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.
Motivation:
We should use the latest commons-compress release to fix CVE-2019-12402 (even it is only a test dependency)
Modifications:
Update commons-compress to 1.19
Result:
Fix security alert
### Motivation:
I've now found two libraries that use Netty to be vulnerable to [CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')](https://cwe.mitre.org/data/definitions/113.html) due to using `new DefaultHttpHeaders(false)`.
Some part of me hopes that this warning will help dissuade library authors from disabling this important security check.
### Modification:
Add documentation to `DefaultHttpHeaders(boolean)` to warn about the implications of `false`.
### Result:
This improves the documentation on `DefaultHttpHeaders`.
Motivation:
In the current implementation of Base64 decoder an invalid
character `\u00BD` treated as `=`.
Also character `\u007F` leads to ArrayIndexOutOfBoundsException.
Modification:
Explicitly checks that all input bytes are ASCII characters
(greater than zero). Fix `decodabet` tables.
Result:
Correctly validation input bytes in Base64 decoder.
Motivation:
031c2e2e88 introduced some change to reduce the risk of have the `ReferenceCountedOpenSslContext` be destroyed while the `ReferenceCountedSslEngine` is still in us. Unfortunaly it missed to adjust a few tests which make assumptions about the refCnt of the context.
Modifications:
Adjust tests to take new semenatics into acount.
Result:
No more tests failures
Motivation:
We should not commit vscode specific files, so at it to gitignore
Modifications:
Add files to .gitignore
Result:
Correctly ignore ide related files
Motivation:
We should use adaptjdk 13 and not oracle openjdk 13 when building with Java 13
Modifications:
Use adopt@1.13.0-0
Result:
More consistent java vendor usage
Motivation
NioEventLoopTest#testChannelsRegistered() fails intermittently due to
use of SingleThreadEventLoop#channelsRegistered() which is not
threadsafe and unreliable when called from outside the event loop.
Modifications
Add static registeredChannels method to NioEventLoopTest and
AbstractSingleThreadEventLoopTest to call from the tests via event loop
instead of directly.
Result
Hopefully fewer test failures
Motivation:
Http2MultiplexCodec extends Http2FrameCodec extends Http2ConnectionHandler. It appears Http2MultiplexCodec overrode the channelWritabilityChanged method, which prevented the flow controller from becoming active. In the case the parent channel becomes unwritable, and then later becomes writable, it needs to indicate that the child channels can still write data. This is slightly confusing, because the child channels may still themselves be unwritable, but should still drain their data to the parent channel.
Modification:
Still propagate writability changes to the HTTP/2 flow controller
Result:
Fixes https://github.com/netty/netty/issues/9636
Motivation:
There is a goto statement above the current position of initialize dynamicMethods, and dynamicMethods is used after the goto which might cause undefined behavior.
Modifications:
Initialize dynamicMehtods at the top.
Result:
No more undefined behavior.
Motivation
This is a vestige that was removed in the original PR #9535 before it
was reverted, but we missed it when re-applying in #9586.
It means there is a possible race condition because a wakeup event could
be missed while shutting down, but the consequences aren't serious since
there's a 1 second safeguard timeout when waiting for it.
Modification
Remove call to epollWaitNow() in EpollEventLoop#closeAll()
Result
Cleanup redundant code, avoid shutdown delay race condition
Motivation
The current event loop shutdown logic is quite fragile and in the
epoll/NIO cases relies on the default 1 second wait/select timeout that
applies when there are no scheduled tasks. Without this default timeout
the shutdown would hang indefinitely.
The timeout only takes effect in this case because queued scheduled
tasks are first cancelled in
SingleThreadEventExecutor#confirmShutdown(), but I _think_ even this
isn't robust, since the main task queue is subsequently serviced which
could result in some new scheduled task being queued with much later
deadline.
It also means shutdowns are unnecessarily delayed by up to 1 second.
