Motivation:
At the moment when EmbeddedChannel is used and a ChannelHandler tries to schedule and task it will throw an UnsupportedOperationException. This makes it impossible to test these handlers or even reuse them with EmbeddedChannel.
Modifications:
- Factor out reusable scheduling code into AbstractSchedulingEventExecutor
- Let EmbeddedEventLoop and SingleThreadEventExecutor extend AbstractSchedulingEventExecutor
- add EmbbededChannel.runScheduledPendingTasks() which allows to run all scheduled tasks that are ready
Result:
Embeddedchannel is now usable even with ChannelHandler that try to schedule tasks.
Motivation:
8fbc513 introduced stray warnings in callsites of
PromiseAggregator#add and PromiseNotifier#(...).
Modifications:
This commit adds the @SafeVarargs annotation to PromiseAggregator#add
and PromiseNotifier#(...). As Netty is built with JDK7, this is a
recognized annotation and should not affect runtime VM versions 1.5 and
1.6.
Result:
Building Netty with JDK7 will no longer produce warnings in the
callsites mentioned above.
Motivation:
Found performance issues via FindBugs and PMD.
Modifications:
- Removed unnecessary boxing/unboxing operations in DefaultTextHeaders.convertToInt(CharSequence) and DefaultTextHeaders.convertToLong(CharSequence). A boxed primitive is created from a string, just to extract the unboxed primitive value.
- Added a static modifier for DefaultHttp2Connection.ParentChangedEvent class. This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Added a static compiled Pattern to avoid compile it each time it is used when we need to replace some part of authority.
- Improved using of StringBuilders.
Result:
Performance improvements.
Motivation:
ChannelPromiseAggregator and ChannelPromiseNotifiers only allow
consumers to work with Channels as the result type. Generic versions
of these classes allow consumers to aggregate or broadcast the results
of an asynchronous execution with other result types.
Modifications:
Add PromiseAggregator and PromiseNotifier. Add unit tests for both.
Remove code in ChannelPromiseAggregator and ChannelPromiseNotifier and
modify them to extend the new base classes.
Result:
Consumers can now aggregate or broadcast the results of an asynchronous
execution with results types other than Channel.
Motivation:
We forgot to do a null check on the cause parameter of
ChannelFuture.setFailure(cause)
Modifications:
Add a null check
Result:
Fixed issue: #2728
Motivation:
Now Netty has a few problems with null values.
Modifications:
- Check HAProxyProxiedProtocol in HAProxyMessage constructor and throw NPE if it is null.
If HAProxyProxiedProtocol is null we will set AddressFamily as null. So we will get NPE inside checkAddress(String, AddressFamily) and it won't be easy to understand why addrFamily is null.
- Check File in DiskFileUpload.toString().
If File is null we will get NPE when calling toString() method.
- Check Result<String> in MqttDecoder.decodeConnectionPayload(...).
If !mqttConnectVariableHeader.isWillFlag() || !mqttConnectVariableHeader.hasUserName() || !mqttConnectVariableHeader.hasPassword() we will get NPE when we will try to create new instance of MqttConnectPayload.
- Check Unsafe before calling unsafe.getClass() in PlatformDependent0 static block.
- Removed unnecessary null check in WebSocket08FrameEncoder.encode(...).
Because msg.content() can not return null.
- Removed unnecessary null check in DefaultStompFrame(StompCommand) constructor.
Because we have this check in the super class.
- Removed unnecessary null checks in ConcurrentHashMapV8.removeTreeNode(TreeNode<K,V>).
- Removed unnecessary null check in OioDatagramChannel.doReadMessages(List<Object>).
Because tmpPacket.getSocketAddress() always returns new SocketAddress instance.
- Removed unnecessary null check in OioServerSocketChannel.doReadMessages(List<Object>).
Because socket.accept() always returns new Socket instance.
- Pass Unpooled.buffer(0) instead of null inside CloseWebSocketFrame(boolean, int) constructor.
If we will pass null we will get NPE in super class constructor.
