Motivation:
Currently, the vast majority of userEventTriggered() implementations
require the user to supply the boilerplate behavior of performing an
instanceof check, handling if appropriate, and calling
fireUserEventTriggered() otherwise.
We can simplify this very common use case by creating a class that only
matches user events of a given type, similar to the existing
SimpleChannelInboundHandler class.
Modifications:
Create a new SimpleUserEventChannelHandler class
Create accompanying SimpleUserEventChannelHandlerTest class
Result:
Users will be able to handle most events in a less verbose manner.
Motivation:
We use FixedChannelPool in production, and we believe we have a leak that doesn't return sockets to the pool (but they should be closed), thus blocking us from creating new connections when we need them. I haven't confirmed this yet, but right now I have to resort to reflection to access this field which makes me sad.
Modification:
Expose the acquiredChannelCount field through a getter method.
Result:
Allows introspection of the pool size in FixedChannelPool.
Motivation
There is a cost to concatenating strings and calling methods that will be wasted if the Logger's level is not enabled.
Modifications
Check if Log level is enabled before producing log statement. These are just a few cases found by RegEx'ing in the code.
Result
Tiny bit more efficient code.
Motivation:
If we can not replace the internal used Set of the Selector there is no need to create an SelectedSelectionKeySet instance.
Modification:
Only create SelectedSelectionKeySet if we will replace the internal set.
Result:
Less object creation in some cases and cleaner code.
Motivation:
We should allow to schedule tasks with a delay up to Long.MAX_VALUE as we did pre 4.1.25.Final.
Modifications:
Just ensure we not overflow and put the correct max limits in place when schedule a timer. At worse we will get a wakeup to early and then schedule a new timeout.
Result:
Fixes https://github.com/netty/netty/issues/7970.
Motivation:
A long time ago we deprecated AUTO_CLOSE but it turned out this feature is still useful because if a write error is detected there still maybe data to read, and if we close the channel automatically we will lose data
Modifications:
- Remove `@Deprecated` tag for AUTO_CLOSE, setAutoClose(...) and isAutoClose(...)
- Fix javadocs on ChannelConfig to correctly tell the default value of AUTO_CLOSE.
Result:
Less warnings.
Motivation:
We need to ensure we only return from close() after all work is done as otherwise we may close the EventExecutor before we dispatched everything.
Modifications:
Correctly wait on operations to complete before return.
Result:
Fixes https://github.com/netty/netty/issues/7901.
Motivation:
We added some code to guard against thread.interrupt() in NioEventLoop but did not added a test.
Modifications:
Add testcase.
Result:
Verify that we correctly handle interrupt().
Motivation:
Closed `FixedChannelPool` fails acquire and release operations with
`IllegalStateException`s. These exceptions had message
"FixedChannelPooled was closed". Here "FixedChannelPooled" looks like
a typo and should probably be "FixedChannelPool".
Modifications:
Changed exception message to "FixedChannelPool was closed".
Result:
A tiny bit cleaner exception message.
Motivation:
ChannelReadHandler is used in tests added via f4d7e8de14. In the handler we verify the number of messages we receive per read() call but missed to sometimes reset the counter which resulted in exceptions.
Modifications:
Correctly reset read counter in all cases.
Result:
No more unexpected exceptions when running LocalChannel tests.
Motivation:
LocalChannel / LocalServerChannel did not respect read limits and just always read all of the messages.
Modifications:
- Correct respect MAX_MESSAGES_PER_READ settings
- Add unit tests
Result:
Fixes https://github.com/netty/netty/issues/7880.
Motivation:
Using a very huge delay when calling schedule(...) may cause an Selector error when calling select(...) later on. We should gaurd against such a big value.
Modifications:
- Add guard against a very huge value.
- Added tests.
Result:
Fixes [#7365]
Motivation:
We need to ensure we only reset readInProgress if the outboundBuffer is not empty as otherwise we may miss to call fireChannelRead(...) later on when using the LocalChannel.
Modifications:
Also check if the outboundBuffer is not empty before setting readInProgress to false again
Result:
Fixes https://github.com/netty/netty/issues/7855
Motivation:
Some `if` statements contains common parts that can be extracted.
Modifications:
Extract common parts from `if` statements.
Result:
Less code and bytecode. The code is simpler and more clear.
Motivation:
AbstractNioByteChannel will detect that the remote end of the socket has
been closed and propagate a user event through the pipeline. However if
the user has auto read on, or calls read again, we may propagate the
same user events again. If the underlying transport continuously
notifies us that there is read activity this will happen in a spin loop
which consumes unnecessary CPU.
Modifications:
- AbstractNioByteChannel's unsafe read() should check if the input side
of the socket has been shutdown before processing the event. This is
consistent with EPOLL and KQUEUE transports.
- add unit test with @normanmaurer's help, and make transports consistent with respect to user events
Result:
No more read spin loop in NIO when the channel is half closed.
Motivation:
Sometimes it is very convenient to remove the handler from pipeline without throwing the exception in case those handler doesn't exist in the pipeline.
Modification:
Added 3 overloaded methods to DefaultChannelPipeline, but not added to ChannelHandler due to back compatibility.
Result:
Fixes#7662
Motivation:
Our code was not correct in AbstractNioMessageChannel.closeOnReadError(....) which lead to the situation that we always tried to continue reading no matter what exception was thrown when using the NioServerSocketChannel. Also even on an IOException we should check if the Channel itself is still active or not and if not stop reading.
Modifications:
Fix closeOnReadError impl and added test.
Result:
Correctly stop reading on NioServerSocketChannel when error happens during read.
Motivation:
DefaultChannelGroup.contains(...) did one more instanceof check then needed.
Modifications:
Simplify contains(...) and remove one instanceof check.
