Motivation:
There is a bug in `StreamBufferingEncoder` such that when client receives GOWAY while there are pending streams due to MAX_CONCURRENT_STREAMS, we see the following error:
```
io.netty.handler.codec.http2.Http2Exception$StreamException: Maximum active streams violated for this endpoint.
at io.netty.handler.codec.http2.Http2Exception.streamError(Http2Exception.java:147)
at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.checkNewStreamAllowed(DefaultHttp2Connection.java:896)
at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.createStream(DefaultHttp2Connection.java:748)
at io.netty.handler.codec.http2.DefaultHttp2Connection$DefaultEndpoint.createStream(DefaultHttp2Connection.java:668)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeHeaders0(DefaultHttp2ConnectionEncoder.java:201)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionEncoder.writeHeaders(DefaultHttp2ConnectionEncoder.java:167)
at io.netty.handler.codec.http2.DecoratingHttp2FrameWriter.writeHeaders(DecoratingHttp2FrameWriter.java:53)
at io.netty.handler.codec.http2.StreamBufferingEncoder.writeHeaders(StreamBufferingEncoder.java:153)
at io.netty.handler.codec.http2.StreamBufferingEncoder.writeHeaders(StreamBufferingEncoder.java:141)
at io.grpc.netty.NettyClientHandler.createStreamTraced(NettyClientHandler.java:584)
at io.grpc.netty.NettyClientHandler.createStream(NettyClientHandler.java:567)
at io.grpc.netty.NettyClientHandler.write(NettyClientHandler.java:328)
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite0(AbstractChannelHandlerContext.java:717)
at io.netty.channel.AbstractChannelHandlerContext.invokeWrite(AbstractChannelHandlerContext.java:709)
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:792)
at io.netty.channel.AbstractChannelHandlerContext.write(AbstractChannelHandlerContext.java:702)
at io.netty.channel.DefaultChannelPipeline.write(DefaultChannelPipeline.java:1015)
at io.netty.channel.AbstractChannel.write(AbstractChannel.java:289)
at io.grpc.netty.WriteQueue$AbstractQueuedCommand.run(WriteQueue.java:213)
at io.grpc.netty.WriteQueue.flush(WriteQueue.java:128)
at io.grpc.netty.WriteQueue.drainNow(WriteQueue.java:114)
at io.grpc.netty.NettyClientHandler.goingAway(NettyClientHandler.java:783)
at io.grpc.netty.NettyClientHandler.access$300(NettyClientHandler.java:91)
at io.grpc.netty.NettyClientHandler$3.onGoAwayReceived(NettyClientHandler.java:280)
at io.netty.handler.codec.http2.DefaultHttp2Connection.goAwayReceived(DefaultHttp2Connection.java:236)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.onGoAwayRead0(DefaultHttp2ConnectionDecoder.java:218)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder$FrameReadListener.onGoAwayRead(DefaultHttp2ConnectionDecoder.java:551)
at io.netty.handler.codec.http2.Http2InboundFrameLogger$1.onGoAwayRead(Http2InboundFrameLogger.java:119)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readGoAwayFrame(DefaultHttp2FrameReader.java:591)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.processPayloadState(DefaultHttp2FrameReader.java:272)
at io.netty.handler.codec.http2.DefaultHttp2FrameReader.readFrame(DefaultHttp2FrameReader.java:160)
at io.netty.handler.codec.http2.Http2InboundFrameLogger.readFrame(Http2InboundFrameLogger.java:41)
at io.netty.handler.codec.http2.DefaultHttp2ConnectionDecoder.decodeFrame(DefaultHttp2ConnectionDecoder.java:174)
at io.netty.handler.codec.http2.Http2ConnectionHandler$FrameDecoder.decode(Http2ConnectionHandler.java:378)
at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:498)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:437)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.handler.ssl.SslHandler.unwrap(SslHandler.java:1486)
at io.netty.handler.ssl.SslHandler.decodeJdkCompatible(SslHandler.java:1235)
at io.netty.handler.ssl.SslHandler.decode(SslHandler.java:1282)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:498)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:437)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:276)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:357)
