Motivation:
All read operations should be safe to execute from multiple threads which was not the case and so could produce a livelock.
Modifications:
Modify methods so these are safe to be called from multiple threads.
Result:
No more livelock.
Motivation:
There are various known issues in netty-codec-dns:
- Message types are not interfaces, which can make it difficult for a
user to implement his/her own message implementation.
- Some class names and field names do not match with the terms in the
RFC.
- The support for decoding a DNS record was limited. A user had to
encode and decode by him/herself.
- The separation of DnsHeader from DnsMessage was unnecessary, although
it is fine conceptually.
- Buffer leak caused by DnsMessage was difficult to analyze, because the
leak detector tracks down the underlying ByteBuf rather than the
DnsMessage itself.
- DnsMessage assumes DNS-over-UDP.
- To send an EDNS message, a user have to create a new DNS record class
instance unnecessarily.
Modifications:
- Make all message types interfaces and add default implementations
- Rename some classes, properties, and constants to match the RFCs
- DnsResource -> DnsRecord
- DnsType -> DnsRecordType
- and many more
- Remove DnsClass and use an integer to support EDNS better
- Add DnsRecordEncoder/DnsRecordDecoder and their default
implementations
- DnsRecord does not require RDATA to be ByteBuf anymore.
- Add DnsRawRecord as the catch-all record type
- Merge DnsHeader into DnsMessage
- Make ResourceLeakDetector track AbstractDnsMessage
- Remove DnsMessage.sender/recipient properties
- Wrap DnsMessage with AddressedEnvelope
- Add DatagramDnsQuest and DatagramDnsResponse for ease of use
- Rename DnsQueryEncoder to DatagramDnsQueryEncoder
- Rename DnsResponseDecoder to DatagramDnsResponseDecoder
- Miscellaneous changes
- Add StringUtil.TAB
Result:
- Cleaner APi
- Can support DNS-over-TCP more easily in the future
- Reduced memory footprint in the default DnsQuery/Response
implementations
- Better leak tracking for DnsMessages
- Possibility to introduce new DnsRecord types in the future and provide
full record encoder/decoder implementation.
- No unnecessary instantiation for an EDNS pseudo resource record
Motivation:
Many projects need some kind a Channel/Connection pool implementation. While the protocols are different many things can be shared, so we should provide a generic API and implementation.
Modifications:
Add ChannelPool / ChannelPoolMap API and implementations.
Result:
Reusable / Generic pool implementation that users can use.
Motivation:
'length2 == 0' is not reachable because length1 and length2 are same at this point.
Motification:
Removed 'length2 == 0'.
Result:
Cleaner code.
Motivation:
Currently, valueOf() and newInstance() use almost same code to create new constant.
For maintainability, it's better to share duplicate code among them.
Motification:
Added new private functions.
- checkNotNullAndNotEmpty() is for checking whether the name of a constant is null and empty.
- newConstant0() is for creating a new constant.
Result:
- Compact source code
- Improvement of maintainability
Motivation:
When a SecurityManager is in place that preven reading the somaxconn file trying to bootstrap a channel later will result in a ClassNotFoundError.
Modifications:
- Reading the file in a privileged block.
Result:
No more ClassNotFoundError when a SecurityManager is in place.
Motivation:
The ByteString class currently assumes the underlying array will be a complete representation of data. This is limiting as it does not allow a subsection of another array to be used. The forces copy operations to take place to compensate for the lack of API support.
Modifications:
- add arrayOffset method to ByteString
- modify all ByteString and AsciiString methods that loop over or index into the underlying array to use this offset
- update all code that uses ByteString.array to ensure it accounts for the offset
- add unit tests to test the implementation respects the offset
Result:
ByteString and AsciiString can represent a sub region of a byte[].
Motivation:
static Package getPackage(Class<?> c) uses synchronized block internally.
Thanks to @jingene for the hint and initial report of the issue.
Modifications:
-Use simple lastIndexOf(...) and substring for a faster implementation
Result:
No more lock condition.
Motivation:
The current implementation does byte by byte comparison, which we have seen
can be a performance bottleneck when the AsciiString is used as the key in
a Map.
Modifications:
Use sun.misc.Unsafe (on supporting platforms) to compare up to eight bytes at a time
and get closer to the performance of String.equals(Object).
Result:
Significant improvement (2x - 6x) in performance over the current implementation.
