diff -r a6d8bf62a61d src/simulator/wscript
--- a/src/simulator/wscript	Sat Sep 06 14:46:01 2008 +0100
+++ b/src/simulator/wscript	Sat Sep 06 15:43:22 2008 +0100
@@ -42,6 +42,14 @@
     e.define = 'HAVE_SYS_INT_TYPES_H'
     e.run()
 
+    e = conf.create_header_configurator()
+    e.mandatory = False
+    e.name = 'sched.h'
+    conf.env['ENABLE_REAL_TIME_SIMULATOR'] = bool(e.run())
+    conf.report_optional_feature("RealTimeSimulator", "Real Time Simulator",
+                                 conf.env['ENABLE_REAL_TIME_SIMULATOR'],
+                                 "include <sched.h> not available")
+
     conf.write_config_header('ns3/simulator-config.h')
 
 
@@ -59,11 +67,9 @@
         'event-impl.cc',
         'simulator.cc',
         'default-simulator-impl.cc',
-        'realtime-simulator-impl.cc',
         'timer.cc',
         'watchdog.cc',
         'synchronizer.cc',
-        'wall-clock-synchronizer.cc',
         ]
 
     headers = bld.create_obj('ns3header')
@@ -76,7 +82,6 @@
         'simulator.h',
         'simulator-impl.h',
         'default-simulator-impl.h',
-        'realtime-simulator-impl.h',
         'scheduler.h',
         'list-scheduler.h',
         'map-scheduler.h',
@@ -86,7 +91,6 @@
         'timer-impl.h',
         'watchdog.h',
         'synchronizer.h',
-        'wall-clock-synchronizer.h',
         ]
 
     env = bld.env_of_name('default')
@@ -107,3 +111,13 @@
             'cairo-wideint-private.h',
             ])
 
+    if env['ENABLE_REAL_TIME_SIMULATOR']:
+        sim.source.extend([
+                'realtime-simulator-impl.cc',
+                'wall-clock-synchronizer.cc',
+                ])
+        headers.source.extend([
+                'wall-clock-synchronizer.h',
+                'realtime-simulator-impl.h',
+                ])
+