simobject.py

来自「M5,一个功能强大的多处理器系统模拟器.很多针对处理器架构,性能的研究都使用它作」· Python 代码 · 共 911 行 · 第 1/3 页

# Copyright (c) 2004, 2005, 2006
# The Regents of The University of Michigan
# All Rights Reserved
#
# This code is part of the M5 simulator.
#
# Permission is granted to use, copy, create derivative works and
# redistribute this software and such derivative works for any
# purpose, so long as the copyright notice above, this grant of
# permission, and the disclaimer below appear in all copies made; and
# so long as the name of The University of Michigan is not used in any
# advertising or publicity pertaining to the use or distribution of
# this software without specific, written prior authorization.
#
# THIS SOFTWARE IS PROVIDED AS IS, WITHOUT REPRESENTATION FROM THE
# UNIVERSITY OF MICHIGAN AS TO ITS FITNESS FOR ANY PURPOSE, AND
# WITHOUT WARRANTY BY THE UNIVERSITY OF MICHIGAN OF ANY KIND, EITHER
# EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE. THE REGENTS OF THE UNIVERSITY OF MICHIGAN SHALL NOT BE
# LIABLE FOR ANY DAMAGES, INCLUDING DIRECT, SPECIAL, INDIRECT,
# INCIDENTAL, OR CONSEQUENTIAL DAMAGES, WITH RESPECT TO ANY CLAIM
# ARISING OUT OF OR IN CONNECTION WITH THE USE OF THE SOFTWARE, EVEN
# IF IT HAS BEEN OR IS HEREAFTER ADVISED OF THE POSSIBILITY OF SUCH
# DAMAGES.
#
# Authors: Steven K. Reinhardt
#          Nathan L. Binkert

import sys, types

import proxy
import m5
from util import *
from multidict import multidict

# These utility functions have to come first because they're
# referenced in params.py... otherwise they won't be defined when we
# import params below, and the recursive import of this file from
# params.py will not find these names.
def isSimObject(value):
    return isinstance(value, SimObject)

def isSimObjectClass(value):
    return issubclass(value, SimObject)

def isSimObjectSequence(value):
    if not isinstance(value, (list, tuple)) or len(value) == 0:
        return False

    for val in value:
        if not isNullPointer(val) and not isSimObject(val):
            return False

    return True

def isSimObjectOrSequence(value):
    return isSimObject(value) or isSimObjectSequence(value)

# Have to import params up top since Param is referenced on initial
# load (when SimObject class references Param to create a class
# variable, the 'name' param)...
from params import *
# There are a few things we need that aren't in params.__all__ since
# normal users don't need them
from params import ParamDesc, VectorParamDesc, isNullPointer, SimObjVector

noDot = False
try:
    import pydot
except:
    noDot = True

#####################################################################
#
# M5 Python Configuration Utility
#
# The basic idea is to write simple Python programs that build Python
# objects corresponding to M5 SimObjects for the desired simulation
# configuration.  For now, the Python emits a .ini file that can be
# parsed by M5.  In the future, some tighter integration between M5
# and the Python interpreter may allow bypassing the .ini file.
#
# Each SimObject class in M5 is represented by a Python class with the
# same name.  The Python inheritance tree mirrors the M5 C++ tree
# (e.g., SimpleCPU derives from BaseCPU in both cases, and all
# SimObjects inherit from a single SimObject base class).  To specify
# an instance of an M5 SimObject in a configuration, the user simply
# instantiates the corresponding Python object.  The parameters for
# that SimObject are given by assigning to attributes of the Python
# object, either using keyword assignment in the constructor or in
# separate assignment statements.  For example:
#
# cache = BaseCache(size='64KB')
# cache.hit_latency = 3
# cache.assoc = 8
#
# The magic lies in the mapping of the Python attributes for SimObject
# classes to the actual SimObject parameter specifications.  This
# allows parameter validity checking in the Python code.  Continuing
# the example above, the statements "cache.blurfl=3" or
# "cache.assoc='hello'" would both result in runtime errors in Python,
# since the BaseCache object has no 'blurfl' parameter and the 'assoc'
# parameter requires an integer, respectively.  This magic is done
# primarily by overriding the special __setattr__ method that controls
# assignment to object attributes.
#
# Once a set of Python objects have been instantiated in a hierarchy,
# calling 'instantiate(obj)' (where obj is the root of the hierarchy)
# will generate a .ini file.
#
#####################################################################

# list of all SimObject classes
allClasses = {}

# dict to look up SimObjects based on path
instanceDict = {}

# The metaclass for SimObject.  This class controls how new classes
# that derive from SimObject are instantiated, and provides inherited
# class behavior (just like a class controls how instances of that
# class are instantiated, and provides inherited instance behavior).
class MetaSimObject(type):
    # Attributes that can be set only at initialization time
    init_keywords = { 'abstract' : types.BooleanType,
                      'cxx_namespace' : types.StringType,
                      'cxx_class' : types.StringType,
                      'cxx_type' : types.StringType,
                      'cxx_predecls' : types.ListType,
                      'swig_objdecls' : types.ListType,
                      'swig_predecls' : types.ListType,
                      'type' : types.StringType }
    # Attributes that can be set any time
    keywords = { 'check' : types.FunctionType }

    # __new__ is called before __init__, and is where the statements
    # in the body of the class definition get loaded into the class's
    # __dict__.  We intercept this to filter out parameter & port assignments
    # and only allow "private" attributes to be passed to the base
    # __new__ (starting with underscore).
    def __new__(mcls, name, bases, dict):
        assert name not in allClasses

