Modifier and Type	Class and Description
public abstract static class	MemorySessionImpl.ResourceList A list of all cleanup actions associated with a memory session.

Modifier and Type	Field and Description
pack-priv static final VarHandle	ACQUIRE_COUNT
pack-priv int	acquireCount
pack-priv static final ScopedMemoryAccess.ScopedAccessError	ALREADY_CLOSED
pack-priv static final int	CLOSED
public static final MemorySessionImpl	GLOBAL_SESSION
pack-priv static final int	MAX_FORKS
pack-priv static final int	NONCLOSEABLE
pack-priv static final int	OPEN The value of the `state` of a `MemorySessionImpl`.
pack-priv final Thread	owner
pack-priv final MemorySessionImpl.ResourceList	resourceList
pack-priv static final VarHandle	STATE
pack-priv int	state
pack-priv static final ScopedMemoryAccess.ScopedAccessError	WRONG_THREAD

Access	Constructor and Description
protected	MemorySessionImpl(Thread owner, MemorySessionImpl.ResourceList resourceList)

Method Summary

Modifier and Type	Method and Description
public abstract void	acquire0()
public void	addCloseAction(Runnable runnable)
pack-priv void	addInternal(MemorySessionImpl.ResourceList.ResourceCleanup resource)
public void	addOrCleanupIfFail(MemorySessionImpl.ResourceList.ResourceCleanup resource) Add a cleanup action.
pack-priv static IllegalStateException	alreadyAcquired(int acquires)
pack-priv static IllegalStateException	alreadyClosed()
public ArenaImpl	asArena()
public void	checkValidState() Checks that this session is still alive (see `isAlive()`).
public static void	checkValidState(MemorySegment segment)
public void	checkValidStateRaw() This is a faster version of `checkValidState()`, which is called upon memory access, and which relies on invariants associated with the memory session implementations (volatile access to the closed state bit is replaced with plain access).
protected Object	clone() Overrides java.lang.Object.clone. Creates and returns a copy of this object.
public void	close() Closes this session, executing any cleanup action (where provided).
public static MemorySessionImpl	createConfined(Thread thread)
public static MemorySessionImpl	createHeap(Object ref)
public static MemorySessionImpl	createImplicit(Cleaner cleaner)
public static MemorySessionImpl	createShared()
public final boolean	isAccessibleBy(Thread thread)
public boolean	Returns: `true` if this session is not closed yet. isAlive() Implements java.lang.foreign.MemorySegment.Scope.isAlive. Returns true, if this session is still open.
public final boolean	isCloseable()
public final boolean	isCloseableBy(Thread thread)
pack-priv abstract void	justClose()
pack-priv static UnsupportedOperationException	nonCloseable()
public final Thread	ownerThread()
public abstract void	release0()
public static MemorySessionImpl	toMemorySession(Arena arena)
pack-priv static IllegalStateException	tooManyAcquires()
public void	whileAlive(Runnable action)
pack-priv static WrongThreadException	wrongThread()

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

Field Detail

ACQUIRE_COUNT	back to summary
pack-priv static final VarHandle ACQUIRE_COUNT

acquireCount	back to summary
pack-priv int acquireCount

ALREADY_CLOSED	back to summary
pack-priv static final ScopedMemoryAccess.ScopedAccessError ALREADY_CLOSED

CLOSED	back to summary
pack-priv static final int CLOSED

GLOBAL_SESSION	back to summary
public static final MemorySessionImpl GLOBAL_SESSION

MAX_FORKS	back to summary
pack-priv static final int MAX_FORKS

NONCLOSEABLE	back to summary
pack-priv static final int NONCLOSEABLE

OPEN	back to summary
pack-priv static final int OPEN The value of the `state` of a `MemorySessionImpl`. The only possible transition is OPEN -> CLOSED. As a result, the states CLOSED and NONCLOSEABLE are stable. This allows us to annotate `state` with `Stable` and elide liveness check on non-closeable constant scopes, such as `GLOBAL_SESSION`.

owner	back to summary
pack-priv final Thread owner

resourceList	back to summary
pack-priv final MemorySessionImpl.ResourceList resourceList

