facebook::yoga::vanillajni::ScopedLocalRef< T > 模板类 参考

#include <ScopedLocalRef.h>

facebook::yoga::vanillajni::ScopedLocalRef< T > 的协作图:

Public 成员函数
	ScopedLocalRef (JNIEnv *env, T localRef)
	ScopedLocalRef (JNIEnv *env)
	ScopedLocalRef (ScopedLocalRef &&s) noexcept
ScopedLocalRef &	operator= (ScopedLocalRef &&s) noexcept
	~ScopedLocalRef ()
void	reset (T ptr=NULL)
T	release ()
T	get () const
	operator bool () const
	ScopedLocalRef (const ScopedLocalRef &ref)=delete
ScopedLocalRef &	operator= (const ScopedLocalRef &other)=delete

Private 属性
JNIEnv *	mEnv
T	mLocalRef

详细描述

template<typename T>
class facebook::yoga::vanillajni::ScopedLocalRef< T >

ScopedLocalRef is a sort of smart reference that allows us to control the lifespan of a JNI local reference.

This class is designed so that when a ScopedLocalRef goes out of scope, its destructor will delete -JNIEnv->DeleteLocalRef()- the underlying JNI reference.

This class should be used to wrap all the local references that JNI gives us other than those that are passed to native methods at invocation time. The idea behind this is that in JNI we should be very explicit about the lifespan of local references. Local references can quickly get out of control, and the developer should always be very aware of the lifespan of each local reference that is created in JNI so that leaks are prevented.

This class is very explicit in its behavior, and it does not allow to perform unexpected conversions or unexpected ownership transfer. In practice, this class acts as a unique pointer where the underlying JNI reference can have one and just one owner. Transferring ownership is allowed but it is an explicit operation (implemented via move semantics and also via explicitly API calls).

As with standard JNI local references it is not a valid operation to keep a reference around between different native method calls.

构造及析构函数说明

ScopedLocalRef() [1/4]

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::ScopedLocalRef ( JNIEnv * env, T localRef )

inline

Constructs a ScopedLocalRef with a JNI local reference.

参数

localRef

the local reference to wrap. Can be NULL.

ScopedLocalRef() [2/4]

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::ScopedLocalRef ( JNIEnv * env )

inlineexplicit

Equivalent to ScopedLocalRef(env, NULL)

ScopedLocalRef() [3/4]

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::ScopedLocalRef ( ScopedLocalRef< T > && s )

inlinenoexcept

Move construction is allowed.

~ScopedLocalRef()

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::~ScopedLocalRef ( )

inline

函数调用图:

ScopedLocalRef() [4/4]

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::ScopedLocalRef ( const ScopedLocalRef< T > & ref )

delete

成员函数说明

get()

template<typename T >

T facebook::yoga::vanillajni::ScopedLocalRef< T >::get ( ) const

inline

Returns the underlying JNI local reference.

这是这个函数的调用关系图:

operator bool()

template<typename T >

facebook::yoga::vanillajni::ScopedLocalRef< T >::operator bool ( ) const

inline

Returns true if the underlying JNI reference is not NULL.

operator=() [1/2]

template<typename T >

ScopedLocalRef & facebook::yoga::vanillajni::ScopedLocalRef< T >::operator= ( const ScopedLocalRef< T > & other )

delete

operator=() [2/2]

template<typename T >

ScopedLocalRef & facebook::yoga::vanillajni::ScopedLocalRef< T >::operator= ( ScopedLocalRef< T > && s )

inlinenoexcept

Move assignment is allowed.

函数调用图:

release()

template<typename T >

T facebook::yoga::vanillajni::ScopedLocalRef< T >::release ( )

inline

Makes this ScopedLocalRef not own the underlying JNI local reference. After calling this method, the ScopedLocalRef will not delete the JNI local reference when the ScopedLocalRef goes out of scope.

reset()

template<typename T >

void facebook::yoga::vanillajni::ScopedLocalRef< T >::reset ( T ptr = NULL )

inline

Deletes the currently held reference and reassigns a new one to the ScopedLocalRef.

这是这个函数的调用关系图:

类成员变量说明

mEnv

template<typename T >

JNIEnv* facebook::yoga::vanillajni::ScopedLocalRef< T >::mEnv

private

mLocalRef

template<typename T >

T facebook::yoga::vanillajni::ScopedLocalRef< T >::mLocalRef

private

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该类的文档由以下文件生成:

• third/yoga/java/jni/ScopedLocalRef.h