scripts/tracetool/vcpu.py

   1 # -*- coding: utf-8 -*-
   2
   3 """
   4 Generic management for the 'vcpu' property.
   5
   6 """
   7
   8 __author__     = "Lluís Vilanova <vilanova@ac.upc.edu>"
   9 __copyright__  = "Copyright 2016, Lluís Vilanova <vilanova@ac.upc.edu>"
  10 __license__    = "GPL version 2 or (at your option) any later version"
  11
  12 __maintainer__ = "Stefan Hajnoczi"
  13 __email__      = "stefanha@redhat.com"
  14
  15
  16 from tracetool import Arguments, try_import
  17
  18
  19 def transform_event(event):
  20     """Transform event to comply with the 'vcpu' property (if present)."""
  21     if "vcpu" in event.properties:
  22         event.args = Arguments([("void *", "__cpu"), event.args])
  23         fmt = "\"cpu=%p \""
  24         event.fmt = fmt + event.fmt
  25     return event
  26
  27
  28 def transform_args(format, event, *args, **kwargs):
  29     """Transforms the arguments to suit the specified format.
  30
  31     The format module must implement function 'vcpu_args', which receives the
  32     implicit arguments added by the 'vcpu' property, and must return suitable
  33     arguments for the given format.
  34
  35     The function is only called for events with the 'vcpu' property.
  36
  37     Parameters
  38     ==========
  39     format : str
  40         Format module name.
  41     event : Event
  42     args, kwargs
  43         Passed to 'vcpu_transform_args'.
  44
  45     Returns
  46     =======
  47     Arguments
  48         The transformed arguments, including the non-implicit ones.
  49
  50     """
  51     if "vcpu" in event.properties:
  52         ok, func = try_import("tracetool.format." + format,
  53                               "vcpu_transform_args")
  54         assert ok
  55         assert func
  56         return Arguments([func(event.args[:1], *args, **kwargs),
  57                           event.args[1:]])
  58     else:
  59         return event.args