STATE	back to summary
pack-priv static final VarHandle STATE

state	back to summary
pack-priv int state Annotations @Stable

WRONG_THREAD	back to summary
pack-priv static final ScopedMemoryAccess.ScopedAccessError WRONG_THREAD

Constructor Detail

MemorySessionImpl	back to summary
protected MemorySessionImpl(Thread owner, MemorySessionImpl.ResourceList resourceList)

Method Detail

acquire0	back to summary
public abstract void acquire0()

addCloseAction	back to summary
public void addCloseAction(Runnable runnable)

addInternal	back to summary
pack-priv void addInternal(MemorySessionImpl.ResourceList.ResourceCleanup resource)

addOrCleanupIfFail	back to summary
public void addOrCleanupIfFail(MemorySessionImpl.ResourceList.ResourceCleanup resource) Add a cleanup action. If a failure occurred (because of an add vs. close race), call the cleanup action. This semantics is useful when allocating new memory segments, since we first do a malloc/mmap and _then_ we register the cleanup (free/munmap) against the session; so, if registration fails, we still have to clean up memory. From the perspective of the client, such a failure would manifest as a factory returning a segment that is already "closed" - which is always possible anyway (e.g. if the session is closed _after_ the cleanup for the segment is registered but _before_ the factory returns the new segment to the client). For this reason, it's not worth adding extra complexity to the segment initialization logic here - and using an optimistic logic works well in practice.

addOrCleanupIfFail

back to summary

public void addOrCleanupIfFail(MemorySessionImpl.ResourceList.ResourceCleanup resource)

Add a cleanup action. If a failure occurred (because of an add vs. close race), call the cleanup action. This semantics is useful when allocating new memory segments, since we first do a malloc/mmap and _then_ we register the cleanup (free/munmap) against the session; so, if registration fails, we still have to clean up memory. From the perspective of the client, such a failure would manifest as a factory returning a segment that is already "closed" - which is always possible anyway (e.g. if the session is closed _after_ the cleanup for the segment is registered but _before_ the factory returns the new segment to the client). For this reason, it's not worth adding extra complexity to the segment initialization logic here - and using an optimistic logic works well in practice.

alreadyAcquired	back to summary
pack-priv static IllegalStateException alreadyAcquired(int acquires)

alreadyClosed	back to summary
pack-priv static IllegalStateException alreadyClosed()

asArena	back to summary
public ArenaImpl asArena()

checkValidState back to summary

checkValidState	back to summary
public void checkValidState() Checks that this session is still alive (see `isAlive()`). Exceptions IllegalStateException: if this session is already closed or if this is a confined session and this method is called outside the owner thread.

public void checkValidState()

Checks that this session is still alive (see isAlive()).

Exceptions

IllegalStateException:: if this session is already closed or if this is a confined session and this method is called outside the owner thread.

checkValidState	back to summary
public static void checkValidState(MemorySegment segment)

checkValidStateRaw back to summary

checkValidStateRaw	back to summary
public void checkValidStateRaw() This is a faster version of `checkValidState()`, which is called upon memory access, and which relies on invariants associated with the memory session implementations (volatile access to the closed state bit is replaced with plain access). This method should be monomorphic, to avoid virtual calls in the memory access hot path. This method is not intended as general purpose method and should only be used in the memory access handle hot path; for liveness checks triggered by other API methods, please use `checkValidState()`. Annotations @ForceInline

public void checkValidStateRaw()

This is a faster version of checkValidState(), which is called upon memory access, and which relies on invariants associated with the memory session implementations (volatile access to the closed state bit is replaced with plain access). This method should be monomorphic, to avoid virtual calls in the memory access hot path. This method is not intended as general purpose method and should only be used in the memory access handle hot path; for liveness checks triggered by other API methods, please use checkValidState().

