvent	See twisted.internet.interfaces.IReactorCore.fireSystemEvent.
Method	addSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.addSystemEventTrigger.
Method	removeSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.removeSystemEventTrigger.
Method	callWhenRunning	See twisted.internet.interfaces.IReactorCore.callWhenRunning.
Method	startRunning	Method called when reactor starts: do some initialization and fire startup events.
Method	callLater	See twisted.internet.interfaces.IReactorTime.callLater.
Method	getDelayedCalls	No summary
Method	timeout	Determine the longest time the reactor may sleep (waiting on I/O notification, perhaps) before it must wake up to service a time-related event.
Method	runUntilCurrent	Run all pending timed calls.
Method	callFromThread 0	See `twisted.internet.interfaces.IReactorFromThreads.callFromThread`.
Method	getThreadPool	See `twisted.internet.interfaces.IReactorThreads.getThreadPool`.
Method	callInThread	See `twisted.internet.interfaces.IReactorInThreads.callInThread`.
Method	suggestThreadPoolSize	See `twisted.internet.interfaces.IReactorThreads.suggestThreadPoolSize`.
Method	callFromThread	Cause a function to be executed by the reactor thread.
Instance Variable	_stopped	A flag which is true between paired calls to `reactor.run` and `reactor.stop`. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_justStopped	A flag which is true between the time `reactor.stop` is called and the time the shutdown system event is fired. This is used to determine whether that event should be fired after each iteration through the mainloop. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_started	A flag which is true from the time `reactor.run` is called until the time `reactor.run` returns. This is used to prevent calls to `reactor.run` on a running reactor. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_registerAsIOThread	A flag controlling whether the reactor will register the thread it is running in as the I/O thread when it starts. If `True`, registration will be done, otherwise it will not be.
Method	_reallyStartRunning	Method called to transition to the running state. This should happen in the during startup event trigger phase.
Method	_moveCallLaterSooner	Undocumented
Method	_cancelCallLater	Undocumented
Method	_insertNewDelayedCalls	Undocumented
Method	_checkProcessArgs	Check for valid arguments and environment to spawnProcess.
Method	_initThreads	Undocumented
Method	_initThreadPool	Create the threadpool accessible with callFromThread.
Method	_stopThreadPool	No summary

Inherited from ReactorBase:

Instance Variable	running	See `IReactorCore.running`
Method	__init__	Undocumented
Method	installResolver	See `IReactorPluggableResolver`.
Method	installNameResolver	See `IReactorPluggableNameResolver`.
Method	nameResolver	Implementation of read-only `IReactorPluggableNameResolver.nameResolver`.
Method	wakeUp	Wake up the event loop.
Method	doIteration	Do one iteration over the readers and writers which have been added.
Method	addReader	Undocumented
Method	addWriter	Undocumented
Method	removeReader	Undocumented
Method	removeWriter	Undocumented
Method	removeAll	Undocumented
Method	getReaders	Undocumented
Method	getWriters	Undocumented
Method	resolve	Return a Deferred that will resolve a hostname.
Method	stop	See twisted.internet.interfaces.IReactorCore.stop.
Method	crash	See twisted.internet.interfaces.IReactorCore.crash.
Method	sigInt	Handle a SIGINT interrupt.
Method	sigBreak	Handle a SIGBREAK interrupt.
Method	sigTerm	Handle a SIGTERM interrupt.
Method	disconnectAll	Disconnect every reader, and writer in the system.
Method	iterate	See twisted.internet.interfaces.IReactorCore.iterate.
Method	fireSystemEvent	See twisted.internet.interfaces.IReactorCore.fireSystemEvent.
Method	addSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.addSystemEventTrigger.
Method	removeSystemEventTrigger	See twisted.internet.interfaces.IReactorCore.removeSystemEventTrigger.
Method	callWhenRunning	See twisted.internet.interfaces.IReactorCore.callWhenRunning.
Method	startRunning	Method called when reactor starts: do some initialization and fire startup events.
Method	callLater	See twisted.internet.interfaces.IReactorTime.callLater.
Method	getDelayedCalls	No summary
Method	timeout	Determine the longest time the reactor may sleep (waiting on I/O notification, perhaps) before it must wake up to service a time-related event.
Method	runUntilCurrent	Run all pending timed calls.
Method	callFromThread 0	See `twisted.internet.interfaces.IReactorFromThreads.callFromThread`.
Method	getThreadPool	See `twisted.internet.interfaces.IReactorThreads.getThreadPool`.
Method	callInThread	See `twisted.internet.interfaces.IReactorInThreads.callInThread`.
Method	suggestThreadPoolSize	See `twisted.internet.interfaces.IReactorThreads.suggestThreadPoolSize`.
Method	callFromThread	Cause a function to be executed by the reactor thread.
Instance Variable	_stopped	A flag which is true between paired calls to `reactor.run` and `reactor.stop`. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_justStopped	A flag which is true between the time `reactor.stop` is called and the time the shutdown system event is fired. This is used to determine whether that event should be fired after each iteration through the mainloop. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_started	A flag which is true from the time `reactor.run` is called until the time `reactor.run` returns. This is used to prevent calls to `reactor.run` on a running reactor. This should be replaced with an explicit state machine. (type: `bool`)
Instance Variable	_registerAsIOThread	A flag controlling whether the reactor will register the thread it is running in as the I/O thread when it starts. If `True`, registration will be done, otherwise it will not be.
Method	_reallyStartRunning	Method called to transition to the running state. This should happen in the during startup event trigger phase.
Method	_moveCallLaterSooner	Undocumented
Method	_cancelCallLater	Undocumented
Method	_insertNewDelayedCalls	Undocumented
Method	_checkProcessArgs	Check for valid arguments and environment to spawnProcess.
Method	_initThreads	Undocumented
Method	_initThreadPool	Create the threadpool accessible with callFromThread.
Method	_stopThreadPool	No summary

