process-cpp: /build/process-cpp/src/process-cpp-3.0.1/src/core/posix/linux/proc/process/oom_adj.cpp Source File

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
19 #include <core/posix/linux/proc/process/oom_adj.h>
20
21 #include <core/posix/process.h>
22
23 #include <fstream>
24 #include <sstream>
25 #include <stdexcept>
26
27 #include <linux/oom.h>
28
29 namespace core
30 {
31 namespace posix
32 {
33 namespace linux
34 {
35 namespace proc
36 {
37 namespace process
38 {
39
40 int OomAdj::disable_value()
41 {
42 return OOM_DISABLE;
43 }
44
45 int OomAdj::min_value()
46 {
47 return OOM_ADJUST_MIN;
48 }
49
50 int OomAdj::max_value()
51 {
52 return OOM_ADJUST_MAX;
53 }
54
55 const 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
65 const 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 }
core::posix::linux::proc::process::operator<<
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
core::posix::linux::proc::process::OomAdj::value
int value
Current value.
Definition: oom_adj.h:82
process.h
core::posix::linux::proc::process::OomAdj
Definition: oom_adj.h:51
core::posix::linux::proc::process::OomAdj::is_valid
bool is_valid() const
is_valid checks whether the contained value is within the predefined bounds.
Definition: oom_adj.h:74
core::posix::linux::proc::process::OomAdj::disable_value
static int disable_value()
Returns the value that makes a process "invisible" to the oom killer.
Definition: oom_adj.cpp:40
core
Definition: child_process.h:32
oom_adj.h
core::posix::Process::pid
virtual pid_t pid() const
Query the pid of the process.
Definition: process.cpp:59
core::posix::linux::proc::process::operator>>
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::linux::proc::process::OomAdj::min_value
static int min_value()
Returns the minimum valid value.
Definition: oom_adj.cpp:45
core::posix::Process
The Process class models a process and possible operations on it.
Definition: process.h:45
core::posix::linux::proc::process::OomAdj::max_value
static int max_value()
Returns the maximum valid value.
Definition: oom_adj.cpp:50