class documentation

class PosixReactorBase(_SignalReactorMixin, _DisconnectSelectableMixin, ReactorBase): (source)

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

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A basis for reactors that use file descriptors.
Method adopt​Datagram​Port Add an existing listening SOCK_DGRAM socket to the reactor to monitor for read and write readiness.
Method adopt​Stream​Connection
Method adopt​Stream​Port Create a new IListeningPort from an already-initialized socket.
Method connect​SSL Connect a client Protocol to a remote SSL socket.
Method connect​TCP Connect a TCP client.
Method connect​UNIX Connect a client protocol to a UNIX socket.
Method connect​UNIXDatagram Connects a ConnectedDatagramProtocol instance to a path.
Method install​Waker Install a `waker' to allow threads and signals to wake up the IO thread.
Method listen​Multicast Connects a given DatagramProtocol to the given numeric UDP port.
Method listen​SSL 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.
Method listen​TCP Connects a given protocol factory to the given numeric TCP/IP port.
Method listen​UDP Connects a given DatagramProtocol to the given numeric UDP port.
Method listen​UNIX Listen on a UNIX socket.
Method listen​UNIXDatagram Connects a given DatagramProtocol to the given path.
Method spawn​Process Spawn a process, with a process protocol.
Instance Variable waker Undocumented
Method _handle​Signals Extend the basic signal handling logic to also support handling SIGCHLD to know when to try to reap child processes.
Method _remove​All Remove all readers and writers, and list of removed IReadDescriptors and IWriteDescriptors.
Method _uninstall​Handler If a child waker was created and installed, uninstall it now.
Class Variable _supported​Address​Families Undocumented
Instance Variable _child​Waker None or a reference to the _SIGCHLDWaker which is used to properly notice child process termination.

Inherited from _SignalReactorMixin:

Method main​Loop Undocumented
Method run Undocumented
Method start​Running Extend the base implementation in order to remember whether signal handlers should be installed later.
Method _really​Start​Running Extend the base implementation by also installing signal handlers, if self._installSignalHandlers is true.
Instance Variable _install​Signal​Handlers A flag which indicates whether any signal handlers will be installed during startup. This includes handlers for SIGCHLD to monitor child processes, and SIGINT, SIGTERM, and SIGBREAK to stop the reactor.

Inherited from _DisconnectSelectableMixin:

Method _disconnect​Selectable Utility function for disconnecting a selectable.

Inherited from ReactorBase:

