Motivation:
Our SelectedSelectionKeySet does not correctly implement various methods which can be done without any performance overhead.
Modifications:
Implement iterator(), contains(...) and remove(...)
Result:
Related to https://github.com/netty/netty/issues/8242.
Motivation:
We had a report that the exception may not be correctly propagated. This test shows it is.
Modifications:
Add testcase.
Result:
Test for https://github.com/netty/netty/issues/8158
Motivation:
There is a JDK bug which will return IP_TOS as supported option for ServerSocketChannel even if its not supported afterwards and cause an AssertionError.
See http://mail.openjdk.java.net/pipermail/nio-dev/2018-August/005365.html.
Modifications:
Add a workaround for the JDK bug.
Result:
ServerSocketChannel.config().getOptions() will not throw anymore and work as expected.
* Support the usage of SocketOption when nio is used and the java version >= 7.
Motivation:
The JDK uses SocketOption since java7 to support configuration options on the underyling Channel. We should allow to create a ChannelOption from a given SocketOption if nio is used. This also allows us to expose the same featureset in terms of configuration as the java nio implementation does without any extra effort.
Modifications:
- Add NioChannelOption which allows to wrap an existing SocketOption which then can be applied to the nio transport.
- Add test-cases
Result:
Support the same configuration options as the JDK. Also fixes https://github.com/netty/netty/issues/8072.
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 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:
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:
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:
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:
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.
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
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
* FIX: force a read operation for peer instead of self
Motivation:
When A is in `writeInProgress` and call self close, A should
`finishPeerRead` for B(A' peer).
Modifications:
Call `finishPeerRead` with peer in `LocalChannel#doClose`
Result:
Clear confuse of code logic
* FIX: preserves order of close after write in same event loop
Motivation:
If client and server(client's peer channel) are in same event loop, client writes data to
server in `ChannelActive`. Server receives the data and write it
back. The client's read can't be triggered becasue client's
`ChannelActive` is not finished at this point and its `readInProgress`
is false. Then server closes itself, it will also close the client's
channel. And client has no chance to receive the data.
Modifications:
1. Add a test case to demonstrate the problem
2. When `doClose` peer, we always call
`peer.eventLoop().execute()` and `registerInProgress` is not needed.
3. Remove test case
`testClosePeerInWritePromiseCompleteSameEventLoopPreservesOrder`. This
test case can't pass becasue of this commit. IMHO, I think it is OK,
becasue it is reasonable that the client flushes the data to socket,
then server close the channel without received the data.
4. For mismatch test in SniClientTest, the client should receive server's alert before closed(caused by server's close)
Result:
The problem is gone.
Motivation:
AdaptiveRecvByteBufAllocator currently adjusts the ByteBuf allocation size guess when readComplete is called. However the default configuration for number of reads before readComplete is called is 16. This means that there will be 16 reads done before any adjustment is done. If there is a large amount of data pending AdaptiveRecvByteBufAllocator will be slow to adjust the allocation size guess. In addition to being slow the result of only updating the guess in readComplete means that we must go back to the selector and wait to be woken up again when data is ready to read. Going back to the selector is an expensive operations and can add significant latency if there is large amount of data pending to read.
Modifications:
- AdaptiveRecvByteBufAllocator should check on each read if a step up is necessary. The step down process is left unchanged and can be more gradual at the cost of potentially over allocating.
Result:
AdaptiveRecvByteBufAllocator increases the guess size during the read loop to reduce latency when large amounts of data is being read.
Motivation:
`FixedChannelPool` allows users to configure `acquireTimeoutMillis`
and expects given value to be greater or equal to zero when timeout
action is supplied. However, validation error message said that
value is expected to be greater or equal to one. Code performs
check against zero.
Modifications:
Changed error message to say that value greater or equal to
zero is expected. Added test to check that zero is an acceptable
value.
Result:
Exception with right error message is thrown.
Motivation:
AbstractCoalescingBufferQueue#add accounts for void promises, but AbstractCoalescingBufferQueue#addFirst does not. These methods should be consistent.
Modifications:
- AbstractCoalescingBufferQueue#addFirst should account for void promises and share code with AbstractCoalescingBufferQueue#add
Result:
More correct void promise handling in AbstractCoalescingBufferQueue.
Motivation:
A regression was introduced in 86e653e which had the effect that the writability was not updated for a Channel while queueing data in the SslHandler.
