Motivation:
The Epoll transport checks to see if there are any scheduled tasks
before entering epoll_wait, and resets the timerfd just before.
This causes an extra syscall to timerfd_settime before doing any
actual work. When scheduled tasks aren't added frequently, or
tasks are added with later deadlines, this is unnecessary.
Modification:
Check the *deadline* of the peeked task in EpollEventLoop, rather
than the *delay*. If it hasn't changed since last time, don't
re-arm the timer
Result:
About 2us faster on gRPC RTT 50pct latency benchmarks.
Before (2 runs for 5 minutes, 1 minute of warmup):
```
50.0%ile Latency (in nanos): 64267
90.0%ile Latency (in nanos): 72851
95.0%ile Latency (in nanos): 78903
99.0%ile Latency (in nanos): 92327
99.9%ile Latency (in nanos): 119691
100.0%ile Latency (in nanos): 13347327
QPS: 14933
50.0%ile Latency (in nanos): 63907
90.0%ile Latency (in nanos): 73055
95.0%ile Latency (in nanos): 79443
99.0%ile Latency (in nanos): 93739
99.9%ile Latency (in nanos): 123583
100.0%ile Latency (in nanos): 14028287
QPS: 14936
```
After:
```
50.0%ile Latency (in nanos): 62123
90.0%ile Latency (in nanos): 70795
95.0%ile Latency (in nanos): 76895
99.0%ile Latency (in nanos): 90887
99.9%ile Latency (in nanos): 117819
100.0%ile Latency (in nanos): 14126591
QPS: 15387
50.0%ile Latency (in nanos): 61021
90.0%ile Latency (in nanos): 70311
95.0%ile Latency (in nanos): 76687
99.0%ile Latency (in nanos): 90887
99.9%ile Latency (in nanos): 119527
100.0%ile Latency (in nanos): 6351615
QPS: 15571
```
Motivation:
When using Epoll based transport, allow applications to configure SO_BUSY_POLL socket option:
SO_BUSY_POLL (since Linux 3.11)
Sets the approximate time in microseconds to busy poll on a
blocking receive when there is no data. Increasing this value
requires CAP_NET_ADMIN. The default for this option is con‐
trolled by the /proc/sys/net/core/busy_read file.
The value in the /proc/sys/net/core/busy_poll file determines
how long select(2) and poll(2) will busy poll when they oper‐
ate on sockets with SO_BUSY_POLL set and no events to report
are found.
In both cases, busy polling will only be done when the socket
last received data from a network device that supports this
option.
While busy polling may improve latency of some applications,
care must be taken when using it since this will increase both
CPU utilization and power usage.
Modification:
Added SO_BUSY_POLL socket option
Result:
Able to configure SO_BUSY_POLL from Netty
Motivation:
We should just directly init the refCnt to 1 and not use the AtomicIntegerFieldUpdater.
Modifications:
Just assing directly to 1.
Result:
Cleaner code and possible a bit faster as the JVM / JIT may be able to optimize the first store easily.
Motiviation:
At the moment whenever ensureAccessible() is called in our ByteBuf implementations (which is basically on each operation) we will do a volatile read. That per-se is not such a bad thing but the problem here is that it will also reduce the the optimizations that the compiler / jit can do. For example as these are volatile it can not eliminate multiple loads of it when inline the methods of ByteBuf which happens quite frequently because most of them a quite small and very hot. That is especially true for all the methods that act on primitives.
It gets even worse as people often call a lot of these after each other in the same method or even use method chaining here.
The idea of the change is basically just ue a non-volatile read for the ensureAccessible() check as its a best-effort implementation to detect acting on already released buffers anyway as even with a volatile read it could happen that the user will release it in another thread before we actual access the buffer after the reference check.
Modifications:
- Try to do a non-volatile read using sun.misc.Unsafe if we can use it.
- Add a benchmark
Result:
Big performance win when multiple ByteBuf methods are called from a method.
With the change:
UnsafeByteBufBenchmark.setGetLongUnsafeByteBuf thrpt 20 281395842,128 ± 5050792,296 ops/s
Before the change:
UnsafeByteBufBenchmark.setGetLongUnsafeByteBuf thrpt 20 217419832,801 ± 5080579,030 ops/s
* Log the correct line-number when using SLF4j with netty if possible.
Motivation:
At the moment we do not log the correct line number in many cases as it will log the line number of the logger wrapper itself. Slf4j does have an extra interface that can be used to filter out these nad make it more usable with logging wrappers.
Modifications:
Detect if the returned logger implements LocationAwareLogger and if so make use of its extra methods to be able to log the correct origin of the log request.
Result:
Better logging when using slf4j.
Motivation:
We should use the latest jmh version which also supports -prof dtraceasm on MacOS.
Modifications:
Update to latest jmh version.
