src/python/m5/util.py

   1 # Copyright (c) 2004-2006 The Regents of The University of Michigan
   2 # All rights reserved.
   3 #
   4 # Redistribution and use in source and binary forms, with or without
   5 # modification, are permitted provided that the following conditions are
   6 # met: redistributions of source code must retain the above copyright
   7 # notice, this list of conditions and the following disclaimer;
   8 # redistributions in binary form must reproduce the above copyright
   9 # notice, this list of conditions and the following disclaimer in the
  10 # documentation and/or other materials provided with the distribution;
  11 # neither the name of the copyright holders nor the names of its
  12 # contributors may be used to endorse or promote products derived from
  13 # this software without specific prior written permission.
  14 #
  15 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  16 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  17 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  18 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  19 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  20 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  21 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  25 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26 #
  27 # Authors: Steve Reinhardt
  28 #          Nathan Binkert
  29
  30 #############################
  31 #
  32 # Utility classes & methods
  33 #
  34 #############################
  35
  36 class Singleton(type):
  37     def __call__(cls, *args, **kwargs):
  38         if hasattr(cls, '_instance'):
  39             return cls._instance
  40
  41         cls._instance = super(Singleton, cls).__call__(*args, **kwargs)
  42         return cls._instance
  43
  44 # Apply method to object.
  45 # applyMethod(obj, 'meth', <args>) is equivalent to obj.meth(<args>)
  46 def applyMethod(obj, meth, *args, **kwargs):
  47     return getattr(obj, meth)(*args, **kwargs)
  48
  49 # If the first argument is an (non-sequence) object, apply the named
  50 # method with the given arguments.  If the first argument is a
  51 # sequence, apply the method to each element of the sequence (a la
  52 # 'map').
  53 def applyOrMap(objOrSeq, meth, *args, **kwargs):
  54     if not isinstance(objOrSeq, (list, tuple)):
  55         return applyMethod(objOrSeq, meth, *args, **kwargs)
  56     else:
  57         return [applyMethod(o, meth, *args, **kwargs) for o in objOrSeq]
  58
  59