Package org.elasticsearch.core

Interface RefCounted

All Known Implementing Classes:

AbstractRefCounted

public interface RefCounted

An interface for objects that need to be notified when all reference to itself are not in user anymore. This implements basic reference counting for instance if async operations holding on to services that are close concurrently but should be functional until all async operations have joined Classes implementing this interface should ref counted at any time ie. if an object is used it's reference count should be increased before using it by calling #incRef and a corresponding #decRef must be called in a try/finally block to release the object again ie.:

      inst.incRef();
      try {
        // use the inst...

      } finally {
          inst.decRef();
      }
 

Method Summary

Modifier and Type	Method	Description
boolean	decRef()	Decreases the refCount of this instance.
boolean	hasReferences()	Returns true only if there was at least one active reference when the method was called; if it returns false then the object is closed; future attempts to acquire references will fail.
void	incRef()	Increments the refCount of this instance.
boolean	tryIncRef()	Tries to increment the refCount of this instance.

Method Details

incRef

void incRef()

Increments the refCount of this instance.

Throws:

IllegalStateException - iff the reference counter can not be incremented.

See Also:

• decRef()
• tryIncRef()

tryIncRef

boolean tryIncRef()

Tries to increment the refCount of this instance. This method will return true iff the refCount was

See Also:

• decRef()
• incRef()

decRef

boolean decRef()

Decreases the refCount of this instance. If the refCount drops to 0, then this instance is considered as closed and should not be used anymore.

Returns:

returns true if the ref count dropped to 0 as a result of calling this method

See Also:

• incRef()

hasReferences

boolean hasReferences()

Returns true only if there was at least one active reference when the method was called; if it returns false then the object is closed; future attempts to acquire references will fail.

Returns:

whether there are currently any active references to this object.