Result:
Better benchmark / profiling support on MacOS.
* PemPrivateKey.toPem(...) should throw IllegalArgumentException when PrivateKey which does not support encoding is used.
Motivation:
At the moment when a PrivateKey is used that does not support encoding we throw a NPE when trying to convert the key. We should better throw an IllegalArgumentException with the details about what key we tried to encode.
Modifications:
- Check if PrivateKey.getEncoded() returns null and if so throw an IllegalArgumentException
- Add unit test.
Result:
Better handling of non-supported PrivateKey implementations.
Motivation:
Some of the flags we used are not supported anymore on more recent JDK versions. We should just remove all of them and only keep what we really need. This may also reflect better what people use in production.
Modifications:
Remove some flags when running the benchmarks.
Result:
Benchmarks also run with JDK11.
Motivation:
It is sometimes useful to be able to run benchmarks easily from the commandline and passs different arguments / options here. We should support this.
Modifications:
Add the benchmark-jar profile which allows to generate such an "uber-jar" that can be used directly to run benchmarks as documented at http://openjdk.java.net/projects/code-tools/jmh/.
Result:
More flexible way to run benchmarks.
Motivation:
In Java8 and earlier we used reflection to replace the used key set if not otherwise told. This does not work on Java9 and later without special flags as its not possible to call setAccessible(true) on the Field anymore.
Modifications:
- Use Unsafe to instrument the Selector with out special set when sun.misc.Unsafe is present and we are using Java9+.
Result:
NIO transport produce less GC on Java9 and later as well.
Motivation:
In Java8 and earlier we used reflection to detect if unaligned access is supported. This fails in Java9 and later as we would need to change the accessible level of the method.
Lucky enough we can use Unsafe directly to read the content of the static field here.
Modifications:
Add special handling for detecting if unaligned access is supported on Java9 and later which does not fail due jigsaw.
Result:
Better and more correct detection on Java9 and later.
Motivation:
We need to reset the offset to 0 when we fail lazy because of a too long frame.
Modifications:
- Reset offset
- Add testcase
Result:
Fixes https://github.com/netty/netty/issues/8256.
Motivation:
Optimizing the Epoll channel needs an objective measure of how fast
it is.
Modification:
Add a simple, closed loop, ping-pong benchmark.
Result:
Benchmark can be used to measure #7816
Initial numbers:
```
Result "io.netty.microbench.channel.epoll.EpollSocketChannelBenchmark.pingPong":
22614.403 ±(99.9%) 797.263 ops/s [Average]
(min, avg, max) = (21093.160, 22614.403, 24977.387), stdev = 918.130
CI (99.9%): [21817.140, 23411.666] (assumes normal distribution)
Benchmark Mode Cnt Score Error Units
EpollSocketChannelBenchmark.pingPong thrpt 20 22614.403 ± 797.263 ops/s
```
Motivation:
The JVM isn't always able to hoist out/reduce bounds checking (due to ref counting operations etc etc) hence making it configurable could improve performances for most CPU intensive use cases.
Modifications:
Each AbstractByteBuf bounds check has been tested against a new static final configuration property similar to checkAccessible ie io.netty.buffer.bytebuf.checkBounds.
Result:
Any user could disable ByteBuf bounds checking in order to get extra performances.
Motivation:
At the moment we will just assume the correct version of log4j2 is used when we find it on the classpath. This may lead to an AbstractMethodError at runtime. We should not use log4j2 if the version is not correct.
Modifications:
Check on class loading if we can use Log4J2 or not.
Result:
Fixes#8217.
Motivation:
We need to implement remove() by ourselves to make it work on Java7 as otherwise it will throw an AbstractMethodError. This is a followup of c1a335446d.
Modifications:
Just implemented remove()
Result:
Works on Java7 as well.
Motivation:
c1a335446d reimplemented remove(...) and contains(...) in a way which made it not work anymore when used by the Selector.
Modifications:
Partly revert changes in c1a335446d.
Result:
Works again as expected
Motivation:
5aaa16b24c introduced a testcase for specific ciphersuites and checked if these are supported by our native implementation before running it. Unfortunally this is not good enough as even on the JDK it may not be supported on various JDK versions (like Java7). Beside this the test leaked buffers.
Modifications:
- Correctly check if ciphersuite is supported on each SslProvider before trying to run test.
- Fix buffer leaks.
Result:
Testsuite pass again on Java7 and others when -Pleak is used.
Motivation:
Our SelectedSelectionKeySet does not correctly implement various methods which can be done without any performance overhead.
Modifications:
Implement iterator(), contains(...) and remove(...)
Result:
Related to https://github.com/netty/netty/issues/8242.
Motivation:
Log4J2Logger had some code-duplication with AbstractInternalLogger
Modifications:
Reuse AbstractInternaLogger.EXCEPTION_MESSAGE in Log4J2Logger and so remove some code-duplication
Result:
Less duplicated code.
Motivation:
We should use the latest netty-tcnative release which contains a fix to correctly support DH based ciphers when using openssl 1.1.x
Modifications:
Update to latest netty-tcnative which has the fix.
Result:
Correctly support DH ciphers in all cases. Fixes https://github.com/netty/netty/issues/8165.
Motivation:
When the MqttDecoder decodes a message larger than the 'maxBytesInMessage' a DecoderException is thrown and a MqttMessage with just the failure cause is returned. Even if I can't handle the message, I might want to send an ACK so that I won't have to worry about it again.
Modification:
The DecoderException is thrown after the variableHeader is decoded. The fixed and variable headers are then added to the MqttMessage along with the failure cause.
Result:
The invalid MqttMessage will have headers if available.
Motivation:
ea626ef8c3 added more debug logging but we can even include a bit more.
Modifications:
Always log the error number as well.
Result:
More informations for debugging SSL errors.
* We should be able to use the ByteBuffer cleaner on java8 (and earlier versions) even if sun.misc.Unsafe is not present.
Motivation:
At the moment we have a hard dependency on sun.misc.Unsafe to use the Cleaner on Java8 and earlier. This is not really needed as we can still use pure reflection if sun.misc.Unsafe is not present.
Modifications:
Refactor Cleaner6 to fallback to pure reflection if sun.misc.Unsafe is not present on system.
Result:
More timely releasing of direct memory on Java8 and earlier when sun.misc.Unsafe is not present.
Motivation:
f77891cc17 changed slightly how we detect if we should prefer direct buffers or not but did miss to also take this into account when logging.
Modifications:
Fix branch for log message to reflect changes in f77891cc17.
Result:
Correct logging.
Motivation:
We should ensure we call *UnLoad when we detect an error during calling *OnLoad and previous *OnLoad calls were succesfull.
Modifications:
Correctly call *UnLoad when needed.
Result:
More correct code and no leaks when an error happens during loading the native lib.
Motivation:
We should log a bit more details about why we shutdown the SSL.
Modifications:
Add the return value of SSL_get_error(...) as well in debug mode.
Result:
More logging to make it easier to understand why an SSL error happened.
Motivation:
There was a race condition between the task submitter and task executor threads such that the last Runnable submitted may not get executed.
Modifications:
The bug was fixed by checking the task queue and state in the task executor thread after it saw the task queue was empty.
Result:
Fixes#8230
* Allow to use native transports when sun.misc.Unsafe is not present on the system
Motivation:
We should be able to use the native transports (epoll / kqueue) even when sun.misc.Unsafe is not present on the system. This is especially important as Java11 will be released soon and does not allow access to it by default.
Modifications:
- Correctly disable usage of sun.misc.Unsafe when -PnoUnsafe is used while running the build
- Correctly increment metric when UnpooledDirectByteBuf is allocated. This was uncovered once -PnoUnsafe usage was fixed.
- Implement fallbacks in all our native transport code for when sun.misc.Unsafe is not present.
Result:
Fixes https://github.com/netty/netty/issues/8229.
Motivation
Ensure classes of cipher suites continue working between releases. Adding just a DHE check for now as it caused #8165 but this test can be expaned to other suites.
Modifications
Adding an unit test that checks for the presence of a cipher suite.
Result
Prevent #8165 from happening in the future.
Motivation:
We should prefer direct buffers whenever we can use the cleaner even if sun.misc.Unsafe is not present.
Modifications:
Correctly prefer direct buffers in all cases.
Result:
More correct code.
Motivation:
CleanerJava9 currently fails whever a SecurityManager is installed. We should make use of AccessController.doPrivileged(...) so the user can give it the correct rights.
Modifications:
Use doPrivileged(...) when needed.
Result:
Fixes https://github.com/netty/netty/issues/8201.
Motivation:
Recycler may produce a NPE when the same object is recycled multiple times from different threads.
Modifications:
- Check if the id has changed or if the Stack became null and if so throw an IllegalStateException
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/8220.
Motivation:
It seems to sometimes confuse people what to do to replace setMaxMessagePerRead(...).
Modifications:
Add some more details to the javadocs about the correct replacement.
Result:
Related to https://github.com/netty/netty/issues/8214.
Motivation:
We should ensure we use the latest Java11 EA during build to catch any regressions etc.
Modifications:
Update from ea19 to ea28.
Result:
Use latest Java11 release.
Motivation:
We should support to parse and read a hosts file which is stored in a different encoding then the system default. Beside this when we are on windows we should just try to parse it with multiple different charset before giving up as there is no real standard what charset to use.
Modifications:
- Add more method overloads to HostsFileParser that take a Charset.
- Try to parse with multiple Charsets in DefaultHostsFileEntriesResolver when windows is used.
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/8208.
* Try to monkey-patch library id when shading is used and we are on MacOS / OSX.
Motivation:
ea4c315b45 did ensure we support using multiple versions of the same shaded native library but the user still needed to run install_name_tool -id on MacOS to ensure the ID is unique.
This is kind of error prone and also means that the shading itself would need to be done on MacOS / OSX.
This is related to https://github.com/netty/netty/issues/7272.
Modifications:
- Monkey patch the shaded native lib on MacOS to ensure the id is unique while unpacking it to the tempory location.
Result:
Easier way of using shaded native libs in netty.
Motiviation:
We incorrectly did ignore NS servers during redirect which had no ADDITIONAL record. This could at worse have the affect that we failed the query completely as none of the NS servers had a ADDITIONAL record. Beside this using a DnsCache to cache authoritative nameservers does not work in practise as we we need different features and semantics when cache these servers (for example we also want to cache unresolved nameservers and resolve these on the fly when needed).
Modifications:
- Correctly take NS records into account that have no matching ADDITIONAL record
- Correctly handle multiple ADDITIONAL records for the same NS record
- Introduce AuthoritativeDnsServerCache as a replacement of the DnsCache when caching authoritative nameservers + adding default implementation
- Add an adapter layer to reduce API breakage as much as possible
- Replace DnsNameResolver.uncachedRedirectDnsServerStream(...) with newRedirectDnsServerStream(...)
- Add unit tests
Result:
Our DnsResolver now correctly handle redirects in all cases.
Motivation:
We should support to load multiple shaded versions of the same netty artifact as netty is often used in multiple dependencies.
This is related to https://github.com/netty/netty/issues/7272.
Modifications:
- Use -fvisibility=hidden when compiling and use JNIEXPORT for things we really want to have exported
- Ensure fields are declared as static so these are not exported
- Adjust testsuite-shading to use install_name_tool on MacOS to change the id of the lib. Otherwise the wrong may be used.
Result:
Be able to use multiple shaded versions of the same netty artifact.
Motivation:
Java9 and later does the safepoint polling by itself so there is not need for us to do it.
Modifications:
Check for java version before doing manual safepoint polling.
Result:
Less custom code and less overhead when using java9 and later. Fixes https://github.com/netty/netty/issues/8122.
Motivation:
OpenSSL itself has an abstraction which allows you to customize some things. For example it is possible to load the PrivateKey from the engine. We should support this.
Modifications:
Add two new static methods to OpenSslX509KeyManagerFactory which allow to create an OpenSslX509KeyManagerFactory that loads its PrivateKey via the OpenSSL Engine directly.
Result:
More flexible usage of OpenSSL possible
Motivation:
In OpenSslCertificateException we should ensure we try to load netty-tcnative before trying to use any class from it as otherwise it may throw an error due missing linking of the native libs.
Modifications:
- Ensure we call OpenSsl.isAvailable() before we try to use netty-tcnative for validation
- Add testcase.
Result:
No more errors causing by not loading native libs before trying to use these.
* Rename SslHandler.close(...) to closeOutbound(...) as it is still useful and delegate to the methods.
Motivation:
Sometimes the user may want to send a close_notify without closing the underlying Channel. For this we offered the SslHandler.close(...) methods which were marked as deeprecated. We should offer an way to still do this without the user calling deprecated methods.
See https://stackoverflow.com/questions/51710231/using-nettys-sslhandlerclosechannelhandlercontext-channelpromise/51753742#comment90555949_51753742 .
Modifications:
- Remove deprecation of the SslHandler.close(...) method that exactly allows this and rename these to closeOutbound(...) as this is more clear.
- Add close(...) methods that delegate to these and mark these as deprecated.
Result:
Be able to send close_notify without closing the Channel.
Motivation:
We are currently always remove all entries from the cache for a hostname if the lowest TTL was reached but schedule one for each of the cached entries. This is wasteful.
Modifications:
- Reimplement logic to schedule TTL to only schedule a new removal task if the requested TTL was actual lower then the one for the already scheduled task.
- Ensure we only remove from the internal map if we did not replace the Entries in the meantime.
Result:
Less overhead in terms of scheduled tasks for the DefaultDnsCache
Motivation:
We had a report that the exception may not be correctly propagated. This test shows it is.
Modifications:
Add testcase.
Result:
Test for https://github.com/netty/netty/issues/8158
Motivation:
We should ensure we return the same cached entries for the hostname and hostname ending with dot. Beside this we also should use it for the searchdomains as well.
Modifications:
- Internally always use hostname with a dot as a key and so ensure we correctly handle it in the cache.
- Also query the cache for each searchdomain
- Add unit tests
Result:
Use the same cached entries for hostname with and without trailing dot. Query the cache for each searchdomain query as well