Result:
Simplier and cheaper implementation.
Motivation:
Right now PendingWriteQueue.removeAndWriteAll collects all promises to
PromiseCombiner instance which sets listener to each given promise throwing
IllegalStateException on VoidChannelPromise which breaks while loop
and "reports" operation as failed (when in fact part of writes might be
actually written).
Modifications:
Check if the promise is not void before adding it to the PromiseCombiner
instance.
Result:
PendingWriteQueue.removeAndWriteAll succesfully writes all pendings
even in case void promise was used.
Motivation:
The flush task is currently using flush() which will have the affect of have the flush traverse the whole ChannelPipeline and also flush messages that were written since we gave up flushing. This is not really correct as we should only continue to flush messages that were flushed at the point in time when the flush task was submitted for execution if the user not explicit call flush() by him/herself.
Modification:
Call *Unsafe.flush0() via the flush task which will only continue flushing messages that were marked as flushed before.
Result:
More correct behaviour when the flush task is used.
Motivation:
b215794de3 recently introduced a change in behavior where writeSpinCount provided a limit for how many write operations were attempted per flush operation. However when the write quantum was meet the selector write flag was not cleared, and the channel unsafe flush0 method has an optimization which prematurely exits if the write flag is set. This may lead to no write progress being made under the following scenario:
- flush is called, but the socket can't accept all data, we set the write flag
- the selector wakes us up because the socket is writable, we write data and use the writeSpinCount quantum
- we then schedule a flush() on the EventLoop to execute later, however it the flush0 optimization prematurely exits because the write flag is still set
In this scenario the socket is still writable so the EventLoop may never notify us that the socket is writable, and therefore we may never attempt to flush data to the OS.
Modifications:
- When the writeSpinCount quantum is exceeded we should clear the selector write flag
Result:
Fixes https://github.com/netty/netty/issues/7729
Motivation:
NioDatagramChannel attempts to unpack a AddressedEnvelope and unconditionally uses internalNioBuffer. However if the ByteBuf is a CompositeByteBuf with more than 1 components, the write will fail and throw an exception.
Modifications:
- NioDatagramChannel should check the nioBufferCount before attempting
to use internalNioBuffer
Result:
No more failure to write UDP packets on NIO when a CompositeByteBuf is
used.
Motivation:
Reflective setAccessible(true) will produce scary warnings on the console when using java9+, while netty still works. That said users may feel uncomfortable with these warnings, we should not try to do it by default when using java9+.
Modifications:
Add io.netty.tryReflectionSetAccessible system property which controls if setAccessible(...) will be used. By default it will bet set to false when using java9+.
Result:
Fixes [#7254].
Motivation:
The methods implement io.netty.util.concurrent.Future#cancel(boolean mayInterruptIfRunning) which actually ignored the param mayInterruptIfRunning.We need to add comments for the `mayInterruptIfRunning` param.
Modifications:
Add comments for the `mayInterruptIfRunning` param.
Result:
People who call the `cancel` method will be more clear about the effect of `mayInterruptIfRunning` param.
Motivation:
When VoidChannelPromise.unvoid() was called we created a new ChannelFutureListener everytime. This is not needed as its stateless.
Modifications:
Reuse the ChannelFutureListener.
Result:
Less object allocations
Motiviation:
DefaultChannelPipeline and AbstractChannelHandlerContext maintain state
which indicates if a ChannelHandler should be invoked or not. However
the state is updated to allow the handler to be invoked only after the
handlerAdded method completes. If the handlerAdded method generates
events which may result in other methods being invoked on that handler
they will be missed.
Modifications:
- DefaultChannelPipeline should set the state before calling
handlerAdded
Result:
DefaultChannelPipeline will allow events to be processed during the
handlerAdded process.
Motivation:
We should fail fast when DefaultChannelPromise is constructed with null as Channel as otherwise it will fail with a NPE once we call setSuccess / setFailure.
Modifications:
Add null check and test.
Result:
Fail fast.
Motivation:
Will allow easy removal of deprecated methods in future.
Modification:
Replaced ctx.attr(), ctx.hasAttr() with ctx.channel().attr(), ctx.channel().hasAttr().
Result:
No deprecated ctx.attr(), ctx.hasAttr() methods usage.
Motivation:
As shown in issues it is sometimes hard to understand why a leak was reported when the user just calles EmbeddedChannel.readInbound() / EmbeddedChannel.readOutbound() and drop the message on the floor.
Modifications:
Add a hint before handover the message to the user and transfer the ownership.
Result:
Easier debugging of leaks caused by EmbeddedChannel.read*().
Motivation :
Avoid unnecessary array allocation when using the function with varargs in the DefaultChannelPipeline class.
Modifications :
Added addLast and addFirst overloaded methods with 1 handler instead of varargs.
Result :
No array allocation when using simple construction like pipeline.addLast(new Handler());
Motivation
There is currently no way to enforce the position of a handler in a ChannelPipeline and assume you wanted to write something like a custom Channel type that acts as a proxy between two other Channels.
ProxyChannel(Channel client, Channel server) {
client calls write(msg) -> server.write(msg)
client calls flush() -> server.flush()
server calls fireChannelRead(msg) -> client.write(msg)
server calls fireChannelReadComplete() -> client.flush()
}
In order to make it work reliably one needs to be able to scoop up the various events at the head and tail of the pipeline. The head side of the pipeline is covered by Unsafe and it's also relatively safe to count on the user to not use the addFirst() method to manipulate the pipeline. The tail side is always at a risk of getting broken because addLast() is the goto method to add handlers.
Modifications
Adding a few extra methods to DefaultChannelPipeline that expose some of the events that reach the pipeline's TailContext.
Result
Fixes#7484
