/**
* Copyright (C) 2012 FuseSource, Inc.
* http://fusesource.com
*
* 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 org.fusesource.hawtdispatch.internal;
import org.fusesource.hawtdispatch.DispatchQueue;
import org.fusesource.hawtdispatch.Task;
import org.fusesource.hawtdispatch.internal.util.TimerHeap;
import java.util.*;
import java.util.concurrent.TimeUnit;
import static org.fusesource.hawtdispatch.internal.TimerThread.Type.*;
/**
*
* @author <a href="http://hiramchirino.com">Hiram Chirino</a>
*/
final public class TimerThread extends Thread {
enum Type {
RELATIVE,
ABSOLUTE,
SHUTDOWN
}
final private static class TimerRequest {
Type type;
long time;
TimeUnit unit;
Task task;
DispatchQueue target;
}
private final Object mutex = new Object();
private ArrayList<TimerRequest> requests = new ArrayList<TimerRequest>();
public TimerThread(HawtDispatcher dispatcher) {
setName(dispatcher.getLabel()+" timer");
setDaemon(true);
}
public final void addAbsolute(Task task, DispatchQueue target, long time, TimeUnit unit) {
TimerRequest request = new TimerRequest();
request.type = ABSOLUTE;
request.time = time;
request.unit = unit;
request.task = task;
request.target = target;
add(request);
}
public final void addRelative(Task task, DispatchQueue target, long delay, TimeUnit unit) {
TimerRequest request = new TimerRequest();
request.type = RELATIVE;
request.time = delay;
request.unit = unit;
request.task = task;
request.target = target;
add(request);
}
public final void shutdown(Task onShutdown, DispatchQueue target) {
TimerRequest request = new TimerRequest();
request.type = SHUTDOWN;
request.target = target;
request.task = onShutdown;
add(request);
}
private void add(TimerRequest request) {
synchronized(mutex) {
requests.add(request);
mutex.notify();
}
}
public void run() {
final HashMap<DispatchQueue, LinkedList<Task>> readyRequests =
new HashMap<DispatchQueue, LinkedList<Task>>();
final TimerHeap<TimerRequest> timerHeap = new TimerHeap<TimerRequest>() {
@Override
public final void execute(TimerRequest request) {
LinkedList<Task> tasks = readyRequests.get(request.target);
if( tasks==null ) {
tasks = new LinkedList<Task>();
readyRequests.put(request.target, tasks);
}
tasks.add(request.task);
}
};
ArrayList<TimerRequest> swapped = new ArrayList<TimerRequest>();
try {
for(;;) {
synchronized(mutex) {
// Swap the arrays.
ArrayList<TimerRequest> t = requests;
requests = swapped;
swapped = t;
}
if( !swapped.isEmpty() ) {
for (TimerRequest request : swapped) {
switch( request.type ) {
case RELATIVE:
timerHeap.addRelative(request, request.time, request.unit);
break;
case ABSOLUTE:
timerHeap.addAbsolute(request, request.time, request.unit);
break;
case SHUTDOWN:
List<TimerRequest> requests = timerHeap.clear();
for (TimerRequest r : requests) {
// execute them all..
r.target.execute(r.task);
}
if( request.task !=null ) {
request.task.run();
}
return;
}
}
swapped.clear();
}
timerHeap.executeReadyTimers();
if( !readyRequests.isEmpty() ) {
for (Map.Entry<DispatchQueue,LinkedList<Task>> entry: readyRequests.entrySet()) {
final DispatchQueue queue = entry.getKey();
final LinkedList<Task> tasks = entry.getValue();
if( tasks.size() > 1 ) {
// execute the tasks as a batch.
queue.execute(new Task(){
public void run() {
for ( Task task: tasks) {
task.run();
}
}
});
} else {
queue.execute(tasks.getFirst());
}
}
readyRequests.clear();
}
long start = System.nanoTime();
long next = timerHeap.timeToNext(TimeUnit.NANOSECONDS);
if( next==0 ) {
continue;
}
// if it's coming up soon.. just spin..
if( next>0 && next < 1000 ) {
while( System.nanoTime()-start < next ) {
}
continue;
}
long waitms = next / 1000000;
int waitns = (int) (next % 1000000);
synchronized(mutex) {
if( requests.isEmpty() ) {
if(next==-1) {
mutex.wait();
} else {
mutex.wait(waitms, waitns);
}
}
}
}
} catch (InterruptedException e) {
}
}
}