* 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:
SpdyOrHttpChooser and Http2OrHttpChooser duplicate fair amount code with each other.
Modification:
- Replace SpdyOrHttpChooser and Http2OrHttpChooser with ApplicationProtocolNegotiationHandler
- Add ApplicationProtocolNames to define the known application-level protocol names
Result:
- Less code duplication
- A user can perform dynamic pipeline configuration that follows ALPN/NPN for any protocols.
Related: #3641 and #3813
Motivation:
When setting up an HTTP/1 or HTTP/2 (or SPDY) pipeline, a user usually
ends up with adding arbitrary set of handlers.
Http2OrHttpChooser and SpdyOrHttpChooser have two abstract methods
(create*Handler()) that expect a user to return a single handler, and
also have add*Handlers() methods that add the handler returned by
create*Handler() to the pipeline as well as the pre-defined set of
handlers.
The problem is, some users (read: I) don't need all of them or the
user wants to add more than one handler. For example, take a look at
io.netty.example.http2.tiles.Http2OrHttpHandler, which works around
this issue by overriding addHttp2Handlers() and making
createHttp2RequestHandler() a no-op.
Modifications:
- Replace add*Handlers() and create*Handler() with configure*()
- Rename getProtocol() to selectProtocol() to make what it does clear
- Provide the default implementation of selectProtocol()
- Remove SelectedProtocol.UNKNOWN and use null instead, because
'UNKNOWN' is not a protocol
- Proper exception handling in the *OrHttpChooser so that the
exception is logged and the connection is closed when failed to
select a protocol
- Make SpdyClient example always use SSL. It was always using SSL
anyway.
- Implement SslHandshakeCompletionEvent.toString() for debuggability
- Remove an orphaned class: JettyNpnSslSession
- Add SslHandler.applicationProtocol() to get the name of the
application protocol
- SSLSession.getProtocol() now returns transport-layer protocol name
only, so that it conforms to its contract.
Result:
- *OrHttpChooser have better API.
- *OrHttpChooser handle protocol selection failure properly.
- SSLSession.getProtocol() now conforms to its contract.
- SpdyClient example works with SpdyServer example out of the box
Motivation:
Examples that are using ALPN/NPN are using a failure mode which is not supported by the JDK SslProvider. The examples fail to run and throw an exception if the JDK SslProvider is used.
Modifications:
- Use SelectorFailureBehavior.NO_ADVERTISE
- Use SelectedListenerFailureBehavior.ACCEPT
Result:
Examples can be run with both OpenSsl and JDK SslProviders.
Motivation:
SslContext factory methods have gotten out of control; it's past time to
swap to a builder.
Modifications:
New Builder class. The existing factory methods must be left as-is for
backward compatibility.
Result:
Fixes#3531
Motivation:
To support HTTP2 we need APLN support. This was not provided before when using OpenSslEngine, so SSLEngine (JDK one) was the only bet.
Beside this CipherSuiteFilter was not supported
Modifications:
- Upgrade netty-tcnative and make use of new features to support ALPN and NPN in server and client mode.
- Guard against segfaults after the ssl pointer is freed
- support correctly different failure behaviours
- add support for CipherSuiteFilter
Result:
Be able to use OpenSslEngine for ALPN / NPN for server and client.
Motivation:
The commit 50e06442c3 changed the type of
the constants in HttpHeaders.Names and HttpHeaders.Values, making 4.1
backward-incompatible with 4.0.
It also introduces newer utility classes such as HttpHeaderUtil, which
deprecates most static methods in HttpHeaders. To ease the migration
between 4.1 and 5.0, we should deprecate all static methods that are
non-existent in 5.0, and provide proper counterpart.
Modification:
- Revert the changes in HttpHeaders.Names and Values
- Deprecate all static methods in HttpHeaders in favor of:
- HttpHeaderUtil
- the member methods of HttpHeaders
- AsciiString
- Add integer and date access methods to HttpHeaders for easier future
migration to 5.0
- Add HttpHeaderNames and HttpHeaderValues which provide standard HTTP
constants in AsciiString
- Deprecate HttpHeaders.Names and Values
- Make HttpHeaderValues.WEBSOCKET lowercased because it's actually
lowercased in all WebSocket versions but the oldest one
- Add RtspHeaderNames and RtspHeaderValues which provide standard RTSP
constants in AsciiString
- Deprecate RtspHeaders.*
- Do not use AsciiString.equalsIgnoreCase(CharSeq, CharSeq) if one of
the parameters are AsciiString
- Avoid using AsciiString.toString() repetitively
- Change the parameter type of some methods from String to
CharSequence
Result:
Backward compatibility is recovered. New classes and methods will make
the migration to 5.0 easier, once (Http|Rtsp)Header(Names|Values) are
ported to master.
Motivation:
Improvements were made on the main line to support ALPN and mutual
authentication for TLS. These should be backported.
Modifications:
- Backport commits from the master branch
- f8af84d599
- e74c8edba3
Result:
Support for ALPN and mutual authentication.
Motivation:
The examples have not been updated since long time ago, showing various
issues fixed in this commit.
Modifications:
- Overall simplification to reduce LoC
- Use system properties to get options instead of parsing args.
- Minimize option validation
- Just use System.out/err instead of Logger
- Do not pass config as parameters - just access it directly
- Move the main logic to main(String[]) instead of creating a new
instance meaninglessly
- Update netty-build-21 to make checkstyle not complain
- Remove 'throws Exception' clause if possible
- Line wrap at 120 (previously at 80)
- Add an option to enable SSL for most examples
- Use ChannelFuture.sync() instead of await()
- Use System.out for the actual result. Use System.err otherwise.
- Delete examples that are not very useful:
- applet
- websocket/html5
- websocketx/sslserver
- localecho/multithreaded
- Add run-example.sh which simplifies launching an example from command
line
- Rewrite FileServer example
Result:
Shorter and simpler examples. A user can focus more on what it actually
does than miscellaneous stuff. A user can launch an example very
easily.
Motivation:
According to TLS ALPN draft-05, a client sends the list of the supported
protocols and a server responds with the selected protocol, which is
different from NPN. Therefore, ApplicationProtocolSelector won't work
with ALPN
Modifications:
- Use Iterable<String> to list the supported protocols on the client
side, rather than using ApplicationProtocolSelector
- Remove ApplicationProtocolSelector
Result:
Future compatibility with TLS ALPN
Motivation:
- OpenSslEngine and JDK SSLEngine (+ Jetty NPN) have different APIs to
support NextProtoNego extension.
- It is impossible to configure NPN with SslContext when the provider
type is JDK.
Modification:
- Implement NextProtoNego extension by overriding the behavior of
SSLSession.getProtocol() for both OpenSSLEngine and JDK SSLEngine.
- SSLEngine.getProtocol() returns a string delimited by a colon (':')
where the first component is the transport protosol (e.g. TLSv1.2)
and the second component is the name of the application protocol
- Remove the direct reference of Jetty NPN classes from the examples
- Add SslContext.newApplicationProtocolSelector
Result:
- A user can now use both JDK SSLEngine and OpenSslEngine for NPN-based
protocols such as HTTP2 and SPDY
Motivation:
Some users already use an SSLEngine implementation in finagle-native. It
wraps OpenSSL to get higher SSL performance. However, to take advantage
of it, finagle-native must be compiled manually, and it means we cannot
pull it in as a dependency and thus we cannot test our SslHandler
against the OpenSSL-based SSLEngine. For an instance, we had #2216.
Because the construction procedures of JDK SSLEngine and OpenSslEngine
are very different from each other, we also need to provide a universal
way to enable SSL in a Netty application.
Modifications:
- Pull netty-tcnative in as an optional dependency.
http://netty.io/wiki/forked-tomcat-native.html
- Backport NativeLibraryLoader from 4.0
- Move OpenSSL-based SSLEngine implementation into our code base.
- Copied from finagle-native; originally written by @jpinner et al.
- Overall cleanup by @trustin.
- Run all SslHandler tests with both default SSLEngine and OpenSslEngine
- Add a unified API for creating an SSL context
- SslContext allows you to create a new SSLEngine or a new SslHandler
with your PKCS#8 key and X.509 certificate chain.
- Add JdkSslContext and its subclasses
- Add OpenSslServerContext
- Add ApplicationProtocolSelector to ensure the future support for NPN
(NextProtoNego) and ALPN (Application Layer Protocol Negotiation) on
the client-side.
- Add SimpleTrustManagerFactory to help a user write a
TrustManagerFactory easily, which should be useful for those who need
to write an alternative verification mechanism. For example, we can
use it to implement an unsafe TrustManagerFactory that accepts
self-signed certificates for testing purposes.
- Add InsecureTrustManagerFactory and FingerprintTrustManager for quick
and dirty testing
- Add SelfSignedCertificate class which generates a self-signed X.509
certificate very easily.
- Update all our examples to use SslContext.newClient/ServerContext()
- SslHandler now logs the chosen cipher suite when handshake is
finished.
Result:
- Cleaner unified API for configuring an SSL client and an SSL server
regardless of its internal implementation.
- When native libraries are available, OpenSSL-based SSLEngine
implementation is selected automatically to take advantage of its
performance benefit.
- Examples take advantage of this modification and thus are cleaner.