Synnefo » snf-ganeti » ganeti-local

	test/ganeti.utils_mlockall_unittest.py \

try:

  import ctypes

except ImportError:

  ctypes = None

# Flags for mlockall() (from bits/mman.h)

_MCL_CURRENT = 1

_MCL_FUTURE = 2

def Mlockall():

  """Lock current process' virtual address space into RAM.

  This is equivalent to the C call mlockall(MCL_CURRENT|MCL_FUTURE),

  see mlock(2) for more details. This function requires ctypes module.

  """

  if ctypes is None:

    logging.warning("Cannot set memory lock, ctypes module not found")

    return

  libc = ctypes.cdll.LoadLibrary("libc.so.6")

  if libc is None:

    logging.error("Cannot set memory lock, ctypes cannot load libc")

    return

  # Some older version of the ctypes module don't have built-in functionality

  # to access the errno global variable, where function error codes are stored.

  # By declaring this variable as a pointer to an integer we can then access

  # its value correctly, should the mlockall call fail, in order to see what

  # the actual error code was.

  libc.__errno_location.restype = ctypes.POINTER(ctypes.c_int)

  if libc.mlockall(_MCL_CURRENT | _MCL_FUTURE):

    logging.error("Cannot set memory lock: %s" %

                  os.strerror(libc.__errno_location().contents.value))

    return

  logging.debug("Memory lock set")

#!/usr/bin/python

#

# Copyright (C) 2010 Google Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful, but

# WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

# General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA

# 02110-1301, USA.

"""Script for testing utils.Mlockall

This test is run in a separate process because it changes memory behaviour.

"""

import unittest

from ganeti import utils

import testutils

class TestResetTempfileModule(unittest.TestCase):

  def test(self):

    utils.Mlockall()

if __name__ == "__main__":

  testutils.GanetiTestProgram()