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socketserver

Generic socket server classes.

This module tries to capture the various aspects of defining a server:

For socket-based servers:

- address family:
        - AF_INET{,6}: IP (Internet Protocol) sockets (default)
        - AF_UNIX: Unix domain sockets
        - others, e.g. AF_DECNET are conceivable (see <socket.h>
- socket type:
        - SOCK_STREAM (reliable stream, e.g. TCP)
        - SOCK_DGRAM (datagrams, e.g. UDP)

For request-based servers (including socket-based):

- client address verification before further looking at the request
        (This is actually a hook for any processing that needs to look
         at the request before anything else, e.g. logging)
- how to handle multiple requests:
        - synchronous (one request is handled at a time)
        - forking (each request is handled by a new process)
        - threading (each request is handled by a new thread)

The classes in this module favor the server type that is simplest to
write: a synchronous TCP/IP server.  This is bad class design, but
saves some typing.  (There's also the issue that a deep class hierarchy
slows down method lookups.)

There are five classes in an inheritance diagram, four of which represent
synchronous servers of four types:

        +------------+
        | BaseServer |
        +------------+
              |
              v
        +-----------+        +------------------+
        | TCPServer |------->| UnixStreamServer |
        +-----------+        +------------------+
              |
              v
        +-----------+        +--------------------+
        | UDPServer |------->| UnixDatagramServer |
        +-----------+        +--------------------+

Note that UnixDatagramServer derives from UDPServer, not from
UnixStreamServer -- the only difference between an IP and a Unix
stream server is the address family, which is simply repeated in both
unix server classes.

Forking and threading versions of each type of server can be created
using the ForkingMixIn and ThreadingMixIn mix-in classes.  For
instance, a threading UDP server class is created as follows:

        class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass

The Mix-in class must come first, since it overrides a method defined
in UDPServer! Setting the various member variables also changes
the behavior of the underlying server mechanism.

To implement a service, you must derive a class from
BaseRequestHandler and redefine its handle() method.  You can then run
various versions of the service by combining one of the server classes
with your request handler class.

The request handler class must be different for datagram or stream
services.  This can be hidden by using the request handler
subclasses StreamRequestHandler or DatagramRequestHandler.

Of course, you still have to use your head!

For instance, it makes no sense to use a forking server if the service
contains state in memory that can be modified by requests (since the
modifications in the child process would never reach the initial state
kept in the parent process and passed to each child).  In this case,
you can use a threading server, but you will probably have to use
locks to avoid two requests that come in nearly simultaneous to apply
conflicting changes to the server state.

On the other hand, if you are building e.g. an HTTP server, where all
data is stored externally (e.g. in the file system), a synchronous
class will essentially render the service "deaf" while one request is
being handled -- which may be for a very long time if a client is slow
to read all the data it has requested.  Here a threading or forking
server is appropriate.

In some cases, it may be appropriate to process part of a request
synchronously, but to finish processing in a forked child depending on
the request data.  This can be implemented by using a synchronous
server and doing an explicit fork in the request handler class
handle() method.

Another approach to handling multiple simultaneous requests in an
environment that supports neither threads nor fork (or where these are
too expensive or inappropriate for the service) is to maintain an
explicit table of partially finished requests and to use a selector to
decide which request to work on next (or whether to handle a new
incoming request).  This is particularly important for stream services
where each client can potentially be connected for a long time (if
threads or subprocesses cannot be used).

Future work:
- Standard classes for Sun RPC (which uses either UDP or TCP)
- Standard mix-in classes to implement various authentication
  and encryption schemes

XXX Open problems:
- What to do with out-of-band data?

BaseServer:
- split generic "request" functionality out into BaseServer class.
  Copyright (C) 2000  Luke Kenneth Casson Leighton <lkcl@samba.org>

  example: read entries from a SQL database (requires overriding
  get_request() to return a table entry from the database).
  entry is processed by a RequestHandlerClass.


Classes

BaseRequestHandler

Base class for request handler classes.

    This class is instantiated for each request to be handled.  The
    constructor sets the instance variables request, client_address
    and server, and then calls the handle() method.  To implement a
    specific service, all you need to do is to derive a class which
    defines a handle() method.

    The handle() method can find the request as self.request, the
    client address as self.client_address, and the server (in case it
    needs access to per-server information) as self.server.  Since a
    separate instance is created for each request, the handle() method
    can define other arbitrary instance variables.

    
finish(self)
handle(self)
setup(self)

BaseServer

Base class for server classes.