Modifications
- Add/extend unit tests to expose the issue
- Adjust SingleThreadEventExecutor shutdown and confirmShutdown methods
to explicitly add no-op tasks to the taskQueue so that the subsequent
event loop iteration doesn't enter blocking wait (as looks like was
originally intended)
Results
Faster and more robust shutdown of event loops, allows removal of the
default wait timeout
Motivation:
Native image compilation is failing without extra flags:
```
Warning: Aborting stand-alone image build. No instances of io.netty.buffer.UnpooledHeapByteBuf are allowed in the image heap as this class should be initialized at image runtime. Object has been initialized by the io.netty.handler.codec.http2.Http2ConnectionHandler class initializer with a trace:
at io.netty.buffer.Unpooled.wrappedBuffer(Unpooled.java:157)
at io.netty.handler.codec.http2.Http2ConnectionHandler.<clinit>(Http2ConnectionHandler.java:74)
. To fix the issue mark io.netty.buffer.UnpooledHeapByteBuf for build-time initialization with --initialize-at-build-time=io.netty.buffer.UnpooledHeapByteBuf or use the the information from the trace to find the culprit and --initialize-at-run-time=<culprit> to prevent its instantiation.
Detailed message:
Trace: object io.netty.buffer.ReadOnlyByteBuf
object io.netty.buffer.UnreleasableByteBuf
method io.netty.handler.codec.http2.Http2ConnectionHandler.access$500()
Call path from entry point to io.netty.handler.codec.http2.Http2ConnectionHandler.access$500():
at io.netty.handler.codec.http2.Http2ConnectionHandler.access$500(Http2ConnectionHandler.java:66)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.readClientPrefaceString(Http2ConnectionHandler.java:299)
at io.netty.handler.codec.http2.Http2ConnectionHandler$PrefaceDecoder.decode(Http2ConnectionHandler.java:239)
at io.netty.handler.codec.http2.Http2ConnectionHandler.decode(Http2ConnectionHandler.java:438)
at io.netty.handler.codec.ByteToMessageDecoder.decodeRemovalReentryProtection(ByteToMessageDecoder.java:505)
at io.netty.handler.codec.ByteToMessageDecoder.callDecode(ByteToMessageDecoder.java:444)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:283)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:374)
at io.netty.channel.AbstractChannelHandlerContext.access$600(AbstractChannelHandlerContext.java:56)
at io.netty.channel.AbstractChannelHandlerContext$7.run(AbstractChannelHandlerContext.java:365)
at com.oracle.svm.core.jdk.RuntimeSupport.executeHooks(RuntimeSupport.java:144)
at com.oracle.svm.core.jdk.RuntimeSupport.executeStartupHooks(RuntimeSupport.java:89)
at com.oracle.svm.core.JavaMainWrapper.runCore(JavaMainWrapper.java:143)
at com.oracle.svm.core.JavaMainWrapper.run(JavaMainWrapper.java:186)
at com.oracle.svm.core.code.IsolateEnterStub.JavaMainWrapper_run_5087f5482cc9a6abc971913ece43acb471d2631b(generated:0)
```
Modification:
Add `io.netty.handler.codec.http2.Http2ConnectionHandler` for runtime compilation, as the buffer library's `io.netty.buffer.UnpooledHeapByteBuf` is also marked for runtime.
Result:
Native image compilation works again.
Motivation:
`DefaultHttp2UnknownFrame#equals` may produce NPE due to
incorrect comparison of `stream` field.
Modification:
- Fix the `stream` field compare.
- Cleanup usage of class fields: use direct access instead of getters
(because the class is final).
Result:
No NPE in `equals` method.
Motivation:
Classes `AbstractHttp2StreamChannel.Http2StreamChannelConfig`
and `DnsNameResolver.AddressedEnvelopeAdapter` may be static:
it doesn't reference its enclosing instance.
Modification:
Add `static` modifier.
Result:
Prevents a possible memory leak and uses less memory per class instance.
Motivation:
With the Netty ref-counted OpenSSL implementation the parent SslContext
maintains state necessary for the SslEngine's it produces. However, it's
possible for the parent context to be closed and release those resources
before the child engines are finished which causes problems.
Modification:
Spawned ReferenceCountedOpenSslEngine's retain a reference to their
parent ReferenceCountedOpenSslContext.
Result:
The lifetime of the shared data is extended to include the lifetime of
the dependents.
Motivation:
On JDK > 9 Netty uses Unsafe to write two internal JDK fields: sun.nio.ch.SelectorImp.selectedKeys and sun.nio.ch.SelectorImpl.publicSelectedKeys. This is done in transport/src/main/java/io/netty/channel/nio/NioEventLoop.java:225, in openSelector() method. The GraalVM analysis cannot do the Unsafe registration automatically because the object field offset computation is hidden behind two layers of calls.
Modifications:
This PR updates the Netty GraalVM configuration by registering those fields for unsafe access.
Result:
Improved support for Netty on GraalVM with JDK > 9.