_childWaker =

None or a reference to the _SIGCHLDWaker which is used to properly notice child process termination.

def installWaker(self): (source)

overrides twisted.internet.base.ReactorBase.installWaker

overridden in twisted.internet.cfreactor.CFReactor

Install a `waker' to allow threads and signals to wake up the IO thread.

We use the self-pipe trick (http://cr.yp.to/docs/selfpipe.html) to wake the reactor. On Windows we use a pair of sockets.

def _handleSignals(self): (source)

overrides twisted.internet.base._SignalReactorMixin._handleSignals

overridden in twisted.internet._glibbase.GlibReactorBase

Extend the basic signal handling logic to also support handling SIGCHLD to know when to try to reap child processes.

def _uninstallHandler(self): (source)

overrides twisted.internet.base.ReactorBase._uninstallHandler

If a child waker was created and installed, uninstall it now.

Since this disables reactor functionality and is only called when the reactor is stopping, it doesn't provide any directly useful functionality, but the cleanup of reactor-related process-global state that it does helps in unit tests involving multiple reactors and is generally just a nice thing.

def spawnProcess(self, processProtocol, executable, args=(), env={}, path=None, uid=None, gid=None, usePTY=0, childFDs=None): (source)

from twisted.internet.interfaces.IReactorProcess

Spawn a process, with a process protocol.

Arguments given to this function that are listed as bytes or unicode may be encoded or decoded depending on the platform and the argument type given. On UNIX systems (Linux, FreeBSD, macOS) and Python 2 on Windows, unicode arguments will be encoded down to bytes using the encoding given by os.getfilesystemencoding, to be used with the "narrow" OS APIs. On Python 3 on Windows, bytes arguments will be decoded up to unicode using the encoding given by os.getfilesystemencoding (mbcs before Python 3.6, utf8 thereafter) and given to Windows's native "wide" APIs.