Benchmark (size) Mode Samples Score Score error Units
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 10 thrpt 10 118843477.518 2347259.347 ops/s
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 50 thrpt 10 43910319.773 198376.996 ops/s
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 100 thrpt 10 26339969.001 159599.252 ops/s
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 1000 thrpt 10 2873119.030 20779.056 ops/s
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 10000 thrpt 10 306370.450 1933.303 ops/s
i.n.m.i.PlatformDependentBenchmark.arraysBytesEqual 100000 thrpt 10 25750.415 108.391 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 10 thrpt 10 248077563.510 635320.093 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 50 thrpt 10 128198943.138 614827.548 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 100 thrpt 10 86195621.349 1063959.307 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 1000 thrpt 10 16920264.598 61615.365 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 10000 thrpt 10 1687454.747 6367.602 ops/s
i.n.m.i.PlatformDependentBenchmark.unsafeBytesEqual 100000 thrpt 10 153717.851 586.916 ops/s
Motivation:
ByteString#hashCode() trashes its own hash code if it's being accessed concurrently
Modifications:
Pull the ByteString#hash into a local variable and calculate it locally.
Result:
ByteString#hashCode() is no longer returning a junk value.
Motivation:
The IntObjectHashMap benchmarks show the Agrona collections to be faster on put, lookup, and remove. One major difference is that we're using 2 modulus operations each time we increment the position index while iterating. Agrona uses a mask instead.
Modifications:
Modified the KObjectHashMap to use masking rather than modulus when wrapping the position index. This requires that the capacity be a power of 2.
Result:
Improved performance of IntObjectHashMap.
Motivation:
The usage and code within AsciiString has exceeded the original design scope for this class. Its usage as a binary string is confusing and on the verge of violating interface assumptions in some spots.
Modifications:
- ByteString will be created as a base class to AsciiString. All of the generic byte handling processing will live in ByteString and all the special character encoding will live in AsciiString.
Results:
The AsciiString interface will be clarified. Users of AsciiString can now be clear of the limitations the class imposes while users of the ByteString class don't have to live with those limitations.
Motivation:
Attribute.getAndRemove() will return the value but also remove the AttributeKey itself from the AttributeMap. This may not
what you want as you may want to keep an instance of it and just set it later again. Document the contract so the user know what to expect.
Modifications:
- Make it clear when to use AttributeKey.getAndRemove() / AttributeKey.remove() and when AttributeKey.getAndSet(null) / AttributeKey.set(null).
Result:
Less suprising behaviour.
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:
Currently we have IntObjectMap/HashMap, but it will be useful to support other primitive-based maps.
Modifications:
Moved the code int the current maps to template files and run Groovy code from common/pom.xml to apply the templates.
Result:
Autogeneration of int and char-based hash maps.
Motivation:
We are allocating a hash map for every HTTP2 Stream to store it's children.
Most streams are leafs in the priority tree and don't have children.
Modification:
- Only allocate children when we actually use them.
- Make EmptyIntObjectMap not throw a UnsupportedOperationException on remove, but return null instead (as is stated in it's javadoc).
Result:
Fewer unnecessary allocations.
Motivation:
The Http2Settings class currently disallows setting non-standard settings, which violates the spec.
Modifications:
Updated Http2Settings to permit arbitrary settings. Also adjusting the default initial capacity to allow setting all of the standard settings without reallocation.
Result:
Fixes#3560
Motivation:
When setting nEventLoops to zero in the MultithreadedEventLoopGroup constructor
the EventLoopGroup chooses the number of EventLoops and Threads to use for you.
We want to make use of this behaviour internally and thus we would like to document
it as a part of the official API, so that we can rely on it.
Modifications:
Document the behaviour when setting nEventLoops to zero.
Fix several spelling / sloppiness mistakes in the documentation.
Result:
nEventLoops=0 is now documented as a part of the official API.
The quality of the documentation is improved.
Motivation:
On a system where ipv4 and ipv6 are supported a user may want to use -Djava.net.preferIPv4Stack=true to restrict it to use ipv4 only.
This is currently ignored with the epoll transport.
Modifications:
Respect java.net.preferIPv4Stack system property.
Result:
-Djava.net.preferIPv4Stack=true will have the effect the user is looking for.
