A std::shared_ptr<T> storage instance to be copied from and released into a java object's long nativeInstance field. More...

#include <helper_jni.hpp>

Collaboration diagram for jau::jni::shared_ptr_ref< T >:

Public Member Functions
	shared_ptr_ref () noexcept
	Default constructor, nullptr.

	shared_ptr_ref (const shared_ptr_ref &o) noexcept
	Copy constructor.

	shared_ptr_ref (const std::shared_ptr< T > &ref)
	Constructs a new instance, copying the given std::shared_ptr<T>.

	shared_ptr_ref (jlong nativeInstance, const bool throw_on_nullptr=true)
	Constructs a new instance, copying the instance from the given java `long nativeInstance` value, representing a java object's shared_ptr<T> storage.

	shared_ptr_ref (JNIEnv *env, jobject obj, const bool throw_on_nullptr=true)
	Constructs a new instance, copying the instance from the java object's `long nativeInstance` field.

	shared_ptr_ref (shared_ptr_ref &&o) noexcept
	Move constructor.

	shared_ptr_ref (std::shared_ptr< T > &&ref) noexcept
	Constructs a new instance, moving the given std::shared_ptr<T>.

	shared_ptr_ref (T *ptr)
	Constructs a new instance, taking ownership of the given T pointer.

	~shared_ptr_ref ()

bool	is_null () const noexcept
	Returns true if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

void	null_check1 () const
	Throws an exception if this instances shared_ptr<T> storage is nullptr.

void	null_check2 () const
	Throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

T &	operator* ()
	Provides access to reference of stored T.

T *	operator-> ()
	Provides access to pointer of stored T.

shared_ptr_ref &	operator= (const shared_ptr_ref &o)
	Assignment operator.

shared_ptr_ref &	operator= (const std::shared_ptr< T > &o)
	Assignment operator.

shared_ptr_ref &	operator= (shared_ptr_ref &&o) noexcept
	Move assignment operator.

std::shared_ptr< T > *	pointer () noexcept
	Provides access to the shared_ptr<T> pointer, l-value of storage.

std::shared_ptr< T > *	release () noexcept
	Release ownership and returns the shared_ptr<T> storage.

void	release_into_object (JNIEnv *env, jobject obj)
	Deletes the `std::shared_ptr<T>` storage of the target java object if exists first and writes this instance's `std::shared_ptr<T>` storage pointer into its `long nativeInstance` field, then releases ownership, see release_to_jlong().

jlong	release_to_jlong () noexcept
	Release ownership and return the jlong representation of the shared_ptr<T> storage.

const std::shared_ptr< T > &	shared_ptr () const
	Provides access to const reference of shared_ptr<T>, r-value.

std::string	toString () const noexcept

Detailed Description

template<typename T>
class jau::jni::shared_ptr_ref< T >

A std::shared_ptr<T> storage instance to be copied from and released into a java object's long nativeInstance field.

An instance holds a shared_ptr<T> storage pointer for a managed object T.

Using a shared_ptr<T> copy increments its reference counter and prohibits its destruction while in use.

We prefer using std::shared_ptr<T> instead of a naked pointer, this way we automatically preserve the native instance lifecycle while within a JNI method.

Template Parameters

T	the managed object type

Definition at line 392 of file helper_jni.hpp.

Constructor & Destructor Documentation

◆ shared_ptr_ref() [1/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( )

inlinenoexcept

Default constructor, nullptr.

Definition at line 423 of file helper_jni.hpp.

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◆ shared_ptr_ref() [2/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( const shared_ptr_ref< T > & o )

inlinenoexcept

Copy constructor.

Definition at line 428 of file helper_jni.hpp.

◆ shared_ptr_ref() [3/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( shared_ptr_ref< T > && o )

inlinenoexcept

Move constructor.

Definition at line 433 of file helper_jni.hpp.

◆ ~shared_ptr_ref()

template<typename T>

jau::jni::shared_ptr_ref< T >::~shared_ptr_ref ( )

inline

Definition at line 461 of file helper_jni.hpp.

◆ shared_ptr_ref() [4/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( T * ptr )

inline

Constructs a new instance, taking ownership of the given T pointer.

Definition at line 468 of file helper_jni.hpp.

◆ shared_ptr_ref() [5/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( const std::shared_ptr< T > & ref )

inline

Constructs a new instance, copying the given std::shared_ptr<T>.

Definition at line 473 of file helper_jni.hpp.

◆ shared_ptr_ref() [6/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref ( std::shared_ptr< T > && ref )

inlinenoexcept

Constructs a new instance, moving the given std::shared_ptr<T>.

Definition at line 478 of file helper_jni.hpp.

◆ shared_ptr_ref() [7/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref	(	jlong	nativeInstance,
		const bool	throw_on_nullptr = true )

inline

Constructs a new instance, copying the instance from the given java long nativeInstance value, representing a java object's shared_ptr<T> storage.

Using a shared_ptr<T> copy increments its reference counter and prohibits its destruction while in use.

If throw_on_nullptr is true, throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Parameters

nativeInstance	the jlong representation of another shared_ptr<T> storage
throw_on_nullptr	if true, throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 528 of file helper_jni.hpp.

◆ shared_ptr_ref() [8/8]

template<typename T>

jau::jni::shared_ptr_ref< T >::shared_ptr_ref	(	JNIEnv *	env,
		jobject	obj,
		const bool	throw_on_nullptr = true )

inline

Constructs a new instance, copying the instance from the java object's long nativeInstance field.

representing its shared_ptr<T> storage

Using a shared_ptr<T> copy increments its reference counter and prohibits its destruction while in use.

If throw_on_nullptr is true, throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Parameters

env	denoting the JVM
obj	denoting the java object holding the `long nativeInstance` field, representing its shared_ptr<T> storage. Maybe `nullptr`, see `throw_on_nullptr`.
throw_on_nullptr	if true, throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 553 of file helper_jni.hpp.

Member Function Documentation

◆ operator=() [1/3]

template<typename T>

shared_ptr_ref & jau::jni::shared_ptr_ref< T >::operator= ( const shared_ptr_ref< T > & o )

inline

Assignment operator.

Definition at line 440 of file helper_jni.hpp.

◆ operator=() [2/3]

template<typename T>

shared_ptr_ref & jau::jni::shared_ptr_ref< T >::operator= ( shared_ptr_ref< T > && o )

inlinenoexcept

Move assignment operator.

Definition at line 452 of file helper_jni.hpp.

◆ operator=() [3/3]

template<typename T>

shared_ptr_ref & jau::jni::shared_ptr_ref< T >::operator= ( const std::shared_ptr< T > & o )

inline

Assignment operator.

Definition at line 483 of file helper_jni.hpp.

◆ null_check1()

template<typename T>

void jau::jni::shared_ptr_ref< T >::null_check1 ( ) const

inline

Throws an exception if this instances shared_ptr<T> storage is nullptr.

The managed object reference may be nullptr.

Definition at line 497 of file helper_jni.hpp.

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◆ null_check2()

template<typename T>

void jau::jni::shared_ptr_ref< T >::null_check2 ( ) const

inline

Throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 507 of file helper_jni.hpp.

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◆ release()

template<typename T>

std::shared_ptr< T > * jau::jni::shared_ptr_ref< T >::release ( )

inlinenoexcept

Release ownership and returns the shared_ptr<T> storage.

This instance shall not be used anymore.

Definition at line 562 of file helper_jni.hpp.

◆ release_to_jlong()

template<typename T>

jlong jau::jni::shared_ptr_ref< T >::release_to_jlong ( )

inlinenoexcept

Release ownership and return the jlong representation of the shared_ptr<T> storage.

This instance shall not be used anymore.

Definition at line 573 of file helper_jni.hpp.

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◆ release_into_object()

template<typename T>

void jau::jni::shared_ptr_ref< T >::release_into_object	(	JNIEnv *	env,
		jobject	obj )

inline

Deletes the std::shared_ptr<T> storage of the target java object if exists first and writes this instance's std::shared_ptr<T> storage pointer into its long nativeInstance field, then releases ownership, see release_to_jlong().

This instance shall not be used anymore.

Throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Parameters

env
obj	the target java object

Definition at line 592 of file helper_jni.hpp.

◆ is_null()

template<typename T>

bool jau::jni::shared_ptr_ref< T >::is_null ( ) const

inlinenoexcept

Returns true if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 613 of file helper_jni.hpp.

◆ pointer()

template<typename T>

std::shared_ptr< T > * jau::jni::shared_ptr_ref< T >::pointer ( )

inlinenoexcept

Provides access to the shared_ptr<T> pointer, l-value of storage.

Definition at line 620 of file helper_jni.hpp.

◆ shared_ptr()

template<typename T>

const std::shared_ptr< T > & jau::jni::shared_ptr_ref< T >::shared_ptr ( ) const

inline

Provides access to const reference of shared_ptr<T>, r-value.

Throws an exception if this instances shared_ptr<T> storage is nullptr.

Definition at line 629 of file helper_jni.hpp.

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◆ operator*()

template<typename T>

T & jau::jni::shared_ptr_ref< T >::operator* ( )

inline

Provides access to reference of stored T.

Throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 640 of file helper_jni.hpp.

◆ operator->()

template<typename T>

T * jau::jni::shared_ptr_ref< T >::operator-> ( )

inline

Provides access to pointer of stored T.

Throws an exception if either this instances shared_ptr<T> storage or the managed object reference is nullptr.

Definition at line 651 of file helper_jni.hpp.

◆ toString()

template<typename T>

std::string jau::jni::shared_ptr_ref< T >::toString ( ) const

inlinenoexcept

Definition at line 656 of file helper_jni.hpp.

The documentation for this class was generated from the following file:

include/jau/jni/helper_jni.hpp

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

◆ shared_ptr_ref() [1/8]

◆ shared_ptr_ref() [2/8]

◆ shared_ptr_ref() [3/8]

◆ ~shared_ptr_ref()

◆ shared_ptr_ref() [4/8]

◆ shared_ptr_ref() [5/8]

◆ shared_ptr_ref() [6/8]

◆ shared_ptr_ref() [7/8]

◆ shared_ptr_ref() [8/8]

Member Function Documentation

◆ operator=() [1/3]

◆ operator=() [2/3]

◆ operator=() [3/3]

◆ null_check1()

◆ null_check2()

◆ release()

◆ release_to_jlong()

◆ release_into_object()

◆ is_null()

◆ pointer()

◆ shared_ptr()

◆ operator*()

◆ operator->()

◆ toString()