Modifications:
- Factor out code that will increment / decrement pending bytes and use it in AbstractCoalescingBufferQueue and PendingWriteQueue
- Add test-case
Result:
Channel writability changes are triggered again.
Motivation:
Without a 'serialVersionUID' field, any change to a class will make
previously serialized versions unreadable.
Modifications:
Add missed 'serialVersionUID' field for all Serializable
classes.
Result:
Proper deserialization of previously serialized objects.
Motivation:
When a user called ctx.close() and used the EmbeddedChannel we did not correctly run all pending tasks which means channelInactive was never called.
Modifications:
Ensure we run all pending tasks after all operations that may change the Channel state and are part of the Channel.Unsafe impl.
Result:
Fixes [#6894].
Motivation:
ErrorProne complains that the array override doesn't match the
vararg super call. See http://errorprone.info/bugpattern/Overrides
Additionally, almost every other Future uses the vararg form, so
it would be stylistically consistent to keep it that way.
Modifications:
Use vararg override.
Result:
Cleaner, less naggy code.
Motivation:
Some ChannelOptions must be set before the Channel is really registered to have the desired effect.
Modifications:
Add another constructor argument which allows to not register the EmbeddedChannel to its EventLoop until the user calls register().
Result:
More flexible usage of EmbeddedChannel. Also Fixes [#6968].
Motivation:
We had recently a report that the issue [#6607] is still not fixed.
Modifications:
Add a testcase to prove the issue is fixed.
Result:
More tests.
Motivation:
The behaviour of the FixedChannelPool.release was inconsistent with the
SimpleChannelPool implementation, in that given promise is returned.
In the FixedChannelPool implementation a new promise was return and
this meant that the completion of that promise can be different.
Specifically on releasing a channel to a closed pool, the parameter
promise is failed with an IllegalStateException but the returned one
will have been successful (as it was completed by call to super
.release)
Modification:
Return the given promise as the result of FixedChannelPool.release
Result:
Returned promise will reflect the result of the release operation.
Motivation:
Channels returned to a FixedChannelPool after closing it remain active.
Since channels that where acquired from the pool are not closed during the close operation, they remain open even after releasing the channel back to the pool where they are then in accessible and become in-effect a connection leak.
Modification:
Close the released channel on releasing back to a closed pool.
Result:
Much harder to create a connection leak by closing an active
FixedChannelPool instance.
Motivation:
We should not fail the promise when a closed Channel is offereed back to the ChannelPool as we explicit mention that the Channel must always be returned.
Modifications:
- Not fail the promise
- Add test-case
Result:
Fixes [#6831]
Motivation:
ChannelPipeline will happily add a handler to a closed Channel's pipeline and will call handlerAdded(...) but will not call handlerRemoved(...).
Modifications:
Check if pipeline was destroyed and if so not add the handler at all but propergate an exception.
Result:
Fixes [#6768]
Motivation:
We need to release all the buffers that may be put into our inbound queue since we closed the Channel to ensure we not leak any memory. This is fine as it basically gives the same guarantees as TCP which means even if the promise was notified before its not really guaranteed that the "remote peer" will see the buffer at all.
Modifications:
Ensure we release all buffers in the inbound buffer if a doClose() is called.
Result:
No more leaks.
Motivation:
When a VoidChannelPromise is used by the user we need to ensure we propergate the exception through the ChannelPipeline otherwise the exception will just be swallowed and so the user has no idea whats going on.
Modifications:
- Always call tryFailure / trySuccess even when we use the VoidChannelPromise
- Add unit test
Result:
Fixes [#6622].
Motivation:
There are numerous usages of internalNioBuffer which hard code 0 for the index when the intention was to use the readerIndex().
Modifications:
- Remove hard coded 0 for the index and use readerIndex()
Result:
We are less susceptible to using the wrong index, and don't make assumptions about the ByteBufAllocator.
Motivation:
We have our own ThreadLocalRandom implementation to support older JDKs . That said we should prefer the JDK provided when running on JDK >= 7
Modification:
Using ThreadLocalRandom implementation of the JDK when possible.
Result:
Make use of JDK implementations when possible.
Motivation:
SelectedSelectionKeySet currently uses 2 arrays internally and users are expected to call flip() to access the underlying array and switch the active array. However we do not concurrently use 2 arrays at the same time and we can get away with using a single array if we are careful about when we reset the elements of the array.
