sim: simulate with multiple threads and event queues

This patch adds support for simulating with multiple threads, each of
which operates on an event queue.  Each sim object specifies which eventq
is would like to be on.  A custom barrier implementation is being added
using which eventqs synchronize.

The patch was tested in two different configurations:
1. ruby_network_test.py: in this simulation L1 cache controllers receive
   requests from the cpu. The requests are replied to immediately without
   any communication taking place with any other level.
2. twosys-tsunami-simple-atomic: this configuration simulates a client-server
   system which are connected by an ethernet link.

We still lack the ability to communicate using message buffers or ports. But
other things like simulation start and end, synchronizing after every quantum
are working.

Committed by: Nilay Vaish

1 files changed, 9 insertions, 3 deletions

diff --git a/src/python/swig/event.i b/src/python/swig/event.i
index 788ea7cfa..23bb31364 100644
--- a/src/python/swig/event.i
+++ b/src/python/swig/event.i
@@ -1,5 +1,7 @@
 /*
  * Copyright (c) 2006 The Regents of The University of Michigan
+ * Copyright (c) 2013 Advanced Micro Devices, Inc.
+ * Copyright (c) 2013 Mark D. Hill and David A. Wood
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -82,12 +84,13 @@
 %include "python/swig/pyevent.hh"
 
 // minimal definition of SimExitEvent interface to wrap
-class SimLoopExitEvent : public Event
+class GlobalSimLoopExitEvent
 {
   public:
     std::string getCause();
     int getCode();
-    SimLoopExitEvent(const std::string &_cause, int c, Tick _repeat = 0);
+    GlobalSimLoopExitEvent(Tick when, const std::string &_cause, int c,
+                           Tick _repeat = 0);
 };
 
 %exception simulate {
@@ -96,5 +99,8 @@ class SimLoopExitEvent : public Event
         return NULL;
     }
 }
-SimLoopExitEvent *simulate(Tick num_cycles = MaxTick);
+
+GlobalSimLoopExitEvent *simulate(Tick num_cycles = MaxTick);
 void exitSimLoop(const std::string &message, int exit_code);
+void curEventQueue( EventQueue *);
+EventQueue *getEventQueue(uint32_t index);