Motivation
Currently an epoll_ctl syscall is made every time there is a change to
the event interest flags (EPOLLIN, EPOLLOUT, etc) of a channel. These
are only done in the event loop so can be aggregated into 0 or 1 such
calls per channel prior to the next call to epoll_wait.
Modifications
I think further streamlining/simplification is possible but for now I've
tried to minimize structural changes and added the aggregation beneath
the existing flag manipulation logic.
A new AbstractChannel#activeFlags field records the flags last set on
the epoll fd for that channel. Calls to setFlag/clearFlag update the
flags field as before but instead of calling epoll_ctl immediately, just
set or clear a bit for the channel in a new bitset in the associated
EpollEventLoop to reflect whether there's any change to the last set
value.
Prior to calling epoll_wait the event loop makes the appropriate
epoll_ctl(EPOLL_CTL_MOD) call once for each channel who's bit is set.
Result
Fewer syscalls, particularly in some auto-read=false cases. Simplified
error handling from centralization of these calls.
Motivation:
peek() is implemented in a similar way to poll() for the mpsc queue, thus it is more like a consumer call.
It is possible that we could have multiple thread call peek() and possibly one thread calls poll() at at the same time.
This lead to multiple consumer scenario, which violates the multiple producer single consumer condition and could lead to spin in an infinite loop in peek()
Modification:
Use isEmpty() instead of peek() to check if task queue is empty
Result:
Dont violate the mpsc semantics.
Motivation:
We should correctly reset the cached local and remote address when a Channel.disconnect() is called and the channel has a notion of disconnect vs close (for example DatagramChannel implementations).
Modifications:
- Correctly reset cached kicak abd remote address
- Update testcase to cover it and so ensure all transports work in a consistent way
Result:
Correctly handle disconnect()
Motivation:
SystemPropertyUtil already uses the AccessController internally so not need to wrap its usage with AccessController as well.
Modifications:
Remove explicit AccessController usage when SystemPropertyUtil is used.
Result:
Code cleanup
Motivation:
We did not correctly handle taskoffloading when using BoringSSL / OpenSSL. This could lead to the situation that we did not write the SSL alert out for the remote peer before closing the connection.
Modifications:
- Correctly handle exceptions when we resume processing on the EventLoop after the task was offloadded
- Ensure we call SSL.doHandshake(...) to flush the alert out to the outboundbuffer when an handshake exception was detected
- Correctly signal back the need to call WRAP again when a handshake exception is pending. This will ensure we flush out the alert in all cases.
Result:
No more failures when task offloading is used.
Motivation:
When using io.netty.handler.ssl.openssl.useTasks=true we may call ReferenceCountedOpenSslEngine.setKeyMaterial(...) from another thread and so need to synchronize and also check if the engine was destroyed in the meantime to eliminate of the possibility of a native crash.
The same is try when trying to access the authentication methods.
Modification:
- Add synchronized and isDestroyed() checks where missing
- Add null checks for the case when a callback is executed by another thread after the engine was destroyed already
- Move code for master key extraction to ReferenceCountedOpenSslEngine to ensure there can be no races.
Result:
No native crash possible anymore when using io.netty.handler.ssl.openssl.useTasks=true
Motivation:
calculateMaxBytesPerGatheringWrite() contains duplicated calculation: getSendBufferSize() << 1
Modifications:
Remove the duplicated calculation
Result:
The method will be clear and better
Motivation:
At the moment it is not possible to build netty on a power 8 systems.
Modifications:
- Improve detection of the possibility of using Conscrypt
- Skip testsuite-shading when not on x86_64 as this is the only platform for which we build tcnative atm
- Only include classifier if on x86_64 for tcnative as dependency as this is the only platform for which we build tcnative atm
- Better detect if UDT test can be run
Result:
Fixes https://github.com/netty/netty/issues/9479
Motivation:
Changes that were done to the EpollEventLoop to optimize some things did break some testsuite and caused timeouts. We need to investigate to see why this is the case but for
now we should just revert so we can do a release.
