src/python/m5/ticks.py

   1 # Copyright (c) 2007 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 from __future__ import print_function
  28 import decimal
  29 import six
  30 if six.PY3:
  31     long = int
  32
  33 import sys
  34 from m5.util import warn
  35
  36 # fix the global frequency
  37 def fixGlobalFrequency():
  38     import _m5.core
  39     _m5.core.fixClockFrequency()
  40
  41 def setGlobalFrequency(ticksPerSecond):
  42     from m5.util import convert
  43     import _m5.core
  44
  45     if isinstance(ticksPerSecond, (int, long)):
  46         tps = ticksPerSecond
  47     elif isinstance(ticksPerSecond, float):
  48         tps = ticksPerSecond
  49     elif isinstance(ticksPerSecond, str):
  50         tps = round(convert.anyToFrequency(ticksPerSecond))
  51     else:
  52         raise TypeError(
  53             "wrong type '%s' for ticksPerSecond" % type(ticksPerSecond))
  54     _m5.core.setClockFrequency(int(tps))
  55
  56 # how big does a rounding error need to be before we warn about it?
  57 frequency_tolerance = 0.001  # 0.1%
  58
  59 def fromSeconds(value):
  60     import _m5.core
  61
  62     if not isinstance(value, float):
  63         raise TypeError("can't convert '%s' to type tick" % type(value))
  64
  65     # once someone needs to convert to seconds, the global frequency
  66     # had better be fixed
  67     if not _m5.core.clockFrequencyFixed():
  68         raise AttributeError(
  69               "In order to do conversions, the global frequency must be fixed")
  70
  71     if value == 0:
  72         return 0
  73
  74     # convert the value from time to ticks
  75     value *= _m5.core.getClockFrequency()
  76
  77     int_value = int(
  78             decimal.Decimal(value).to_integral_value( decimal.ROUND_HALF_UP))
  79     err = (value - int_value) / value
  80     if err > frequency_tolerance:
  81         warn("rounding error > tolerance\n    %f rounded to %d", value,
  82             int_value)
  83     return int_value
  84
  85 __all__ = [ 'setGlobalFrequency', 'fixGlobalFrequency', 'fromSeconds',
  86             'frequency_tolerance' ]