oshi.software.os.linux.LinuxProcess Maven / Gradle / Ivy
/**
* Oshi (https://github.com/dblock/oshi)
*
* Copyright (c) 2010 - 2016 The Oshi Project Team
*
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Maintainers:
* dblock[at]dblock[dot]org
* widdis[at]gmail[dot]com
* enrico.bianchi[at]gmail[dot]com
*
* Contributors:
* https://github.com/dblock/oshi/graphs/contributors
*/
package oshi.software.os.linux;
import java.io.File;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import oshi.software.common.AbstractProcess;
import oshi.software.os.OSProcess;
import oshi.util.ExecutingCommand;
import oshi.util.FileUtil;
import oshi.util.ParseUtil;
import oshi.util.platform.linux.ProcUtil;
/**
* A process is an instance of a computer program that is being executed. It
* contains the program code and its current activity. Depending on the
* operating system (OS), a process may be made up of multiple threads of
* execution that execute instructions concurrently.
*
* @author widdis[at]gmail[dot]com
*/
public class LinuxProcess extends AbstractProcess {
private static final long serialVersionUID = 1L;
private static final Logger LOG = LoggerFactory.getLogger(LinuxProcess.class);
/**
* Jiffies per second, used for process time counters.
*/
private static long hz = 1000L;
/**
* Boot time in MS.
*/
private static long bootTime = 0L;
static {
init();
}
/**
* Correlate the youngest process start time in seconds with start time in
* jiffies
*/
private static void init() {
// Search through all processes to find the youngest one, with the
// latest start time since boot.
// Iterate /proc/[pid]/stat checking the creation time (field 22,
// jiffies since boot) for the largest value
File[] pids = ProcUtil.getPidFiles();
long youngestJiffies = 0L;
String youngestPid = "";
for (File pid : pids) {
List stat = FileUtil.readFile(String.format("/proc/%s/stat", pid.getName()));
if (stat.size() != 0) {
String[] split = stat.get(0).split("\\s+");
if (split.length < 22) {
continue;
}
long jiffies = ParseUtil.parseLongOrDefault(split[21], 0L);
if (jiffies > youngestJiffies) {
youngestJiffies = jiffies;
youngestPid = pid.getName();
}
}
}
LOG.debug("Youngest PID is {} with {} jiffies", youngestPid, youngestJiffies);
// Shouldn't happen but avoiding Division by zero
if (youngestJiffies == 0) {
LOG.error("Couldn't find any running processes, which is odd since we are in a running process. "
+ "Process time values are in jiffies, not milliseconds.");
return;
}
float startTimeSecsSinceBoot = ProcUtil.getSystemUptimeFromProc();
bootTime = System.currentTimeMillis() - (long) (1000 * startTimeSecsSinceBoot);
// Now execute `ps -p -o etimes=` to get the elapsed time of this
// process in seconds.Timeline:
// BOOT|<----jiffies---->|<----etime---->|NOW
// BOOT|<------------uptime------------->|NOW
// This takes advantage of the fact that ps does all the heavy lifting
// of sorting out HZ internally.
String etime = ExecutingCommand.getFirstAnswer(String.format("ps -p %s -o etimes=", youngestPid));
// Since we picked the youngest process, it's safe to assume an
// etime close to 0 in case this command fails; the longer the system
// has been up, the less impact this assumption will have
if (!etime.isEmpty()) {
LOG.debug("Etime is {} seconds", etime.trim());
startTimeSecsSinceBoot -= Float.parseFloat(etime.trim());
}
// By subtracting etime (secs) from uptime (secs) we get uptime (in
// secs) when the process was started. This correlates with startTime in
// jiffies for this process
LOG.debug("Start time in secs: {}", startTimeSecsSinceBoot);
if (startTimeSecsSinceBoot <= 0) {
LOG.warn("Couldn't calculate jiffies per second. "
+ "Process time values are in jiffies, not milliseconds.");
return;
}
// divide jiffies (since boot) by seconds (since boot)
hz = (long) (youngestJiffies / startTimeSecsSinceBoot + 0.5f);
}
public LinuxProcess(String name, String path, char state, int processID, int parentProcessID, int threadCount,
int priority, long virtualSize, long residentSetSize, long kernelTime, long userTime, long startTime,
long now) {
this.name = name;
this.path = path;
switch (state) {
case 'R':
this.state = OSProcess.State.RUNNING;
break;
case 'S':
this.state = OSProcess.State.SLEEPING;
break;
case 'D':
this.state = OSProcess.State.WAITING;
break;
case 'Z':
this.state = OSProcess.State.ZOMBIE;
break;
case 'T':
this.state = OSProcess.State.STOPPED;
break;
default:
this.state = OSProcess.State.OTHER;
break;
}
this.processID = processID;
this.parentProcessID = parentProcessID;
this.threadCount = threadCount;
this.priority = priority;
this.virtualSize = virtualSize;
this.residentSetSize = residentSetSize;
this.kernelTime = kernelTime * 1000L / hz;
this.userTime = userTime * 1000L / hz;
this.startTime = bootTime + startTime * 1000L / hz;
this.upTime = now - this.startTime;
}
}