Modifications:
- Introduce SelectedSelectionKeySetSelector which wraps a Selector and ensures we reset the underlying SelectedSelectionKeySet data structures before we select
- The loop bounds in NioEventLoop#processSelectedKeysOptimized can be defined more precisely because we know the real size of the underlying array
Result:
Fixes https://github.com/netty/netty/issues/6058
Motiviation:
Simplify implementation of compareTo/equals/hashCode for ChannelIds.
Modifications:
We simplfy the hashCode implementation for DefaultChannelId by not
making it random, but making it based on the underlying data. We fix the
compareTo implementation for DefaultChannelId by using lexicographic
comparison of the underlying data array. We fix the compareTo
implementation for CustomChannelId to avoid the possibility of overflow.
Result:
Cleaner code that is easier to maintain.
Motivation:
Result of validatePromise() is always inverted with if (!validatePromise()).
Modification:
validatePromise() renamed to isNotValidPromise() and now returns inverted state so you don't need to invert state in conditions. Also name is now more meaningful according to returned result.
Added more tests for validatePromise corner cases with Exceptions.
Result:
Code easier to read. No need in inverted result.
Motivation:
We used various mocking frameworks. We should only use one...
Modifications:
Make usage of mocking framework consistent by only using Mockito.
Result:
Less dependencies and more consistent mocking usage.
Motivation:
`SimpleChannelPool` subclasses are likely to override the `connectChannel` method, and are likely to clobber the cloned `Bootstrap` handler in the process. To allow subclasses to properly notify the pool listener of new connections, we should expose (at least) the `handler` property of the pool to subclasses.
Modifications:
Expose `SimpleChannelPool` properties to subclasses via `protected` getters.
Result:
Subclasses can now use the bootstrap, handler, health checker, and health-check-on-release preoperties from their superclass.
Motivation:
Netty provides a adaptor from ByteBuf to Java's InputStream interface. The JDK Stream interfaces have an explicit lifetime because they implement the Closable interface. This lifetime may be differnt than the ByteBuf which is wrapped, and controlled by the interface which accepts the JDK Stream. However Netty's ByteBufInputStream currently does not take reference count ownership of the underlying ByteBuf. There may be no way for existing classes which only accept the InputStream interface to communicate when they are done with the stream, other than calling close(). This means that when the stream is closed it may be appropriate to release the underlying ByteBuf, as the ownership of the underlying ByteBuf resource may be transferred to the Java Stream.
Motivation:
- ByteBufInputStream.close() supports taking reference count ownership of the underyling ByteBuf
Result:
ByteBufInputStream can assume reference count ownership so the underlying ByteBuf can be cleaned up when the stream is closed.
Motivation:
To guard against the case that a user will enqueue a lot of empty or small buffers and so raise an OOME we need to also take the overhead of the ChannelOutboundBuffer / PendingWriteQueue into account when detect if a Channel is writable or not. This is related to #5856.
Modifications:
When calculate the memory for an message that is enqueued also add some extra bytes depending on the implementation.
Result:
Better guard against OOME.
Motivation:
Some unit tests in SingleThreadEventLoopTest rely upon Thread.sleep for sequencing events between threads. This can be unreliable and result in spurious test failures if thread scheduling does not occur in a fair predictable manner.
Modifications:
- Reduce the reliance on Thread.sleep in SingleThreadEventLoopTest
Result:
Fixes https://github.com/netty/netty/issues/5851
Motivation:
the build doesnt seem to enforce this, so they piled up
Modifications:
removed unused import lines
Result:
less unused imports
Signed-off-by: radai-rosenblatt <radai.rosenblatt@gmail.com>
the implicit #fireChannelReadComplete() in EmbeddedChannel#writeInbound().
Motivation
We use EmbeddedChannels to implement a ProxyChannel of some sorts that shovels
messages between a source and a destination Channel. The latter are real network
channels (such as Epoll) and they may or may not be managed in a ChannelPool. We
could fuse both ends directly together but the EmbeddedChannel provides a nice
disposable section of a ChannelPipeline that can be used to instrument the messages
that are passing through the proxy portion.
The ideal flow looks abount like this:
source#channelRead() -> proxy#writeOutbound() -> destination#write()
source#channelReadComplete() -> proxy#flushOutbound() -> destination#flush()
destination#channelRead() -> proxy#writeInbound() -> source#write()
destination#channelReadComplete() -> proxy#flushInbound() -> source#flush()
The problem is that #writeOutbound() and #writeInbound() emit surplus #flush()
and #fireChannelReadComplete() events which in turn yield to surplus #flush()
calls on both ends of the pipeline.
