hu.akarnokd.rxjava2.internal.schedulers.ExecutorScheduler Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of rxjava2-backport Show documentation
rxjava2-backport developed by David Karnok
There is a newer version: 2.0.0-RC3
/**
 * Copyright 2015 David Karnok and Netflix, Inc.
 * 
 * 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
 * 
 * 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 hu.akarnokd.rxjava2.internal.schedulers;

import java.util.Queue;
import java.util.concurrent.*;
import java.util.concurrent.atomic.*;

import hu.akarnokd.rxjava2.Scheduler;
import hu.akarnokd.rxjava2.disposables.*;
import hu.akarnokd.rxjava2.internal.disposables.*;
import hu.akarnokd.rxjava2.internal.queue.MpscLinkedQueue;
import hu.akarnokd.rxjava2.internal.schedulers.ExecutorScheduler.ExecutorWorker.BooleanRunnable;
import hu.akarnokd.rxjava2.plugins.RxJavaPlugins;
import hu.akarnokd.rxjava2.schedulers.Schedulers;

public final class ExecutorScheduler extends Scheduler {
    
    final Executor executor;

    static final Scheduler HELPER = Schedulers.single();
    
    public ExecutorScheduler(Executor executor) {
        this.executor = executor;
    }
    
    @Override
    public Worker createWorker() {
        return new ExecutorWorker(executor);
    }
    
    @Override
    public Disposable scheduleDirect(Runnable run) {
        Runnable decoratedRun = RxJavaPlugins.onSchedule(run);
        try {
            if (executor instanceof ExecutorService) {
                Future f = ((ExecutorService)executor).submit(decoratedRun);
                return Disposables.from(f);
            }
            
            BooleanRunnable br = new BooleanRunnable(decoratedRun);
            executor.execute(br);
            return br;
        } catch (RejectedExecutionException ex) {
            RxJavaPlugins.onError(ex);
            return EmptyDisposable.INSTANCE;
        }
    }
    
    @Override
    public Disposable scheduleDirect(Runnable run, long delay, TimeUnit unit) {
        final Runnable decoratedRun = RxJavaPlugins.onSchedule(run);
        if (executor instanceof ScheduledExecutorService) {
            try {
                Future f = ((ScheduledExecutorService)executor).schedule(decoratedRun, delay, unit);
                return Disposables.from(f);
            } catch (RejectedExecutionException ex) {
                RxJavaPlugins.onError(ex);
                return EmptyDisposable.INSTANCE;
            }
        }
        MultipleAssignmentResource first = new MultipleAssignmentResource(Disposables.consumeAndDispose());

        final MultipleAssignmentResource mar = new MultipleAssignmentResource(Disposables.consumeAndDispose(), first);

        Disposable delayed = HELPER.scheduleDirect(new Runnable() {
            @Override
            public void run() {
                mar.setResource(scheduleDirect(decoratedRun));
            }
        }, delay, unit);
        
        first.setResource(delayed);
        
        return mar;
    }
    
    @Override
    public Disposable schedulePeriodicallyDirect(Runnable run, long initialDelay, long period, TimeUnit unit) {
        if (executor instanceof ScheduledExecutorService) {
            Runnable decoratedRun = RxJavaPlugins.onSchedule(run);
            try {
                Future f = ((ScheduledExecutorService)executor).scheduleAtFixedRate(decoratedRun, initialDelay, period, unit);
                return Disposables.from(f);
            } catch (RejectedExecutionException ex) {
                RxJavaPlugins.onError(ex);
                return EmptyDisposable.INSTANCE;
            }
        }
        return super.schedulePeriodicallyDirect(run, initialDelay, period, unit);
    }
    /* public: test support. */
    public static final class ExecutorWorker extends Scheduler.Worker implements Runnable {
        final Executor executor;
        
        final MpscLinkedQueue queue;
        
        volatile boolean disposed;
        
        volatile int wip;
        static final AtomicIntegerFieldUpdater WIP =
                AtomicIntegerFieldUpdater.newUpdater(ExecutorWorker.class, "wip");
        
        final SetCompositeResource tasks = new SetCompositeResource(Disposables.consumeAndDispose());
        
        public ExecutorWorker(Executor executor) {
            this.executor = executor;
            this.queue = new MpscLinkedQueue();
        }
        
        @Override
        public Disposable schedule(Runnable run) {
            if (disposed) {
                return EmptyDisposable.INSTANCE;
            }
            
            Runnable decoratedRun = RxJavaPlugins.onSchedule(run);
            BooleanRunnable br = new BooleanRunnable(decoratedRun);
            
            queue.offer(br);
            
            if (WIP.getAndIncrement(this) == 0) {
                try {
                    executor.execute(this);
                } catch (RejectedExecutionException ex) {
                    disposed = true;
                    queue.clear();
                    RxJavaPlugins.onError(ex);
                    return EmptyDisposable.INSTANCE;
                }
            }
            
            return br;
        }
        
        @Override
        public Disposable schedule(Runnable run, long delay, TimeUnit unit) {
            if (delay <= 0) {
                return schedule(run);
            }
            if (disposed) {
                return EmptyDisposable.INSTANCE;
            }
            

            MultipleAssignmentResource first = new MultipleAssignmentResource(Disposables.consumeAndDispose());

            final MultipleAssignmentResource mar = new MultipleAssignmentResource(Disposables.consumeAndDispose(), first);
            
            final Runnable decoratedRun = RxJavaPlugins.onSchedule(run);
            
            ScheduledRunnable sr = new ScheduledRunnable(new Runnable() {
                @Override
                public void run() {
                    mar.setResource(schedule(decoratedRun));
                }
            }, tasks);
            tasks.add(sr);
            
            if (executor instanceof ScheduledExecutorService) {
                try {
                    Future f = ((ScheduledExecutorService)executor).schedule(sr, delay, unit);
                    sr.setFuture(f);
                } catch (RejectedExecutionException ex) {
                    disposed = true;
                    RxJavaPlugins.onError(ex);
                    return EmptyDisposable.INSTANCE;
                }
            } else {
                final Disposable d = HELPER.scheduleDirect(sr, delay, unit);
                sr.setFuture(new Future