oshi.hardware.platform.linux

Class LinuxCentralProcessor

java.lang.Object

oshi.hardware.common.AbstractCentralProcessor

oshi.hardware.platform.linux.LinuxCentralProcessor

All Implemented Interfaces:

Serializable, CentralProcessor

public class LinuxCentralProcessor
extends AbstractCentralProcessor

A CPU as defined in Linux /proc.

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface oshi.hardware.CentralProcessor

CentralProcessor.LogicalProcessor, CentralProcessor.TickType

Field Summary

Fields inherited from class oshi.hardware.common.AbstractCentralProcessor

logicalProcessorCount, physicalPackageCount, physicalProcessorCount

Constructor Summary

Constructors

Constructor and Description
LinuxCentralProcessor() Create a Processor

Method Summary

Modifier and Type	Method and Description
long	getContextSwitches() Get the number of context switches which have occurred
long[]	getCurrentFreq() Current frequeny (in Hz), of the logical processors on this CPU.
long	getInterrupts() Get the number of interrupts which have occurred
long[][]	getProcessorCpuLoadTicks() Get Processor CPU Load tick counters.
long[]	getSystemCpuLoadTicks() Get System-wide CPU Load tick counters.
double[]	getSystemLoadAverage(int nelem) Returns the system load average for the number of elements specified, up to 3, representing 1, 5, and 15 minutes.
protected CentralProcessor.LogicalProcessor[]	initProcessorCounts() Updates logical and physical processor counts and arrays
long	queryMaxFreq() Get processor max frequency.

Methods inherited from class oshi.hardware.common.AbstractCentralProcessor

createProcessorID, getFamily, getIdentifier, getLogicalProcessorCount, getLogicalProcessors, getMaxFreq, getModel, getName, getPhysicalPackageCount, getPhysicalProcessorCount, getProcessorCpuLoadBetweenTicks, getProcessorID, getStepping, getSystemCpuLoadBetweenTicks, getVendor, getVendorFreq, isCpu64bit, setCpu64, setFamily, setIdentifier, setModel, setName, setProcessorID, setStepping, setVendor, setVendorFreq, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

LinuxCentralProcessor

public LinuxCentralProcessor()

Create a Processor

Method Detail

initProcessorCounts

protected CentralProcessor.LogicalProcessor[] initProcessorCounts()

Updates logical and physical processor counts and arrays Updates logical and physical processor counts from /proc/cpuinfo

Specified by:

initProcessorCounts in class AbstractCentralProcessor

Returns:

An array of initialized Logical Processors

getSystemCpuLoadTicks

public long[] getSystemCpuLoadTicks()

Get System-wide CPU Load tick counters. Returns an array with seven elements representing milliseconds spent in User (0), Nice (1), System (2), Idle (3), IOwait (4), Hardware interrupts (IRQ) (5), Software interrupts/DPC (SoftIRQ) (6), or Steal (7) states. Use CentralProcessor.TickType.getIndex() to retrieve the appropriate index. By measuring the difference between ticks across a time interval, CPU load over that interval may be calculated.

Note that while tick counters are in units of milliseconds, they may advance in larger increments along with (platform dependent) clock ticks. For example, by default Windows clock ticks are 1/64 of a second (about 15 or 16 milliseconds) and Linux ticks are distribution and configuration dependent but usually 1/100 of a second (10 milliseconds).

Nice and IOWait information is not available on Windows, and IOwait and IRQ information is not available on macOS, so these ticks will always be zero.

To calculate overall Idle time using this method, include both Idle and IOWait ticks. Similarly, IRQ, SoftIRQ, and Steal ticks should be added to the System value to get the total. System ticks also include time executing other virtual hosts (steal).

Returns:

An array of 7 long values representing time spent in User, Nice, System, Idle, IOwait, IRQ, SoftIRQ, and Steal states.

getCurrentFreq

public long[] getCurrentFreq()

Current frequeny (in Hz), of the logical processors on this CPU.

Returns:

An array of processor frequency or -1 if unknown.

queryMaxFreq

public long queryMaxFreq()

Get processor max frequency.

Specified by:

queryMaxFreq in class AbstractCentralProcessor

Returns:

The max frequency.

getSystemLoadAverage

public double[] getSystemLoadAverage(int nelem)

Returns the system load average for the number of elements specified, up to 3, representing 1, 5, and 15 minutes. The system load average is the sum of the number of runnable entities queued to the available processors and the number of runnable entities running on the available processors averaged over a period of time. The way in which the load average is calculated is operating system specific but is typically a damped time-dependent average. If the load average is not available, a negative value is returned. This method is designed to provide a hint about the system load and may be queried frequently. The load average may be unavailable on some platforms (e.g., Windows) where it is expensive to implement this method.

Parameters:

nelem - Number of elements to return.

Returns:

an array of the system load averages for 1, 5, and 15 minutes with the size of the array specified by nelem; or negative values if not available.

getProcessorCpuLoadTicks

public long[][] getProcessorCpuLoadTicks()

Get Processor CPU Load tick counters. Returns a two dimensional array, with CentralProcessor.getLogicalProcessorCount() arrays, each containing seven elements representing milliseconds spent in User (0), Nice (1), System (2), Idle (3), IOwait (4), Hardware interrupts (IRQ) (5), Software interrupts/DPC (SoftIRQ) (6), or Steal (7) states. Use CentralProcessor.TickType.getIndex() to retrieve the appropriate index. By measuring the difference between ticks across a time interval, CPU load over that interval may be calculated.

Note that while tick counters are in units of milliseconds, they may advance in larger increments along with (platform dependent) clock ticks. For example, by default Windows clock ticks are 1/64 of a second (about 15 or 16 milliseconds) and Linux ticks are distribution and configuration dependent but usually 1/100 of a second (10 milliseconds).

Nice and IOwait per processor information is not available on Windows, and IOwait and IRQ information is not available on macOS, so these ticks will always be zero.

To calculate overall Idle time using this method, include both Idle and IOWait ticks. Similarly, IRQ, SoftIRQ and Steal ticks should be added to the System value to get the total. System ticks also include time executing other virtual hosts (steal).

Returns:

A 2D array of logicalProcessorCount x 7 long values representing time spent in User, Nice, System, Idle, IOwait, IRQ, SoftIRQ, and Steal states.

getContextSwitches

public long getContextSwitches()

Get the number of context switches which have occurred

Returns:

The number of context switches

getInterrupts

public long getInterrupts()

Get the number of interrupts which have occurred

Returns:

The number of interrupts