Motivation:
In 4.1 and master branch we allow to construct an EmbeddedChannel without ChannelHandlers, we should do the same in 4.0.
Modifications:
Backport behavoir.
Result:
It's now possible to construct an EmbeddedChannel without any ChannelHandler
Motivation:
When using an EmbeddedChannel often it either does inbound or outbound processing which means we only often need one queue.
Modifications:
Lazy init the inbound and outbound message queues.
Result:
Less memory usage.
Motivation:
At the moment we directly closed the Channel when an exception accoured durring initChannel(...) without giving the user any way to do extra or special handling.
Modifications:
Handle the exception in exceptionCaught(...) of the ChannelInitializer which will by default log and close the Channel. This way the user can override this.
Result:
More felixible handling of exceptions.
Motivation:
Currently in EmbeddedChannel we add the ChannelHandlers before the Channel is registered which leads to have the handlerAdded(...) callback
be called from outside the EventLoop and also prevent the user to obtain a reference to the EventLoop in the callback itself.
Modifications:
Delay adding ChannelHandlers until EmbeddedChannel is registered.
Result:
Correctly call handlerAdded(...) after EmbeddedChannel is registered.
Motivation:
If you set a ChannelHandler via ServerBootstrap.handler(...) it is added to the ChannelPipeline before the Channel is registered. This will lead to and IllegalStateException if a user tries to access the EventLoop in the ChannelHandler.handlerAdded(...) method.
Modifications:
Delay the adding of the ChannelHandler until the Channel was registered.
Result:
No more IllegalStateException.
Motivation:
Only one of the three FixedChannelPool constructors checks for the constructor
arguments. Therfore it was possible to create a pool with zero maxConnections.
This change chains all constructors together, so that the last one
in the chain always checks the validity of the arguments, regardless of the
constructor used.
Result:
It is no longer possible to create a FixedChannelPool instance with invalid
maxConnections or maxPendingAcquires parameters.
Motivation:
FixedChannelPool should enforce a number of maximal used channels, but due a bug we fail to correctly enforce this.
Modifications:
Change check to correctly only acquire channel if we not hit the limit yet.
Result:
Correct limiting.
Motiviation:
To be consistent with changes in 4.1 and master. This is a new method and should not impact compatibility.
Modifications:
- ChannelOutboundBuffer method bytesBeforeUnWritable -> bytesBeforeUnwritable
Result:
Consistent interface for 4.0, 4.1, and master.
Motivation:
It's useful to be able to be notified once all Channels that are part of the ChannelGroup are notified. This can for example be useful if you want to do a graceful shutdown.
Modifications:
- Add ChannelGroup.newCloseFuture(...) which will be notified once all Channels are notified that are part of the ChannelGroup at the time of calling.
Result:
Easier to be notified once all Channels within a ChannelGroup are closed.
Motiviation:
There are currently no accessors which provide visbility into how many bytes must be written in order for a writability change to occur. This feature would be useful for codecs which intent to control how many bytes are queued at any given time.
Modifications:
- add bytesBeforeUnWritable() which will give the number of bytes before the buffer (and associated channel) transitions to not writable
- add bytesBeforeWritable() which will give the number of bytes that must be drained from the queue until the channel becomes writable.
Result:
More visibility into writability for the ChannelOutboundBuffer.
Motivation:
the ByteBuffer[] that we keep in the ThreadLocal are never nulled out which can lead to have ByteBuffer instances sit there forever.
This is even a bigger problem if nioBuffer() of ByteBuffer returns a new ByteBuffer that can not be destroyed by ByteBuffer.release().
Modifications:
Null out ByteBuffer array after processing.
Result:
No more dangling references after done.
Motivation:
SingleThreadEventLoopTest.testScheduleTaskAtFixedRate() fails often due to:
- too little tolerance
- incorrect assertion (it compares only with the previous timestamp)
Modifications:
- Increase the timestamp difference tolerance from 10ms to 20ms
- Improve the timestamp assertion so that the comparison is performed against the first recorded timestamp
- Misc: Fix broken Javadoc tag
Result:
More build stability
Motivation:
When trying to write more then Integer.MAX_VALUE / SSIZE_MAX via writev(...) the OS may return EINVAL depending on the kernel or the actual OS (bsd / osx always return EINVAL). This will trigger an IOException.
Modifications:
Never try to write more then Integer.MAX_VALUE / SSIZE_MAX when using writev.
Result:
No more IOException when write more data then Integer.MAX_VALUE / SSIZE_MAX via writev.
Motivation:
In the SslHandler we schedule a timeout at which we close the Channel if a timeout was detected during close_notify. Because this can race with notify the flushFuture we can see an IllegalStateException when the Channel is closed.
Modifications:
- Use a trySuccess() and tryFailure(...) to guard against race.
Result:
No more race.
Motivation:
We should not trigger channelWritabilityChanged during failing message when we are about to close the Channel as otherwise the use may try again writing even if the Channel is about to get closed.
Modifications:
Add new boolean param to ChannelOutboundBuffer.failFlushed(...) which allows to specify if we should notify or not.
Result:
channelWritabilityChanged is not triggered anymore if we cloe the Channel because of an IOException during write.
Motivation:
Previously, we deferred the closing of the Channel when we were flushing. This is problematic as this means that if the user adds a ChannelFutureListener, that will close the Channel, the closing will not happen until we are done with flushing. This can lead to more data is sent than expected.
Modifications:
- Do not defer closing when in flush
Result:
Correctly respect order of events and closing the Channel ASAP
Motivation:
The semantic of LocalChannel.doWrite(...) were a bit off as it notified the ChannelFuture before the data was actual moved to the peer buffer.
Modifications:
- Use our MPSC queue as inbound buffer
- Directly copy to data to the inbound buffer of the peer and either success or fail the promise after each copy.
Result:
Correct semantic and less memory copies.
Motiviation:
If user events or excpetions reach the tail end of the pipeline they are not released. This could result in buffer leaks.
Motivation:
- Use the ReferenceCountUtil.release to release objects for the userEventTriggered and exceptionCaught methods on DefaultChannelPipeline
Result:
2 less areas where buffer leaks can occur.
Motivation:
Many projects need some kind a Channel/Connection pool implementation. While the protocols are different many things can be shared, so we should provide a generic API and implementation.
Modifications:
Add ChannelPool / ChannelPoolMap API and implementations.
Result:
Reusable / Generic pool implementation that users can use.
Motivation:
Because of a bug we missed to fail the connect future when doClose() is called. This can lead to a future which is never notified and so may lead to deadlocks in user-programs.
Modifications:
Correctly fail the connect future when doClose() is called and the connection was not established yet.
Result:
Connect future is always notified.
Related: #3464
Motivation:
When a connection attempt is failed,
NioSocketChannelUnsafe.closeExecutor() triggers a SocketException,
suppressing the channelUnregistered() event.
Modification:
Do not attempt to get SO_LINGER value when a socket is not open yet.
Result:
One less bug
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:
We should allow to get a ChannelOption/AttributeKey from a String. This will make it a lot easier to make use of configuration files in applications.
Modifications:
- Add exists(...), newInstance(...) method to ChannelOption and AttributeKey and alter valueOf(...) to return an existing instance for a String or create one.
- Add unit tests.
Result:
Much more flexible usage of ChannelOption and AttributeKey.
Motivation:
As we plan to have other native transports soon (like a kqueue transport) we should move unix classes/interfaces out of the epoll package so we
introduce other implementations without breaking stuff before the next stable release.
Modifications:
Create a new io.netty.channel.unix package and move stuff over there.
Result:
Possible to introduce other native impls beside epoll.
