org.apache.ratis.util

Interface ReferenceCountedObject<T>

Type Parameters:

T - The object type.

public interface ReferenceCountedObject<T>

A reference-counted object can be retained for later use and then be released for returning the resource. - When the object is retained, the reference count is incremented by 1. - When the object is released, the reference count is decremented by 1. - If the object is retained, it must be released afterward. Otherwise, the object will not be returned, and it will cause a resource leak. - If the object is retained multiple times, it must be released the same number of times. - If the object has been retained and then completely released (i.e. the reference count becomes 0), it must not be retained/released/accessed anymore since it may have been allocated for other use.

Method Summary

Modifier and Type	Method and Description
T	get()
boolean	release() Release the object.
T	retain() Retain the object for later use.
static <V> ReferenceCountedObject<V>	wrap(V value, Runnable retainMethod, Runnable releaseMethod) Wrap the given value as a ReferenceCountedObject.

Method Detail

get

T get()

Returns:

the object.

retain

T retain()

Retain the object for later use. The reference count will be increased by 1. The release() method must be invoked afterward. Otherwise, the object is not returned, and it will cause a resource leak.

Returns:

the object.

release

boolean release()

Release the object. The reference count will be decreased by 1.

Returns:

true if the object is completely released (i.e. reference count becomes 0); otherwise, return false.

wrap

static <V> ReferenceCountedObject<V> wrap(V value,
                                          Runnable retainMethod,
                                          Runnable releaseMethod)

Wrap the given value as a ReferenceCountedObject.

Type Parameters:

V - The value type.

Parameters:

value - the value being wrapped.

retainMethod - a method to run when retain() is invoked.

releaseMethod - a method to run when release() is invoked.

Returns:

the wrapped reference-counted object.