gnu.java.lang.management

Class VMMemoryPoolMXBeanImpl

java.lang.Object

gnu.java.lang.management.VMMemoryPoolMXBeanImpl

public final class VMMemoryPoolMXBeanImpl
extends Object

NOTE: Features related to memory usage are currently not implemented.

Constructor Summary

Constructors

Constructor and Description
VMMemoryPoolMXBeanImpl()

Method Summary

Modifier and Type	Method and Description
(package private) static MemoryUsage	getCollectionUsage(String name) Collection usage refers to memory usage within the specified pool after a garbage collection run.
(package private) static long	getCollectionUsageThreshold(String name) Returns the current threshold level for collection usage on the specified pool.
(package private) static long	getCollectionUsageThresholdCount(String name) Returns the number of times the threshold level for collection usage has been met or exceeded for the specified pool.
(package private) static String[]	getMemoryManagerNames(String name) Returns the name of the memory manager which manages the specified pool.
(package private) static MemoryUsage	getPeakUsage(String name) Returns the peak usage of the specified pool.
static String[]	getPoolNames() Retrieves a list of names for all the pools.
(package private) static MemoryType	getType(String name) Returns the type of the specified pool, which can be either "HEAP" or "NON_HEAP".
(package private) static MemoryUsage	getUsage(String name) Returns the memory usage of the specified pool.
(package private) static long	getUsageThreshold(String name) Returns the current threshold level for usage on the specified pool.
(package private) static long	getUsageThresholdCount(String name) Returns the number of times the threshold level for usage has been met or exceeded for the specified pool.
(package private) static boolean	isValid(String name) We simply assume a pool is valid if it is in the list of pool names we maintain.
(package private) static void	resetPeakUsage() Resets the current peak usage value to the current usage.
(package private) static void	setCollectionUsageThreshold(String name, long threshold) Sets the threshold level for collection usage.
(package private) static void	setUsageThreshold(String name, long threshold) Sets the threshold level for memory usage.

Methods inherited from class java.lang.Object

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

Constructor Detail

VMMemoryPoolMXBeanImpl

public VMMemoryPoolMXBeanImpl()

Method Detail

getPoolNames

public static String[] getPoolNames()

Retrieves a list of names for all the pools.

Returns:

a list of names of the pools.

getCollectionUsage

static MemoryUsage getCollectionUsage(String name)

Collection usage refers to memory usage within the specified pool after a garbage collection run. We currently do no support this feature and so return null.

Parameters:

name - the name of the pool whose usage should be returned.

Returns:

null.

getCollectionUsageThreshold

static long getCollectionUsageThreshold(String name)

Returns the current threshold level for collection usage on the specified pool. This is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose usage threshold should be returned.

Returns:

the threshold level.

getCollectionUsageThresholdCount

static long getCollectionUsageThresholdCount(String name)

Returns the number of times the threshold level for collection usage has been met or exceeded for the specified pool. This is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose usage threshold count should be returned.

Returns:

the number of times the threshold level.

getMemoryManagerNames

static String[] getMemoryManagerNames(String name)

Returns the name of the memory manager which manages the specified pool. All our pools are managed by our single memory manager (the active MMTk plan) and so we just return the name of that, regardless of the pool given.

Parameters:

name - the name of the pool whose memory managers should be returned.

Returns:

the name of the active plan.

getPeakUsage

static MemoryUsage getPeakUsage(String name)

Returns the peak usage of the specified pool.

Parameters:

name - the name of the pool whose peak usage should be returned.

Returns:

the peak memory usage.

getType

static MemoryType getType(String name)

Returns the type of the specified pool, which can be either "HEAP" or "NON_HEAP". We consider immortal spaces to be non-heap allocated and all others to be from the heap (as objects can be both created and removed from them).

Parameters:

name - the name of the pool whose peak usage should be returned.

Returns:

the type of the memory pool.

getUsage

static MemoryUsage getUsage(String name)

Returns the memory usage of the specified pool. The total memory is considered to be the size of the extent of the pool, while the used and committed sizes refer to the reserved and committed pages respectively. All sizes are in bytes and the initial size is assumed to be zero.

Parameters:

name - the name of the pool whose usage should be returned.

Returns:

the usage of the specified pool.

getUsageThreshold

static long getUsageThreshold(String name)

Returns the current threshold level for usage on the specified pool. This is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose usage threshold should be returned.

Returns:

the threshold level.

getUsageThresholdCount

static long getUsageThresholdCount(String name)

Returns the number of times the threshold level for usage has been met or exceeded for the specified pool. This is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose usage threshold count should be returned.

Returns:

the number of times the threshold level.

isValid

static boolean isValid(String name)

We simply assume a pool is valid if it is in the list of pool names we maintain.

Parameters:

name - the pool whose validity should be checked.

Returns:

true if the pool is valid.

resetPeakUsage

static void resetPeakUsage()

Resets the current peak usage value to the current usage.

setCollectionUsageThreshold

static void setCollectionUsageThreshold(String name,
                                        long threshold)

Sets the threshold level for collection usage. This method is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose threshold should be set.

threshold - the new threshold value.

setUsageThreshold

static void setUsageThreshold(String name,
                              long threshold)

Sets the threshold level for memory usage. This method is never called as we don't set the appropriate property.

Parameters:

name - the name of the pool whose threshold should be set.

threshold - the new threshold value.