com.ericsson.research.trap.utils.WeakDelay Maven / Gradle / Ivy
package com.ericsson.research.trap.utils;
/*
* ##_BEGIN_LICENSE_##
* Transport Abstraction Package (trap)
* ----------
* Copyright (C) 2014 Ericsson AB
* ----------
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. Neither the name of the Ericsson AB nor the names of its contributors
* may be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
* OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
* ##_END_LICENSE_##
*/
import java.lang.ref.WeakReference;
import java.util.concurrent.Delayed;
import java.util.concurrent.TimeUnit;
public class WeakDelay implements Delayed, Runnable
{
private final long expiry;
private final WeakReference task;
public WeakDelay(RunnableFuture task, long delay)
{
this.task = new WeakReference(task);
this.expiry = System.currentTimeMillis() + delay;
}
public int compareTo(Delayed other)
{
return (int) (this.getDelay(TimeUnit.MILLISECONDS) - other.getDelay(TimeUnit.MILLISECONDS));
}
public boolean equals(Object obj)
{
if (obj instanceof WeakDelay)
return this.compareTo((Delayed) obj) == 0 && ((WeakDelay) obj).task.equals(this.task);
return super.equals(obj);
}
// WeakDelay is not hashCode() compliant.
public int hashCode()
{
assert false : "hashCode not designed";
return 42; // any arbitrary constant will do
}
public long getDelay(TimeUnit unit)
{
long remaining = this.expiry - System.currentTimeMillis();
return unit.convert(remaining, TimeUnit.MILLISECONDS);
}
public void run()
{
RunnableFuture t = this.task.get();
if (t != null)
t.run();
}
}