- Added throw new IllegalStateException in GlobalEventExecutor.awaitInactivity(long, TimeUnit) if it will be called before GlobalEventExecutor.execute(Runnable).
Because now we will get NPE. IllegalStateException will be better in this case.
- Fixed null check in OpenSslServerContext.setTicketKeys(byte[]).
Now we throw new NPE if byte[] is not null.
Result:
Added new null checks when it is necessary, removed unnecessary null checks and fixed some NPE problems.
Motivation:
We use the nanoTime of the scheduledTasks to calculate the milli-seconds to wait for a select operation to select something. Once these elapsed we check if there was something selected or some task is ready for processing. Unfortunally we not take into account scheduled tasks here so the selection loop will continue if only scheduled tasks are ready for processing. This will delay the execution of these tasks.
Modification:
- Check if a scheduled task is ready after selecting
- also make a tiny change in NioEventLoop to not trigger a rebuild if nothing was selected because the timeout was reached a few times in a row.
Result:
Execute scheduled tasks on time.
Motivation:
When Netty runs in a managed environment such as web application server,
Netty needs to provide an explicit way to remove the thread-local
variables it created to prevent class loader leaks.
FastThreadLocal uses different execution paths for storing a
thread-local variable depending on the type of the current thread.
It increases the complexity of thread-local removal.
Modifications:
- Moved FastThreadLocal and FastThreadLocalThread out of the internal
package so that a user can use it.
- FastThreadLocal now keeps track of all thread local variables it has
initialized, and calling FastThreadLocal.removeAll() will remove all
thread-local variables of the caller thread.
- Added FastThreadLocal.size() for diagnostics and tests
- Introduce InternalThreadLocalMap which is a mixture of hard-wired
thread local variable fields and extensible indexed variables
- FastThreadLocal now uses InternalThreadLocalMap to implement a
thread-local variable.
- Added ThreadDeathWatcher.unwatch() so that PooledByteBufAllocator
tells it to stop watching when its thread-local cache has been freed
by FastThreadLocal.removeAll().
- Added FastThreadLocalTest to ensure that removeAll() works
- Added microbenchmark for FastThreadLocal and JDK ThreadLocal
- Upgraded to JMH 0.9
Result:
- A user can remove all thread-local variables Netty created, as long as
he or she did not exit from the current thread. (Note that there's no
way to remove a thread-local variable from outside of the thread.)
- FastThreadLocal exposes more useful operations such as isSet() because
we always implement a thread local variable via InternalThreadLocalMap
instead of falling back to JDK ThreadLocal.
- FastThreadLocalBenchmark shows that this change improves the
performance of FastThreadLocal even more.
Motivation:
Provide a faster ThreadLocal implementation
Modification:
Add a "FastThreadLocal" which uses an EnumMap and a predefined fixed set of possible thread locals (all of the static instances created by netty) that is around 10-20% faster than standard ThreadLocal in my benchmarks (and can be seen having an effect in the direct PooledByteBufAllocator benchmark that uses the DEFAULT ByteBufAllocator which uses this FastThreadLocal, as opposed to normal instantiations that do not, and in the new RecyclableArrayList benchmark);
Result:
Improved performance
Motivation:
When running Netty on a container environment, the container will often
complain about the lingering threads such as the worker threads of
ThreadDeathWatcher and GlobalEventExecutor. We should provide an
operation that allows a use to wait until such threads are terminated.
Modifications:
- Add awaitInactivity()
- (misc) Fix typo in GlobalEventExecutorTest
- (misc) Port ThreadDeathWatch's CAS-based thread life cycle management
to GlobalEventExecutor
Result:
- Fixes#2084
- Less overhead on task submission of GlobalEventExecutor
Motivation:
When (listeners == null && lateListeners == null) and (stackDepth >= MAX_LISTENER_STACK_DEPTH), the listener is not notified at all. The discard client does not work.
Modification:
Make sure to submit the notification task.
Result:
The discard client works again and all listeners are notified.
Motivation:
4 and 5 were diverged long time ago and we recently reverted some of the
early commits in master. We must make sure 4.1 and master are not very
different now.
