Interface OperatingSystemMXBean

All Superinterfaces:

OperatingSystemMXBean, OperatingSystemMXBean, PlatformManagedObject

All Known Subinterfaces:

UnixOperatingSystemMXBean

All Known Implementing Classes:

ExtendedOperatingSystemMXBeanImpl, UnixExtendedOperatingSystem

public interface OperatingSystemMXBean
extends OperatingSystemMXBean

OpenJ9 platform management extension interface for the Operating System on which the Java Virtual Machine is running.

Usage example for the OperatingSystemMXBean

 
 ...
 com.ibm.lang.management.OperatingSystemMXBean osmxbean = null;
 osmxbean = (com.ibm.lang.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
 ...
 
 

The following methods depend on certain information that is not available on z/OS; their return values are listed here:

Methods not fully supported on z/OS

Method	Return Value
getCommittedVirtualMemorySize()	-1
OperatingSystemMXBean.getCpuLoad()	-3.0 (CpuLoadCalculationConstants.UNSUPPORTED_VALUE)
OperatingSystemMXBean.getFreeMemorySize()	-1
OperatingSystemMXBean.getFreePhysicalMemorySize()	-1
getProcessPhysicalMemorySize()	-1
getProcessPrivateMemorySize()	-1
OperatingSystemMXBean.getSystemCpuLoad()	-3.0 (CpuLoadCalculationConstants.UNSUPPORTED_VALUE)

Since:

1.5

See Also:

• CpuLoadCalculationConstants

Method Summary

Modifier and Type	Method	Description
long	getCommittedVirtualMemorySize()	Returns the amount of virtual memory used by the process in bytes.
long	getFreeSwapSpaceSize()	Returns the amount of free swap space in bytes.
String	getHardwareModel()	Instantiates and returns an instance of a String object containing hardware model information
double	getProcessCpuLoad()	Returns the recent CPU usage for the Java Virtual Machine process.
long	getProcessCpuTime()	Returns total amount of time the process has been scheduled or executed so far in both kernel and user modes.
int	getProcessingCapacity()	Returns the collective capacity of the virtual processors in the partition the VM is running in.
long	getProcessPhysicalMemorySize()	Returns the amount of physical memory being used by the process in bytes.
long	getProcessPrivateMemorySize()	Returns the amount of private memory used by the process in bytes.
long	getTotalSwapSpaceSize()	Returns the total amount of swap space in bytes.
boolean	isHardwareEmulated()	Identify whether the underlying hardware is being emulated
boolean	isProcessRunning(long pid)	Indicates if the specified process is running
MemoryUsage	retrieveMemoryUsage()	Instantiates and returns an instance of MemoryUsage object that represents the current snapshot of Memory usage statistics.
MemoryUsage	retrieveMemoryUsage(MemoryUsage memObj)	Returns an updated MemoryUsage object that represents the current snapshot of Memory usage statistics.
ProcessorUsage[]	retrieveProcessorUsage()	Instantiates and returns an array of ProcessorUsage objects that represent the current snapshot of individual Processor usage times.
ProcessorUsage[]	retrieveProcessorUsage(ProcessorUsage[] procArray)	Returns an updated array of ProcessorUsage objects that represent the current snapshot of individual Processor usage times.
ProcessorUsage	retrieveTotalProcessorUsage()	Instantiate and return a new ProcessorUsage object that represents the current snapshot of Processor usage statistics.
ProcessorUsage	retrieveTotalProcessorUsage(ProcessorUsage procObj)	Returns an updated ProcessorUsage object that represents the current snapshot of Processor usage statistics.

Methods declared in interface com.sun.management.OperatingSystemMXBean

getCpuLoad, getFreeMemorySize, getFreePhysicalMemorySize, getSystemCpuLoad, getTotalMemorySize, getTotalPhysicalMemorySize

Methods declared in interface java.lang.management.OperatingSystemMXBean

getArch, getAvailableProcessors, getName, getSystemLoadAverage, getVersion

Methods declared in interface java.lang.management.PlatformManagedObject

getObjectName

Method Details

getProcessingCapacity

int getProcessingCapacity()

Returns the collective capacity of the virtual processors in the partition the VM is running in. The value returned is in units of 1% of a physical processor's capacity, so a value of 100 is equal to 1 physical processor. In environments without such partitioning support, this call will return getAvailableProcessors() * 100.

Returns:

the collective capacity of the virtual processors available to the VM.

getProcessCpuTime

long getProcessCpuTime()

Returns total amount of time the process has been scheduled or executed so far in both kernel and user modes. Returns -1 if the value is unavailable on this platform or in the case of an error. Note that as of Java 8 SR5 the returned value is in 1 ns units, unless the system property com.ibm.lang.management.OperatingSystemMXBean.isCpuTime100ns is set to "true".

Specified by:

getProcessCpuTime in interface OperatingSystemMXBean

Returns:

process CPU time.

getCommittedVirtualMemorySize

long getCommittedVirtualMemorySize()

Returns the amount of virtual memory used by the process in bytes. Returns -1 if the value is unavailable on this platform or in the case of an error.

• This information is not available on the z/OS platform.

Specified by:

getCommittedVirtualMemorySize in interface OperatingSystemMXBean

Returns:

amount of virtual memory used by the process in bytes.

Since:

1.8

getProcessPrivateMemorySize

long getProcessPrivateMemorySize()

Returns the amount of private memory used by the process in bytes. Returns -1 if the value is unavailable on this platform or in the case of an error.

• This information is not available on the z/OS platform.

Returns:

amount of private memory used by the process in bytes.

getProcessPhysicalMemorySize

long getProcessPhysicalMemorySize()

Returns the amount of physical memory being used by the process in bytes. Returns -1 if the value is unavailable on this platform or in the case of an error.

