1 files changed, 66 insertions, 27 deletions

diff --git a/Lib/SocketServer.py b/Lib/SocketServer.py
index 47d8728..2a9ec8a 100644
--- a/Lib/SocketServer.py
+++ b/Lib/SocketServer.py
@@ -130,8 +130,13 @@ __version__ = "0.4"
 
 
 import socket
+import select
 import sys
 import os
+try:
+    import threading
+except ImportError:
+    import dummy_threading as threading
 
 __all__ = ["TCPServer","UDPServer","ForkingUDPServer","ForkingTCPServer",
            "ThreadingUDPServer","ThreadingTCPServer","BaseRequestHandler",
@@ -149,7 +154,8 @@ class BaseServer:
     Methods for the caller:
 
     - __init__(server_address, RequestHandlerClass)
-    - serve_forever()
+    - serve_forever(poll_interval=0.5)
+    - shutdown()
     - handle_request()  # if you do not use serve_forever()
     - fileno() -> int   # for select()
 
@@ -190,6 +196,8 @@ class BaseServer:
         """Constructor.  May be extended, do not override."""
         self.server_address = server_address
         self.RequestHandlerClass = RequestHandlerClass
+        self.__is_shut_down = threading.Event()
+        self.__serving = False
 
     def server_activate(self):
         """Called by constructor to activate the server.
@@ -199,27 +207,73 @@ class BaseServer:
         """
         pass
 
-    def serve_forever(self):
-        """Handle one request at a time until doomsday."""
-        while 1:
-            self.handle_request()
+    def 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.
+        """
+        self.__serving = True
+        self.__is_shut_down.clear()
+        while self.__serving:
+            # XXX: Consider using another file descriptor or
+            # connecting to the socket to wake this up instead of
+            # polling. Polling reduces our responsiveness to a
+            # shutdown request and wastes cpu at all other times.
+            r, w, e = select.select([self], [], [], poll_interval)
+            if r:
+                self._handle_request_noblock()
+        self.__is_shut_down.set()
+
+    def 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.
+        """
+        self.__serving = False
+        self.__is_shut_down.wait()
 
     # The distinction between handling, getting, processing and
     # finishing a request is fairly arbitrary.  Remember:
     #
     # - handle_request() is the top-level call.  It calls
-    #   await_request(), verify_request() and process_request()
-    # - get_request(), called by await_request(), is different for
-    #   stream or datagram sockets
+    #   select, get_request(), verify_request() and process_request()
+    # - get_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;
     #   this constructor will handle the request all by itself
 
     def handle_request(self):
-        """Handle one request, possibly blocking."""
+        """Handle one request, possibly blocking.
+
+        Respects self.timeout.
+        """
+        # Support people who used socket.settimeout() to escape
+        # handle_request before self.timeout was available.
+        timeout = self.socket.gettimeout()
+        if timeout is None:
+            timeout = self.timeout
+        elif self.timeout is not None:
+            timeout = min(timeout, self.timeout)
+        fd_sets = select.select([self], [], [], timeout)
+        if not fd_sets[0]:
+            self.handle_timeout()
+            return
+        self._handle_request_noblock()
+
+    def _handle_request_noblock(self):
+        """Handle one request, without blocking.
+
+        I assume that select.select has returned that the socket is
+        readable before this function was called, so there should be
+        no risk of blocking in get_request().
+        """
         try:
-            request, client_address = self.await_request()
+            request, client_address = self.get_request()
         except socket.error:
             return
         if self.verify_request(request, client_address):
@@ -229,21 +283,6 @@ class BaseServer:
                 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.
 
@@ -307,7 +346,8 @@ class TCPServer(BaseServer):
     Methods for the caller:
 
     - __init__(server_address, RequestHandlerClass, bind_and_activate=True)
-    - serve_forever()
+    - serve_forever(poll_interval=0.5)
+    - shutdown()
     - handle_request()  # if you don't use serve_forever()
     - fileno() -> int   # for select()
 
@@ -523,7 +563,6 @@ class ThreadingMixIn:
 
     def process_request(self, request, client_address):
         """Start a new thread to process the request."""
-        import threading
         t = threading.Thread(target = self.process_request_thread,
                              args = (request, client_address))
         if self.daemon_threads: