root / lib / utils / mlock.py @ 2dbc6857
History | View | Annotate | Download (2.3 kB)
1 | 36a4acd4 | Michael Hanselmann | #
|
---|---|---|---|
2 | 36a4acd4 | Michael Hanselmann | #
|
3 | 36a4acd4 | Michael Hanselmann | |
4 | 36a4acd4 | Michael Hanselmann | # Copyright (C) 2009, 2010, 2011 Google Inc.
|
5 | 36a4acd4 | Michael Hanselmann | #
|
6 | 36a4acd4 | Michael Hanselmann | # This program is free software; you can redistribute it and/or modify
|
7 | 36a4acd4 | Michael Hanselmann | # it under the terms of the GNU General Public License as published by
|
8 | 36a4acd4 | Michael Hanselmann | # the Free Software Foundation; either version 2 of the License, or
|
9 | 36a4acd4 | Michael Hanselmann | # (at your option) any later version.
|
10 | 36a4acd4 | Michael Hanselmann | #
|
11 | 36a4acd4 | Michael Hanselmann | # This program is distributed in the hope that it will be useful, but
|
12 | 36a4acd4 | Michael Hanselmann | # WITHOUT ANY WARRANTY; without even the implied warranty of
|
13 | 36a4acd4 | Michael Hanselmann | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
14 | 36a4acd4 | Michael Hanselmann | # General Public License for more details.
|
15 | 36a4acd4 | Michael Hanselmann | #
|
16 | 36a4acd4 | Michael Hanselmann | # You should have received a copy of the GNU General Public License
|
17 | 36a4acd4 | Michael Hanselmann | # along with this program; if not, write to the Free Software
|
18 | 36a4acd4 | Michael Hanselmann | # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
19 | 36a4acd4 | Michael Hanselmann | # 02110-1301, USA.
|
20 | 36a4acd4 | Michael Hanselmann | |
21 | 36a4acd4 | Michael Hanselmann | """Wrapper around mlockall(2).
|
22 | 36a4acd4 | Michael Hanselmann |
|
23 | 36a4acd4 | Michael Hanselmann | """
|
24 | 36a4acd4 | Michael Hanselmann | |
25 | 36a4acd4 | Michael Hanselmann | import os |
26 | 36a4acd4 | Michael Hanselmann | import logging |
27 | 36a4acd4 | Michael Hanselmann | |
28 | 36a4acd4 | Michael Hanselmann | from ganeti import errors |
29 | 36a4acd4 | Michael Hanselmann | |
30 | 36a4acd4 | Michael Hanselmann | try:
|
31 | b459a848 | Andrea Spadaccini | # pylint: disable=F0401
|
32 | 36a4acd4 | Michael Hanselmann | import ctypes |
33 | 36a4acd4 | Michael Hanselmann | except ImportError: |
34 | 36a4acd4 | Michael Hanselmann | ctypes = None
|
35 | 36a4acd4 | Michael Hanselmann | |
36 | 36a4acd4 | Michael Hanselmann | |
37 | 36a4acd4 | Michael Hanselmann | # Flags for mlockall() (from bits/mman.h)
|
38 | 36a4acd4 | Michael Hanselmann | _MCL_CURRENT = 1
|
39 | 36a4acd4 | Michael Hanselmann | _MCL_FUTURE = 2
|
40 | 36a4acd4 | Michael Hanselmann | |
41 | 36a4acd4 | Michael Hanselmann | |
42 | 36a4acd4 | Michael Hanselmann | def Mlockall(_ctypes=ctypes): |
43 | 36a4acd4 | Michael Hanselmann | """Lock current process' virtual address space into RAM.
|
44 | 36a4acd4 | Michael Hanselmann |
|
45 | 36a4acd4 | Michael Hanselmann | This is equivalent to the C call mlockall(MCL_CURRENT|MCL_FUTURE),
|
46 | 36a4acd4 | Michael Hanselmann | see mlock(2) for more details. This function requires ctypes module.
|
47 | 36a4acd4 | Michael Hanselmann |
|
48 | 36a4acd4 | Michael Hanselmann | @raises errors.NoCtypesError: if ctypes module is not found
|
49 | 36a4acd4 | Michael Hanselmann |
|
50 | 36a4acd4 | Michael Hanselmann | """
|
51 | 36a4acd4 | Michael Hanselmann | if _ctypes is None: |
52 | 36a4acd4 | Michael Hanselmann | raise errors.NoCtypesError()
|
53 | 36a4acd4 | Michael Hanselmann | |
54 | adc523ab | Iustin Pop | try:
|
55 | adc523ab | Iustin Pop | libc = _ctypes.cdll.LoadLibrary("libc.so.6")
|
56 | adc523ab | Iustin Pop | except EnvironmentError, err: |
57 | adc523ab | Iustin Pop | logging.error("Failure trying to load libc: %s", err)
|
58 | adc523ab | Iustin Pop | libc = None
|
59 | 36a4acd4 | Michael Hanselmann | if libc is None: |
60 | 36a4acd4 | Michael Hanselmann | logging.error("Cannot set memory lock, ctypes cannot load libc")
|
61 | 36a4acd4 | Michael Hanselmann | return
|
62 | 36a4acd4 | Michael Hanselmann | |
63 | 36a4acd4 | Michael Hanselmann | # Some older version of the ctypes module don't have built-in functionality
|
64 | 36a4acd4 | Michael Hanselmann | # to access the errno global variable, where function error codes are stored.
|
65 | 36a4acd4 | Michael Hanselmann | # By declaring this variable as a pointer to an integer we can then access
|
66 | 36a4acd4 | Michael Hanselmann | # its value correctly, should the mlockall call fail, in order to see what
|
67 | 36a4acd4 | Michael Hanselmann | # the actual error code was.
|
68 | b459a848 | Andrea Spadaccini | # pylint: disable=W0212
|
69 | 36a4acd4 | Michael Hanselmann | libc.__errno_location.restype = _ctypes.POINTER(_ctypes.c_int) |
70 | 36a4acd4 | Michael Hanselmann | |
71 | 36a4acd4 | Michael Hanselmann | if libc.mlockall(_MCL_CURRENT | _MCL_FUTURE):
|
72 | b459a848 | Andrea Spadaccini | # pylint: disable=W0212
|
73 | 36a4acd4 | Michael Hanselmann | logging.error("Cannot set memory lock: %s",
|
74 | 36a4acd4 | Michael Hanselmann | os.strerror(libc.__errno_location().contents.value)) |
75 | 36a4acd4 | Michael Hanselmann | return
|
76 | 36a4acd4 | Michael Hanselmann | |
77 | 36a4acd4 | Michael Hanselmann | logging.debug("Memory lock set") |