Allow loading the NS3 library manually (nef needs it to avoid threading issues)

diff --git a/src/nepi/testbeds/ns3/execute.py b/src/nepi/testbeds/ns3/execute.py
index d031090..e21f8ba 100644 (file)
--- a/src/nepi/testbeds/ns3/execute.py
+++ b/src/nepi/testbeds/ns3/execute.py
@@ -13,6 +13,42 @@ import random
 import socket
 import weakref
 
+def init():
+        if 'ns3' in sys.modules:
+            return
+
+        import ctypes
+        import imp
+
+       bindings = os.environ["NEPI_NS3BINDINGS"] \
+               if "NEPI_NS3BINDINGS" in os.environ else None
+       libfile = os.environ["NEPI_NS3LIBRARY"] \
+               if "NEPI_NS3LIBRARY" in os.environ else None
+
+       if libfile:
+           ctypes.CDLL(libfile, ctypes.RTLD_GLOBAL)
+
+       path = [ os.path.dirname(__file__) ] + sys.path
+       if bindings:
+           path = [ bindings ] + path
+
+       try:
+           module = imp.find_module ('ns3', path)
+           mod = imp.load_module ('ns3', *module)
+       except ImportError:
+           # In some environments, ns3 per-se does not exist,
+           # only the low-level _ns3
+           module = imp.find_module ('_ns3', path)
+           mod = imp.load_module ('_ns3', *module)
+           sys.modules["ns3"] = mod # install it as ns3 too
+           
+           # When using _ns3, we have to make sure we destroy
+           # the simulator when the process finishes
+           import atexit
+           atexit.register(mod.Simulator.Destroy)
+
+ 
+
 class TestbedController(testbed_impl.TestbedController):
     from nepi.util.tunchannel_impl import TunChannel
     
@@ -244,41 +280,15 @@ class TestbedController(testbed_impl.TestbedController):
         return ns3_value
 
     def _load_ns3_module(self):
-        import ctypes
-        import imp
-
         simu_impl_type = self._attributes.get_attribute_value(
                 "SimulatorImplementationType")
         checksum = self._attributes.get_attribute_value("ChecksumEnabled")
         stop_time = self._attributes.get_attribute_value("StopTime")
 
-        bindings = os.environ["NEPI_NS3BINDINGS"] \
-                if "NEPI_NS3BINDINGS" in os.environ else None
-        libfile = os.environ["NEPI_NS3LIBRARY"] \
-                if "NEPI_NS3LIBRARY" in os.environ else None
-
-        if libfile:
-            ctypes.CDLL(libfile, ctypes.RTLD_GLOBAL)
-
-        path = [ os.path.dirname(__file__) ] + sys.path
-        if bindings:
-            path = [ bindings ] + path
-
-        try:
-            module = imp.find_module ('ns3', path)
-            mod = imp.load_module ('ns3', *module)
-        except ImportError:
-            # In some environments, ns3 per-se does not exist,
-            # only the low-level _ns3
-            module = imp.find_module ('_ns3', path)
-            mod = imp.load_module ('_ns3', *module)
-            sys.modules["ns3"] = mod # install it as ns3 too
-            
-            # When using _ns3, we have to make sure we destroy
-            # the simulator when the process finishes
-            import atexit
-            atexit.register(mod.Simulator.Destroy)
-    
+        init()
+
+        import ns3 as mod
+ 
         if simu_impl_type:
             value = mod.StringValue(simu_impl_type)
             mod.GlobalValue.Bind ("SimulatorImplementationType", value)