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This artifact provides a single jar that contains all classes required to use remote EJB and JMS, including all dependencies. It is intended for use by those not using maven, maven users should just import the EJB and JMS BOM's instead (shaded JAR's cause lots of problems with maven, as it is very easy to inadvertently end up with different versions on classes on the class path).

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/*
 * 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:
 *
 *   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 io.netty.util.concurrent;

import java.util.concurrent.Callable;
import java.util.concurrent.RunnableFuture;

class PromiseTask extends DefaultPromise implements RunnableFuture {

    private static final class RunnableAdapter implements Callable {
        final Runnable task;
        final T result;

        RunnableAdapter(Runnable task, T result) {
            this.task = task;
            this.result = result;
        }

        @Override
        public T call() {
            task.run();
            return result;
        }

        @Override
        public String toString() {
            return "Callable(task: " + task + ", result: " + result + ')';
        }
    }

    private static final Runnable COMPLETED = new SentinelRunnable("COMPLETED");
    private static final Runnable CANCELLED = new SentinelRunnable("CANCELLED");
    private static final Runnable FAILED = new SentinelRunnable("FAILED");

    private static class SentinelRunnable implements Runnable {
        private final String name;

        SentinelRunnable(String name) {
            this.name = name;
        }

        @Override
        public void run() { } // no-op

        @Override
        public String toString() {
            return name;
        }
    }

    // Strictly of type Callable or Runnable
    private Object task;

    PromiseTask(EventExecutor executor, Runnable runnable, V result) {
        super(executor);
        task = result == null ? runnable : new RunnableAdapter(runnable, result);
    }

    PromiseTask(EventExecutor executor, Runnable runnable) {
        super(executor);
        task = runnable;
    }

    PromiseTask(EventExecutor executor, Callable callable) {
        super(executor);
        task = callable;
    }

    @Override
    public final int hashCode() {
        return System.identityHashCode(this);
    }

    @Override
    public final boolean equals(Object obj) {
        return this == obj;
    }

    @SuppressWarnings("unchecked")
    V runTask() throws Throwable {
        final Object task = this.task;
        if (task instanceof Callable) {
            return ((Callable) task).call();
        }
        ((Runnable) task).run();
        return null;
    }

    @Override
    public void run() {
        try {
            if (setUncancellableInternal()) {
                V result = runTask();
                setSuccessInternal(result);
            }
        } catch (Throwable e) {
            setFailureInternal(e);
        }
    }

    private boolean clearTaskAfterCompletion(boolean done, Runnable result) {
        if (done) {
            // The only time where it might be possible for the sentinel task
            // to be called is in the case of a periodic ScheduledFutureTask,
            // in which case it's a benign race with cancellation and the (null)
            // return value is not used.
            task = result;
        }
        return done;
    }

    @Override
    public final Promise setFailure(Throwable cause) {
        throw new IllegalStateException();
    }

    protected final Promise setFailureInternal(Throwable cause) {
        super.setFailure(cause);
        clearTaskAfterCompletion(true, FAILED);
        return this;
    }

    @Override
    public final boolean tryFailure(Throwable cause) {
        return false;
    }

    protected final boolean tryFailureInternal(Throwable cause) {
        return clearTaskAfterCompletion(super.tryFailure(cause), FAILED);
    }

    @Override
    public final Promise setSuccess(V result) {
        throw new IllegalStateException();
    }

    protected final Promise setSuccessInternal(V result) {
        super.setSuccess(result);
        clearTaskAfterCompletion(true, COMPLETED);
        return this;
    }

    @Override
    public final boolean trySuccess(V result) {
        return false;
    }

    protected final boolean trySuccessInternal(V result) {
        return clearTaskAfterCompletion(super.trySuccess(result), COMPLETED);
    }

    @Override
    public final boolean setUncancellable() {
        throw new IllegalStateException();
    }

    protected final boolean setUncancellableInternal() {
        return super.setUncancellable();
    }

    @Override
    public boolean cancel(boolean mayInterruptIfRunning) {
        return clearTaskAfterCompletion(super.cancel(mayInterruptIfRunning), CANCELLED);
    }

    @Override
    protected StringBuilder toStringBuilder() {
        StringBuilder buf = super.toStringBuilder();
        buf.setCharAt(buf.length() - 1, ',');

        return buf.append(" task: ")
                  .append(task)
                  .append(')');
    }
}