Merge pull request #15 from userrl/master

Added quit() method.  This method sends the 'quit' command to the servers and then closes the connections, reducing the number of TIME_WAIT sockets hanging around the OS.

memcache.py

@@ -364,6 +364,11 @@ def get_slab_stats(self):
                     serverData[slab[0]][slab[1]] = item[2]
         return data
 
+    def quit_all(self):
+        '''Send a "quit" command to all servers and wait for the connection to close.'''
+        for s in self.servers:
+            s.quit()
+
     def get_slabs(self):
         data = []
         for s in self.servers:
@@ -1475,6 +1480,23 @@ def recv(self, rlen):
         self.buffer = buf[rlen:]
         return buf[:rlen]
 
+    def quit(self):
+        '''Send a "quit" command to remote server and wait for connection to close.'''
+        if self.socket:
+            # Using self.send_cmd, so no need for '\r\n'.
+            self.send_cmd('quit')
+
+            # We can't close the local socket until the remote end processes the quit
+            # command and sends us a FIN packet.  When that happens, socket.recv()
+            # will stop blocking and return an empty string.  If we try to close the
+            # socket before then, the OS will think we're initiating the connection
+            # close and will put the socket into TIME_WAIT.
+            self.socket.recv(1)
+
+            # At this point, socket should be in CLOSE_WAIT.  Closing the socket should
+            # release the port back to the OS.
+            self.close_socket()
+
     def flush(self):
         self.send_cmd('flush_all')
         self.expect(b'OK')