at io.netty.channel.DefaultChannelPipeline$HeadContext.channelRead(DefaultChannelPipeline.java:1410)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:379)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:365)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:919)
at io.netty.channel.epoll.AbstractEpollStreamChannel$EpollStreamUnsafe.epollInReady(AbstractEpollStreamChannel.java:792)
at io.netty.channel.epoll.EpollEventLoop.processReady(EpollEventLoop.java:475)
at io.netty.channel.epoll.EpollEventLoop.run(EpollEventLoop.java:378)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:989)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Unknown Source)
```
The bug should come from the way that `StreamBufferingEncoder.writeHeaders()` handles the condition `connection().goAwayReceived()`. The current behavior is to delegate to `super.writeHeaders()` and let the stream fail, but this will end up with `Http2Exception` with the message "Maximum active streams violated for this endpoint" which is horrible. See e5951d46fc/codec-http2/src/main/java/io/netty/handler/codec/http2/StreamBufferingEncoder.java (L152-L155)
Modification:
Abort new stream immediately if goaway received *and* MAX_CONCURRENT_STREAM reached in `StreamBufferingEncoder` rather than delegating to the `writeHeaders()` method of its super class.
Result:
In the situation when GOAWAY received as well as MAX_CONCURRENT_STREAM exceeded, the client will fail the buffered streams with `Http2Error.NO_ERROR` and message "GOAWAY received" instead of "Maximum active streams violated for this endpoint".
Co-authored-by: Norman Maurer <norman_maurer@apple.com>
Motivation:
We also need to ensure that all the header validation is done when a single header with the endStream flag is received
Modifications:
- Adjust code to always enforce the validation
- Add more unit tests
Result:
Always correctly validate
Motivation:
CONNECT requests have no path defined as stated in the HTTP/2 spec, at the moment we will throw an exception if we try to convert such a request to HTTP/1.1
Modifications:
- Don't throw an exception if we try to convert a HTTP/2 CONNECT request that has no path
- Add unit test
Result:
Related to https://github.com/netty/netty-incubator-codec-http3/pull/112.
Motivation:
We need to ensure we are still be able to correctly map errors to streams in all cases. The problem was that we sometimes called closeStreamRemote(...) in a finally block and so closed the underyling stream before the actual exception was propagated. This was only true in some cases and not in all. Generally speaking we should only call closeStreamRemote(...) if there was no error as in a case of error we should generate a RST frame.
Modifications:
- Only call closeStreamRemote(...) if no exeption was thrown and so let the Http2ConnectionHandler handle the exception correctly
- Add unit tests
Result:
Correctly handle errors even when endStream is set to true
Motivation
A GOAWAY frame (or any other HTTP/2 frame) should not be sent before the
connection preface. Clients that immediately close the channel may
currently attempt to send a GOAWAY frame before the connection preface,
resulting in servers receiving a seemingly-corrupt connection preface.
Modifications
* Ensure that the preface has been sent before attempting to
automatically send a GOAWAY frame as part of channel shutdown logic
* Add unit test that only passes with new behavior
Result
Fixes https://github.com/netty/netty/issues/11026
Co-authored-by: Bennett Lynch <Bennett-Lynch@users.noreply.github.com>
Motivation:
There are several overloads of streamError(), with one receiving the
Throwable to be made the cause of the new exception. However, the wrong
overload was being called and instead the IllegalArgumentException was
being passed as a message format argument which was summarily thrown
away as the message format didn't reference it.
Modifications:
Move IllegalArgumentException to proper argument position.
Result:
A useful exception, with the underlying cause available.
Motivation:
As stated by https://tools.ietf.org/html/rfc7540#section-8.1.2.6 we should report a stream error if the content-length does not match the sum of all data frames.
Modifications:
- Verify that the sum of data frames match if a content-length header was send.
- Handle multiple content-length headers and also handle negative values
- Add io.netty.http2.validateContentLength system property which allows to disable the more strict validation
- Add unit tests
Result:
Correctly handle the case when the content-length header was included but not match what is send and also when content-length header is invalid
Motivation:
When TLSv1.3 is used (or TLS_FALSE_START) together with mTLS the handshake is considered successful before the server actually did verify the key material that was provided by the client. If the verification fails we currently will just close the stream without any extra information which makes it very hard to debug on the client side.
Modifications:
- Propagate SSLExceptions to the active streams
- Add unit test
Result:
Better visibility into why a stream was closed
Motivation:
https://github.com/netty/netty/pull/10765 added support for push promise and priority frames when using the Http2FrameCodec. Unfortunally it didnt correctly guard against the possibility to receive a priority frame for an non-existing stream, which resulted in a NPE
Modifications:
- Ignore priority frame for non existing stream
- Correctly implement equals / hashcode for DefaultHttp2PriorityFrame
- Add unit tests
Result:
Fixes https://github.com/netty/netty/issues/10941
Motivation:
We should use GracefulShutdown when we try to create a stream and fail it because the stream space is exhausted as we may still want to process the active streams.
Modifications:
- Use graceful shutdown
- Add unit test
Result:
More graceful handling of stream creation failure due stream space exhaustation
Motivation:
Right now, we don't have to handle Push Promise Read in `Http2FrameCodec`. Push Promise is one of the key features of HTTP/2 and we should support it in our `Http2FrameCodec`.
Modification:
Added `Http2PushPromiseFrame` and `Http2PushPromiseFrame` to handle Push Promise and Promise Frame.
Result:
Fixes#10748
Motivation:
HPACK static table is organized in a way that fields with the same
name are sequential. Which means when doing sequential scan we can
short-circuit scan on name mismatch.
Modifications:
* `HpackStaticTable.getIndexIndensitive` returns -1 on name mismatch
rather than keep scanning.
* `HpackStaticTable` statically defined max position in the array
where name duplication is possible (after the given index there's
no need to check for other fields with the same name)
* Benchmark for different lookup patterns
Result:
Better HPACK static table lookup performance.
Co-authored-by: Norman Maurer <norman_maurer@apple.com>
Motivation:
Http2ConnectionHandler tries to addListener to the future without checking if it's void. If it is void, this will fail and generate an exception.
Modifications:
Unvoid the promise in writeData()
Result:
Fixes#10816, Writing with a voidPromise no longer generates exceptions.
Motivation:
`DelegatingDecompressorFrameListener#initDecompressor` has multiple dots `.` in comments. However, it should not have that.
Modification:
Removed multiple dots.
Result:
Clean comment
Motivation:
https in xmlns URIs does not work and will let the maven release plugin fail:
```
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 1.779 s
[INFO] Finished at: 2020-11-10T07:45:21Z
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare (default-cli) on project netty-parent: Execution default-cli of goal org.apache.maven.plugins:maven-release-plugin:2.5.3:prepare failed: The namespace xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" could not be added as a namespace to "project": The namespace prefix "xsi" collides with an additional namespace declared by the element -> [Help 1]
[ERROR]
```
See also https://issues.apache.org/jira/browse/HBASE-24014.
Modifications:
Use http for xmlns
Result:
Be able to use maven release plugin
Motivation:
`HttpConversionUtil#toFullHttpResponse` and `HttpConversionUtil#toFullHttpRequest` has `ByteBufAllocator` which is used for building `FullHttpMessage` and then data can be appended with `FullHttpMessage#content`. However, there can be cases when we already have `ByteBuf` ready with data. So we need a parameter to add `ByteBuf` directly into `FullHttpMessage` while creating it.
Modification:
Added `ByteBuf` parameter,
Result:
More functionality for handling `FullHttpMessage` content.
Motivation:
We should have a method to add `HttpScheme` if `HttpRequest` does not contain `x-http2-scheme` then we should use add it if `HttpToHttp2ConnectionHandler` is build using specified `HttpScheme`.
Modification:
Added `HttpScheme` in `HttpToHttp2ConnectionHandlerBuilder`.
Result:
Automatically add `HttpScheme` if missing in `HttpRequest`.
Motivation:
When parsing HEADERS, connection errors can occur (e.g., too large of
headers, such that we don't want to HPACK decode them). These trigger a
GOAWAY with a last-stream-id telling the client which streams haven't
been processed.
Unfortunately that last-stream-id didn't include the stream for the
HEADERS that triggered the error. Since clients are free to silently
retry streams not included in last-stream-id, the client is free to
retransmit the request on a new connection, which will fail the
connection with the wrong last-stream-id, and the client is still free
to retransmit the request.
Modifications:
Have fatal connection errors (those that hard-cut the connection)
include all streams in last-stream-id, which guarantees the HEADERS'
stream is included and thus should not be silently retried by the HTTP/2
client.
This modification is heavy-handed, as it will cause racing streams to
also fail, but alternatives that provide precise last-stream-id tracking
are much more invasive. Hard-cutting the connection is already
heavy-handed and so is rare.
Result:
Fixes#10670
Motivation:
We received a [bug report](https://bugs.chromium.org/p/chromium/issues/detail?id=1143320) from the Chrome team at Google, their canary builds are failing [HTTP/2 GREASE](https://tools.ietf.org/html/draft-bishop-httpbis-grease-00) testing to netflix.com.
The reason it's failing is that Netty can't handle unknown frames without an active stream created. Let me know if you'd like more info, such as stack traces or repro steps.
Modification:
The change is minor and simply ignores unknown frames on the connection stream, similarly to `onWindowUpdateRead`.
Result:
I figured I would just submit a PR rather than filing an issue, but let me know if you want me to do that for tracking purposes.
Motivation:
There is no need for ByteProcessor to throw a checked exception.
The declared checked exception causes unnecessary code complications just to propagate it.
This can be cleaned up.
Modification:
ByteProcessor.process no longer declares to throw a checked exception, and all the places that were trying to cope with the checked exception have been simplified.
Result:
Simpler code.
Motivation:
There is no need for ByteProcessor to throw a checked exception.
The declared checked exception causes unnecessary code complications just to propagate it.
This can be cleaned up.
Modification:
ByteProcessor.process no longer declares to throw a checked exception, and all the places that were trying to cope with the checked exception have been simplified.
Result:
Simpler code.
Motivation:
`HttpConversionUtil#toHttpResponse` translates `Http2Headers` to `HttpResponse`. It uses `#addHttp2ToHttpHeaders(..., boolean isRequest)` to do so. However, `isRequest` field is set to `true` instead of `false`. It should be set to `false` because we're doing conversion of Response not Request.
Modification:
Changed `true` to `false`.
Result:
Correctly translates `Http2Headers` to `HttpResponse`.
Motivation:
We should have the `toString` method in `DefaultHttp2WindowUpdateFrame` because it makes debugging a little easy.
Modification:
Added `toString` method.
Result:
`toString` method to help in debugging.
Co-authored-by: Norman Maurer <norman_maurer@apple.com>
Motivation:
`Http2Frame` has extra empty line after `String name();`. However, it should not be there.
Modification:
Removed extra empty line.
Result:
Empty-line code style now matching with other classes.
Motivation:
`Http2FrameCodec#write(...)` has typo in comment.
`// In the event of manual SETTINGS ACK is is assumed the encoder will apply the earliest received but not`.
The typo is `is is`. However, it should be `it is`.
Modification:
Changed `is is` to `it is`.
Result:
Correct comment without typos.
Motivation:
`Http2DataFrame#isEndStream()` JavaDoc says `Returns {@code true} if the END_STREAM flag ist set.`. The typo is `ist` word. However, it should be `is`.
Modification:
Changed `ist` to `is`.
Result:
Better JavaDoc by fixing the typo.
Motivation:
`Http2HeadersFrame#isEndStream()` JavaDoc says `Returns {@code true} if the END_STREAM flag ist set.`. The typo is `ist` word. However, it should be `is`.
Modification:
Changed `ist` to `is`.
Result:
Better JavaDoc by fixing the typo.
Motivation:
`addHttp2ToHttpHeaders(int streamId, Http2Headers sourceHeaders, FullHttpMessage destinationMessage, boolean addToTrailer)`
should match
`addHttp2ToHttpHeaders(int streamId, Http2Headers inputHeaders, HttpHeaders outputHeaders, HttpVersion httpVersion, boolean isTrailer, boolean isRequest)`.
However, the `Http2Headers` variable name is different.
Modification:
Changed `sourceHeaders` to `inputHeaders`.
Result:
Variable and JavaDoc naming now correct.
Motivation:
Http2ToHttpHeaderTranslator is a private class but translateHeaders(Iterable<Entry<CharSequence, CharSequence>>) is public but it should be package-private.
Modification:
Removed public.
Result:
Correct access modifer.
Motivation:
Http2Headers has JavaDoc error which says Sets the {@link PseudoHeaderName#AUTHORITY} header or {@code null} if there is no such header however it should be Sets the {@link PseudoHeaderName#AUTHORITY} header in Http2Headers#authority(CharSequence) methods because it only sets CharSequence.
This is true for all setters in Http2Headers.
Modification:
Fixed all JavaDoc errors.
Result:
Better JavaDoc.
Motivation:
HTTP is a plaintext protocol which means that someone may be able
to eavesdrop the data. To prevent this, HTTPS should be used whenever
possible. However, maintaining using https:// in all URLs may be
difficult. The nohttp tool can help here. The tool scans all the files
in a repository and reports where http:// is used.
Modifications:
- Added nohttp (via checkstyle) into the build process.
- Suppressed findings for the websites
that don't support HTTPS or that are not reachable
Result:
- Prevent using HTTP in the future.
- Encourage users to use HTTPS when they follow the links they found in
the code.
Motivation:
junit deprecated Assert.assertThat(...)
Modifications:
Use MatcherAssert.assertThat(...) as replacement for deprecated method
Result:
Less deprecation warnings
Motivation:
We have a few classes in which we store and reuse static instances of various exceptions. When doing so it is important to also override fillInStacktrace() and so prevent the leak of the ClassLoader in the internal backtrace field.
Modifications:
- Add overrides of fillInStracktrace when needed
- Move ThrowableUtil usage in the static methods
Result:
Fixes https://github.com/netty/netty/pull/10686
Motivation:
We should use ObjectUtil for checking if Compression parameters are in range. This will reduce LOC and make code more readable.
Modification:
Used ObjectUtil
Result:
More readable code
Motivation:
We should simplify and remove useless bit operations to make code more efficient, faster, and easier to understand.
Modification:
Simplified and Removed Useless Bit Operations
Result:
Simpler Code.
Motivation:
`Http2MultiplexHandler` have to 2 empty lines at the end instead of 1.
Modification:
Removed 1 extra line.
Result:
Little better code style.
Motivation:
We can use ObjectUtil#checkPositive instead of manually checking maxContentLength. Also, there was a missing JavaDoc for Http2Exception,
Modification:
Used ObjectUtil#checkPositive for checking maxContentLength.
Added missing JavaDoc.
Result:
More readable code.
Motivation:
We wish to use Unsafe as little as possible, and Java 8 allows us
to take some short-cuts or play some tricks with generics,
for the purpose of working around having to declare all checked
exceptions. Ideally all checked exceptions would be declared, but
the code base is not ready for that yet.
Modification:
The call to UNSAFE.throwException has been removed, so when we need
that feature, we instead use the generic exception trick.
In may cases, Java 8 allows us to throw Throwable directly. This
happens in cases where no exception is declared to be thrown in a
scope.
Finally, some warnings have also been fixed, and some imports have
been reorganised and cleaned up while I was modifying the files
anyway.
Result:
We no longer use Unsafe for throwing any exceptions.
Motivation:
be able to modify Http2Settings of Http2ConnectionHandlerBuilder.
Modifications:
make initialSettings() of Http2ConnectionHandlerBuilder public.
Result:
public initialSettings() of Http2ConnectionHandlerBuilder allow Http2Settings modification.
Motivation:
Fix a TODO that was due since the "master" branch is baselined on at least Java 8.
Modification:
Remove our own copy of the Consumer interface and fix usage sites to use j.u.Consumer.
Also some cleanup.
Result:
Cleaner code.
Motivation
ByteBuf has an isAccessible method which was introduced as part of ref
counting optimizations but there are some places still doing
accessibility checks by accessing the volatile refCnt() directly.
Modifications
- Have PooledNonRetained(Duplicate|Sliced)ByteBuf#isAccessible() use
their refcount delegate's isAccessible() method
- Add static isAccessible(buf) and ensureAccessible(buf) methods to
ByteBufUtil
(since ByteBuf#isAccessible() is package-private)
- Adjust DefaultByteBufHolder and similar classes to use these methods
rather than access refCnt() directly
Result
- More efficient accessibility checks in more places
Motivation:
There should be a validation for the input arguments when constructing Http2FrameLogger
Modification:
Check that the provided arguments are not null
Result:
Proper validation when constructing Http2FrameLogger
Motivation:
We should include TLSv1.3 ciphers as well as recommented ciphers these days for HTTP/2. That is especially true as Java supports TLSv1.3 these days out of the box
Modifications:
- Add TLSv1.3 ciphers that are recommended by mozilla as was for HTTP/2
- Add unit test
Result:
Include TLSv1.3 ciphers as well
Motivation:
testStreamIsNotCreatedIfParentConnectionIsClosedConcurrently() made some assumptions about sequencing which may not be true all the time and racy.
Modifications:
Fix the testcase so its not racy anymore
Result:
Fix build failure on master branch
Motivation:
Setting a dependency on the connection is normal and permitted; streams
actually default to depending on the connection. Using a PRIORITY frame
with a dependency on the connection could reset a previous PRIORITY,
change the relative weight, or make all streams dependent on one stream.
The previous code was disallowing these usages as it considered
depending on the connection to be a validation failure.
Modifications:
Loosen validation check to also allow depending on the connection. Fix
error message when the validation check fails.
Result:
Setting a dependency on connection would be permitted. Fixes#10416
Motivation:
If a request to open a new h2 stream was made from outside of the
EventLoop it will be scheduled for future execution on the EventLoop.
However, during the time before the `open0` task will be executed the
parent channel may already be closed. As the result,
`Http2MultiplexHandler#newOutboundStream()` will throw an
`IllegalStateException` with the message that is hard to
interpret correctly for this use-case: "Http2FrameCodec not found. Has
the handler been added to a pipeline?".
Modifications:
- Check that the parent h2 `Channel` is still active before creating a
new stream when `open0` task is picked up by EventLoop;
Result:
Users see a correct `ClosedChannelException` in case the parent h2
`Channel` was closed concurrently with a request for a new stream.
Motivation:
`Http2StreamChannelBootstrap#open0` invokes
`Http2MultiplexHandler#newOutboundStream()` which may throw an
`IllegalStateException`. In this case, it will never complete
the passed promise.
Modifications:
- `try-catch` all invocations of `newOutboundStream()` and fail
promise in case of any exception;
Result:
New H2 stream promise always completes.
