process-cpp 3.0.0
A simple convenience library for handling processes in C++11.
oom_adj.cpp
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1/*
2 * Copyright © 2013 Canonical Ltd.
3 *
4 * This program is free software: you can redistribute it and/or modify it
5 * under the terms of the GNU Lesser General Public License version 3,
6 * as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU Lesser General Public License for more details.
12 *
13 * You should have received a copy of the GNU Lesser General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
15 *
16 * Authored by: Thomas Voß <thomas.voss@canonical.com>
17 */
18
20
21#include <core/posix/process.h>
22
23#include <fstream>
24#include <sstream>
25#include <stdexcept>
26
27#include <linux/oom.h>
28
29namespace core
30{
31namespace posix
32{
33namespace linux
34{
35namespace proc
36{
37namespace process
38{
39
41{
42 return OOM_DISABLE;
43}
44
46{
47 return OOM_ADJUST_MIN;
48}
49
51{
52 return OOM_ADJUST_MAX;
53}
54
55const posix::Process& operator>>(const posix::Process& process, OomAdj& adj)
56{
57 std::stringstream ss; ss << "/proc/" << process.pid() << "/oom_adj";
58 std::ifstream in(ss.str());
59
60 in >> adj.value;
61
62 return process;
63}
64
65const posix::Process& operator<<(const posix::Process& process, const OomAdj& adj)
66{
67 if (!adj.is_valid())
68 throw std::logic_error("Value for adjusting the oom score is invalid.");
69
70 std::stringstream ss; ss << "/proc/" << process.pid() << "/oom_adj";
71 std::ofstream out(ss.str());
72
73 out << adj.value;
74
75 return process;
76}
77}
78}
79}
80}
81}
The Process class models a process and possible operations on it.
Definition process.h:45
virtual pid_t pid() const
Query the pid of the process.
Definition process.cpp:59
CORE_POSIX_DLL_PUBLIC const posix::Process & operator>>(const posix::Process &process, OomAdj &adj)
Read the OomAdj value for a process instance.
Definition oom_adj.cpp:55
CORE_POSIX_DLL_PUBLIC const posix::Process & operator<<(const posix::Process &process, const OomAdj &adj)
Write the OomAdj value for a process instance.
Definition oom_adj.cpp:65
bool is_valid() const
is_valid checks whether the contained value is within the predefined bounds.
Definition oom_adj.h:74
static int max_value()
Returns the maximum valid value.
Definition oom_adj.cpp:50
static int disable_value()
Returns the value that makes a process "invisible" to the oom killer.
Definition oom_adj.cpp:40
static int min_value()
Returns the minimum valid value.
Definition oom_adj.cpp:45