Modifications
Introduce a new set of write methods that reain the same sematics as the #write()
method and #flushOutbound() and #flushInbound().
Result
It's possible to implement the above ideal flow.
Fix for EmbeddedChannel#ensureOpen() and Unit Tests for it
Some PR stuff.
Motivation:
The API documentation in ChannelConfig states that a a channel is writable,
if the number of pending bytes is below the low watermark and a
channel is not writable, if the number of pending bytes exceeds the high
watermark.
Therefore, we should use < operators instead of <= as well as > instead of >=.
Using <= and >= is also problematic, if the low watermark is equal to the high watermark,
as then a channel could be both writable and unwritable with the same number of pending
bytes (depending on whether remove() or addMessage() is called first).
The use of <= and >= was introduced in PR https://github.com/netty/netty/pull/3036, but
I don't understand why, as there doesn't seem to have been any discussion around that.
Modifications:
Use < and > operators instead of <= and >=.
Result:
High and low watermarks are treated as stated in the API docs.
Motivation:
PendingWriteQueue should guard against re-entrant writes once removeAndWriteAll() is run.
Modifications:
Continue writing until queue is empty.
Result:
Correctly guard against re-entrance.
Motivation:
If the user uses 0 as quiet period we should shutdown without any delay if possible.
Modifications:
Ensure we not introduce extra delay when a shutdown quit period of 0 is used.
Result:
EventLoop shutdown as fast as expected.
Motivation:
At the moment we call initChannel(...) in the channelRegistered(...) method which has the effect that if another ChannelInitializer is added within the initChannel(...) method the ordering of the added handlers is not correct and surprising. This is as the whole initChannel(...) method block is executed before the initChannel(...) block of the added ChannelInitializer is handled.
Modifications:
Call initChannel(...) from within handlerAdded(...) if the Channel is registered already. This is true in all cases for our DefaultChannelPipeline implementation. This way the ordering is always as expected. We still keep the old behaviour as well to not break code for other ChannelPipeline implementations (if someone ever wrote one).
Result:
Correct and expected ordering of ChannelHandlers.
Motivation:
I received a report the its not possible to add another ChannelInitialiter in the initChannel(...) method, so we should add a test case for it.
Modifications:
Added testcase.
Result:
Validate that all works as expected.
Motivation:
When a ChannelInitializer is used via ServerBootstrap.handler(...) the users handlers may be added after the internal ServerBootstrapAcceptor. This should not happen.
Modifications:
Delay the adding of the ServerBootstrapAcceptor until the initChannel(....) method returns.
Result:
Correct order of handlers in the ServerChannels ChannelPipeline.
Motivation:
This change is part of the change done in PR #5395 to provide an `AUTO_FLUSH` capability.
Splitting this change will enable to try other ways of implementing `AUTO_FLUSH`.
Modifications:
Two methods:
```java
void executeAfterEventLoopIteration(Runnable task);
boolean removeAfterEventLoopIterationTask(Runnable task);
```
are added to `SingleThreadEventLoop` class for adding/removing a task to be executed at the end of current/next iteration of this `eventloop`.
In order to support the above, a few methods are added to `SingleThreadEventExecutor`
```java
protected void afterRunningAllTasks() { }
```
This is invoked after all tasks are run for this executor OR if the passed timeout value for `runAllTasks(long timeoutNanos)` is expired.
Added a queue of `tailTasks` to `SingleThreadEventLoop` to hold all tasks to be executed at the end of every iteration.
Result:
`SingleThreadEventLoop` now has the ability to execute tasks at the end of an eventloop iteration.
Motivation:
For some use-cases it would be useful to know the number of bytes queued in the PendingWriteQueue without the need to dequeue them.
Modifications:
Add PendingWriteQueue.bytes().
Result:
Be able to get the number of bytes queued.
Motivation:
Commit 4c048d069d moved the logic of calling handlerAdded(...) to the channelRegistered(...) callback of the head of the DefaultChannelPipeline. Unfortunatlly this may execute the callbacks to late as a user may add handlers to the pipeline in the ChannelFutureListener attached to the registration future. This can lead to incorrect ordering.
Modifications:
Ensure we always invoke ChannelHandler.handlerAdded(...) for all handlers before the registration promise is notified.
Result:
Not possible of incorrect ordering or missed events.
Motivation:
We pinned the EventExecutor for a Channel in DefaultChannelPipeline. Which means if the user added multiple handlers with the same EventExecutorGroup to the ChannelPipeline it will use the same EventExecutor for all of these handlers. This may be unexpected and even not what the user wants. If the user want to use the same one for all of them it can be done by obtain an EventExecutor and pass the same instance to the add methods. Because of this we should allow to not pin.
Modifications:
Allow to disable pinning of EventExecutor for Channel based on EventExecutorGroup via ChannelOption.
Result:
Less confusing and more flexible usage of EventExecutorGroup when adding ChannelHandlers to the ChannelPipeline.
Motivation:
In commit f984870ccc I made a change which operated under invalide assumption that tasks executed by an EventExecutor will always be processed in a serial fashion. This is true for SingleThreadEventExecutor sub-classes but not part of the EventExecutor interface contract.
Because of this change implementations of EventExecutor which not strictly execute tasks in a serial fashion may miss events before handlerAdded(...) is called. This is strictly speaking not correct as there is not guarantee in this case that handlerAdded(...) will be called as first task (as there is no ordering guarentee).
Cassandra itself ships such an EventExecutor implementation which has no strict ordering to spread load across multiple threads.
Modifications:
- Add new OrderedEventExecutor interface and let SingleThreadEventExecutor / EventLoop implement / extend it.
- Only expose "restriction" of skipping events until handlerAdded(...) is called for OrderedEventExecutor implementations
- Add ThreadPoolEventExecutor implementation which executes tasks in an unordered fashion. This is used in added unit test but can also be used for protocols which not expose an strict ordering.
- Add unit test.
Result:
Resurrect the possibility to implement an EventExecutor which does not enforce serial execution of events and be able to use it with the DefaultChannelPipeline.
Motivation:
When `ChannelFactory#newChannel` crashed, `AbstractBootstrap#initAndRegister` propagates the exception to the caller instead of failing the promise.
Modifications:
- Catch exceptions from `ChannelFactory#newChannel`.
- Notify promise of such failure.
Result:
`AbstractBootstrap` gracefully handles connect failures.
Motivation:
JCTools supports both non-unsafe, unsafe versions of queues and JDK6 which allows us to shade the library in netty-common allowing it to stay "zero dependency".
Modifications:
- Remove copy paste JCTools code and shade the library (dependencies that are shaded should be removed from the <dependencies> section of the generated POM).
- Remove usage of OneTimeTask and remove it all together.
Result:
Less code to maintain and easier to update JCTools and less GC pressure as the queue implementation nt creates so much garbage
Motivation:
There is a small race while adding handlers to the pipeline because callHandlerAddedForAllHandlers() may not be run when the user calls add* but the Channel is already registered.
Modifications:
Ensure we always delay handlerAdded(..) / handlerRemoved(...) until callHandlerAddedForAllHandlers() was called.
Result:
No more race on pipeline modifications possible.
Motivation:
While doing 8fe3c83e4c I made a change which disallowed using null as name for handlers in the pipeline (this generated a new name before).
Modifications:
Revert to old behaviour and adding test case.
Result:
Allow null name again
Motivation:
At the moment the user is responsible to increase the writer index of the composite buffer when a new component is added. We should add some methods that handle this for the user as this is the most popular usage of the composite buffer.
Modifications:
Add new methods that autoamtically increase the writerIndex when buffers are added.
Result:
Easier usage of CompositeByteBuf.
Motivation:
EventLoopGroup.register doesn't need the Channel paramter when ChannelPromise is provided as we can get the Channel from ChannelPromise. Resolves#2422.
Modifications:
- Add EventLoopGroup.register(ChannelPromise)
- Deprecate EventLoopGroup.register(Channel, ChannelPromise)
Result:
EventLoopGroup.register is more convenient as people only need to set one parameter.
Motivation:
If the user will use addLast(...) on the ChannelPipeline of EmbeddedChannel after its constructor was run it will break the EmbeddedChannel as it will not be able to collect inbound messages and exceptions.
Modifications:
Ensure addLast(...) work as expected by move the logic of handling messages and exceptions ti protected methods of DefaultChannelPipeline and use a custom implementation for EmbeddedChannel
Result:
addLast(...) works as expected when using EmbeddedChannel.
Motivation:
When a user has multiple EventLoops in an EventLoopGroup and calls pipeline.add* / remove* / replace from an EventLoop that belongs to another Channel it is possible to deadlock if the other EventLoop does the same.
Modification:
- Only ensure the actual modification takes place in a synchronized block and not wait until the handlerAdded(...) / handlerRemoved(...) method is called. This is ok as we submit the task to the executor while still holding the look and so ensure correct order of pipeline modifications.
- Ensure if an AbstractChannelHandlerContext is put in the linked-list structure but the handlerAdded(...) method was not called we skip it until handlerAdded(...) was called. This is needed to ensure handlerAdded(...) is always called first.
Result:
Its not possible to deadlock when modify the DefaultChannelPipeline.
Related: #4333#4421#5128
Motivation:
slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.
Modifications:
- Add the following methods which creates a non-recyclable derived buffer
- retainedSlice()
- retainedDuplicate()
- readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
- a user can replace the content of the holder in a consistent way
- copy/duplicate/retainedDuplicate() can delegate the holder
construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
- Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
- Make ReplayingDecoderByteBuf.reject() return an exception instead of
throwing it so that its callers don't need to add dummy return
statement
Result:
Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
Motivation:
We tried to provide the ability for the user to change the semantics of the threading-model by delegate the invoking of the ChannelHandler to the ChannelHandlerInvoker. Unfortunually this not really worked out quite well and resulted in just more complexity and splitting of code that belongs together. We should remove the ChannelHandlerInvoker again and just do the same as in 4.0
Modifications:
Remove ChannelHandlerInvoker again and replace its usage in Http2MultiplexCodec
Result:
Easier code and less bad abstractions.
Motivation:
To be more consistent we should use ConnectException when we fail the connect attempt because no LocalServerChannel exists with the given address.
Modifications:
Use correct exception.
Result:
More consistent handling of connection refused between different transports.
Motivation:
Bootstrap.connect(...) tries to obtain the EventLoop of a Channel before it may be registered. This will cause an IllegalStateException. We need to ensure we handle the cause of late registration and not throw in this case.
Modifications:
Ensure we only try to access the EventLoop after the Channel is registered and handle the case of late registration.
Result:
Bootstrap.connect(...) not fails on late registration.
Motivation:
The LateListener logic is prone to infinite loops and relies on being processed in the EventExecutor's thread for synchronization, but this EventExecutor may not be constant. An infinite loop can occur if the EventExecutor's execute method does not introduce a context switch in LateListener.run. The EventExecutor can be changed by classes which inherit from DefaultPromise. For example the DefaultChannelPromise will return w/e EventLoop the channel is registered to, but this EventLoop can change (re-registration).
Modifications:
- Remove the LateListener concept and instead use a single Object to maintain the listeners while still preserving notification order
- Make the result member variable an atomic variable so it can be outside the synchronized(this) blocks
- Cleanup/simplify existing state management code
Result:
Fixes https://github.com/netty/netty/issues/5185
Motivation:
Revert d0943dcd30. Delaying the notification of writability change may lead to notification being missed. This is a ABA type of concurrency problem.
Modifications:
- Revert d0943dcd30.
Result:
channelWritabilityChange will be called on every change, and will not be suppressed due to ABA scenario.
Motivation:
When always triggered fireChannelWritabilityChanged() directly when the update the pending bytes in the ChannelOutboundBuffer was made from within the EventLoop. This is problematic as this can cause some re-entrance issue if the user has a custom ChannelOutboundHandler that does multiple writes from within the write(...) method and also has a handler that will intercept the channelWritabilityChanged event and trigger another write when the Channel is writable. This can also easily happen if the user just use a MessageToMessageEncoder subclass and triggers a write from channelWritabilityChanged().
Beside this we also triggered fireChannelWritabilityChanged() too often when a user did a write from outside the EventLoop. In this case we increased the pending bytes of the outboundbuffer before scheduled the actual write and decreased again before the write then takes place. Both of this may trigger a fireChannelWritabilityChanged() event which then may be re-triggered once the actual write ends again in the ChannelOutboundBuffer.
The third gotcha was that a user may get multiple events even if the writability of the channel not changed.
Modification:
- Always invoke the fireChannelWritabilityChanged() later on the EventLoop.
- Only trigger the fireChannelWritabilityChanged() if the channel is still active and if the writability of the channel changed. No need to cause events that were already triggered without a real writability change.
