Root.py revision 11320:42ecb523c64a 
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
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9# notice, this list of conditions and the following disclaimer;
10# redistributions in binary form must reproduce the above copyright
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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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28#
29# Authors: Nathan Binkert
30
31from m5.SimObject import SimObject
32from m5.defines import buildEnv
33from m5.params import *
34from m5.util import fatal
35
36class Root(SimObject):
37
38    _the_instance = None
39
40    def __new__(cls, **kwargs):
41        if Root._the_instance:
42            fatal("Attempt to allocate multiple instances of Root.")
43            return None
44
45        # first call: allocate the unique instance
46        #
47        # If SimObject ever implements __new__, we may want to pass
48        # kwargs here, but for now this goes straight to
49        # object.__new__ which prints an ugly warning if you pass it
50        # args.  Seems like a bad design but that's the way it is.
51        Root._the_instance = SimObject.__new__(cls)
52        return Root._the_instance
53
54    @classmethod
55    def getInstance(cls):
56        return Root._the_instance
57
58    def path(self):
59        return 'root'
60
61    type = 'Root'
62    cxx_header = "sim/root.hh"
63
64    # By default, root sim object and hence all other sim objects schedule
65    # event on the eventq with index 0.
66    eventq_index = 0
67
68    # Simulation Quantum for multiple main event queue simulation.
69    # Needs to be set explicitly for a multi-eventq simulation.
70    sim_quantum = Param.Tick(0, "simulation quantum")
71
72    full_system = Param.Bool("if this is a full system simulation")
73
74    # Time syncing prevents the simulation from running faster than real time.
75    time_sync_enable = Param.Bool(False, "whether time syncing is enabled")
76    time_sync_period = Param.Clock("100ms", "how often to sync with real time")
77    time_sync_spin_threshold = \
78            Param.Clock("100us", "when less than this much time is left, spin")
79