Modifivations:
- Partly revert 1fa7a5e697 and a22d4ba859
Result:
Testsuites pass again.
Motivation:
291f80733a introduced a change to use a byte[] to construct the InetAddress when receiving datagram messages to reduce the overhead. Unfortunally it introduced a regression when handling IPv6-mapped-IPv4 addresses and so produced an IndexOutOfBoundsException when trying to fill the byte[] in native code.
Modifications:
- Correctly use the offset on the pointer of the address.
- Add testcase
- Make tests more robust and include more details when the test fails
Result:
No more IndexOutOfBoundsException
Motivation:
At the current moment HttpContentEncoder handle only first value of multiple accept-encoding headers.
Modification:
Join multiple accept-encoding headers to one separated by comma.
Result:
Fixes#9553
Motivation:
There appears to be a thread-safety issue in the way that `SocksAuthRequest` is using its `CharsetEncoder` instance. `CharsetUtil#encoder` returns a cached thread-local encoder instance, so it is not correct to store this instance in a static member variable and reuse it across multiple threads. The result is an occasional `IllegalStateException` as in the following example:
```
java.lang.IllegalStateException: Current state = RESET, new state = FLUSHED
at java.base/java.nio.charset.CharsetEncoder.throwIllegalStateException(CharsetEncoder.java:989)
at java.base/java.nio.charset.CharsetEncoder.flush(CharsetEncoder.java:672)
at java.base/java.nio.charset.CharsetEncoder.encode(CharsetEncoder.java:801)
at java.base/java.nio.charset.CharsetEncoder.canEncode(CharsetEncoder.java:907)
at java.base/java.nio.charset.CharsetEncoder.canEncode(CharsetEncoder.java:982)
at io.netty.handler.codec.socks.SocksAuthRequest.<init>(SocksAuthRequest.java:43)
```
Modification:
Instead of retrieving the thread-local encoder instance once and storing it as a static member instance, the encoder should be retrieved each time the constructor is invoked. This change prevents any potential concurrency issues where multiple threads may end up using the same encoder instance.
Result:
Fixes#9556.
Motivation:
The java doc doesn't match the real case: The exception only happen when a write operation
cannot finish in a certain period of time instead of write idle happen.
Modification:
Correct java doc
Result:
java doc matched the real case
Motivation
Currently every call to get() on a promise results in two reads of the
volatile result field when one would suffice. Maybe this is optimized
away but it seems sensible not to rely on that.
Modification
Reimplement get() and get(...) in DefaultPromise to reduce volatile access.
Result
Fewer volatile reads.
Motivation:
It is noticed that SimpleChannelPool's POOL_KEY attribute name channelPool is easy to get conflict with user code and throws an exception 'channelPool' is already in use. Being a generic framework - it would be great if we can name the attribute something unique - may be use UUID for the name since the name is not required later.
Modifications:
This change make sure that the POOL_KEY used inside SimpleChannelPool is unique by appending the object hashcode in the name.
Result:
No unwanted channel attribute name conflict with user code.
Motivation:
394a1b3485 added support for recvmmsg(...) for unconnected datagram channels, this change also allows to use recvmmsg(...) with connected datagram channels.
Modifications:
- Always try to use recvmmsg(...) if configured to do so
- Adjust unit test to cover it
Result:
Less syscalls when reading datagram packets
Motivation:
We should also use sendmmsg on connected channels whenever possible to reduce the overhead of syscalls.
Modifications:
No matter if the channel is connected or not try to use sendmmsg when supported to reduce the overhead of syscalls
Result:
Better performance on connected UDP channels due less syscalls
Motivation:
394a1b3485 introduced the possibility to use recvmmsg(...) but did not correctly handle ipv6 mapped ip4 addresses to make it consistent with other transports.
