Motivation
Currently the visibility of the various Recycler inner classes and their
fields isn't optimal. Some private members are accessed by other classes
resulting in synthetic methods, and other non-private classes/members
are only accessed privately and so can be made private.
Modifications
- Increase/reduce visibility of various fields/methods/classes within
Recycler
- Have WeakOrderQueue extend WeakReference<Thread> to eliminate the
owner field
- Change local DefaultHandle var to DefaultHandle<?> to avoid raw type
compiler warning
Result
Tidier code, fewer implicit methods on hot paths (reducing inlining
depths)
Motivation
This is already done internally for various reasons but it would make
sense i.m.o. as a top level concept: submitting a task to be run on the
event loop which doesn't need to run immediately but must still be
executed in FIFO order relative all other submitted tasks (be those
"lazy" or otherwise).
It's nice to separate this abstract "relaxed" semantic from concrete
implementations - the simplest is to just delegate to existing execute,
but for the main EL impls translates to whether a wakeup is required
after enqueuing.
Having a "global" abstraction also allows for simplification of our
internal use - for example encapsulating more of the common scheduled
future logic within AbstractScheduledEventExecutor.
Modifications
- Introduce public LazyRunnable interface and
AbstractEventExecutor#lazyExecute method (would be nice for this to be
added to EventExecutor interface in netty 5)
- Tweak existing SingleThreadEventExecutor mechanics to support these
- Replace internal use of NonWakeupRunnable (such as for pre-flush
channel writes)
- Uplift scheduling-related hooks into AbstractScheduledEventExecutor,
eliminating intermediate executeScheduledRunnable method
Result
Simpler code, cleaner and more useful/flexible abstractions - cleaner in
that they fully communicate the intent in a more general way, without
implying/exposing/restricting implementation details
Motivation:
We currently use a finalizer to ensure we correctly return the reserved back to the Stack but this is not really needed as we can ensure we return it when needed before dropping the WeakOrderQueue
Modifications:
Use explicit method call to ensure we return the reserved space back before dropping the object
Result:
Less finalizer usage and so less work for the GC
Motivation:
We null out the element in the array after we decrement the current size of the Stack but not directly write back the updated size to the stored field. This is problematic as we do some validation before we write it back and so may never do so if the validation fails. This then later can lead to have null objects returned where not expected
Modifications:
Update size directly after null out object
Result:
No more unexpected null value possible
##Motivation
The InternalLoggerFactory attempts to instantiate different logger
implementations to discover what is available on the class path,
accepting the first implementation that does not throw an exception.
Currently, the default ordering will attempt to instantiate a Log4j1
logger before Log4j2. For environments where both Log4j1 and Log4j2 are
available, this will result in using the older version. It seems that it
would be more intuitive to prefer the newer version, when possible.
##Modifications
Change the default ordering to attempt to use the Log4J2LoggerFactory
before the Log4JLoggerFactory.
##Result
For environments where both Log4j1 and Log4j2 are available on the class
path (but Slf4J is not available), Netty will now use Log4j2 instead of
Log4j1.
### Motivation:
Introduction of `WebSocketDecoderConfig` made our server-side code more elegant and simpler for support.
However there is still some problem with maintenance and new features development for WebSocket codecs (`WebSocketServerProtocolHandler`, `WebSocketServerProtocolHandler`).
Particularly, it makes me ~~crying with blood~~ extremely sad to add new parameter and yet another one constructor into these handlers, when I want to contribute new feature.
### Modification:
I've extracted all parameters for client and server WebSocket handlers into config/builder structures, like it was made for decoders in PR #9116.
### Result:
* Fixes#9698: Simplify WebSocket handlers constructor arguments hell
* Unblock further development in this module (configurable close frame handling on server-side; automatic close-frame sending, when missed; memory leaks on protocol violations; etc...)
Bonuses:
* All defaults are gathered in one place and could be easily found/reused.
* New API greatly simplifies usage, but does NOT allow inheritance or modification.
* New API would simplify long-term maintenance of WebSockets module.
### Example
WebSocketClientProtocolConfig config = WebSocketClientProtocolConfig.newBuilder()
.webSocketUri("wss://localhost:8443/fx-spot")
.subprotocol("trading")
.handshakeTimeoutMillis(15000L)
.build();
ctx.pipeline().addLast(new WebSocketClientProtocolHandler(config));
Motivation:
The javadocs of Http2Headers.method(...) are incorrect, we should fix these.
Modifications:
Correct javadocs
Result:
Fixes https://github.com/netty/netty/issues/8068.
Motivation:
At the moment we miss to poll the method queue when we see an Informational response code. This can lead to out-of-sync of request / response pairs when later try to compare these.
Modifications:
Always poll the queue correctly
Result:
Always compare the correct request / response pairs
Motivation:
If maxDelayedQueues == 0 we should never put any WeakHashMap into the FastThreadLocal for a Thread.
Modifications:
Check if maxDelayedQueues == 0 and if so return directly. This will ensure we never call FastThreadLocal.initialValue() in this case
Result:
Less overhead / memory usage when maxDelayedQueues == 0
Motivation:
On MacOS it is not really good enough to check /etc/resolv.conf to determine the nameservers to use. We should retrieve the nameservers using the same way as mDNSResponser and chromium does by doing a JNI call.
Modifications:
Add MacOSDnsServerAddressStreamProvider and testcase
Result:
Use correct nameservers by default on MacOS.
Motivation:
Easier to debug SelfSignedCertificate failures.
Modifications:
Add first throwable as suppressed to thrown exception.
Result:
Less technical debt.
Motivation:
HTTP 102 (WebDAV) is not correctly treated as an informational response
Modification:
Delegate all `1XX` status codes to superclass, not just `100` and `101`.
Result:
Supports WebDAV response.
Removes a huge maintenance [headache](https://github.com/line/armeria/pull/2210) in Armeria which has forked the class for these features
Motivation:
Netty HTTP/2 implementation is not 100% compliant to the spec. This
commit improves the compliance regarding headers validation,
in particular pseudo-headers and connection ones.
According to the spec:
All HTTP/2 requests MUST include exactly one valid value for the
":method", ":scheme", and ":path" pseudo-header fields, unless it is
a CONNECT request (Section 8.3). An HTTP request that omits
mandatory pseudo-header fields is malformed (Section 8.1.2.6).
Modifications:
- Introduce Http2HeadersValidator class capable of validating HTTP/2
headers
- Invoke validation from DefaultHttp2ConnectionDecoder#onHeadersRead
- Modify tests to use valid headers when required
- Modify HttpConversionUtil#toHttp2Headers to not add :scheme and
:path header on CONNECT method in order to conform to the spec
Result:
- Initial requests without :method, :path, :scheme will fail
- Initial requests with multiple values for :method, :path, :scheme
will fail
- Initial requests with an empty :path fail
- Requests with connection-specific header field will fail
- Requests with TE header different than "trailers" will fail
-
- Fixes 8.1.2.2 tests from h2spec #5761
- Fixes 8.1.2.3 tests from h2spec #5761
Motivation:
At the moment we directly extend the Recycler base class in our code which makes it hard to experiment with different Object pool implementation. It would be nice to be able to switch from one to another by using a system property in the future. This would also allow to more easily test things like https://github.com/netty/netty/pull/8052.
Modifications:
- Introduce ObjectPool class with static method that we now use internally to obtain an ObjectPool implementation.
- Wrap the Recycler into an ObjectPool and return it for now
Result:
Preparation for different ObjectPool implementations
Motivation:
We do not correct guard against the gact that when applying our workaround for windows we may end up with a 0 sleep period. In this case we should just sleep for 1 ms.
Modifications:
Guard agains the case when our calculation will produce 0 as sleep time on windows
Result:
Fixes https://github.com/netty/netty/issues/9710.
Motivation:
Netty is an asynchronous framework.
If somebody uses a blocking call inside Netty's event loops,
it may lead to a severe performance degradation.
BlockHound is a tool that helps detecting such calls.
Modifications:
This change adds a BlockHound's SPI integration that marks
threads created by Netty (`FastThreadLocalThread`s) as non-blocking.
It also marks some of Netty's internal methods as whitelisted
as they are required to run the event loops.
Result:
When BlockHound is installed, any blocking call inside event loops
is intercepted and reported (by default an error will be thrown).
Motivation:
It is common, especially in frameworks, for the parameters to `SslContextBuilder` methods to be built up as a `List` or similar `Iterable`. It is currently difficult to use `SslContextBuilder` in this case because it requires a conversion to array.
Modification:
Add overloads for methods that accept varargs to also accept `Iterable`, delegating by copying into an array.
Result:
Fixes#9293
Motivation
Currently doc != code and so one needs to change. Though behaviour as
currently documented might be more intuitive, we don't want to break
anyone so will adjust the doc instead. See #9503 for discussion.
Modifications
Correct the javadoc of indexOf(...) method in ByteBuf abstract class.
Results
Correct javadoc
Motivation:
Netty should respect JVM flags to control SSL protocols, eg. `-Djdk.tls.client.protocols`
Modification:
Changed `JdkSslContext` to use `SSLContext.getDefaultSSLParameters().getProtocols()` instead of `engine.getSupportedProtocols()` which is hardcoded as `SSLv2Hello, SSLv3, TLSv1, TLSv1.1, TLSv1.2`.
Result:
Without `-Djdk.tls.client.protocols`, `SSLContext.getDefaultSSLParameters().getProtocols()` returns `TLSv1, TLSv1.1, TLSv1.2`.
With `-Djdk.tls.client.protocols=TLSv1.2`, `SSLContext.getDefaultSSLParameters().getProtocols()` returns `TLSv1.2`.
Fixes#9706
Motivation:
Constant time comparison functions are used to compare HTTP/2 header
values, even if they are not sensitive.
Modification:
After checking for sensitivity, use fast comparison.
Result: Faster HPACK table reads/writes
Motivation:
In PR https://github.com/netty/netty/pull/9695 IdleStateEvents
were made to cache their string representation. The reason for this
was to avoid creating garbage as these values would be used frequently.
However, these objects may be used on multiple event loops and this
may cause an unexpected race to occur.
Modification:
Only make the events that Netty creates cache their toString representation.
Result:
No races.
Motivation:
We should aim to always use heap buffers when using the JDK SSLEngine for now as it wants to operate on byte[] and so will do internal memory copies if a non heap buffer is used. Beside this it will always return BUFFER_OVERFLOW when a smaller buffer then 16kb is used when calling wrap(...) (even if a very small amount of bytes should be encrypted). This can lead to excercive direct memory usage and pressure for no good reason.
Modifications:
Refactor internals of SslHandler to ensure we use heap buffers for the JDK SSLEngine impelementation
Result:
Less direct memory usage when JDK SSLEngine implementation is used
### Motivation:
FlowControllerHandler currently may swell read-complete events in some situations.
### Modification:
* Fire read-complete event from flow controller, when it previously was swallowed
* New unit test to cover this case
### Result:
Fixes#9667: FlowControllerHandler swallows read-complete event when auto-read is disabled
### Motivation:
IdleStateEvent is very convenient and frequently used type of events. However both in runtime (logs) and in debug you need some manual steps to see their actual content. Default implementation generates worthless trash like this:
io.netty.handler.timeout.IdleStateEvent@27f674d
There are examples already, where event has convenient and useful toString implementation:
* io.netty.handler.proxy.ProxyConnectionEvent
* io.netty.handler.ssl.SslCompletionEvent
### Modification:
* Implement 'IdleStateEvent.toString' method.
* Unit test.
### Result:
More useful String representation of IdleStateEvent
Motivation:
HttpPostRequestDecoder.splitHeaderContentType() throws a StringIndexOutOfBoundsException when it parses a Content-Type header that starts with a semicolon ;. We should skip the execution for incorrect multipart form data.
Modification:
Avoid invocation of HttpPostRequestDecoder#splitHeaderContentType(...) for incorrect multipart form data content-type.
Result:
Fixes#8554
Motivation:
We have a public utility `OpenSsl.isAlpnSupported()` that helps users to
check if ALPN is available for `SslProvider.OPENSSL`. However, we do not
provide a similar utility for `SslProvider.JDK`. Therefore, users who
configured ALPN with `SslProvider.JDK` will get a runtime exception at
the time when a new connection will be created.
Modifications:
- Add public `SslProvider.isAlpnSupported(SslProvider)` utility method
that returns `true` if the `SslProvider` supports ALPN;
- Deprecate `OpenSsl.isAlpnSupported()`;
Result:
Users can verify if their environment supports ALPN with
`SslProvider` upfront (at bootstrap), instead of failing with
runtime exception when a new connection will be created.
Motivation:
Sometimes it is useful to be able to set attributes on a SslContext.
Modifications:
Add new method that will return a AttributeMap that is tied to a SslContext instance
Result:
Fixes https://github.com/netty/netty/issues/6542.
Motivation:
We may fail to update the flow-controller and in this case need to notify the stream channel and close it.
Modifications:
Attach a future to the write of the update frame and in case of a failure propagate it to the channel and close it
Result:
Fixes https://github.com/netty/netty/issues/9663
Motivation:
We should just ignore (and so skip) invalid entries in /etc/resolver.conf.
Modifications:
- Skip invalid entries
- Add unit test
Result:
Fix https://github.com/netty/netty/issues/9684
Motivation:
Data flowing in from the decoder flows out in sequence，Whether decoder removed or not.
Modification:
fire data in out and clear out when hander removed
before call method handlerRemoved(ctx)
Result:
Fixes#9668 .
Motivation:
bbc34d0eda introduced correct handling of "in process" setup of streams but there is some room for improvements. Often the writeHeaders(...) is completed directly which means there is not need to create the extra listener object.
Modifications:
- Only create the listener if we really need too.
Result:
Less GC
Motivation
Currently when future tasks are scheduled via schedule(Runnable, ...)
methods, the supplied Runnable is wrapped in a newly allocated Callable
adapter prior to being wrapped in a ScheduledFutureTask.
This can be avoided which saves an object allocation per scheduled task.
Modifications
Change the Callable task field of ScheduledFutureTask to be of type
Object so that it can hold/run Runnables directly in addition to
Callables.
An "adapter" is still used in the case a Runnable is scheduled with an
explicit constant non-null completion value, assumed to be rare.
Result
Less garbage
Motivation:
In https://github.com/netty/netty/issues/8692, `Http2FrameCodec` was
updated to keep track of all "being initialized" streams, allocating
memory before initialization begins, and releasing memory after
initialization completes successfully.
In some instances where stream initialization fails (e.g. because this
connection has received a GOAWAY frame), this memory is never released.
Modifications:
This change updates the `Http2FrameCodec` to use a separate promise
for monitoring the success of sending HTTP2 headers. When sending of
headers fails, we now make sure to release memory allocated for stream
initialization.
Result:
After this change, failures in writing HTTP2 Headers (e.g. because this
connection has received a GOAWAY frame) will no longer leak memory.
Motivation:
At the moment we do a ByteBuf.readBytes(...) on removal of the ByteToMessageDecoder if there are any bytes left and forward the returned ByteBuf to the next handler in the pipeline. This is not really needed as we can just forward the cumulation buffer directly and so eliminate the extra memory copy
Modifications:
Just forward the cumulation buffer directly on removal of the ByteToMessageDecoder
Result:
Less memory copies
Motivation
A memory leak related to DNS resolution was reported in #9634,
specifically linked to the TCP retry fallback functionality that was
introduced relatively recently. Upon inspection it's apparent that there
are some error paths where the original UDP response might not be fully
released, and more significantly the TCP response actually leaks every
time on the fallback success path.
It turns out that a bug in the unit test meant that the intended TCP
fallback path was not actually exercised, so it did not expose the main
leak in question.
Modifications
- Fix DnsNameResolverTest#testTruncated0 dummy server fallback logic to
first read transaction id of retried query and use it in replayed
response
- Adjust semantic of internal DnsQueryContext#finish method to always
take refcount ownership of passed in envelope
- Reorder some logic in DnsResponseHandler fallback handling to verify
the context of the response is expected, and ensure that the query
response are either released or propagated in all cases. This also
reduces a number of redundant retain/release pairings
Result
Fixes#9634
Motivation:
We can use the `@SuppressJava6Requirement` annotation to be more precise about when we use Java6+ APIs. This helps us to ensure we always protect these places.
Modifications:
Make use of `@SuppressJava6Requirement` explicit
Result:
Fixes https://github.com/netty/netty/issues/2509.
Motivation:
There is not need to use a CAS as everything is synchronized anyway. We can simplify the code a bit by not using it.
Modifications:
- Just remove the CAS operation
- Change from int to boolean
Result:
Code cleanup
Motivation
The recently-introduced event loop scheduling hooks can be exploited by
the epoll transport to avoid waking the event loop when scheduling
future tasks if there is a timer already set to wake up sooner.
There is also a "default" timeout which will wake the event
loop after 1 second if there are no pending future tasks. The
performance impact of these wakeups themselves is likely negligible but
there's significant overhead in having to re-arm the timer every time
the event loop goes to sleep (see #7816). It's not 100% clear why this
timeout was there originally but we're sure it's no longer needed.
Modification
Combine the existing volatile wakenUp and non-volatile prevDeadlineNanos
fields into a single AtomicLong that stores the next scheduled wakeup
time while the event loop is in epoll_wait, and is -1 while it is awake.
Use this as a guard to debounce wakeups from both immediate scheduled
tasks and future scheduled tasks, the latter using the new
before/afterScheduledTaskSubmitted overrides and based on whether the
new deadline occurs prior to an already-scheduled timer.
A similar optimization was already added to NioEventLoop, but it still
uses two separate volatiles. We should consider similar streamlining of
that in a future update.
Result
Fewer event loop wakeups when scheduling future tasks, greatly reduced
overhead when no future tasks are scheduled.
Motivation:
Currently when the SslHandler coalesces outbound bytes it always
allocates a direct byte buffer. This does not make sense if the JDK
engine is being used as the bytes will have to be copied back to heap
bytes for the engine to operate on them.
Modifications:
Inspect engine type when coalescing outbound bytes and allocate heap
buffer if heap bytes are preferred by the engine.
Result:
Improved performance for JDK engine. Better performance in environments
without direct buffer pooling.