Method __init__ Undocumented
Method add​Reader Undocumented
Method add​System​Event​Trigger See twisted.internet.interfaces.IReactorCore.addSystemEventTrigger.
Method add​Writer Undocumented
Method call​From​Thread See twisted.internet.interfaces.IReactorFromThreads.callFromThread.
Method call​In​Thread See twisted.internet.interfaces.IReactorInThreads.callInThread.
Method call​Later See twisted.internet.interfaces.IReactorTime.callLater.
Method call​When​Running See twisted.internet.interfaces.IReactorCore.callWhenRunning.
Method crash See twisted.internet.interfaces.IReactorCore.crash.
Method disconnect​All Disconnect every reader, and writer in the system.
Method do​Iteration Do one iteration over the readers and writers which have been added.
Method fire​System​Event See twisted.internet.interfaces.IReactorCore.fireSystemEvent.
Method get​Delayed​Calls No summary
Method get​Readers Undocumented
Method get​Thread​Pool See twisted.internet.interfaces.IReactorThreads.getThreadPool.
Method get​Writers Undocumented
Method iterate See twisted.internet.interfaces.IReactorCore.iterate.
Method remove​All Undocumented
Method remove​Reader Undocumented
Method remove​System​Event​Trigger See twisted.internet.interfaces.IReactorCore.removeSystemEventTrigger.
Method remove​Writer Undocumented
Method resolve Return a Deferred that will resolve a hostname.
Method run Fire 'startup' System Events, move the reactor to the 'running' state, then run the main loop until it is stopped with stop() or crash().
Method run​Until​Current Run all pending timed calls.
Method sig​Break Handle a SIGBREAK interrupt.
Method sig​Int Handle a SIGINT interrupt.
Method sig​Term Handle a SIGTERM interrupt.
Method start​Running Method called when reactor starts: do some initialization and fire startup events.
Method stop See twisted.internet.interfaces.IReactorCore.stop.
Method suggest​Thread​Pool​Size See twisted.internet.interfaces.IReactorThreads.suggestThreadPoolSize.
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 wake​Up Wake up the event loop.
Class Variable __name__ Undocumented
Class Variable installed Undocumented
Class Variable seconds Get the current time in seconds.
Instance Variable running See IReactorCore.running
Instance Variable thread​Call​Queue Undocumented
Instance Variable threadpool Undocumented
Instance Variable threadpool​Shutdown​ID Undocumented
Instance Variable using​Threads Undocumented
Method _cancel​Call​Later Undocumented
Method _check​Process​Args Check for valid arguments and environment to spawnProcess.
Method _init​Thread​Pool Create the threadpool accessible with callFromThread.
Method _init​Threads Undocumented
Method _insert​New​Delayed​Calls Undocumented
Method _move​Call​Later​Sooner Undocumented
Method _really​Start​Running Method called to transition to the running state. This should happen in the during startup event trigger phase.
Method _stop​Thread​Pool No summary
Class Variable _lock Undocumented
Instance Variable _cancellations Undocumented
Instance Variable _event​Triggers Undocumented
Instance Variable _exit​Signal See _ISupportsExitSignalCapturing._exitSignal
Instance Variable _internal​Readers Undocumented
Instance Variable _just​Stopped 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.
Instance Variable _new​Timed​Calls Undocumented
Instance Variable _pending​Timed​Calls Undocumented
Instance Variable _register​As​IOThread 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.
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.
Instance Variable _started​Before Undocumented
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.
Instance Variable _threadpool​Startup​ID Undocumented

Inherited from PluggableResolverMixin (via ReactorBase):

Method install​Name​Resolver See IReactorPluggableNameResolver.
Method install​Resolver See IReactorPluggableResolver.
Instance Variable resolver The installed IResolverSimple.
Property name​Resolver Implementation of read-only IReactorPluggableNameResolver.nameResolver.
Instance Variable _name​Resolver The installed IHostnameResolver.
def adoptDatagramPort(self, fileDescriptor, addressFamily, protocol, maxPacketSize=8192): (source)
Add an existing listening SOCK_DGRAM socket to the reactor to monitor for read and write readiness.
Parameters
file​DescriptorA 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.
address​FamilyThe address family or domain of the socket. For example, socket.AF_INET6.
protocolA DatagramProtocol instance to connect to a UDP transport.
max​Packet​SizeThe maximum packet size to accept.
Returns
An object providing IListeningPort.
Raises
UnsupportedAddressFamilyIf the given address family is not supported by this reactor, or not supported with the given socket type.
UnsupportedSocketTypeIf the given socket type is not supported by this reactor, or not supported with the given socket type.
def adoptStreamConnection(self, fileDescriptor, addressFamily, factory): (source)
def adoptStreamPort(self, fileDescriptor, addressFamily, factory): (source)