Modifications:
- Correctly handle ipv6 mapped ipv4 addresses by only copy over the relevant bytes
- Small improvement on how to detect ipv6 mapped ipv4 addresses by using memcmp and not byte by byte compare
- Adjust test to cover this bug
Result:
Correctly handle ipv6 mapped ipv4 addresses
Motivation
#9152 reverted some static exception reuse optimizations due to the
problem with Throwable#addSuppressed() raised in #9151. This introduced
a performance issue when promises are cancelled at a high frequency due
to the construction cost of CancellationException at the time that
DefaultPromise#cancel() is called.
Modifications
- Reinstate the prior static CANCELLATION_CAUSE_HOLDER but use it just
as a sentinel to indicate cancellation, constructing a new
CancellationException only if/when one needs to be explicitly
returned/thrown
- Subclass CancellationException, overriding fillInStackTrace() to
minimize the construction cost in these cases
Result
Promises are much cheaper to cancel. Fixes#9522.
Motivation:
Following up on discussion with @normanmaurer with suggestion to improve code clarity.
Modification:
Method is synchronized, no need for assert or verbose sync blocks around calls.
Result:
Reduce verbosity and more idiomatic use of keyword. Also rename the method to better describe what it's for.
Motivation
This is another iteration of #9476.
Modifications
Instead of maintaining a count of all writes performed and then using
reads during shutdown to ensure all are accounted for, just set a flag
after each write and don't reset it until the corresponding event has
been returned from epoll_wait.
This requires that while a write is still pending we don't reset
wakenUp, i.e. continue to block writes from the wakeup() method.
Result
Race condition eliminated. Fixes#9362
Motivation:
When using datagram sockets which need to handle a lot of packets it makes sense to use recvmmsg to be able to read multiple datagram packets with one syscall.
Modifications:
- Add support for recvmmsg on linux
- Add new EpollChannelOption.MAX_DATAGRAM_PACKET_SIZE
- Add tests
Result:
Fixes https://github.com/netty/netty/issues/8446.
Motivation:
We need to update the doubly-linked list nodes while holding a lock via synchronized in all cases as otherwise we may end-up with a corrupted pipeline. We missed this when calling remove0(...) due handlerAdded(...) throwing an exception.
Modifications:
- Correctly hold lock while update node
- Add assert
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9528
Motivation
This is a "simpler" alternative to #9416 which fixes the same
CompositeByteBuf bugs described there, originally reported by @jingene
in #9398.
Modifications
- Add fields to Component class for the original buffer along with its
adjustment, which may be different to the already-stored unwrapped
buffer. Use it in appropriate places to ensure correctness and
equivalent behaviour to that prior to the earlier optimizations
- Add comments explaining purpose of each of the Component fields
- Unwrap more kinds of buffers in newComponent method to extend scope of
the existing indirection-reduction optimization
- De-duplicate common buffer consolidation logic
- Unit test for the original bug provided by @jingene
Result
- Correct behaviour / fixed bugs
- Some code deduplication / simplification
- Unwrapping optimization applied to more types of buffers
The downside is increased mem footprint from the two new fields, and
additional allocations in some specific cases, though those should be
rare.
Co-authored-by: jingene <jingene0206@gmail.com>
Motivation:
There are some extra log level checks (logger.isWarnEnabled()).
Modification:
Remove log level checks (logger.isWarnEnabled()) from io.netty.channel.epoll.AbstractEpollStreamChannel, io.netty.channel.DefaultFileRegion, io.netty.channel.nio.AbstractNioChannel, io.netty.util.HashedWheelTimer, io.netty.handler.stream.ChunkedWriteHandler and io.netty.channel.udt.nio.NioUdtMessageConnectorChannel
Result:
Fixes#9456
Motivation:
At the moment we use the String representation of the IP to create the DatagramSocketAddress. This is not for free and we should better use the byte[] directly to reduce the overhead of parsing the String (and creating it in the first place)
Modifications:
Directly use byte[] as input for the DatagramSocketAddress
Result:
Less overhead when using Datagrams with native transports
Motivation:
The Netty classes are initialized at build time by default for GraalVM Native Image compilation. This is configured via the `--initialize-at-build-time=io.netty` option. While this reduces start-up time it can lead to some problems:
- The class initializer of `io.netty.buffer.PooledByteBufAllocator` looks at the maximum memory size to compute the size of internal buffers. If the class initializer runs during image generation, then the buffers are sized according to the very large heap size that the image generator uses, and Netty allocates several arrays that are 16 MByte. The fix is to initialize the following 3 classes at run time: `io.netty.buffer.PooledByteBufAllocator,io.netty.buffer.ByteBufAllocator,io.netty.buffer.ByteBufUtil`. This fix was dependent on a GraalVM Native Image fix that was included in 19.2.0.