Annotations

@ForceInline

clone back to summary

clone	back to summary
protected Object clone() throws CloneNotSupportedException Overrides java.lang.Object.clone. Doc from java.lang.Object.clone. Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object `x`, the expression: x.clone() != x will be true, and that the expression: x.clone().getClass() == x.getClass() will be `true`, but these are not absolute requirements. While it is typically the case that: x.clone().equals(x) will be `true`, this is not an absolute requirement. By convention, the returned object should be obtained by calling `super.clone`. If a class and all of its superclasses (except `Object`) obey this convention, it will be the case that `x.clone().getClass() == x.getClass()`. By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by `super.clone` before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by `super.clone` need to be modified. Annotations @Override Exceptions CloneNotSupportedException: if the object's class does not support the `Cloneable` interface. Subclasses that override the `clone` method can also throw this exception to indicate that an instance cannot be cloned.

protected Object clone() throws CloneNotSupportedException

Overrides java.lang.Object.clone.

Doc from java.lang.Object.clone.

Creates and returns a copy of this object. The precise meaning of "copy" may depend on the class of the object. The general intent is that, for any object x, the expression:

x.clone() != x

will be true, and that the expression:

x.clone().getClass() == x.getClass()

will be true, but these are not absolute requirements. While it is typically the case that:

x.clone().equals(x)

will be true, this is not an absolute requirement.

By convention, the returned object should be obtained by calling super.clone. If a class and all of its superclasses (except Object) obey this convention, it will be the case that x.clone().getClass() == x.getClass().

By convention, the object returned by this method should be independent of this object (which is being cloned). To achieve this independence, it may be necessary to modify one or more fields of the object returned by super.clone before returning it. Typically, this means copying any mutable objects that comprise the internal "deep structure" of the object being cloned and replacing the references to these objects with references to the copies. If a class contains only primitive fields or references to immutable objects, then it is usually the case that no fields in the object returned by super.clone need to be modified.

Annotations

@Override

Exceptions

CloneNotSupportedException:: if the object's class does not support the Cloneable interface. Subclasses that override the clone method can also throw this exception to indicate that an instance cannot be cloned.

close	back to summary
public void close() Closes this session, executing any cleanup action (where provided). Exceptions IllegalStateException: if this session is already closed or if this is a confined session and this method is called outside the owner thread.

back to summary

public void close()

Closes this session, executing any cleanup action (where provided).

Exceptions

IllegalStateException:: if this session is already closed or if this is a confined session and this method is called outside the owner thread.

createConfined	back to summary
public static MemorySessionImpl createConfined(Thread thread)

createHeap	back to summary
public static MemorySessionImpl createHeap(Object ref)

createImplicit	back to summary
public static MemorySessionImpl createImplicit(Cleaner cleaner)

createShared	back to summary
public static MemorySessionImpl createShared()

isAccessibleBy	back to summary
public final boolean isAccessibleBy(Thread thread)

isAlive back to summary

isAlive	back to summary
public boolean isAlive() Implements java.lang.foreign.MemorySegment.Scope.isAlive. Returns true, if this session is still open. This method may be called in any thread. Returns:boolean `true` if this session is not closed yet.

public boolean isAlive()

Implements java.lang.foreign.MemorySegment.Scope.isAlive.

Returns true, if this session is still open. This method may be called in any thread.

Returns:boolean: true if this session is not closed yet.

isCloseable	back to summary
public final boolean isCloseable()

isCloseableBy	back to summary
public final boolean isCloseableBy(Thread thread)

justClose	back to summary
pack-priv abstract void justClose()

nonCloseable	back to summary
pack-priv static UnsupportedOperationException nonCloseable()

ownerThread	back to summary
public final Thread ownerThread()

release0	back to summary
public abstract void release0()

toMemorySession	back to summary
public static MemorySessionImpl toMemorySession(Arena arena) Annotations @ForceInline

tooManyAcquires	back to summary
pack-priv static IllegalStateException tooManyAcquires()

whileAlive	back to summary
public void whileAlive(Runnable action)

wrongThread	back to summary
pack-priv static WrongThreadException wrongThread()

jdk.internal.foreign back to summary

public abstract Class MemorySessionImpl.ResourceList

Class Inheritance

extends Object
implements Runnable

java.lang.Object
jdk.internal.foreign.MemorySessionImpl.ResourceList

All Implemented Interfaces

java.lang.Runnable

Known Direct Subclasses

jdk.internal.foreign.SharedSession.SharedResourceList, jdk.internal.foreign.ConfinedSession.ConfinedResourceList

A list of all cleanup actions associated with a memory session. Cleanup actions are modelled as instances of the ResourceCleanup class, and, together, form a linked list. Depending on whether a session is shared or confined, different implementations of this class will be used, see ConfinedSession.ConfinedResourceList and SharedSession.SharedResourceList.