    Methods for the caller:

    - __init__(server_address, RequestHandlerClass)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you do not use serve_forever()
    - fileno() -> int   # for selector

    Methods that may be overridden:

    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - server_close()
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - service_actions()
    - handle_error()

    Methods for derived classes:

    - finish_request(request, client_address)

    Class variables that may be overridden by derived classes or
    instances:

    - timeout
    - address_family
    - socket_type
    - allow_reuse_address

    Instance variables:

    - RequestHandlerClass
    - socket

    
close_request(self, request)

  Called to clean up an individual request.
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Call finish_request.

          Overridden by ForkingMixIn and ThreadingMixIn.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_close(self)

  Called to clean-up the server.

          May be overridden.

        
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
timeout = None

BufferedIOBase

Base class for buffered IO objects.

The main difference with RawIOBase is that the read() method
supports omitting the size argument, and does not have a default
implementation that defers to readinto().

In addition, read(), readinto() and write() may raise
BlockingIOError if the underlying raw stream is in non-blocking
mode and not ready; unlike their raw counterparts, they will never
return None.

A typical implementation should not inherit from a RawIOBase
implementation, but wrap one.

close(self, /)

  Flush and close the IO object.

  This method has no effect if the file is already closed.
detach(self, /)

  Disconnect this buffer from its underlying raw stream and return it.

  After the raw stream has been detached, the buffer is in an unusable
  state.
fileno(self, /)

  Returns underlying file descriptor if one exists.

  OSError is raised if the IO object does not use a file descriptor.
flush(self, /)

  Flush write buffers, if applicable.

  This is not implemented for read-only and non-blocking streams.
isatty(self, /)

  Return whether this is an 'interactive' stream.

  Return False if it can't be determined.
read(...)

  Read and return up to n bytes.

  If the argument is omitted, None, or negative, reads and
  returns all data until EOF.

  If the argument is positive, and the underlying raw stream is
  not 'interactive', multiple raw reads may be issued to satisfy
  the byte count (unless EOF is reached first).  But for
  interactive raw streams (as well as sockets and pipes), at most
  one raw read will be issued, and a short result does not imply
  that EOF is imminent.

  Returns an empty bytes object on EOF.

  Returns None if the underlying raw stream was open in non-blocking
  mode and no data is available at the moment.

read1(...)

  Read and return up to n bytes, with at most one read() call
  to the underlying raw stream. A short result does not imply
  that EOF is imminent.

  Returns an empty bytes object on EOF.

readable(self, /)

  Return whether object was opened for reading.

  If False, read() will raise OSError.
readinto(self, buffer, /)
readinto1(self, buffer, /)
readline(self, size=-1, /)

  Read and return a line from the stream.

  If size is specified, at most size bytes will be read.

  The line terminator is always b'\n' for binary files; for text
  files, the newlines argument to open can be used to select the line
  terminator(s) recognized.
readlines(self, hint=-1, /)

  Return a list of lines from the stream.

  hint can be specified to control the number of lines read: no more
  lines will be read if the total size (in bytes/characters) of all
  lines so far exceeds hint.
seek(...)

  Change stream position.

  Change the stream position to the given byte offset. The offset is
  interpreted relative to the position indicated by whence.  Values
  for whence are:

  * 0 -- start of stream (the default); offset should be zero or positive
  * 1 -- current stream position; offset may be negative
  * 2 -- end of stream; offset is usually negative

  Return the new absolute position.
seekable(self, /)

  Return whether object supports random access.

  If False, seek(), tell() and truncate() will raise OSError.
  This method may need to do a test seek().
tell(self, /)

  Return current stream position.
truncate(...)

  Truncate file to size bytes.

  File pointer is left unchanged.  Size defaults to the current IO
  position as reported by tell().  Returns the new size.
writable(self, /)

  Return whether object was opened for writing.

  If False, write() will raise OSError.
write(...)

  Write the given buffer to the IO stream.

  Returns the number of bytes written, which is always the length of b
  in bytes.

  Raises BlockingIOError if the buffer is full and the
  underlying raw stream cannot accept more data at the moment.

writelines(self, lines, /)

  Write a list of lines to stream.