- The class initializer of `io.netty.handler.ssl.util.ThreadLocalInsecureRandom` needs to be initialized at runtime to ensure that the generated values are trully random and not fixed for each generated image.
- The class initializers of `io.netty.buffer.AbstractReferenceCountedByteBuf` and `io.netty.util.AbstractReferenceCounted` compute field offsets. While the field offset recomputation is necessary for correct execution as a native image these initializers also have logic that depends on the presence/absence of `sun.misc.Unsafe`, e.g., via the `-Dio.netty.noUnsafe=true` flag. The fix is to push these initializers to runtime so that the field offset lookups (and the logic depending on them) run at run time. This way no manual substitutions are necessary either.
Modifications:
Add `META-INF/native-image` configuration files that correctly trigger the inialization of the above classes at run time via `--initialize-at-run-time=...` flags.
Result:
Fixes the initialisation issues described above for Netty executables built with GraalVM.
Motivation:
Currently when HttpPostStandardRequestDecoder throws a ErrorDataDecoderException during construction we leak memory. We need to ensure all is released correctly.
Modifications:
- Call destroy() if parseBody() throws and rethrow the ErrorDataDecoderException
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9513.
Motivation:
We need to also include the native-image configuration files in the netty all jar to be able to use it with GraalVM native.
Modifications:
Add files in META-INF/native-image as well
Result:
Fixes https://github.com/netty/netty/issues/9514
Motivation:
We currently try to access the the domain search list via reflection on windows which will print a illegal access warning when using Java9 and later.
Modifications:
Add a guard against the used java version.
Result:
Fixes https://github.com/netty/netty/issues/9500.
Motivation:
Right now you can cancel the Future returned by
`Http2StreamChannelBootstrap.open()` and that will race with the
registration of the stream channel with the event loop, potentially
culminating in an `IllegalStateException` and potential resource leak.
Modification:
Ensure that the returned promise is uncancellable.
Result:
Should no longer see `IllegalStateException`s.
Motivation:
We did not correctly pass all supplied parameters to the called constructor and so did not apply the timeout.
Modification:
Correctly pass on the parameters.
Result:
Use timeout
Motivation:
AbstractByteBuf.indexOf(...) currently delegates to ByteBufUtils.indexOf(...) which will create a new ByteBufProcessor on each call. This is done to reduce overhead of bounds-checks. Unfortunally while this reduces bounds checks it produces a lot of GC. We can just implement our own version in AbstractByteBuf which makes use of _getByte(...) and so does no bound checks as well but also not need to create any garbage.
Modifications:
Write optimized implementation of indexOf(...) for AbstractByteBuf
Result:
Fixes https://github.com/netty/netty/issues/9499.
Motivation:
In the release (4.1.37) 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
Http2ClientUpgradeCodec and so did not correctly add Http2MultiplexHandler
to the pipeline before calling Http2FrameCodec.onHttpClientUpgrade(...).
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.onHttpClientUpgrade(...)
Result:
Fixes#9495.
Motivation:
We should not only include the java source files but also the c source file in our source jars.
Modifications:
Add files from src/main/c as well
Result:
Fixes https://github.com/netty/netty/issues/9494
Motivation:
Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.
Modifications:
Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.
Result:
Correct links in javadoc.
