/**
* Creates a new timer.
*
* @param threadFactory a {@link ThreadFactory} that creates a background {@link Thread} which is
* dedicated to {@link TimerTask} execution.
* @param tickDuration the duration between tick
* @param unit the time unit of the {@code tickDuration}
* @param ticksPerWheel the size of the wheel
*/
public HashedWheelTimer(
ThreadFactory threadFactory, long tickDuration, TimeUnit unit, int ticksPerWheel) {
if (threadFactory == null) {
throw new NullPointerException("threadFactory");
}
if (unit == null) {
throw new NullPointerException("unit");
}
if (tickDuration <= 0) {
throw new IllegalArgumentException("tickDuration must be greater than 0: " + tickDuration);
}
if (ticksPerWheel <= 0) {
throw new IllegalArgumentException("ticksPerWheel must be greater than 0: " + ticksPerWheel);
}
// Normalize ticksPerWheel to power of two and initialize the wheel.
wheel = createWheel(ticksPerWheel);
mask = wheel.length - 1;
// Convert tickDuration to milliseconds.
this.tickDuration = tickDuration = unit.toMillis(tickDuration);
// Prevent overflow.
if (tickDuration == Long.MAX_VALUE || tickDuration >= Long.MAX_VALUE / wheel.length) {
throw new IllegalArgumentException("tickDuration is too long: " + tickDuration + ' ' + unit);
}
roundDuration = tickDuration * wheel.length; // 每一轮的时间
workerThread = threadFactory.newThread(worker); // 创建一个线程
// Misuse check
misuseDetector.increase(); // 增加一个实例计数
}
/**
* Creates a new instance.
*
* @param corePoolSize the maximum number of active threads
* @param maxChannelMemorySize the maximum total size of the queued events per channel. Specify
* {@code 0} to disable.
* @param maxTotalMemorySize the maximum total size of the queued events for this pool Specify
* {@code 0} to disable.
* @param keepAliveTime the amount of time for an inactive thread to shut itself down
* @param unit the {@link TimeUnit} of {@code keepAliveTime}
* @param threadFactory the {@link ThreadFactory} of this pool
* @param objectSizeEstimator the {@link ObjectSizeEstimator} of this pool
*/
public MemoryAwareThreadPoolExecutor(
int corePoolSize,
long maxChannelMemorySize,
long maxTotalMemorySize,
long keepAliveTime,
TimeUnit unit,
ObjectSizeEstimator objectSizeEstimator,
ThreadFactory threadFactory) {
super(
corePoolSize,
corePoolSize,
keepAliveTime,
unit,
QueueFactory.createQueue(Runnable.class),
threadFactory,
new NewThreadRunsPolicy());
if (objectSizeEstimator == null) {
throw new NullPointerException("objectSizeEstimator");
}
if (maxChannelMemorySize < 0) {
throw new IllegalArgumentException("maxChannelMemorySize: " + maxChannelMemorySize);
}
if (maxTotalMemorySize < 0) {
throw new IllegalArgumentException("maxTotalMemorySize: " + maxTotalMemorySize);
}
allowCoreThreadTimeOut(true);
settings = new Settings(objectSizeEstimator, maxChannelMemorySize);
if (maxTotalMemorySize == 0) {
totalLimiter = null;
} else {
totalLimiter = new Limiter(maxTotalMemorySize);
}
// Misuse check
misuseDetector.increase();
}
@Override
public synchronized Set<Timeout> stop() {
if (Thread.currentThread() == workerThread) {
throw new IllegalStateException(
HashedWheelTimer.class.getSimpleName()
+ ".stop() cannot be called from "
+ TimerTask.class.getSimpleName());
}
if (!shutdown.compareAndSet(false, true)) {
return Collections.emptySet();
}
boolean interrupted = false;
while (workerThread.isAlive()) {
workerThread.interrupt();
try {
workerThread.join(100);
} catch (InterruptedException e) {
interrupted = true;
}
}
if (interrupted) {
Thread.currentThread().interrupt();
}
misuseDetector.decrease();
Set<Timeout> unprocessedTimeouts = new HashSet<Timeout>();
for (Set<HashedWheelTimeout> bucket : wheel) {
unprocessedTimeouts.addAll(bucket);
bucket.clear();
}
return Collections.unmodifiableSet(unprocessedTimeouts);
}
@Override
protected void terminated() {
super.terminated();
misuseDetector.decrease();
}