- when write(...) is called from outside the EventLoop we only increase the pending bytes in the outbound buffer (so that Channel.isWritable() is updated directly) but not cause a fireChannelWritabilityChanged(). The fireChannelWritabilityChanged() is then triggered once the task is picked up by the EventLoop as usual.
Result:
No more re-entrance possible because of writes from within channelWritabilityChanged(...) method and no events without a real writability change.
Motivation:
If a handler is added to the pipeline within ChannelInitializer::initChannel via
addFirst(...) then it will not receive the channelRegistered event. The same
handler added via addLast(...) will receive the event. This different behavior
is unlikely to be expected by users and can cause confusion.
Modifications:
Let ChannelInitializer::channelRegistered propagate the event by passing it to
the pipeline instead of firing it on the ChannelHandlerContext.
Result:
The channelRegistered event is propagated to handlers regardless of the method
used to add it to the pipeline (addFirst/addLast).
Motivation:
We need to ensure we run all pending tasks before doing any flush in writeOutbound(...) to ensure all pending tasks are run first. Also we should remove the assert of the future and just add a listener to it so it is processed later if needed. This is true as a user may schedule a write for later execution.
Modifications:
- Remove assert of future in writeOutbound(...)
- Correctly run pending tasks before doing the flush and also before doing the close of the channel.
- Add unit tests to proof the defect is fixed.
Result:
Correclty handle the situation of delayed writes.
Motivation:
Often the user uses EmbeddedChannel within unit tests where the only "important" thing is to know if any pending messages were in the buffer and then release these.
We should provide methods for this so the user not need to manually loop through these and release.
Modifications:
Add methods to easily handle releasing of messages.
Result:
Less boiler-plate code for the user to write.
Motivation:
PendingWriteQueue should guard against re-entrant writes once
removeAndFailAll() is run.
Modifications:
removeAndFailAll() should repeat until the queue is finally empty.
Result:
assertEmpty() will always hold.
Motivation:
e2f5012 added unit tests which did not verify the buffer was released as it was intended to.
Modification:
- Unit tests must verify release is called
Result:
Unit tests enforce that ByteBufs are released.
Motivation:
DefaultChannelHandlerInvoker.invokeWrite calls a utility method validatePromise which may throw if the arguments are not valid. If this method throws then the message will not be released.
Modifications:
- If an exception is thrown the message should be released
Result:
No more leak in DefaultChannelHandlerInvoker.invokeWrite
Motiviation:
We should ensure that handlerAdded(...) and handlerRemoved(...) is always called from the EventExecutor that also invokes the other methods of the ChannelHandler. Also we need to ensure we always call handlerAdded(...) before any other method can be calld to ensure correct ordering.
Motifications:
- Ensure that the right thread is used to call the methods
- Ensure correct ordering
- Add tests
Result:
Respect the thread-model for handlerAdded(...) and handlerRemoved(...) and preserve correct ordering in all cases.
Motivation:
When a channel was registered before and is re-registered we need to respect ChannelConfig.isAutoRead() and so start reading one the registration task completes. This was done "by luck" before 15162202fb.
Modifications:
Explicit start reading once a Channel was re-registered if isAutoRead() is true.
Result:
Correctly receive data after re-registration completes.
Motivation:
Due a regression introduced by e969b6917c we missed to pass the original ChannelPromise to the next ChannelOutboundHandler and so
may never notify the origin ChannelPromise. This is related to #4805.
Modifications:
- Correctly pass the ChannelPromise
- Add unit test.
Result:
Correctly pass the ChannelPromise on deregister(...)
Motivation:
The AbstractChannel(Channel parent) constructor was previously hard-coded to always
call DefaultChannelId.newInstance(), and this made it difficult to use a custom
ChannelId implementation with some commonly used Channel implementations.
Modifications:
Introduced newId() method in AbstractChannel, which by default returns
DefaultChannelId.newInstance() but can be overridden by subclasses. Added
ensureDefaultChannelId() test to AbstractChannelTest, to ensure the prior
behavior of calling DefaultChannelId.newInstance() still holds with the
AbstractChannel(Channel parent) constructor.
Result:
AbstractChannel now has the protected newId() method, but there is no functional
difference.
Motivation:
ChannelInboundHandler and ChannelOutboundHandler both can implement exceptionCaught(...) method and so we need to dispatch to both of them.