Parameters	processProtocol	An object which will be notified of all events related to the created process. (type: `IProcessProtocol` provider)
	executable	the file name to spawn - the full path should be used. (type: `bytes` or `unicode`)
	args	the command line arguments to pass to the process; a sequence of strings. The first string should be the executable's name. (type: `list` with `bytes` or `unicode` items.)
	env	the environment variables to pass to the child process. The resulting behavior varies between platforms. If: `env` is not set: On POSIX: pass an empty environment. On Windows: pass `os.environ`. `env` is `None`: On POSIX: pass `os.environ`. On Windows: pass `os.environ`. `env` is a `dict`: On POSIX: pass the key/value pairs in `env` as the complete environment. On Windows: update `os.environ` with the key/value pairs in the `dict` before passing it. As a consequence of bug #1640, passing keys with empty values in an effort to unset environment variables won't unset them. (type: a `dict` mapping `bytes`/`unicode` keys to `bytes`/`unicode` items, or `None`.)
	path	the path to run the subprocess in - defaults to the current directory. (type: `bytes` or `unicode` or `None`)
	uid	user ID to run the subprocess as. (Only available on POSIX systems.)
	gid	group ID to run the subprocess as. (Only available on POSIX systems.)
	usePTY	if true, run this process in a pseudo-terminal. optionally a tuple of `(masterfd, slavefd, ttyname)`, in which case use those file descriptors. (Not available on all systems.)
	childFDs	A dictionary mapping file descriptors in the new child process to an integer or to the string 'r' or 'w'. If the value is an integer, it specifies a file descriptor in the parent process which will be mapped to a file descriptor (specified by the key) in the child process. This is useful for things like inetd and shell-like file redirection. If it is the string 'r', a pipe will be created and attached to the child at that file descriptor: the child will be able to write to that file descriptor and the parent will receive read notification via the `IProcessProtocol.childDataReceived` callback. This is useful for the child's stdout and stderr. If it is the string 'w', similar setup to the previous case will occur, with the pipe being readable by the child instead of writeable. The parent process can write to that file descriptor using `IProcessTransport.writeToChild`. This is useful for the child's stdin. If childFDs is not passed, the default behaviour is to use a mapping that opens the usual stdin/stdout/stderr pipes. (type: `dict` of `int` to `int` or `str`)
Returns	An object which provides `IProcessTransport`.
Raises	OSError	Raised with errno `EAGAIN` or `ENOMEM` if there are insufficient system resources to create a new process.
See Also	`twisted.internet.protocol.ProcessProtocol`

def listenUDP(self, port, protocol, interface='', maxPacketSize=8192): (source)

from twisted.internet.interfaces.IReactorUDP

Connects a given DatagramProtocol to the given numeric UDP port.

Returns object conforming to IListeningPort.

def listenMulticast(self, port, protocol, interface='', maxPacketSize=8192, listenMultiple=False): (source)

from twisted.internet.interfaces.IReactorMulticast

Connects a given DatagramProtocol to the given numeric UDP port.

EXPERIMENTAL.

Returns object conforming to IListeningPort.

def connectUNIX(self, address, factory, timeout=30, checkPID=0): (source)

from twisted.internet.interfaces.IReactorUNIX

Connect a client protocol to a UNIX socket.

Parameters	address	a path to a unix socket on the filesystem.
	factory	a `twisted.internet.protocol.ClientFactory` instance
	timeout	number of seconds to wait before assuming the connection has failed.
	checkPID	if True, check for a pid file to verify that a server is listening. If `address` is a Linux abstract namespace path, this must be `False`.
Returns	An object which provides `IConnector`.

def listenUNIX(self, address, factory, backlog=50, mode=438, wantPID=0): (source)

from twisted.internet.interfaces.IReactorUNIX

Listen on a UNIX socket.

Parameters	address	a path to a unix socket on the filesystem.
	factory	a `twisted.internet.protocol.Factory` instance.
	backlog	number of connections to allow in backlog.
	mode	The mode (not umask) to set on the unix socket. See platform specific documentation for information about how this might affect connection attempts. (type: `int`)
	wantPID	if True, create a pidfile for the socket. If `address` is a Linux abstract namespace path, this must be `False`.
Returns	An object which provides `IListeningPort`.

def listenUNIXDatagram(self, address, protocol, maxPacketSize=8192, mode=438): (source)

from twisted.internet.interfaces.IReactorUNIXDatagram

Connects a given DatagramProtocol to the given path.

EXPERIMENTAL.

Returns object conforming to IListeningPort.

def connectUNIXDatagram(self, address, protocol, maxPacketSize=8192, mode=438, bindAddress=None): (source)

from twisted.internet.interfaces.IReactorUNIXDatagram

Connects a ConnectedDatagramProtocol instance to a path.

EXPERIMENTAL.

def adoptStreamPort(self, fileDescriptor, addressFamily, factory): (source)

from twisted.internet.interfaces.IReactorSocket

Create a new IListeningPort from an already-initialized socket.

This just dispatches to a suitable port implementation (eg from IReactorTCP, etc) based on the specified addressFamily.

