netty5/common/src/main/java/io/netty/util/ReferenceCounted.java
Trustin Lee 0f1b1be0aa Enable a user specify an arbitrary information with ReferenceCounted.touch()
- Related: #2163
- Add ResourceLeakHint to allow a user to provide a meaningful information about the leak when touching it
- DefaultChannelHandlerContext now implements ResourceLeakHint to tell where the message is going.
- Cleaner resource leak report by excluding noisy stack trace elements
2014-01-29 11:44:59 +09:00

78 lines
3.1 KiB
Java

/*
* Copyright 2013 The Netty Project
*
* The Netty Project licenses this file to you under the Apache License,
* version 2.0 (the "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at:
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*/
package io.netty.util;
/**
* A reference-counted object that requires explicit deallocation.
* <p>
* When a new {@link ReferenceCounted} is instantiated, it starts with the reference count of {@code 1}.
* {@link #retain()} increases the reference count, and {@link #release()} decreases the reference count.
* If the reference count is decreased to {@code 0}, the object will be deallocated explicitly, and accessing
* the deallocated object will usually result in an access violation.
* </p>
* <p>
* If an object that implements {@link ReferenceCounted} is a container of other objects that implement
* {@link ReferenceCounted}, the contained objects will also be released via {@link #release()} when the container's
* reference count becomes 0.
* </p>
*/
public interface ReferenceCounted {
/**
* Returns the reference count of this object. If {@code 0}, it means this object has been deallocated.
*/
int refCnt();
/**
* Increases the reference count by {@code 1}.
*/
ReferenceCounted retain();
/**
* Increases the reference count by the specified {@code increment}.
*/
ReferenceCounted retain(int increment);
/**
* Records the current access location of this object for debugging purposes.
* If this object is determined to be leaked, the information recorded by this operation will be provided to you
* via {@link ResourceLeakDetector}. This method is a shortcut to {@link #touch(Object) touch(null)}.
*/
ReferenceCounted touch();
/**
* Records the current access location of this object with an additonal arbitrary information for debugging
* purposes. If this object is determined to be leaked, the information recorded by this operation will be
* provided to you via {@link ResourceLeakDetector}.
*/
ReferenceCounted touch(Object hint);
/**
* Decreases the reference count by {@code 1} and deallocates this object if the reference count reaches at
* {@code 0}.
*
* @return {@code true} if and only if the reference count became {@code 0} and this object has been deallocated
*/
boolean release();
/**
* Decreases the reference count by the specified {@code decrement} and deallocates this object if the reference
* count reaches at {@code 0}.
*
* @return {@code true} if and only if the reference count became {@code 0} and this object has been deallocated
*/
boolean release(int decrement);
}