src/sim/Root.py

   1 # Copyright (c) 2005-2007 The Regents of The University of Michigan
   2 # Copyright (c) 2010-2013 Advanced Micro Devices, Inc.
   3 # Copyright (c) 2013 Mark D. Hill and David A. Wood
   4 # All rights reserved.
   5 #
   6 # Redistribution and use in source and binary forms, with or without
   7 # modification, are permitted provided that the following conditions are
   8 # met: redistributions of source code must retain the above copyright
   9 # notice, this list of conditions and the following disclaimer;
  10 # redistributions in binary form must reproduce the above copyright
  11 # notice, this list of conditions and the following disclaimer in the
  12 # documentation and/or other materials provided with the distribution;
  13 # neither the name of the copyright holders nor the names of its
  14 # contributors may be used to endorse or promote products derived from
  15 # this software without specific prior written permission.
  16 #
  17 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  18 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  20 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  21 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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  27 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  28
  29 from m5.SimObject import SimObject
  30 from m5.params import *
  31 from m5.util import fatal
  32
  33 class Root(SimObject):
  34
  35     _the_instance = None
  36
  37     def __new__(cls, **kwargs):
  38         if Root._the_instance:
  39             fatal("Attempt to allocate multiple instances of Root.")
  40             return None
  41
  42         # first call: allocate the unique instance
  43         #
  44         # If SimObject ever implements __new__, we may want to pass
  45         # kwargs here, but for now this goes straight to
  46         # object.__new__ which prints an ugly warning if you pass it
  47         # args.  Seems like a bad design but that's the way it is.
  48         Root._the_instance = SimObject.__new__(cls)
  49         return Root._the_instance
  50
  51     @classmethod
  52     def getInstance(cls):
  53         return Root._the_instance
  54
  55     def path(self):
  56         return 'root'
  57
  58     type = 'Root'
  59     cxx_header = "sim/root.hh"
  60
  61     # By default, root sim object and hence all other sim objects schedule
  62     # event on the eventq with index 0.
  63     eventq_index = 0
  64
  65     # Simulation Quantum for multiple main event queue simulation.
  66     # Needs to be set explicitly for a multi-eventq simulation.
  67     sim_quantum = Param.Tick(0, "simulation quantum")
  68
  69     full_system = Param.Bool("if this is a full system simulation")
  70
  71     # Time syncing prevents the simulation from running faster than real time.
  72     time_sync_enable = Param.Bool(False, "whether time syncing is enabled")
  73     time_sync_period = Param.Clock("100ms", "how often to sync with real time")
  74     time_sync_spin_threshold = \
  75             Param.Clock("100us", "when less than this much time is left, spin")