[Python-checkins] r60080 - in python/trunk: Doc/library/socketserver.rst Lib/SocketServer.py Misc/ACKS Misc/NEWS

Sat Jan 19 17:26:13 CET 2008

Author: andrew.kuchling
Date: Sat Jan 19 17:26:13 2008
New Revision: 60080
Modified:
 python/trunk/Doc/library/socketserver.rst
 python/trunk/Lib/SocketServer.py
 python/trunk/Misc/ACKS
 python/trunk/Misc/NEWS
Log:
Patch #742598 from Michael Pomraning: add .timeout attribute to SocketServer that will call
.handle_timeout() method when no requests are received within the timeout period.
Modified: python/trunk/Doc/library/socketserver.rst
==============================================================================

--- python/trunk/Doc/library/socketserver.rst	(original)
+++ python/trunk/Doc/library/socketserver.rst	Sat Jan 19 17:26:13 2008
@@ -44,7 +44,7 @@
 not exit until all threads created by :class:`ThreadingMixIn` have exited.
 
 Server classes have the same external methods and attributes, no matter what
-network protocol they use:
+network protocol they use.
 
 
 Server Creation Notes
@@ -193,6 +193,13 @@
 The type of socket used by the server; :const:`socket.SOCK_STREAM` and
 :const:`socket.SOCK_DGRAM` are two possible values.
 
+.. data:: timeout
+
+ Timeout duration, measured in seconds, or :const:`None` if no timeout is desired.
+ If no incoming requests are received within the timeout period, 
+ the :meth:`handle_timeout` method is called and then the server resumes waiting for 
+ requests.
+
 There are various server methods that can be overridden by subclasses of base
 server classes like :class:`TCPServer`; these methods aren't useful to external
 users of the server object.
@@ -220,6 +227,13 @@
 method raises an exception. The default action is to print the traceback to
 standard output and continue handling further requests.
 
+.. function:: handle_timeout()
+
+ This function is called when the :attr:`timeout` attribute has been set to a 
+ value other than :const:`None` and the timeout period has passed with no 
+ requests being received. The default action for forking servers is
+ to collect the status of any child processes that have exited, while
+ in threading servers this method does nothing.
 
 .. function:: process_request(request, client_address)
 
Modified: python/trunk/Lib/SocketServer.py
==============================================================================
--- python/trunk/Lib/SocketServer.py	(original)
+++ python/trunk/Lib/SocketServer.py	Sat Jan 19 17:26:13 2008
@@ -158,6 +158,7 @@
 - server_bind()
 - server_activate()
 - get_request() -> request, client_address
+ - handle_timeout()
 - verify_request(request, client_address)
 - server_close()
 - process_request(request, client_address)
@@ -171,6 +172,7 @@
 Class variables that may be overridden by derived classes or
 instances:
 
+ - timeout
 - address_family
 - socket_type
 - allow_reuse_address
@@ -182,6 +184,8 @@
 
 """
 
+ timeout = None
+
 def __init__(self, server_address, RequestHandlerClass):
 """Constructor. May be extended, do not override."""
 self.server_address = server_address
@@ -204,8 +208,9 @@
 # finishing a request is fairly arbitrary. Remember:
 #
 # - handle_request() is the top-level call. It calls
- # get_request(), verify_request() and process_request()
- # - get_request() is different for stream or datagram sockets
+ # await_request(), verify_request() and process_request()
+ # - get_request(), called by await_request(), is different for
+ # stream or datagram sockets
 # - process_request() is the place that may fork a new process
 # or create a new thread to finish the request
 # - finish_request() instantiates the request handler class;
@@ -214,7 +219,7 @@
 def handle_request(self):
 """Handle one request, possibly blocking."""
 try:
- request, client_address = self.get_request()
+ request, client_address = self.await_request()
 except socket.error:
 return
 if self.verify_request(request, client_address):
@@ -224,6 +229,28 @@
 self.handle_error(request, client_address)
 self.close_request(request)
 
+ def await_request(self):
+ """Call get_request or handle_timeout, observing self.timeout.
+
+ Returns value from get_request() or raises socket.timeout exception if
+ timeout was exceeded.
+ """
+ if self.timeout is not None:
+ # If timeout == 0, you're responsible for your own fd magic.
+ import select
+ fd_sets = select.select([self], [], [], self.timeout)
+ if not fd_sets[0]:
+ self.handle_timeout()
+ raise socket.timeout("Listening timed out")
+ return self.get_request()
+
+ def handle_timeout(self):
+ """Called if no new request arrives within self.timeout.
+
+ Overridden by ForkingMixIn.
+ """
+ pass
+
 def verify_request(self, request, client_address):
 """Verify the request. May be overridden.
 
@@ -289,6 +316,7 @@
 - server_bind()
 - server_activate()
 - get_request() -> request, client_address
+ - handle_timeout()
 - verify_request(request, client_address)
 - process_request(request, client_address)
 - close_request(request)
@@ -301,6 +329,7 @@
 Class variables that may be overridden by derived classes or
 instances:
 
+ - timeout
 - address_family
 - socket_type
 - request_queue_size (only for stream sockets)
@@ -405,11 +434,12 @@
 
 """Mix-in class to handle each request in a new process."""
 
+ timeout = 300
 active_children = None
 max_children = 40
 
 def collect_children(self):
- """Internal routine to wait for died children."""
+ """Internal routine to wait for children that have exited."""
 while self.active_children:
 if len(self.active_children) < self.max_children:
 options = os.WNOHANG
@@ -424,6 +454,13 @@
 if not pid: break
 self.active_children.remove(pid)
 
+ def handle_timeout(self):
+ """Wait for zombies after self.timeout seconds of inactivity.
+
+ May be extended, do not override.
+ """
+ self.collect_children()
+
 def process_request(self, request, client_address):
 """Fork a new subprocess to process the request."""
 self.collect_children()
Modified: python/trunk/Misc/ACKS
==============================================================================
--- python/trunk/Misc/ACKS	(original)
+++ python/trunk/Misc/ACKS	Sat Jan 19 17:26:13 2008
@@ -521,6 +521,7 @@
 François Pinard
 Zach Pincus
 Michael Piotrowski
+Michael Pomraning
 Iustin Pop
 John Popplewell
 Amrit Prem
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Sat Jan 19 17:26:13 2008
@@ -704,6 +704,9 @@
 be equal to calling getsockname() on the server's socket. Fixed by
 patch #1545011.
 
+- Patch #742598: Add .timeout attribute to SocketServer that calls
+ .handle_timeout() when no requests are received.
+
 - Bug #1651235: When a tuple was passed to a ctypes function call,
 Python would crash instead of raising an error.
 
