Synchronizing access to ns-3 linux client

diff --git a/src/nepi/resources/linux/ns3/ns3client.py b/src/nepi/resources/linux/ns3/ns3client.py
index f81e449..1dd0c5a 100644 (file)
--- a/src/nepi/resources/linux/ns3/ns3client.py
+++ b/src/nepi/resources/linux/ns3/ns3client.py
@@ -24,6 +24,7 @@ import os
 import socket
 import time
 import weakref
+import threading
 
 from optparse import OptionParser, SUPPRESS_HELP
 
@@ -34,8 +35,7 @@ class LinuxNS3Client(NS3Client):
     def __init__(self, simulation):
         super(LinuxNS3Client, self).__init__()
         self._simulation = weakref.ref(simulation)
-
-        self._socat_proc = None
+        self._socket_lock = threading.Lock()
 
     @property
     def simulation(self):
@@ -50,35 +50,36 @@ class LinuxNS3Client(NS3Client):
 
         encoded = "|".join(map(encode, msg))
 
-        if self.simulation.node.get("hostname") in ['localhost', '127.0.0.1']:
-            sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-            sock.connect(self.simulation.remote_socket)
-            sock.send("%s\n" % encoded)
-            reply = sock.recv(1024)
-            sock.close()
-        else:
-            command = ( "python -c 'import socket;"
-                "sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM);"
-                "sock.connect(\"%(socket_addr)s\");"
-                "msg = \"%(encoded_message)s\\n\";"
-                "sock.send(msg);"
-                "reply = sock.recv(1024);"
-                "sock.close();"
-                "print reply'") % {
-                    "encoded_message": encoded,
-                    "socket_addr": self.simulation.remote_socket,
-                    }
-
-            (reply, err), proc = self.simulation.node.execute(command, 
-                    with_lock = True) 
-
-            if (err and proc.poll()) or reply.strip() == "":
-                msg = (" Couldn't connect to remote socket %s - REPLY: %s "
-                      "- ERROR: %s ") % (
-                        self.simulation.remote_socket, reply, err)
-                self.simulation.error(msg, reply, err)
-                raise RuntimeError(msg)
-                   
+        with self._socket_lock:
+            if self.simulation.node.get("hostname") in ['localhost', '127.0.0.1']:
+                sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
+                sock.connect(self.simulation.remote_socket)
+                sock.send("%s\n" % encoded)
+                reply = sock.recv(1024)
+                sock.close()
+            else:
+                command = ( "python -c 'import socket;"
+                    "sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM);"
+                    "sock.connect(\"%(socket_addr)s\");"
+                    "msg = \"%(encoded_message)s\\n\";"
+                    "sock.send(msg);"
+                    "reply = sock.recv(1024);"
+                    "sock.close();"
+                    "print reply'") % {
+                        "encoded_message": encoded,
+                        "socket_addr": self.simulation.remote_socket,
+                        }
+
+                (reply, err), proc = self.simulation.node.execute(command, 
+                        with_lock = True) 
+
+                if (err and proc.poll()) or reply.strip() == "":
+                    msg = (" Couldn't connect to remote socket %s - REPLY: %s "
+                          "- ERROR: %s ") % (
+                            self.simulation.remote_socket, reply, err)
+                    self.simulation.error(msg, reply, err)
+                    raise RuntimeError(msg)
+                       
         reply = cPickle.loads(base64.b64decode(reply))
 
         return reply