net.obvj.performetrics.util

Class SystemUtils

java.lang.Object

net.obvj.performetrics.util.SystemUtils

public class SystemUtils
extends Object

A utility class for retrieving system data.

Author:

oswaldo.bapvic.jr

Method Summary

Modifier and Type	Method and Description
static long	getCpuTimeNanos() Returns the total time spent using a CPU for the current thread in nanoseconds.
static long	getSystemTimeNanos() Returns system time (the time spent running OS kernel code on behalf of your application) in nanoseconds, by calculating the difference between CPU time and user time for the current thread.
static long	getUserTimeNanos() Returns the CPU time that the current thread has executed in user mode in nanoseconds (i.e., the time spent running current thread's own code).
static long	getWallClockTimeMillis() Returns the current time in milliseconds.
static long	getWallClockTimeNanos() Returns the current value of the current Java Virtual Machine's high-resolution time source in nanoseconds.

Methods inherited from class java.lang.Object

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

Method Detail

getWallClockTimeMillis

public static long getWallClockTimeMillis()

Returns the current time in milliseconds.

Returns:

the difference, measured in milliseconds, between the current time and midnight, January 1, 1970 UTC.

getWallClockTimeNanos

public static long getWallClockTimeNanos()

Returns the current value of the current Java Virtual Machine's high-resolution time source in nanoseconds.

Returns:

the difference, measured in nanoseconds between current time and some arbitrary origin time for the current JVM, that can be used for measuring elapsed times.

getCpuTimeNanos

public static long getCpuTimeNanos()

Returns the total time spent using a CPU for the current thread in nanoseconds.

Returns:

the total CPU time for the current thread if CPU time measurement is enabled; -1 otherwise.

getUserTimeNanos

public static long getUserTimeNanos()

Returns the CPU time that the current thread has executed in user mode in nanoseconds (i.e., the time spent running current thread's own code).

Returns:

the user-level CPU time for the current thread if CPU time measurement is enabled; -1 otherwise.

getSystemTimeNanos

public static long getSystemTimeNanos()

Returns system time (the time spent running OS kernel code on behalf of your application) in nanoseconds, by calculating the difference between CPU time and user time for the current thread.

Returns:

the system time for the current thread if CPU time measurement is enabled; -1 otherwise.