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/*
 * Copyright 2014-2025 Real Logic Limited.
 *
 * Licensed 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
 *
 * https://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 org.agrona.concurrent;

/**
 * Low-latency idle strategy to be employed in loops that do significant work on each iteration such that any
 * work in the idle strategy would be wasteful.
 *
 * 
 * The {@link NoOpIdleStrategy} should be used with care:
 * 

 *     It could increase power consumption.
 *     The increased power consumption could lead to thermal throttling causing an overall performance drop.
 *     It could consume resources that otherwise would be used by the hyper-sibling.
 *     It could lead to a memory order violation at the end of the loop causing a pipeline reset.
 * 
 * The {@link BusySpinIdleStrategy} might be a better alternative in some scenarios. That being said, using
 * {@link NoOpIdleStrategy} is perfectly fine if the underlying duty cycle loops is performing syscalls (e.g. in sender
 * and receiver threads in Aeron).
 */
public final class NoOpIdleStrategy implements IdleStrategy
{
    /**
     * Name to be returned from {@link #alias()}.
     */
    public static final String ALIAS = "noop";

    /**
     * As there is no instance state then this object can be used to save on allocation.
     */
    public static final NoOpIdleStrategy INSTANCE = new NoOpIdleStrategy();

    /**
     * Create a new instance.
     */
    public NoOpIdleStrategy()
    {
    }

    /**
     * Note: this implementation will result in no safepoint poll once inlined.
     * 
     * {@inheritDoc}
     */
    public void idle(final int workCount)
    {
    }

    /**
     * Note: this implementation will result in no safepoint poll once inlined.
     * 
     * {@inheritDoc}
     */
    public void idle()
    {
    }

    /**
     * {@inheritDoc}
     */
    public void reset()
    {
    }

    /**
     * {@inheritDoc}
     */
    public String alias()
    {
        return ALIAS;
    }

    /**
     * {@inheritDoc}
     */
    public String toString()
    {
        return "NoOpIdleStrategy{alias=" + ALIAS + "}";
    }
}