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//
// Copyright (c) 2015-2016, Geek Zoo Studio
// http://www.geek-zoo.com
//
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
// IN THE SOFTWARE.
//
package com.BeeFramework.Utils;
import java.io.IOException;
import java.io.RandomAccessFile;
public final class LinuxUtils {
/** Return the first line of /proc/stat or null if failed. */
public String readSystemStat() {
RandomAccessFile reader = null;
String load = null;
try {
reader = new RandomAccessFile("/proc/stat", "r");
load = reader.readLine();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
//Streams.close(reader);
}
return load;
}
/**
* Compute and return the total CPU usage, in percent.
*
* @param start
* first content of /proc/stat. Not null.
* @param end
* second content of /proc/stat. Not null.
* @return the CPU use in percent, or -1f if the stats are inverted or on
* error
* @see {@link #readSystemStat()}
*/
public float getSystemCpuUsage(String start, String end) {
String[] stat = start.split(" ");
long idle1 = getSystemIdleTime(stat);
long up1 = getSystemUptime(stat);
stat = end.split(" ");
long idle2 = getSystemIdleTime(stat);
long up2 = getSystemUptime(stat);
// don't know how it is possible but we should care about zero and
// negative values.
float cpu = -1f;
if (idle1 >= 0 && up1 >= 0 && idle2 >= 0 && up2 >= 0) {
if ((up2 + idle2) > (up1 + idle1) && up2 >= up1) {
cpu = (up2 - up1) / (float) ((up2 + idle2) - (up1 + idle1));
cpu *= 100.0f;
}
}
return cpu;
}
/**
* Return the sum of uptimes read from /proc/stat.
*
* @param stat
* see {@link #readSystemStat()}
*/
public long getSystemUptime(String[] stat) {
/*
* (from man/5/proc) /proc/stat kernel/system statistics. Varies with
* architecture. Common entries include: cpu 3357 0 4313 1362393
*
* The amount of time, measured in units of USER_HZ (1/100ths of a
* second on most architectures, use sysconf(_SC_CLK_TCK) to obtain the
* right value), that the system spent in user mode, user mode with low
* priority (nice), system mode, and the idle task, respectively. The
* last value should be USER_HZ times the second entry in the uptime
* pseudo-file.
*
* In Linux 2.6 this line includes three additional columns: iowait -
* time waiting for I/O to complete (since 2.5.41); irq - time servicing
* interrupts (since 2.6.0-test4); softirq - time servicing softirqs
* (since 2.6.0-test4).
*
* Since Linux 2.6.11, there is an eighth column, steal - stolen time,
* which is the time spent in other operating systems when running in a
* virtualized environment
*
* Since Linux 2.6.24, there is a ninth column, guest, which is the time
* spent running a virtual CPU for guest operating systems under the
* control of the Linux kernel.
*/
// with the following algorithm, we should cope with all versions and
// probably new ones.
long l = 0L;
for (int i = 2; i < stat.length; i++) {
if (i != 5) { // bypass any idle mode. There is currently only one.
try {
l += Long.parseLong(stat[i]);
} catch (NumberFormatException ex) {
ex.printStackTrace();
return -1L;
}
}
}
return l;
}
/**
* Return the sum of idle times read from /proc/stat.
*
* @param stat
* see {@link #readSystemStat()}
*/
public long getSystemIdleTime(String[] stat) {
try {
return Long.parseLong(stat[5]);
} catch (NumberFormatException ex) {
ex.printStackTrace();
}
return -1L;
}
/** Return the first line of /proc/pid/stat or null if failed. */
public String readProcessStat(int pid) {
RandomAccessFile reader = null;
String line = null;
try {
reader = new RandomAccessFile("/proc/" + pid + "/stat", "r");
line = reader.readLine();
} catch (IOException ex) {
ex.printStackTrace();
} finally {
//Streams.close(reader);
}
return line;
}
/**
* Compute and return the CPU usage for a process, in percent.
*
* <p>
* The parameters {@code totalCpuTime} is to be the one for the same period
* of time delimited by {@code statStart} and {@code statEnd}.
* </p>
*
* @param start
* first content of /proc/pid/stat. Not null.
* @param end
* second content of /proc/pid/stat. Not null.
* @return the CPU use in percent or -1f if the stats are inverted or on
* error
* @param uptime
* sum of user and kernel times for the entire system for the
* same period of time.
* @return 12.7 for a cpu usage of 12.7% or -1 if the value is not available
* or an error occurred.
* @see {@link #readProcessStat(int)}
*/
public float getProcessCpuUsage(String start, String end, long uptime) {
String[] stat = start.split(" ");
long up1 = getProcessUptime(stat);
stat = end.split(" ");
long up2 = getProcessUptime(stat);
float ret = -1f;
if (up1 >= 0 && up2 >= up1 && uptime > 0.) {
ret = 100.f * (up2 - up1) / (float) uptime;
}
return ret;
}
/**
* Decode the fields of the file {@code /proc/pid/stat} and return (utime +
* stime)
*
* @param stat
* obtained with {@link #readProcessStat(int)}
*/
public long getProcessUptime(String[] stat) {
return Long.parseLong(stat[14]) + Long.parseLong(stat[15]);
}
/**
* Decode the fields of the file {@code /proc/pid/stat} and return (cutime +
* cstime)
*
* @param stat
* obtained with {@link #readProcessStat(int)}
*/
public long getProcessIdleTime(String[] stat) {
return Long.parseLong(stat[16]) + Long.parseLong(stat[17]);
}
/**
* Return the total CPU usage, in percent.
* <p>
* The call is blocking for the time specified by elapse.
* </p>
*
* @param elapse
* the time in milliseconds between reads.
* @return 12.7 for a CPU usage of 12.7% or -1 if the value is not
* available.
*/
public float syncGetSystemCpuUsage(long elapse) {
String stat1 = readSystemStat();
if (stat1 == null) {
return -1.f;
}
try {
Thread.sleep(elapse);
} catch (Exception e) {
}
String stat2 = readSystemStat();
if (stat2 == null) {
return -1.f;
}
return getSystemCpuUsage(stat1, stat2);
}
/**
* Return the CPU usage of a process, in percent.
* <p>
* The call is blocking for the time specified by elapse.
* </p>
*
* @param pid
* @param elapse
* the time in milliseconds between reads.
* @return 6.32 for a CPU usage of 6.32% or -1 if the value is not
* available.
*/
public float syncGetProcessCpuUsage(int pid) {
String pidStat1 = readProcessStat(pid);
String totalStat1 = readSystemStat();
if (pidStat1 == null || totalStat1 == null) {
return -1.f;
}
try {
Thread.sleep(1000);
} catch (Exception e) {
e.printStackTrace();
return -1.f;
}
String pidStat2 = readProcessStat(pid);
String totalStat2 = readSystemStat();
if (pidStat2 == null || totalStat2 == null) {
return -1.f;
}
String[] toks = totalStat1.split(" ");
long cpu1 = getSystemUptime(toks);
toks = totalStat2.split(" ");
long cpu2 = getSystemUptime(toks);
return getProcessCpuUsage(pidStat1, pidStat2, cpu2 - cpu1);
}
}