/**
* Copyright 2014 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 rx.internal.schedulers;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicReference;
import rx.*;
import rx.exceptions.Exceptions;
import rx.functions.Action0;
import rx.internal.util.*;
import rx.plugins.*;
import rx.subscriptions.*;
/**
* @warn class description missing
*/
public class NewThreadWorker extends Scheduler.Worker implements Subscription {
private final ScheduledExecutorService executor;
private final RxJavaSchedulersHook schedulersHook;
volatile boolean isUnsubscribed;
/** The purge frequency in milliseconds. */
private static final String FREQUENCY_KEY = "rx.scheduler.jdk6.purge-frequency-millis";
/** Force the use of purge (true/false). */
private static final String PURGE_FORCE_KEY = "rx.scheduler.jdk6.purge-force";
private static final String PURGE_THREAD_PREFIX = "RxSchedulerPurge-";
/** Forces the use of purge even if setRemoveOnCancelPolicy is available. */
private static final boolean PURGE_FORCE;
/** The purge frequency in milliseconds. */
public static final int PURGE_FREQUENCY;
private static final ConcurrentHashMap<ScheduledThreadPoolExecutor, ScheduledThreadPoolExecutor> EXECUTORS;
private static final AtomicReference<ScheduledExecutorService> PURGE;
static {
EXECUTORS = new ConcurrentHashMap<ScheduledThreadPoolExecutor, ScheduledThreadPoolExecutor>();
PURGE = new AtomicReference<ScheduledExecutorService>();
PURGE_FORCE = Boolean.getBoolean(PURGE_FORCE_KEY);
PURGE_FREQUENCY = Integer.getInteger(FREQUENCY_KEY, 1000);
}
/**
* Registers the given executor service and starts the purge thread if not already started.
* <p>{@code public} visibility reason: called from other package(s) within RxJava
* @param service a scheduled thread pool executor instance
*/
public static void registerExecutor(ScheduledThreadPoolExecutor service) {
do {
ScheduledExecutorService exec = PURGE.get();
if (exec != null) {
break;
}
exec = Executors.newScheduledThreadPool(1, new RxThreadFactory(PURGE_THREAD_PREFIX));
if (PURGE.compareAndSet(null, exec)) {
exec.scheduleAtFixedRate(new Runnable() {
@Override
public void run() {
purgeExecutors();
}
}, PURGE_FREQUENCY, PURGE_FREQUENCY, TimeUnit.MILLISECONDS);
break;
}
} while (true);
EXECUTORS.putIfAbsent(service, service);
}
/**
* Deregisters the executor service.
* <p>{@code public} visibility reason: called from other package(s) within RxJava
* @param service a scheduled thread pool executor instance
*/
public static void deregisterExecutor(ScheduledExecutorService service) {
EXECUTORS.remove(service);
}
/** Purges each registered executor and eagerly evicts shutdown executors. */
static void purgeExecutors() {
try {
Iterator<ScheduledThreadPoolExecutor> it = EXECUTORS.keySet().iterator();
while (it.hasNext()) {
ScheduledThreadPoolExecutor exec = it.next();
if (!exec.isShutdown()) {
exec.purge();
} else {
it.remove();
}
}
} catch (Throwable t) {
Exceptions.throwIfFatal(t);
RxJavaPlugins.getInstance().getErrorHandler().handleError(t);
}
}
/**
* Tries to enable the Java 7+ setRemoveOnCancelPolicy.
* <p>{@code public} visibility reason: called from other package(s) within RxJava.
* If the method returns false, the {@link #registerExecutor(ScheduledThreadPoolExecutor)} may
* be called to enable the backup option of purging the executors.
* @param exec the executor to call setRemoveOnCaneclPolicy if available.
* @return true if the policy was successfully enabled
*/
public static boolean tryEnableCancelPolicy(ScheduledExecutorService exec) {
if (!PURGE_FORCE) {
for (Method m : exec.getClass().getMethods()) {
if (m.getName().equals("setRemoveOnCancelPolicy")
&& m.getParameterTypes().length == 1
&& m.getParameterTypes()[0] == Boolean.TYPE) {
try {
m.invoke(exec, true);
return true;
} catch (Exception ex) {
RxJavaPlugins.getInstance().getErrorHandler().handleError(ex);
}
}
}
}
return false;
}
/* package */
public NewThreadWorker(ThreadFactory threadFactory) {
ScheduledExecutorService exec = Executors.newScheduledThreadPool(1, threadFactory);
// Java 7+: cancelled future tasks can be removed from the executor thus avoiding memory leak
boolean cancelSupported = tryEnableCancelPolicy(exec);
if (!cancelSupported && exec instanceof ScheduledThreadPoolExecutor) {
registerExecutor((ScheduledThreadPoolExecutor)exec);
}
schedulersHook = RxJavaPlugins.getInstance().getSchedulersHook();
executor = exec;
}
@Override
public Subscription schedule(final Action0 action) {
return schedule(action, 0, null);
}
@Override
public Subscription schedule(final Action0 action, long delayTime, TimeUnit unit) {
if (isUnsubscribed) {
return Subscriptions.unsubscribed();
}
return scheduleActual(action, delayTime, unit);
}
/**
* @warn javadoc missing
* @param action
* @param delayTime
* @param unit
* @return
*/
public ScheduledAction scheduleActual(final Action0 action, long delayTime, TimeUnit unit) {
Action0 decoratedAction = schedulersHook.onSchedule(action);
ScheduledAction run = new ScheduledAction(decoratedAction);
Future<?> f;
if (delayTime <= 0) {
f = executor.submit(run);
} else {
f = executor.schedule(run, delayTime, unit);
}
run.add(f);
return run;
}
public ScheduledAction scheduleActual(final Action0 action, long delayTime, TimeUnit unit, CompositeSubscription parent) {
Action0 decoratedAction = schedulersHook.onSchedule(action);
ScheduledAction run = new ScheduledAction(decoratedAction, parent);
parent.add(run);
Future<?> f;
if (delayTime <= 0) {
f = executor.submit(run);
} else {
f = executor.schedule(run, delayTime, unit);
}
run.add(f);
return run;
}
public ScheduledAction scheduleActual(final Action0 action, long delayTime, TimeUnit unit, SubscriptionList parent) {
Action0 decoratedAction = schedulersHook.onSchedule(action);
ScheduledAction run = new ScheduledAction(decoratedAction, parent);
parent.add(run);
Future<?> f;
if (delayTime <= 0) {
f = executor.submit(run);
} else {
f = executor.schedule(run, delayTime, unit);
}
run.add(f);
return run;
}
@Override
public void unsubscribe() {
isUnsubscribed = true;
executor.shutdownNow();
deregisterExecutor(executor);
}
@Override
public boolean isUnsubscribed() {
return isUnsubscribed;
}
}