See Also twisted.internet.interfaces.IReactorSocket.adoptStreamPort

def adoptStreamConnection(self, fileDescriptor, addressFamily, factory): (source)

from twisted.internet.interfaces.IReactorSocket

See Also twisted.internet.interfaces.IReactorSocket.adoptStreamConnection

def adoptDatagramPort(self, fileDescriptor, addressFamily, protocol, maxPacketSize=8192): (source)

from twisted.internet.interfaces.IReactorSocket

Add an existing listening SOCK_DGRAM socket to the reactor to monitor for read and write readiness.

Parameters	fileDescriptor	A file descriptor associated with a socket which is already bound to an address and marked as listening. The socket must be set non-blocking. Any additional flags (for example, close-on-exec) must also be set by application code. Application code is responsible for closing the file descriptor, which may be done as soon as `adoptDatagramPort` returns. (type: `int`)
	addressFamily	The address family or domain of the socket. For example, `socket.AF_INET6`. (type: `int`)
	protocol	A `DatagramProtocol` instance to connect to a UDP transport. (type: `DatagramProtocol`)
	maxPacketSize	The maximum packet size to accept. (type: `int`)
Returns	An object providing `IListeningPort`.
Raises	UnsupportedAddressFamily	If the given address family is not supported by this reactor, or not supported with the given socket type.
	UnsupportedSocketType	If the given socket type is not supported by this reactor, or not supported with the given socket type.

def listenTCP(self, port, factory, backlog=50, interface=''): (source)

from twisted.internet.interfaces.IReactorTCP

Connects a given protocol factory to the given numeric TCP/IP port.

Parameters	port	a port number on which to listen
	factory	a `twisted.internet.protocol.ServerFactory` instance
	backlog	size of the listen queue
	interface	The local IPv4 or IPv6 address to which to bind; defaults to '', ie all IPv4 addresses. To bind to all IPv4 and IPv6 addresses, you must call this method twice.
Returns	an object that provides `IListeningPort`.
Raises	CannotListenError	as defined here `twisted.internet.error.CannotListenError`, if it cannot listen on this port (e.g., it cannot bind to the required port number)

def connectTCP(self, host, port, factory, timeout=30, bindAddress=None): (source)

from twisted.internet.interfaces.IReactorTCP

Connect a TCP client.

Parameters	host	A hostname or an IPv4 or IPv6 address literal. (type: `bytes`)
	port	a port number
	factory	a `twisted.internet.protocol.ClientFactory` instance
	timeout	number of seconds to wait before assuming the connection has failed.
	bindAddress	a (host, port) tuple of local address to bind to, or None.
Returns	An object which provides `IConnector`. This connector will call various callbacks on the factory when a connection is made, failed, or lost - see `ClientFactory` docs for details.

def connectSSL(self, host, port, factory, contextFactory, timeout=30, bindAddress=None): (source)

from twisted.internet.interfaces.IReactorSSL

Connect a client Protocol to a remote SSL socket.

Parameters	host	a host name
	port	a port number
	factory	a `twisted.internet.protocol.ClientFactory` instance
	contextFactory	a `twisted.internet.ssl.ClientContextFactory` object.
	timeout	number of seconds to wait before assuming the connection has failed.
	bindAddress	a (host, port) tuple of local address to bind to, or `None`.
Returns	An object which provides `IConnector`.

def listenSSL(self, port, factory, contextFactory, backlog=50, interface=''): (source)

from twisted.internet.interfaces.IReactorSSL

Connects a given protocol factory to the given numeric TCP/IP port. The connection is a SSL one, using contexts created by the context factory.

Parameters	port	a port number on which to listen
	factory	a `twisted.internet.protocol.ServerFactory` instance
	contextFactory	an implementor of `IOpenSSLContextFactory`
	backlog	size of the listen queue
	interface	the hostname to bind to, defaults to '' (all)

def _removeAll(self, readers, writers): (source)

Remove all readers and writers, and list of removed IReadDescriptors and IWriteDescriptors.

Meant for calling from subclasses, to implement removeAll, like:

 def removeAll(self):
     return self._removeAll(self._reads, self._writes)

where self._reads and self._writes are iterables.

API Documentation for Twisted, generated by pydoctor at 2017-06-11 10:59:01.

twisted.internet.posixbase.PosixReactorBase(_SignalReactorMixin, _DisconnectSelectableMixin, ReactorBase) class documentation

`twisted.internet.posixbase.PosixReactorBase(_SignalReactorMixin, _DisconnectSelectableMixin, ReactorBase)` class documentation