Nested and Inner Type Summary

Modifier and Type	Class and Description
public abstract static class	MemorySessionImpl.ResourceList.ResourceCleanup

Field Summary

Modifier and Type	Field and Description
pack-priv MemorySessionImpl.ResourceList.ResourceCleanup	fst

Constructor Summary

Access	Constructor and Description
public	ResourceList()

Method Summary

Modifier and Type	Method and Description
pack-priv abstract void	add(MemorySessionImpl.ResourceList.ResourceCleanup cleanup)
pack-priv abstract void	cleanup()
pack-priv static void	cleanup(MemorySessionImpl.ResourceList.ResourceCleanup first)
pack-priv static void	cleanup(MemorySessionImpl.ResourceList.ResourceCleanup first, RuntimeException pendingException)
pack-priv static RuntimeException	cleanupSingle(MemorySessionImpl.ResourceList.ResourceCleanup resource, RuntimeException pendingException)
public final void	run() Implements java.lang.Runnable.run. Runs this operation.

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

Field Detail

fst	back to summary
pack-priv MemorySessionImpl.ResourceList.ResourceCleanup fst

Constructor Detail

ResourceList	back to summary
public ResourceList()

Method Detail

add	back to summary
pack-priv abstract void add(MemorySessionImpl.ResourceList.ResourceCleanup cleanup)

cleanup	back to summary
pack-priv abstract void cleanup()

cleanup	back to summary
pack-priv static void cleanup(MemorySessionImpl.ResourceList.ResourceCleanup first)

cleanup	back to summary
pack-priv static void cleanup(MemorySessionImpl.ResourceList.ResourceCleanup first, RuntimeException pendingException)

cleanupSingle	back to summary
pack-priv static RuntimeException cleanupSingle(MemorySessionImpl.ResourceList.ResourceCleanup resource, RuntimeException pendingException)

run

back to summary

public final void run()

Implements java.lang.Runnable.run.

Doc from java.lang.Runnable.run.

Runs this operation.

jdk.internal.foreign back to summary

public abstract Class MemorySessionImpl.ResourceList.ResourceCleanup

Class Inheritance

extends Object

java.lang.Object
jdk.internal.foreign.MemorySessionImpl.ResourceList.ResourceCleanup

Field Summary

Modifier and Type	Field and Description
pack-priv static final MemorySessionImpl.ResourceList.ResourceCleanup	CLOSED_LIST
pack-priv MemorySessionImpl.ResourceList.ResourceCleanup	next

Constructor Summary

Access	Constructor and Description
public	ResourceCleanup()

Method Summary

Modifier and Type	Method and Description
public abstract void	cleanup()
pack-priv static MemorySessionImpl.ResourceList.ResourceCleanup	ofRunnable(Runnable cleanupAction)

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

Field Detail

CLOSED_LIST	back to summary
pack-priv static final MemorySessionImpl.ResourceList.ResourceCleanup CLOSED_LIST

next	back to summary
pack-priv MemorySessionImpl.ResourceList.ResourceCleanup next

Constructor Detail

ResourceCleanup	back to summary
public ResourceCleanup()

Method Detail

cleanup	back to summary
public abstract void cleanup()

ofRunnable	back to summary
pack-priv static MemorySessionImpl.ResourceList.ResourceCleanup ofRunnable(Runnable cleanupAction)

public abstract sealed Class MemorySessionImpl

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public abstract Class MemorySessionImpl.ResourceList

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public abstract Class MemorySessionImpl.ResourceList.ResourceCleanup

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail