com.vaadin.open

Class LinuxProcFileReader

java.lang.Object

com.vaadin.open.LinuxProcFileReader

public class LinuxProcFileReader
extends Object

Linux /proc file reader. Read tick information for the system and the current process in order to provide stats on the cloud page about CPU utilization. Tick counts are monotonically increasing since boot. Find definitions of /proc file info here. http://man7.org/linux/man-pages/man5/proc.5.html

Constructor Summary

Constructors

Constructor and Description
LinuxProcFileReader() Constructor.

Method Summary

Modifier and Type	Method and Description
long[][]	getCpuTicks() Array of ticks.
int	getProcessCpusAllowed()
String	getProcessID()
int	getProcessNumOpenFds()
long	getProcessRss()
long	getProcessTotalTicks()
long	getSystemIdleTicks()
long	getSystemTotalTicks()
boolean	isWsl()
static int	numSetBitsHex(String s)
void	read() Read and parse data from /proc/stat and /proc/<pid>/stat.
boolean	valid()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LinuxProcFileReader

public LinuxProcFileReader()

Constructor.

Method Detail

isWsl

public boolean isWsl()

Returns:

whether this java process is running in Windows Subsystem for Linux environment.

getSystemIdleTicks

public long getSystemIdleTicks()

Returns:

ticks the system was idle. in general: idle + busy == 100%

getSystemTotalTicks

public long getSystemTotalTicks()

Returns:

ticks the system was up.

getProcessTotalTicks

public long getProcessTotalTicks()

Returns:

ticks this process was running.

getCpuTicks

public long[][] getCpuTicks()

Array of ticks. [cpu number][tick type] tick types are: [0] user ticks [1] system ticks [2] other ticks (i/o) [3] idle ticks

Returns:

ticks array for each cpu of the system.

getProcessRss

public long getProcessRss()

Returns:

resident set size (RSS) of this process.

getProcessCpusAllowed

public int getProcessCpusAllowed()

Returns:

number of CPUs allowed by this process.

getProcessNumOpenFds

public int getProcessNumOpenFds()

Returns:

number of currently open fds of this process.

getProcessID

public String getProcessID()

Returns:

process id for this node as a String.

read

public void read()

Read and parse data from /proc/stat and /proc/<pid>/stat. If this doesn't work for some reason, the values will be -1.

valid

public boolean valid()

Returns:

true if all the values are ok to use; false otherwise.

numSetBitsHex

public static int numSetBitsHex(String s)

Returns:

number of set bits in hexadecimal string (chars must be 0-F)