pass code check

INSTALL

@@ -2,7 +2,7 @@
 Mininet Installation/Configuration Notes
 ----------------------------------------
 
-Mininet 2.3.0d3
+Mininet 2.3.0d4
 ---
 
 The supported installation methods for Mininet are 1) using a

LICENSE

@@ -1,4 +1,4 @@
-Mininet 2.3.0d3 License
+Mininet 2.3.0d4 License
 
 Copyright (c) 2013-2018 Open Networking Laboratory
 Copyright (c) 2009-2012 Bob Lantz and The Board of Trustees of

README.md

@@ -2,7 +2,7 @@ Mininet: Rapid Prototyping for Software Defined Networks
 ========================================================
 *The best way to emulate almost any network on your laptop!*
 
-Mininet 2.3.0d3
+Mininet 2.3.0d4
 
 [![Build Status][1]](https://travis-ci.org/mininet/mininet)
 

mininet/net.py

@@ -108,7 +108,7 @@ from mininet.util import ( quietRun, fixLimits, numCores, ensureRoot,
 from mininet.term import cleanUpScreens, makeTerms
 
 # Mininet version: should be consistent with README and LICENSE
-VERSION = "2.3.0d3"
+VERSION = "2.3.0d4"
 
 class Mininet( object ):
     "Network emulation with hosts spawned in network namespaces."

mininet/node.py

@@ -107,6 +107,7 @@ class Node( object ):
         self.readbuf = ''
 
         # Start command interpreter shell
+        self.master, self.slave = None, None  # pylint
         self.startShell()
         self.mountPrivateDirs()
 
@@ -145,12 +146,12 @@ class Node( object ):
         # Spawn a shell subprocess in a pseudo-tty, to disable buffering
         # in the subprocess and insulate it from signals (e.g. SIGINT)
         # received by the parent
-        master, slave = pty.openpty()
-        self.shell = self._popen( cmd, stdin=slave, stdout=slave, stderr=slave,
-                                  close_fds=False )
+        self.master, self.slave = pty.openpty()
+        self.shell = self._popen( cmd, stdin=self.slave, stdout=self.slave,
+                                  stderr=self.slave, close_fds=False )
         # XXX BL: This doesn't seem right, and we should also probably
         # close our files when we exit...
-        self.stdin = os.fdopen( master, 'r' )
+        self.stdin = os.fdopen( self.master, 'r' )
         self.stdout = self.stdin
         self.pid = self.shell.pid
         self.pollOut = select.poll()
@@ -217,9 +218,13 @@ class Node( object ):
         # for intfName in self.intfNames():
         # if self.name in intfName:
         # quietRun( 'ip link del ' + intfName )
-        if self.waitExited and self.shell:
-            debug( 'waiting for', self.pid, 'to terminate\n' )
-            self.shell.wait()
+        if self.shell:
+            # Close ptys
+            self.stdin.close()
+            os.close(self.slave)
+            if self.waitExited:
+                debug( 'waiting for', self.pid, 'to terminate\n' )
+                self.shell.wait()
         self.shell = None
 
     # Subshell I/O, commands and control