OpenJDK 1.23 · jdk.vm.ci.hotspot.HotSpotObjectConstantScope

A mechanism for limiting the lifetime of a foreign object reference encapsulated in a HotSpotObjectConstant. A HotSpotObjectConstant allocated in a local scope will have its reference to any foreign object cleared when the scope closes. This allows the foreign memory manager to reclaim the foreign object (once there are no other strong references to it). HotSpotObjectConstantScopes have no impact on HotSpotObjectConstants that do not encapsulate a foreign object reference. The object returned by enterGlobalScope() or openLocalScope(Object) should always be used in a try-with-resources statement. Failure to close a scope will almost certainly result in foreign objects being leaked.

Field Summary

Modifier and Type	Field and Description
pack-priv static final ThreadLocal<HotSpotObjectConstantScope>	CURRENT
private List<IndirectHotSpotObjectConstantImpl>	foreignObjects
pack-priv final Object	localScopeDescription An object whose `Object#toString()` value describes a non-global scope.
private final HotSpotObjectConstantScope	parent

Access	Constructor and Description
private	HotSpotObjectConstantScope(Object localScopeDescription)

Method Summary

Modifier and Type	Method and Description
pack-priv void	add(IndirectHotSpotObjectConstantImpl obj)
public void	close() Implements java.lang.AutoCloseable.close. Closes this resource, relinquishing any underlying resources.
public static HotSpotObjectConstantScope	Returns: `null` if the current runtime does not support remote object references or if this thread is currently in the global scope enterGlobalScope() Enters the global scope.
pack-priv boolean	isGlobal() Determines if this scope is global.
public static HotSpotObjectConstantScope	Returns: `null` if the current runtime does not support remote object references openLocalScope(Object an non-null object whose `Object#toString()` value describes the scope being opened description) Opens a local scope that upon closing, will release foreign object references encapsulated by `HotSpotObjectConstant`s created in the scope.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

CURRENT	back to summary
pack-priv static final ThreadLocal<HotSpotObjectConstantScope> CURRENT

foreignObjects	back to summary
private List<IndirectHotSpotObjectConstantImpl> foreignObjects

localScopeDescription	back to summary
pack-priv final Object localScopeDescription An object whose `Object#toString()` value describes a non-global scope. This is `null` iff this is a global scope.

parent	back to summary
private final HotSpotObjectConstantScope parent

Constructor Detail

HotSpotObjectConstantScope	back to summary
private HotSpotObjectConstantScope(Object localScopeDescription)

Method Detail

add	back to summary
pack-priv void add(IndirectHotSpotObjectConstantImpl obj)

close back to summary

close	back to summary
public void close() Implements java.lang.AutoCloseable.close. Doc from java.lang.AutoCloseable.close. Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the `try`-with-resources statement. Annotations @VMEntryPoint @Override

public void close()

Implements java.lang.AutoCloseable.close.

Doc from java.lang.AutoCloseable.close.

Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the try-with-resources statement.

Annotations

@VMEntryPoint
@Override

enterGlobalScope back to summary

enterGlobalScope	back to summary
public static HotSpotObjectConstantScope enterGlobalScope() Enters the global scope. This is useful to escape a local scope for execution that will create foreign object references that need to outlive the local scope. Foreign object references encapsulated by `HotSpotObjectConstant`s created in the global scope are only subject to reclamation once the `HotSpotObjectConstant` wrapper dies. Returns:HotSpotObjectConstantScope `null` if the current runtime does not support remote object references or if this thread is currently in the global scope

public static HotSpotObjectConstantScope enterGlobalScope()

Enters the global scope. This is useful to escape a local scope for execution that will create foreign object references that need to outlive the local scope. Foreign object references encapsulated by HotSpotObjectConstants created in the global scope are only subject to reclamation once the HotSpotObjectConstant wrapper dies.

Returns:HotSpotObjectConstantScope: null if the current runtime does not support remote object references or if this thread is currently in the global scope

isGlobal	back to summary
pack-priv boolean isGlobal() Determines if this scope is global.

openLocalScope back to summary

openLocalScope	back to summary
public static HotSpotObjectConstantScope openLocalScope(Object description) Opens a local scope that upon closing, will release foreign object references encapsulated by `HotSpotObjectConstant`s created in the scope. Parameters description:Object an non-null object whose `Object#toString()` value describes the scope being opened Returns:HotSpotObjectConstantScope `null` if the current runtime does not support remote object references

public static HotSpotObjectConstantScope openLocalScope(Object description)

Opens a local scope that upon closing, will release foreign object references encapsulated by HotSpotObjectConstants created in the scope.

Parameters

description:Object: an non-null object whose Object#toString() value describes the scope being opened

Returns:HotSpotObjectConstantScope

null if the current runtime does not support remote object references

public final Class HotSpotObjectConstantScope

Field Summary

Constructor Summary

Method Summary

Field Detail

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Method Detail