Modifications:
- Correctly first dispatch exceptionCaught to the ChannelInboundHandler but also make sure the next handler it will be dispatched to will be the ChannelOutboundHandler
- Add removeInboundHandler() and removeOutboundHandler() which allows to remove one of the combined handlers
- Let *Codec extends it and not ChannelHandlerAppender
- Remove ChannelHandlerAppender
Result:
Correctly handle events and also have same behavior as in 4.0
Motivation:
Our contract in Channels is that the promise should always be notified before the actual callbacks of the ChannelInboundHandler are called. This was not done in the LocalChannel and so the behavior was different to other Channel implementations.
Modifications:
- First complete the ChannelPromise then call fireChannelActive()
- Guard against NPE when doClose() was called before the task was executed.
Result:
Consistent behavior between LocalChannel and other Channel implementations.
Motivation:
In AbstractChannelTest we not correctly mocked some methods which could lead to test errors. That said it only showed up here when running from the IDE and not from the cmdLine.
Modifications:
Mock methods that are needed for the test
Result:
Test pass in the IDE as well.
Motivation:
At the moment EmbeddedChannel always handle close() and disconnect() the same way which also means that ChannelOutboundHandler.disconnect(...) will never called. We should allow to specify if these are handle different or not to make the use of EmbeddedChannel more flexible.
Modifications:
Add 2 other constructors which allow to specify if disconnect / close are handled the same way or differently.
Result:
More flexible usage of EmbeddedChannel possible.
Motivation:
As discussed in #4529, NameResolver design shouldn't be resolving SocketAddresses (or String name + port) and return InetSocketAddresses. It should resolve String names and return InetAddresses.
This SocketAddress to InetSocketAddresses resolution is actually a different concern, used by Bootstrap.
Modifications:
Extract SocketAddress to InetSocketAddresses resolution concern to a new class hierarchy named AddressResolver.
These AddressResolvers delegate to NameResolvers.
Result:
Better separation of concerns.
Note that new AddressResolvers generate a bit more allocations because of the intermediate Promise and List<InetAddress>.
Motivation:
ChannelMetadata has a field minMaxMessagesPerRead which can be confusing. There are also some cases where static instances are used and the default value for channel type is not being applied.
Modifications:
- use a default value which is set unconditionally to simplify
- make sure static instances of MaxMessagesRecvByteBufAllocator are not used if the intention is that the default maxMessagesPerRead should be derived from the channel type.
Result:
Less confusing interfaces in ChannelMetadata and ChannelConfig. Default maxMessagesPerRead is correctly applied.
Motivation:
The CoalescingBufferQueueTest is somewhat relaxed with its releasing of test buffers, using safeRelease to generically deal with tests that may or may not release the buffers. SafeRelease generates logs, however, when the release fails.
Modifications:
Tightened up the individual test methods to verify that the buffers are released properly.
Result:
Fixes#4497
Motivation:
The previous DefaultChannelPipeline#destroy() implementation, introduced in #3156, is suboptimal as it can cause the for loop to continuously spin if the executor used by a given handler is unable to "recognize" the event loop.
It could be objected that it's the custom executor responsibility to properly implement the inEventLoop() method, but some implementetaions might not be able to do that for performance reasons, and even so, it's always better to be safe against API misuse, in particular when it is not possible to fail fast and the alternative is rather some sutle behaviour.
Modifications:
The patch simply avoids the recursive spin by explicitly passing the "in event loop" condition as a boolean parameter, preserving the same guarantees offered by #3156. A unit test has also been added.
Result:
All channel events are correctly called and no high CPU usage is seen anymore.
Motivation:
Once a FixedChannelPool was closed we must not allow to acquire or release Channels to prevent assert errors.
Modifications:
Fail release and acquire calls when FixedChannelPool is closed.
Result:
No more assert errors.1
Motivation:
EmbeddedChannelId#hashCode() and equals() do not behave correctly if an
instance is serialized and then deserialized. Additionally,
EmbeddedChannel does not allow use of any other type of ChannelId, and
EmbeddedChannelId is (mostly) a singleton instance. This creates a
problem for unit tests that construct multiple EmbeddedChannels and
expect each channel to have a unique ID.
Modifications:
EmbeddedChannelId is modified so equals() will return true and
hashCode() will return the same value for any instance of the class.
EmbeddedChannel is modified to allow a ChannelId to be specified when
the channel is constructed. Tests added for both changes.
Result:
EmbeddedChannelId now behaves correctly when deserialized, and
EmbeddedChannels can now have unique IDs.