        # Copy "private" attributes, functions, and classes to the
        # official dict.  Everything else goes in _init_dict to be
        # filtered in __init__.
        cls_dict = {}
        value_dict = {}
        for key,val in dict.items():
            if key.startswith('_') or isinstance(val, (types.FunctionType,
                                                       types.TypeType)):
                cls_dict[key] = val
            else:
                # must be a param/port setting
                value_dict[key] = val
        if 'abstract' not in value_dict:
            value_dict['abstract'] = False
        cls_dict['_value_dict'] = value_dict
        cls = super(MetaSimObject, mcls).__new__(mcls, name, bases, cls_dict)
        if 'type' in value_dict:
            allClasses[name] = cls
        return cls

    # subclass initialization
    def __init__(cls, name, bases, dict):
        # calls type.__init__()... I think that's a no-op, but leave
        # it here just in case it's not.
        super(MetaSimObject, cls).__init__(name, bases, dict)

        # initialize required attributes

        # class-only attributes
        cls._params = multidict() # param descriptions
        cls._ports = multidict()  # port descriptions

        # class or instance attributes
        cls._values = multidict()   # param values
        cls._port_refs = multidict() # port ref objects
        cls._instantiated = False # really instantiated, cloned, or subclassed

        # We don't support multiple inheritance.  If you want to, you
        # must fix multidict to deal with it properly.
        if len(bases) > 1:
            raise TypeError, "SimObjects do not support multiple inheritance"

        base = bases[0]

        # Set up general inheritance via multidicts.  A subclass will
        # inherit all its settings from the base class.  The only time
        # the following is not true is when we define the SimObject
        # class itself (in which case the multidicts have no parent).
        if isinstance(base, MetaSimObject):
            cls._params.parent = base._params
            cls._ports.parent = base._ports
            cls._values.parent = base._values
            cls._port_refs.parent = base._port_refs
            # mark base as having been subclassed
            base._instantiated = True

        # default keyword values
        if 'type' in cls._value_dict:
            _type = cls._value_dict['type']
            if 'cxx_class' not in cls._value_dict:
                cls._value_dict['cxx_class'] = _type

            namespace = cls._value_dict.get('cxx_namespace', None)

            _cxx_class = cls._value_dict['cxx_class']
            if 'cxx_type' not in cls._value_dict:
                t = _cxx_class + '*'
                if namespace:
                    t = '%s::%s' % (namespace, t)
                cls._value_dict['cxx_type'] = t
            if 'cxx_predecls' not in cls._value_dict:
                # A forward class declaration is sufficient since we are
                # just declaring a pointer.
                decl = 'class %s;' % _cxx_class
                if namespace:
                    decl = 'namespace %s { %s }' % (namespace, decl)
                cls._value_dict['cxx_predecls'] = [decl]

            if 'swig_predecls' not in cls._value_dict:
                # A forward class declaration is sufficient since we are
                # just declaring a pointer.
                cls._value_dict['swig_predecls'] = \
                    cls._value_dict['cxx_predecls']

        if 'swig_objdecls' not in cls._value_dict:
            cls._value_dict['swig_objdecls'] = []

        # Now process the _value_dict items.  They could be defining
        # new (or overriding existing) parameters or ports, setting
        # class keywords (e.g., 'abstract'), or setting parameter
        # values or port bindings.  The first 3 can only be set when
        # the class is defined, so we handle them here.  The others
        # can be set later too, so just emulate that by calling
        # setattr().
        for key,val in cls._value_dict.items():
            # param descriptions
            if isinstance(val, ParamDesc):
                cls._new_param(key, val)

            # port objects
            elif isinstance(val, Port):
                cls._new_port(key, val)

            # init-time-only keywords
            elif cls.init_keywords.has_key(key):
                cls._set_keyword(key, val, cls.init_keywords[key])

            # default: use normal path (ends up in __setattr__)
            else:
                setattr(cls, key, val)

    def _set_keyword(cls, keyword, val, kwtype):
        if not isinstance(val, kwtype):
            raise TypeError, 'keyword %s has bad type %s (expecting %s)' % \
                  (keyword, type(val), kwtype)
        if isinstance(val, types.FunctionType):
            val = classmethod(val)
        type.__setattr__(cls, keyword, val)

    def _new_param(cls, name, pdesc):
        # each param desc should be uniquely assigned to one variable
        assert(not hasattr(pdesc, 'name'))
        pdesc.name = name
        cls._params[name] = pdesc
        if hasattr(pdesc, 'default'):
            cls._set_param(name, pdesc.default, pdesc)

    def _set_param(cls, name, value, param):
        assert(param.name == name)
        try:
            cls._values[name] = param.convert(value)
        except Exception, e:
            msg = "%s\nError setting param %s.%s to %s\n" % \
                  (e, cls.__name__, name, value)
            e.args = (msg, )
            raise

    def _new_port(cls, name, port):
        # each port should be uniquely assigned to one variable
        assert(not hasattr(port, 'name'))
        port.name = name
        cls._ports[name] = port
        if hasattr(port, 'default'):
            cls._cls_get_port_ref(name).connect(port.default)

    # same as _get_port_ref, effectively, but for classes
    def _cls_get_port_ref(cls, attr):
        # Return reference that can be assigned to another port
        # via __setattr__.  There is only ever one reference
        # object per port, but we create them lazily here.
        ref = cls._port_refs.get(attr)
        if not ref:
            ref = cls._ports[attr].makeRef(cls)
            cls._port_refs[attr] = ref
        return ref

    # Set attribute (called on foo.attr = value when foo is an
    # instance of class cls).
    def __setattr__(cls, attr, value):
        # normal processing for private attributes