Modification:
Remove ChannelHandlerInvoker.writeAndFlush(...) and the related
implementations.
Result:
4.1 and master got closer.
Motivation:
4 and 5 were diverged long time ago and we recently reverted some of the
early commits in master. We must make sure 4.1 and master are not very
different now.
Modification:
Fix found differences
Result:
4.1 and master got closer.
Motivation:
EventExecutor.iterator() is fixed to return Iterator<EventExecutor> and there's no way to change that as long as we don't extend Iterable. However, a user should have a way to cast the returned set of executors painlessly. Currently, it is only possible with an explicit cast like (Iterator<NioEventLoop>).
Modifications:
Instead, I added a new method called 'children()' which returns an immutable collection of child executors whose method signature looks like the following:
<E extends EventExecutor> Set<E> children();
Result:
A user can now do this:
Set<NioEventLoop> loops = group.children();
for (NioEventLoop l: loops) { ... }
Unfortunately, this is not possible:
for (NioEventLoop l: group.children()) { ... }
However, it's still a gain that a user doesn't need to down-cast explicitly and to add the '@SuppressWarnings` annotation.
Motivation:
There's no reason to keep our users from using DefaultEventExecutor directly. It should be actually very useful to them.
Modifications:
Make DefaultEventExecutor public and add useful public constructors.
Result:
DefaultEventExecutor got usable by anyone, yielding more value as a generic library.
Motivation:
AbstractEventExecutor and AbstractEventExecutorGroup have hard-coded magic timeout numbers. They should have the same timeout numbers, but it's easy to break that rule because they are hard-coded in each place.
Modifications:
Add package private constants to AbstractEventExecutor and let AbstractEventExecutorGroup use them.
Result:
Single timeout change affects two classes.
Motivation:
EventExecutor.parent() and EventLoop.parent() almost always return a constant parent executor. There's not much reason to let it implemented in subclasses.
Modifications:
- Implement AbstractEventExecutor.parent() with an additional contructor
- Add AbstractEventLoop so that subclasses extend AbstractEventLoop, which implements parent() appropriately
- Remove redundant parent() implementations in the subclasses
- Fix inspector warnings
Result:
Less duplication.
Motivation:
Remove the synchronization bottleneck in startThread() which is called by each execute(..) call from outside the EventLoop.
Modifications:
Replace the synchronized block with the use of AtomicInteger and compareAndSet loops.
Result:
Less conditions during SingleThreadEventExecutor.execute(...)
- Fixes#2220
- Its Javadoc says it returns true when the promise is done (but not cancelled) or the promise is uncancellable, but it returns false when the promise is done.
.. which occurs when a user adds a listener from different threads after the promise is done and the notifications for the listeners, that were added before the promise is done, is in progress. For instance:
Thread-1: p.addListener(listenerA);
Thread-1: p.setSuccess(null);
Thread-2: p.addListener(listenerB);
Thread-2: p.executor.execute(taskNotifyListenerB);
Thread-1: p.executor.execute(taskNotifyListenerA);
taskNotifyListenerB should not really notify listenerB until taskNotifyListenerA is finished.
To fix this issue:
- Change the semantic of (listeners == null) to determine if the early
listeners [1] were notified
- If a late listener is added before the early listeners are notified,
the notification of the late listener is deferred until the early
listeners are notified (i.e. until listeners == null)
- The late listeners with deferred notifications are stored in a lazily
instantiated queue to preserve ordering, and then are notified once
the early listeners are notified.
[1] the listeners that were added before the promise is done
[2] the listeners that were added after the promise is done
The problem was that with OioSocketChannel there was always a read Task in the taskQueue and with the old logic it never tried to execute scheduled tasks if there was at least one task in the taskQueue.
- Fix a bug in DefaultProgressivePromise.tryProgress() where the notification is dropped
- Fix a bug in AbstractChannel.calculateMessageSize() where FileRegion is not counted
- HttpStaticFileServer example now uses zero copy file transfer if possible.