• This information is not available on the AIX and z/OS platforms.

Returns:

amount of physical memory being used by the process in bytes.

getTotalSwapSpaceSize

long getTotalSwapSpaceSize()

Returns the total amount of swap space in bytes.

Specified by:

getTotalSwapSpaceSize in interface OperatingSystemMXBean

Returns:

the total amount of swap space in bytes.

Since:

1.7

getFreeSwapSpaceSize

long getFreeSwapSpaceSize()

Returns the amount of free swap space in bytes.

Specified by:

getFreeSwapSpaceSize in interface OperatingSystemMXBean

Returns:

the amount of free swap space in bytes.

Since:

1.7

getProcessCpuLoad

double getProcessCpuLoad()

Returns the recent CPU usage for the Java Virtual Machine process. This value is a double in the [0.0,1.0] interval. A value of 0.0 means that none of the CPUs were running threads from the JVM process during the recent period of time observed, while a value of 1.0 means that all CPUs were actively running threads from the JVM 100% of the time during the recent period of time observed. Threads from the JVM include application threads as well as JVM internal threads. All values between 0.0 and 1.0 are possible. The first call to the method always returns CpuLoadCalculationConstants.ERROR_VALUE (-1.0), which marks the starting point. If the Java Virtual Machine's recent CPU usage is not available, the method returns a negative error code from CpuLoadCalculationConstants.

Specified by:

getProcessCpuLoad in interface OperatingSystemMXBean

Returns:

A value between 0 and 1.0, or a negative error code from CpuLoadCalculationConstants in case of an error. On the first call to the API, CpuLoadCalculationConstants.ERROR_VALUE (-1.0) shall be returned.

Since:

1.7

See Also:

• CpuLoadCalculationConstants

retrieveTotalProcessorUsage

ProcessorUsage retrieveTotalProcessorUsage(ProcessorUsage procObj)
                                    throws NullPointerException,
ProcessorUsageRetrievalException

Returns an updated ProcessorUsage object that represents the current snapshot of Processor usage statistics. The snapshot is the aggregate of all Processors that are online at the time of sampling.

Parameters:

procObj - User provided ProcessorUsage object.

Returns:

The updated ProcessorUsage object.

Throws:

NullPointerException - if a null reference is passed as parameter.

ProcessorUsageRetrievalException - if it failed obtaining Processor usage statistics.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

retrieveTotalProcessorUsage

ProcessorUsage retrieveTotalProcessorUsage()
                                    throws ProcessorUsageRetrievalException

Instantiate and return a new ProcessorUsage object that represents the current snapshot of Processor usage statistics. The snapshot is the aggregate of all Processors that are online at the time of sampling.

Returns:

The new ProcessorUsage object.

Throws:

ProcessorUsageRetrievalException - if it failed obtaining Processor usage statistics.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

retrieveProcessorUsage

ProcessorUsage[] retrieveProcessorUsage(ProcessorUsage[] procArray)
                                 throws NullPointerException,
ProcessorUsageRetrievalException,
IllegalArgumentException

Returns an updated array of ProcessorUsage objects that represent the current snapshot of individual Processor usage times.

Parameters:

procArray - User provided array of ProcessorUsage objects.

Returns:

The updated array of ProcessorUsage objects.

Throws:

NullPointerException - if a null reference is passed as parameter.

ProcessorUsageRetrievalException - if it failed obtaining Processor usage statistics.

IllegalArgumentException - if array provided has insufficient entries and there are more Processors to report on.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

retrieveProcessorUsage

ProcessorUsage[] retrieveProcessorUsage()
                                 throws ProcessorUsageRetrievalException

Instantiates and returns an array of ProcessorUsage objects that represent the current snapshot of individual Processor usage times.

Returns:

The new array of ProcessorUsage objects.

Throws:

ProcessorUsageRetrievalException - if it failed obtaining Processor usage statistics.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

retrieveMemoryUsage

MemoryUsage retrieveMemoryUsage(MemoryUsage memObj)
                         throws NullPointerException,
MemoryUsageRetrievalException

Returns an updated MemoryUsage object that represents the current snapshot of Memory usage statistics.

Parameters:

memObj - User provided MemoryUsage object.

Returns:

The updated MemoryUsage object.

Throws:

NullPointerException - if a null reference is passed as parameter.

MemoryUsageRetrievalException - if it failed obtaining Memory usage statistics.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

retrieveMemoryUsage

MemoryUsage retrieveMemoryUsage()
                         throws MemoryUsageRetrievalException

Instantiates and returns an instance of MemoryUsage object that represents the current snapshot of Memory usage statistics.

Returns:

The new MemoryUsage object.

Throws:

MemoryUsageRetrievalException - if it failed obtaining Memory usage statistics.

In case of an exception, the handler code might use toString() on the exception code to obtain a description of the exception.

Since:

1.7.1

getHardwareModel

String getHardwareModel()
                 throws UnsupportedOperationException

Instantiates and returns an instance of a String object containing hardware model information

Returns:

The new String object or NULL in case of an error.

Throws:

UnsupportedOperationException - if the operation is not implemented on this platform. UnsupportedOperationException will also be thrown if the operation is implemented but it cannot be performed because the system does not satisfy all the requirements, for example, an OS service is not installed.

Since:

1.7

isHardwareEmulated

boolean isHardwareEmulated()
                    throws UnsupportedOperationException

Identify whether the underlying hardware is being emulated

Returns:

True if it is possible to identify that the hardware is being emulated. False otherwise.

Throws:

UnsupportedOperationException - if the emulated status cannot be determined

Since:

1.7

isProcessRunning

boolean isProcessRunning(long pid)

Indicates if the specified process is running

Parameters:

pid - Operating system process ID

Returns:

True if the specified process exists

Since:

1.8