src/sim/Root.py

   1 # Copyright (c) 2005-2007 The Regents of The University of Michigan
   2 # Copyright (c) 2010 Advanced Micro Devices, Inc.
   3 # All rights reserved.
   4 #
   5 # Redistribution and use in source and binary forms, with or without
   6 # modification, are permitted provided that the following conditions are
   7 # met: redistributions of source code must retain the above copyright
   8 # notice, this list of conditions and the following disclaimer;
   9 # redistributions in binary form must reproduce the above copyright
  10 # notice, this list of conditions and the following disclaimer in the
  11 # documentation and/or other materials provided with the distribution;
  12 # neither the name of the copyright holders nor the names of its
  13 # contributors may be used to endorse or promote products derived from
  14 # this software without specific prior written permission.
  15 #
  16 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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  19 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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  26 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27 #
  28 # Authors: Nathan Binkert
  29
  30 from m5.SimObject import SimObject
  31 from m5.params import *
  32 from m5.util import fatal
  33
  34 class Root(SimObject):
  35
  36     _the_instance = None
  37
  38     def __new__(cls, **kwargs):
  39         if Root._the_instance:
  40             fatal("Attempt to allocate multiple instances of Root.")
  41             return None
  42
  43         # first call: allocate the unique instance
  44         #
  45         # If SimObject ever implements __new__, we may want to pass
  46         # kwargs here, but for now this goes straight to
  47         # object.__new__ which prints an ugly warning if you pass it
  48         # args.  Seems like a bad design but that's the way it is.
  49         Root._the_instance = SimObject.__new__(cls)
  50         return Root._the_instance
  51
  52     @classmethod
  53     def getInstance(cls):
  54         return Root._the_instance
  55
  56     def path(self):
  57         return 'root'
  58
  59     type = 'Root'
  60
  61     # Time syncing prevents the simulation from running faster than real time.
  62     time_sync_enable = Param.Bool(False, "whether time syncing is enabled")
  63     time_sync_period = Param.Clock("100ms", "how often to sync with real time")
  64     time_sync_spin_threshold = \
  65             Param.Clock("100us", "when less than this much time is left, spin")