Motivation:
In the latest release we introduced Http2MultiplexHandler as a replacement of Http2MultiplexCodec. This did split the frame parsing from the multiplexing to allow a more flexible way to handle frames and to make the code cleaner. Unfortunally we did miss to special handle this in Http2ServerUpgradeCodec and so did not correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpServerUpgrade(...). This did lead to the situation that we did not correctly receive the event on the Http2MultiplexHandler and so did not correctly created the Http2StreamChannel for the upgrade stream. Because of this we ended up with an NPE if a frame was dispatched to the upgrade stream later on.
Modifications:
- Correctly add Http2MultiplexHandler to the pipeline before calling Http2FrameCodec.onHttpServerUpgrade(...)
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9314.
Motivation:
b3dba317d7 added AbstractHttp2ConnectionBuilder.autoAckSettingsFrame(...) as protected method and made it public for Http2MultiplexCodecBuilder. Unfortunally it did miss to also make it public in Http2FrameCodecBuilder
Modifications:
Correctly override autoAckSettingsFrame in Http2FrameCodecBuilder and so make it usable when building Http2FrameCodec.
Result:
Be able to also configure autoAckSettingsFrame when Http2FrameCodec is used.
Motivation:
We should not propage Http2WindowUpdateFrames to the child channels at all as these are not really use-ful and should not be flow-controlled via `read()` anyway. In the other hand Http2ResetFrame is very useful but should be propagated via an user event so the user is aware of it directly even if the user stops reading.
Modifications:
- Dont propagate Http2WindowUpdateFrames when using Http2MultiplexHandler
- Use user event for Http2ResetFrame when using Http2MultiplexHandler
- Adjust javadoc of Http2MultiplexHandler
- Add unit tests
Result:
Fixes https://github.com/netty/netty/pull/8889 and https://github.com/netty/netty/pull/7635
Motivation:
Http2MultiplexCodec and Http2MultiplexHandler had a very strong coupling with Http2FrameCodec which we can reduce easily. The end-goal should be to have no coupling at all.
Modifications:
- Reduce coupling by move some common logic to Http2CodecUtil
- Move logic to check if a stream may have existed before to Http2FrameCodec
- Use ArrayDeque as replacement for custom double-linked-list which makes the code a lot more readable
- Use WindowUpdateFrame to signal consume bytes (just as users do when they use Http2FrameCodec directly)
Result:
Less coupling and cleaner code.
Motivation:
In the past we had the following class hierarchy:
Http2ConnectionHandler --- Http2FrameCodec -- Http2MultiplexCodec
This hierarchy makes it impossible to plug in any code that would like to act on Http2Frame and Http2StreamFrame which can be quite useful for various situations (like metrics, logging etc). Beside this it also made the implementtion very hacky. To allow easier maintainance and also allow more flexible costumizations we should split Http2MultiplexCodec and Http2FrameCode.
Modifications:
- Introduce Http2MultiplexHandler (which is a replacement for Http2MultiplexCodec when used together with Http2FrameCodec)
- Mark Http2MultiplexCodecBuilder and Http2MultiplexCodec as deprecated. People should use Http2FrameCodecBuilder / Http2FrameCodec together with Http2MultiplexHandlder in the future
- Adjust / Add tests
- Adjust examples
Result:
More flexible usage possible and less hacky / coupled implementation for http2 multiplexing
Motivation:
For HTTP/2 messages with multiple cookies HttpConversionUtil.addHttp2ToHttpHeaders spends a good portion of time creating throwaway StringBuilders.
Modification:
Handle cookies lazily by using a ThreadLocal StringBuilder and then converting it to the H1 header at the end.
Result:
Less allocations.
Motivation:
f945a071db decoupled the writability state from the flow controller but could lead to the situation of a lot of writability updates events were propagated to the child channels. This change ensure we only take into account if the parent channel becomes writable again before we try to set the child channels to writable.
Modifications:
Only listen for channel writability changes for if the parent channel becomes writable again.
Result:
Less writability updates.
Motivation:
We should decouple the writability state of the http2 child channels from the flow-controller and just tie it to its own pending bytes counter that is decremented by the parent Channel once the bytes were written.
Modifications:
- Decouple writability state of child channels from flow-contoller
- Update tests
Result:
Less coupling and more correct behavior. Fixes https://github.com/netty/netty/issues/8148.
Motivation:
b4e3c12b8e introduced code to avoid coupling
close() to graceful close. It also added some code which attempted to infer when
a graceful close was being done in writing of a GOAWAY to preserve the
"connection is closed when all streams are closed behavior" for the child
channel API. However the implementation was too overzealous and may preemptively
close the connection if there are not currently any open streams (and close if
there are any frames which create streams in flight).
Modifications:
- Decouple writing a GOAWAY from trying to infer if a graceful close is being
done and closing the connection. Even if we could enhance this logic (e.g.
wait to close until the second GOAWAY with no error) it is possible the user
doesn't want the connection to be closed yet. We can add a means for the codec
to orchestrate the graceful close in the future (e.g. write some special "close
the connection when all streams are closed") but for now we can just let the
application handle this.
Result:
Fixes https://github.com/netty/netty/issues/9207
Motivation:
The first final version of GraalVM was released which deprecated some flags. We should use the new ones.
Modifications:
Removes the use of deprecated GraalVM native-image flags
Adds a flag to initialize netty at build time.
Result:
Do not use deprecated flags
Motivation:
OOME is occurred by increasing suppressedExceptions because other libraries call Throwable#addSuppressed. As we have no control over what other libraries do we need to ensure this can not lead to OOME.
Modifications:
Only use static instances of the Exceptions if we can either dissable addSuppressed or we run on java6.
Result:
Not possible to OOME because of addSuppressed. Fixes https://github.com/netty/netty/issues/9151.
Motivation:
Http2MultiplexCodec.DefaultHttp2StreamChannel currently only act on ClosedChannelException exceptions when checking for isAutoClose(). We should widen the scope here to IOException to be more consistent with AbstractChannel.
Modifications:
Replace instanceof ClosedChannelException with instanceof IOException
Result:
More consistent handling of isAutoClose()
Motivation:
GraalVM native images are a new way to deliver java applications. Netty is one of the most popular libraries however there are a few limitations that make it impossible to use with native images out of the box. Adding a few metadata (in specific modules will allow the compilation to success and produce working binaries)
Modification:
Added properties files in `META-INF` and substitutions classes (under `internal.svm`) will solve the compilation issues. The substitutions classes are not visible and do not have a public constructor so they are not visible to end users.
Result:
Fixes#8959
This fix is very conservative as it applies the minimum config required to build:
* pure netty servers
* vert.x applications
* grpc applications
The build is having trouble due to checkstyle which does not seem to be able to find the copyright notice on property files.
Motivation:
Http2ConnectionHandler#close(..) always runs the GOAWAY and graceful close
logic. This coupling means that a user would have to override
Http2ConnectionHandler#close(..) to modify the behavior, and the
Http2FrameCodec and Http2MultiplexCodec are not extendable so you cannot
override at this layer. Ideally we can totally decouple the close(..) of the
transport and the GOAWAY graceful closure process completely, but to preserve
backwards compatibility we can add an opt-out option to decouple where the
application is responsible for sending a GOAWAY with error code equal to
NO_ERROR as described in https://tools.ietf.org/html/rfc7540#section-6.8 in
order to initiate graceful close.
Modifications:
- Http2ConnectionHandler supports an additional boolean constructor argument to
opt out of close(..) going through the graceful close path.
- Http2FrameCodecBuilder and Http2MultiplexCodec expose
gracefulShutdownTimeoutMillis but do not hook them up properly. Since these
are already exposed we should hook them up and make sure the timeout is applied
properly.
- Http2ConnectionHandler's goAway(..) method from Http2LifecycleManager should
initiate the graceful closure process after writing a GOAWAY frame if the error
code is NO_ERROR. This means that writing a Http2GoAwayFrame from
Http2FrameCodec will initiate graceful close.
Result:
Http2ConnectionHandler#close(..) can now be decoupled from the graceful close
process, and immediately close the underlying transport if desired.
Motivaiton:
DefaultHttp2ConnectionEncoder uses SimpleChannelPromiseAggregator to combine two
operations into a single future status. However it directly uses the
SimpleChannelPromiseAggregator object instead of using the newPromise() method
in one case. This may result in premature completion of the aggregated future.
Modifications:
- DefaultHttp2ConnectionEncoder to use
SimpleChannelPromiseAggregator#newPromise() instead of directly using the
SimpleChannelPromiseAggregator instance when writing the settings ACK frame
Result:
More correct status for the SETTING ACK frame writing when auto settings ACK is
disabled.
Motivation:
The HTTP/2 codec will synchronously respond to a SETTINGS frame with a SETTINGS
ACK before the application sees the SETTINGS frame. The application may need to
adjust its state depending upon what is in the SETTINGS frame before applying
the remote settings and responding with an ACK (e.g. to adjust for max
concurrent streams). In order to accomplish this the HTTP/2 codec should allow
for the application to opt-in to sending the SETTINGS ACK.
Modifications:
- DefaultHttp2ConnectionDecoder should support a mode where SETTINGS frames can
be queued instead of immediately applying and ACKing.
- DefaultHttp2ConnectionEncoder should attempt to poll from the queue (if it
exists) to apply the earliest received but not yet ACKed SETTINGS frame.
- AbstractHttp2ConnectionHandlerBuilder (and sub classes) should support a new
option to enable the application to opt-in to managing SETTINGS ACK.
Result:
HTTP/2 allows for asynchronous SETTINGS ACK managed by the application.
Motivation:
Http2FrameCodec currently fails the write promise associated with creating a
stream with a Http2NoMoreStreamIdsException. However this means the user code
will have to listen to all write futures in order to catch this scenario which
is the same as receiving a GOAWAY frame. We can also simulate receiving a GOAWAY
frame from our remote peer and that allows users to consolidate graceful close
logic in the GOAWAY processing.
Modifications:
- Http2FrameCodec should simulate a DefaultHttp2GoAwayFrame when trying to
create a stream but the stream IDs have been exhausted.
Result:
Applications can rely upon GOAWAY for graceful close processing instead of also
processing write futures.
Motivation:
We should not throw check exceptions when the user calls sync*() but should better wrap it in a CompletionException to make it easier for people to reason about what happens.
Modifications:
- Change sync*() to throw CompletionException
- Adjust tests
- Add some more tests
Result:
Fixes https://github.com/netty/netty/issues/8521.
Motivation:
DefaultPromise requires an EventExecutor which provides the thread to notify listeners on and this EventExecutor can never change. We can remove the code that supported the possibility of a changing the executor as this is not possible anymore.
Modifications:
- Remove constructor which allowed to construct a *Promise without an EventExecutor
- Remove extra state
- Adjusted SslHandler and ProxyHandler for new code
Result:
Fixes https://github.com/netty/netty/issues/8517.
Motivation:
For what-ever reason Http2FrameLogger did extend ChannelHandlerAdapter but not override any of its methods. We should not extend it at all as it is not a ChannelHandler.
Modifications:
Remove extends
Result:
Less confusing / more correct / clear code.
Motivation:
In 42742e233f we already added default methods to Channel*Handler and deprecated the Adapter classes to simplify the class hierarchy. With this change we go even further and merge everything into just ChannelHandler. This simplifies things even more in terms of class-hierarchy.
Modifications:
- Merge ChannelInboundHandler | ChannelOutboundHandler into ChannelHandler
- Adjust code to just use ChannelHandler
- Deprecate old interfaces.
Result:
Cleaner and simpler code in terms of class-hierarchy.
Motivation:
com.puppycrawl.tools checkstyle < 8.18 was reported to contain a possible security flaw. We should upgrade.
Modifications:
- Upgrade netty-build and checkstyle.
- Fix checkstyle errors
Result:
Fixes https://github.com/netty/netty/issues/8968.
Motivation:
As we now us java8 as minimum java version we can deprecate ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter and just move the default implementations into the interfaces. This makes things a bit more flexible for the end-user and also simplifies the class-hierarchy.
Modifications:
- Mark ChannelInboundHandlerAdapter and ChannelOutboundHandlerAdapter as deprecated
- Add default implementations to ChannelInboundHandler / ChannelOutboundHandler
- Refactor our code to not use ChannelInboundHandlerAdapter / ChannelOutboundHandlerAdapter anymore
Result:
Cleanup class-hierarchy and make things a bit more flexible.
Motivation:
PromiseCombiner is not thread-safe and even assumes all added Futures are using the same EventExecutor. This is kind of fragile as we do not enforce this. We need to enforce this contract to ensure it's safe to use and easy to spot concurrency problems.
Modifications:
- Add new contructor to PromiseCombiner that takes an EventExecutor and deprecate the old non-arg constructor.
- Check if methods are called from within the EventExecutor thread and if not fail
- Correctly dispatch on the right EventExecutor if the Future uses a different EventExecutor to eliminate concurrency issues.
Result:
More safe use of PromiseCombiner + enforce correct usage / contract.
Motivation:
When more than one connection header is present in h2c upgrade request, upgrade fails. This is to fix that.
Modification:
In HttpServerUpgradeHandler's upgrade() method, check whether any of the connection header value is upgrade, not just the first header value which might return a different value other than upgrade.
Result:
Fixes#8846.
With this PR, now when multiple connection headers are sent with the upgrade request, upgrade will not fail.
Motivation:
We can replace some "hand-rolled" integer checks with our own static utility method to simplify the code.
Modifications:
Use methods provided by `ObjectUtil`.
Result:
Cleaner code and less duplication
Motivation:
We can just use Objects.requireNonNull(...) as a replacement for ObjectUtil.checkNotNull(....)
Modifications:
- Use Objects.requireNonNull(...)
Result:
Less code to maintain.
Motivation:
ChannelHandler.exceptionCaught(...) was marked as @deprecated as it should only exist in inbound handlers.
Modifications:
Remove ChannelHandler.exceptionCaught(...) and adjust code / tests.
Result:
Fixes https://github.com/netty/netty/issues/8527
Motivation:
We can use lambdas now as we use Java8.
Modification:
use lambda function for all package, #8751 only migrate transport package.
Result:
Code cleanup.
Motivation:
We need to update to a new checkstyle plugin to allow the usage of lambdas.
Modifications:
- Update to new plugin version.
- Fix checkstyle problems.
Result:
Be able to use checkstyle plugin which supports new Java syntax.
* Decouble EventLoop details from the IO handling for each transport to allow easy re-use of code and customization
Motiviation:
As today extending EventLoop implementations to add custom logic / metrics / instrumentations is only possible in a very limited way if at all. This is due the fact that most implementations are final or even package-private. That said even if these would be public there are the ability to do something useful with these is very limited as the IO processing and task processing are very tightly coupled. All of the mentioned things are a big pain point in netty 4.x and need improvement.
Modifications:
This changeset decoubled the IO processing logic from the task processing logic for the main transport (NIO, Epoll, KQueue) by introducing the concept of an IoHandler. The IoHandler itself is responsible to wait for IO readiness and process these IO events. The execution of the IoHandler itself is done by the SingleThreadEventLoop as part of its EventLoop processing. This allows to use the same EventLoopGroup (MultiThreadEventLoupGroup) for all the mentioned transports by just specify a different IoHandlerFactory during construction.
Beside this core API change this changeset also allows to easily extend SingleThreadEventExecutor / SingleThreadEventLoop to add custom logic to it which then can be reused by all the transports. The ideas are very similar to what is provided by ScheduledThreadPoolExecutor (that is part of the JDK). This allows for example things like:
* Adding instrumentation / metrics:
* how many Channels are registered on an SingleThreadEventLoop
* how many Channels were handled during the IO processing in an EventLoop run
* how many task were handled during the last EventLoop / EventExecutor run
* how many outstanding tasks we have
...
...
* Implementing custom strategies for choosing the next EventExecutor / EventLoop to use based on these metrics.
* Use different Promise / Future / ScheduledFuture implementations
* decorate Runnable / Callables when submitted to the EventExecutor / EventLoop
As a lot of functionalities are folded into the MultiThreadEventLoopGroup and SingleThreadEventLoopGroup this changeset also removes:
* AbstractEventLoop
* AbstractEventLoopGroup
* EventExecutorChooser
* EventExecutorChooserFactory
* DefaultEventLoopGroup
* DefaultEventExecutor
* DefaultEventExecutorGroup
Result:
Fixes https://github.com/netty/netty/issues/8514 .
Motivation:
We can use the diamond operator these days.
Modification:
Use diamond operator whenever possible.
Result:
More modern code and less boiler-plate.
Motivation:
Netty uses own Integer.compare and Long.compare methods. Since Java 7 we can use Java implementation instead.
Modification:
Remove own implementation
Result:
Less code to maintain
Motivation:
When a write error happens during writing of flowcontrolled data frames we miss to correctly detect this in the write loop which may result in an infinite loop as we will never detect that the frame should be removed from the queue.
Modifications:
- When we fail a flowcontrolled data frame we ensure that the next frame.write(...) call will signal back that the whole frame was handled and so can be removed.
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8707.
Motiviation:
Because of how we implemented the registration / deregistration of an EventLoop it was not possible to wrap an EventLoop implementation and use it with a Channel.
Modification:
- Introduce EventLoop.Unsafe which is responsible for the actual registration.
- Move validation of EventLoop / Channel combo to the EventLoop
- Add unit test that verifies that wrapping works
Result:
Be able to wrap an EventLoop and so add some extra functionality.
Motivation:
At the moment it’s possible to have a Channel in Netty that is not registered / assigned to an EventLoop until register(...) is called. This is suboptimal as if the Channel is not registered it is also not possible to do anything useful with a ChannelFuture that belongs to the Channel. We should think about if we should have the EventLoop as a constructor argument of a Channel and have the register / deregister method only have the effect of add a Channel to KQueue/Epoll/... It is also currently possible to deregister a Channel from one EventLoop and register it with another EventLoop. This operation defeats the threading model assumptions that are wide spread in Netty, and requires careful user level coordination to pull off without any concurrency issues. It is not a commonly used feature in practice, may be better handled by other means (e.g. client side load balancing), and therefore we propose removing this feature.
Modifications:
- Change all Channel implementations to require an EventLoop for construction ( + an EventLoopGroup for all ServerChannel implementations)
- Remove all register(...) methods from EventLoopGroup
- Add ChannelOutboundInvoker.register(...) which now basically means we want to register on the EventLoop for IO.
- Change ChannelUnsafe.register(...) to not take an EventLoop as parameter (as the EventLoop is supplied on custruction).
- Change ChannelFactory to take an EventLoop to create new Channels and introduce ServerChannelFactory which takes an EventLoop and one EventLoopGroup to create new ServerChannel instances.
- Add ServerChannel.childEventLoopGroup()
- Ensure all operations on the accepted Channel is done in the EventLoop of the Channel in ServerBootstrap
- Change unit tests for new behaviour
Result:
A Channel always has an EventLoop assigned which will never change during its life-time. This ensures we are always be able to call any operation on the Channel once constructed (unit the EventLoop is shutdown). This also simplifies the logic in DefaultChannelPipeline a lot as we can always call handlerAdded / handlerRemoved directly without the need to wait for register() to happen.
Also note that its still possible to deregister a Channel and register it again. It's just not possible anymore to move from one EventLoop to another (which was not really safe anyway).
Fixes https://github.com/netty/netty/issues/8513.
Motivation:
In Http2FrameCodec we made the incorrect assumption that we can only have 1 buffered outboundstream as maximum. This is not correct and we need to account for multiple buffered streams.
Modifications:
- Use a map to allow buffer multiple streams
- Add unit test.
Result:
Fixes https://github.com/netty/netty/issues/8692.
* Handling AUTO_READ should not be the responsibility of DefaultChannelPipeline but the Channel itself.
Motivation:
At the moment we do automatically call read() in the DefaultChannelPipeline when fireChannelReadComplete() / fireChannelActive() is called and the Channel is using auto read. This is nice in terms of sharing code but imho is not the responsibility of the ChannelPipeline implementation but the responsibility of the Channel implementation.
Modifications:
Move handing of auto read from DefaultChannelPipeline to Channel implementations.
Result:
More clear responsibiliy and not depending on implemention details of the ChannelPipeline.
Motiviation:
Http2FrameCodecTest and Http2MultiplexCodecTest were quite fragile and often not went through the whole pipeline which made testing sometimes hard and error-prone.
Modification:
- Refactor tests to have data flow through the whole pipeline and so made the test more robust (by testing the while implementation).
Result:
Easier to write tests for the codecs in the future and more robust testing in general.
Beside this it also fixes https://github.com/netty/netty/issues/6036.
Motivation:
We should always call ctx.read() even when AUTO_READ is false as flow-control is enforced by the HTTP/2 protocol.
See also https://tools.ietf.org/html/rfc7540#section-5.2.2.
We already did this before but not explicit and only did so because of some implementation details of ByteToMessageDecoder. It's better to be explicit here to not risk of breakage later on.
Modifications:
- Ensure we always call ctx.read() when AUTO_READ is false
- Add unit test.
Result:
No risk of staling the connection when HTTP/2 is used.