Motivation:
`HttpObjectDecoder` pre-checks that it doesn't request characters
outside of the `AppendableCharSequence`'s length. `0` is always allowed
because the minimal length of `AppendableCharSequence` is `1`. We can
legally skip index check by using
`AppendableCharSequence.charAtUnsafe(int)` in all existing cases in
`HttpObjectDecoder`.
Modifications:
- Use `AppendableCharSequence.charAtUnsafe(int)` instead of
`AppendableCharSequence.charAt(int)` in `HttpObjectDecoder`.
Result:
No unnecessary index checks in `HttpObjectDecoder`.
Motivation:
14607979f6 added tests for using ACCP but did miss to use the same unwrapping technique of exceptions as JdkSslEngineTest. This can lead to test-failures on specific JDK versions
Modifications:
Add the same unwrapping code
Result:
No more test failures
Motivation
The epoll transport was updated in #7834 to decouple setting of the
timerFd from the event loop, so that scheduling delayed tasks does not
require waking up epoll_wait. To achieve this, new overridable hooks
were added in the AbstractScheduledEventExecutor and
SingleThreadEventExecutor superclasses.
However, the minimumDelayScheduledTaskRemoved hook has no current
purpose and I can't envisage a _practical_ need for it. Removing
it would reduce complexity and avoid supporting this specific
API indefinitely. We can add something similar later if needed
but the opposite is not true.
There also isn't a _nice_ way to use the abstractions for
wakeup-avoidance optimizations in other EventLoops that don't have a
decoupled timer.
This PR replaces executeScheduledRunnable and
wakesUpForScheduledRunnable
with two new methods before/afterFutureTaskScheduled that have slightly
different semantics:
- They only apply to additions; given the current internals there's no
practical use for removals
- They allow per-submission wakeup decisions via a boolean return val,
which makes them easier to exploit from other existing EL impls (e.g.
NIO/KQueue)
- They are subjectively "cleaner", taking just the deadline parameter
and not exposing Runnables
- For current EL/queue impls, only the "after" hook is really needed,
but specialized blocking queue impls can conditionally wake on task
submission (I have one lined up)
Also included are further optimization/simplification/fixes to the
timerFd manipulation logic.
Modifications
- Remove AbstractScheduledEventExecutor#minimumDelayScheduledTaskRemoved()
and supporting methods
- Uplift NonWakeupRunnable and corresponding default wakesUpForTask()
impl from SingleThreadEventLoop to SingleThreadEventExecutor
- Change executeScheduledRunnable() to be package-private, and have a
final impl in SingleThreadEventExecutor which triggers new overridable
hooks before/afterFutureTaskScheduled()
- Remove unnecessary use of bookend tasks while draining the task queue
- Use new hooks to add simpler wake-up avoidance optimization to
NioEventLoop (primarily to demonstrate utility/simplicity)
- Reinstate removed EpollTest class
In EpollEventLoop:
- Refactor to use only the new afterFutureTaskScheduled() hook for
updating timerFd
- Fix setTimerFd race condition using a monitor
- Set nextDeadlineNanos to a negative value while the EL is awake and
use this to block timer changes from outside the EL. Restore the
known-set value prior to sleeping, updating timerFd first if necessary
- Don't read from timerFd when processing expiry event
Result
- Cleaner API for integrating with different EL/queue timing impls
- Fixed race condition to avoid missing scheduled wakeups
- Eliminate unnecessary timerFd updates while EL is awake, and
unnecessary expired timerFd reads
- Avoid unnecessary scheduled-task wakeups when using NIO transport
I did not yet further explore the suggestion of using
TFD_TIMER_ABSTIME for the timerFd.
Motivation:
Amazon lately released Amazon Corretto Crypto Provider, so we should include it in our testsuite
Modifications:
Add tests related to Amazon Corretto Crypto Provider
Result:
Test netty with Amazon Corretto Crypto Provider
Motivation:
Http post request may be encoded as 'multipart/form-data' without any files and consist mixed attributes only.
Modifications:
- Do not double release attributes
- Add unit test
Result:
Code does not throw an IllegalReferenceCountException.