  Line separators are not added, so it is usual for each of the
  lines provided to have a line separator at the end.
closed = <attribute 'closed' of '_io._IOBase' objects>

DatagramRequestHandler

Define self.rfile and self.wfile for datagram sockets.
finish(self)
handle(self)
setup(self)

ForkingMixIn

Mix-in class to handle each request in a new process.
collect_children(self, *, blocking=False)

  Internal routine to wait for children that have exited.
handle_timeout(self)

  Wait for zombies after self.timeout seconds of inactivity.

              May be extended, do not override.
            
process_request(self, request, client_address)

  Fork a new subprocess to process the request.
server_close(self)
service_actions(self)

  Collect the zombie child processes regularly in the ForkingMixIn.

              service_actions is called in the BaseServer's serve_forever loop.
            
active_children = None
block_on_close = True
max_children = 40
timeout = 300

ForkingTCPServer

close_request(self, request)

  Called to clean up an individual request.
collect_children(self, *, blocking=False)

  Internal routine to wait for children that have exited.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)

  Get the request and client address from the socket.

          May be overridden.

        
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Wait for zombies after self.timeout seconds of inactivity.

              May be extended, do not override.
            
process_request(self, request, client_address)

  Fork a new subprocess to process the request.
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Collect the zombie child processes regularly in the ForkingMixIn.

              service_actions is called in the BaseServer's serve_forever loop.
            
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
active_children = None
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
block_on_close = True
max_children = 40
request_queue_size = 5
socket_type = <SocketKind.SOCK_STREAM: 1>
timeout = 300

ForkingUDPServer

close_request(self, request)
collect_children(self, *, blocking=False)

  Internal routine to wait for children that have exited.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Wait for zombies after self.timeout seconds of inactivity.

              May be extended, do not override.
            
process_request(self, request, client_address)

  Fork a new subprocess to process the request.
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Collect the zombie child processes regularly in the ForkingMixIn.

              service_actions is called in the BaseServer's serve_forever loop.
            
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
active_children = None
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
block_on_close = True
max_children = 40
max_packet_size = 8192
request_queue_size = 5
socket_type = <SocketKind.SOCK_DGRAM: 2>
timeout = 300

StreamRequestHandler

Define self.rfile and self.wfile for stream sockets.
finish(self)
handle(self)
setup(self)
disable_nagle_algorithm = False
rbufsize = -1
timeout = None
wbufsize = 0

TCPServer

Base class for various socket-based server classes.

    Defaults to synchronous IP stream (i.e., TCP).

    Methods for the caller:

    - __init__(server_address, RequestHandlerClass, bind_and_activate=True)
    - serve_forever(poll_interval=0.5)
    - shutdown()
    - handle_request()  # if you don't use serve_forever()
    - fileno() -> int   # for selector

    Methods that may be overridden:

    - server_bind()
    - server_activate()
    - get_request() -> request, client_address
    - handle_timeout()
    - verify_request(request, client_address)
    - process_request(request, client_address)
    - shutdown_request(request)
    - close_request(request)
    - handle_error()

    Methods for derived classes:

    - finish_request(request, client_address)

    Class variables that may be overridden by derived classes or
    instances:

    - timeout
    - address_family
    - socket_type
    - request_queue_size (only for stream sockets)
    - allow_reuse_address

    Instance variables:

    - server_address
    - RequestHandlerClass
    - socket

    
close_request(self, request)

  Called to clean up an individual request.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)

  Get the request and client address from the socket.

          May be overridden.

        
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Call finish_request.

          Overridden by ForkingMixIn and ThreadingMixIn.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)

  Called to clean-up the server.

          May be overridden.

        
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
request_queue_size = 5
socket_type = <SocketKind.SOCK_STREAM: 1>
timeout = None

ThreadingMixIn

Mix-in class to handle each request in a new thread.
process_request(self, request, client_address)

  Start a new thread to process the request.
process_request_thread(self, request, client_address)

  Same as in BaseServer but as a thread.

          In addition, exception handling is done here.

        
server_close(self)
block_on_close = True
daemon_threads = False

ThreadingTCPServer

close_request(self, request)

  Called to clean up an individual request.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)

  Get the request and client address from the socket.

          May be overridden.

        
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Start a new thread to process the request.
process_request_thread(self, request, client_address)

  Same as in BaseServer but as a thread.