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 connectSSL(self, host, port, factory, contextFactory, timeout=30, bindAddress=None): (source)
Connect a client Protocol to a remote SSL socket.
Parameters
hosta host name
porta port number
factorya twisted.internet.protocol.ClientFactory instance
context​Factorya twisted.internet.ssl.ClientContextFactory object.
timeoutnumber of seconds to wait before assuming the connection has failed.
bind​Addressa (host, port) tuple of local address to bind to, or None.
Returns
An object which provides IConnector.
def connectTCP(self, host, port, factory, timeout=30, bindAddress=None): (source)
Connect a TCP client.
Parameters
hostA hostname or an IPv4 or IPv6 address literal.
porta port number
factorya twisted.internet.protocol.ClientFactory instance
timeoutnumber of seconds to wait before assuming the connection has failed.
bind​Addressa (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 connectUNIX(self, address, factory, timeout=30, checkPID=0): (source)
Connect a client protocol to a UNIX socket.
Parameters
addressa path to a unix socket on the filesystem.
factorya twisted.internet.protocol.ClientFactory instance
timeoutnumber of seconds to wait before assuming the connection has failed.
check​PIDif 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 connectUNIXDatagram(self, address, protocol, maxPacketSize=8192, mode=438, bindAddress=None): (source)

Connects a ConnectedDatagramProtocol instance to a path.

EXPERIMENTAL.

def installWaker(self): (source)

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

Connects a given DatagramProtocol to the given numeric UDP port.

EXPERIMENTAL.

Returns
object conforming to IListeningPort.
def listenSSL(self, port, factory, contextFactory, backlog=50, interface=''): (source)
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
porta port number on which to listen
factorya twisted.internet.protocol.ServerFactory instance
context​Factoryan implementor of IOpenSSLContextFactory
backlogsize of the listen queue
interfacethe hostname to bind to, defaults to '' (all)
def listenTCP(self, port, factory, backlog=50, interface=''): (source)
Connects a given protocol factory to the given numeric TCP/IP port.
Parameters
porta port number on which to listen
factorya twisted.internet.protocol.ServerFactory instance
backlogsize of the listen queue
interfaceThe 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
CannotListenErroras defined here twisted.internet.error.CannotListenError, if it cannot listen on this port (e.g., it cannot bind to the required port number)
def listenUDP(self, port, protocol, interface='', maxPacketSize=8192): (source)
Connects a given DatagramProtocol to the given numeric UDP port.
Returns
object conforming to IListeningPort.
def listenUNIX(self, address, factory, backlog=50, mode=438, wantPID=0): (source)
Listen on a UNIX socket.
Parameters
addressa path to a unix socket on the filesystem.
factorya twisted.internet.protocol.Factory instance.
backlognumber of connections to allow in backlog.
modeThe mode (not umask) to set on the unix socket. See platform specific documentation for information about how this might affect connection attempts.
want​PIDif 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)

Connects a given DatagramProtocol to the given path.

EXPERIMENTAL.

Returns
object conforming to IListeningPort.
def spawnProcess(self, processProtocol, executable, args=(), env={}, path=None, uid=None, gid=None, usePTY=0, childFDs=None): (source)

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 sys.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 sys.getfilesystemencoding (mbcs before Python 3.6, utf8 thereafter) and given to Windows's native "wide" APIs.

Parameters
process​ProtocolAn object which will be notified of all events related to the created process.
executablethe file name to spawn - the full path should be used.
argsthe command line arguments to pass to the process; a sequence of strings. The first string should be the executable's name.
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:
  • 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.
paththe path to run the subprocess in - defaults to the current directory.
uiduser ID to run the subprocess as. (Only available on POSIX systems.)
gidgroup ID to run the subprocess as. (Only available on POSIX systems.)
use​PTYif 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.)
child​FDs

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.

Returns
An object which provides IProcessTransport.
Raises
OSErrorRaised with errno EAGAIN or ENOMEM if there are insufficient system resources to create a new process.
See Also
twisted.internet.protocol.ProcessProtocol
def _handleSignals(self): (source)
Extend the basic signal handling logic to also support handling SIGCHLD to know when to try to reap child processes.
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.

def _uninstallHandler(self): (source)

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.

_supportedAddressFamilies: Sequence[socket.AddressFamily] = (source)

Undocumented

_childWaker = (source)
None or a reference to the _SIGCHLDWaker which is used to properly notice child process termination.