          In addition, exception handling is done here.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
block_on_close = True
daemon_threads = False
request_queue_size = 5
socket_type = <SocketKind.SOCK_STREAM: 1>
timeout = None

ThreadingUDPServer

close_request(self, request)
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Start a new thread to process the request.
process_request_thread(self, request, client_address)

  Same as in BaseServer but as a thread.

          In addition, exception handling is done here.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
block_on_close = True
daemon_threads = False
max_packet_size = 8192
request_queue_size = 5
socket_type = <SocketKind.SOCK_DGRAM: 2>
timeout = None

ThreadingUnixDatagramServer

close_request(self, request)
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Start a new thread to process the request.
process_request_thread(self, request, client_address)

  Same as in BaseServer but as a thread.

          In addition, exception handling is done here.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_UNIX: 1>
allow_reuse_address = False
block_on_close = True
daemon_threads = False
max_packet_size = 8192
request_queue_size = 5
socket_type = <SocketKind.SOCK_DGRAM: 2>
timeout = None

ThreadingUnixStreamServer

close_request(self, request)

  Called to clean up an individual request.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)

  Get the request and client address from the socket.

          May be overridden.

        
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Start a new thread to process the request.
process_request_thread(self, request, client_address)

  Same as in BaseServer but as a thread.

          In addition, exception handling is done here.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_UNIX: 1>
allow_reuse_address = False
block_on_close = True
daemon_threads = False
request_queue_size = 5
socket_type = <SocketKind.SOCK_STREAM: 1>
timeout = None

UDPServer

UDP server class.
close_request(self, request)
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Call finish_request.

          Overridden by ForkingMixIn and ThreadingMixIn.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)

  Called to clean-up the server.

          May be overridden.

        
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_INET: 2>
allow_reuse_address = False
max_packet_size = 8192
request_queue_size = 5
socket_type = <SocketKind.SOCK_DGRAM: 2>
timeout = None

UnixDatagramServer

close_request(self, request)
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Call finish_request.

          Overridden by ForkingMixIn and ThreadingMixIn.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)

  Called to clean-up the server.

          May be overridden.

        
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_UNIX: 1>
allow_reuse_address = False
max_packet_size = 8192
request_queue_size = 5
socket_type = <SocketKind.SOCK_DGRAM: 2>
timeout = None

UnixStreamServer

close_request(self, request)

  Called to clean up an individual request.
fileno(self)

  Return socket file number.

          Interface required by selector.

        
finish_request(self, request, client_address)

  Finish one request by instantiating RequestHandlerClass.
get_request(self)

  Get the request and client address from the socket.

          May be overridden.

        
handle_error(self, request, client_address)

  Handle an error gracefully.  May be overridden.

          The default is to print a traceback and continue.

        
handle_request(self)

  Handle one request, possibly blocking.

          Respects self.timeout.
        
handle_timeout(self)

  Called if no new request arrives within self.timeout.

          Overridden by ForkingMixIn.
        
process_request(self, request, client_address)

  Call finish_request.

          Overridden by ForkingMixIn and ThreadingMixIn.

        
serve_forever(self, poll_interval=0.5)

  Handle one request at a time until shutdown.

          Polls for shutdown every poll_interval seconds. Ignores
          self.timeout. If you need to do periodic tasks, do them in
          another thread.
        
server_activate(self)

  Called by constructor to activate the server.

          May be overridden.

        
server_bind(self)

  Called by constructor to bind the socket.

          May be overridden.

        
server_close(self)

  Called to clean-up the server.

          May be overridden.

        
service_actions(self)

  Called by the serve_forever() loop.

          May be overridden by a subclass / Mixin to implement any code that
          needs to be run during the loop.
        
shutdown(self)

  Stops the serve_forever loop.

          Blocks until the loop has finished. This must be called while
          serve_forever() is running in another thread, or it will
          deadlock.
        
shutdown_request(self, request)

  Called to shutdown and close an individual request.
verify_request(self, request, client_address)

  Verify the request.  May be overridden.

          Return True if we should proceed with this request.

        
address_family = <AddressFamily.AF_UNIX: 1>
allow_reuse_address = False
request_queue_size = 5
socket_type = <SocketKind.SOCK_STREAM: 1>
timeout = None

Functions

time

monotonic(...)

  monotonic() -> float

  Monotonic clock, cannot go backward.

Modules

os

selectors

socket

sys

threading