Motivation:
When remove0() is called multiple times for an DefaultAttribute it can cause corruption of the internal linked-list structure.
Modifications:
- Ensure remove0() can not cause corruption by null out prev and next references.
Result:
No more corruption possible
Motivation:
At the moment when EmbeddedChannel is used and a ChannelHandler tries to schedule and task it will throw an UnsupportedOperationException. This makes it impossible to test these handlers or even reuse them with EmbeddedChannel.
Modifications:
- Factor out reusable scheduling code into AbstractSchedulingEventExecutor
- Let EmbeddedEventLoop and SingleThreadEventExecutor extend AbstractSchedulingEventExecutor
- add EmbbededChannel.runScheduledPendingTasks() which allows to run all scheduled tasks that are ready
Result:
Embeddedchannel is now usable even with ChannelHandler that try to schedule tasks.
Motivation:
At the moment if you want to return a HTTP header containing multiple
values you have to set/add that header once with the values wanted. If
you used set/add with an array/iterable multiple HTTP header fields will
be returned in the response.
Note, that this is indeed a suggestion and additional work and tests
should be added. This is mainly to bring up a discussion.
Modifications:
Added a flag to specify that when multiple values exist for a single
HTTP header then add them as a comma separated string.
In addition added a method to StringUtil to help escape comma separated
value charsequences.
Result:
Allows for responses to be smaller.
Conflicts:
codec-http/src/main/java/io/netty/handler/codec/http/DefaultHttpHeaders.java
codec-http/src/test/java/io/netty/handler/codec/http/cors/CorsHandlerTest.java
codec/src/main/java/io/netty/handler/codec/DefaultTextHeaders.java
codec/src/test/java/io/netty/handler/codec/DefaultTextHeadersTest.java
Motivation:
We should allow to get a ChannelOption/AttributeKey from a String. This will make it a lot easier to make use of configuration files in applications.
Modifications:
- Add exists(...), newInstance(...) method to ChannelOption and AttributeKey and alter valueOf(...) to return an existing instance for a String or create one.
- Add unit tests.
Result:
Much more flexible usage of ChannelOption and AttributeKey.
While implementing netty-handler-proxy, I realized various issues in our
current socksx package. Here's the list of the modifications and their
background:
- Split message types into interfaces and default implementations
- so that a user can implement an alternative message implementations
- Use classes instead of enums when a user might want to define a new
constant
- so that a user can extend SOCKS5 protocol, such as:
- defining a new error code
- defining a new address type
- Rename the message classes
- to avoid abbreviated class names. e.g:
- Cmd -> Command
- Init -> Initial
- so that the class names align better with the protocol
specifications. e.g:
- AuthRequest -> PasswordAuthRequest
- AuthScheme -> AuthMethod
- Rename the property names of the messages
- so that the property names align better when the field names in the
protocol specifications
- Improve the decoder implementations
- Give a user more control over when a decoder has to be removed
- Use DecoderResult and DecoderResultProvider to handle decode failure
gracefully. i.e. no more Unknown* message classes
- Add SocksPortUnifinicationServerHandler since it's useful to the users
who write a SOCKS server
- Cleaned up and moved from the socksproxy example
Motivation:
isRoot() is an expensive operation. We should avoid calling it if
possible.
Modifications:
Move the isRoot() checks to the end of the 'if' block, so that isRoot()
is evaluated only when really necessary.
Result:
isRoot() is evaluated only when SO_BROADCAST is set and the bind address
is anylocal address.
Motivation:
When a user sees an error message, sometimes he or she does not know
what exactly he or she has to do to fix the problem.
Modifications:
Log the URL of the wiki pages that might help the user troubleshoot.
Result:
We are more friendly.
Related: #3166
Motivation:
When the recyclable object created at one thread is returned at the
other thread, it is stored in a WeakOrderedQueue.
The objects stored in the WeakOrderedQueue is added back to the stack by
WeakOrderedQueue.transfer() when the owner thread ran out of recyclable
objects.
However, WeakOrderedQueue.transfer() does not have any mechanism that
prevents the stack from growing beyond its maximum capacity.
Modifications:
- Make WeakOrderedQueue.transfer() increase the capacity of the stack
only up to its maximum
- Add tests for the cases where the recyclable object is returned at the
non-owner thread
- Fix a bug where Stack.scavengeSome() does not scavenge the objects
when it's the first time it ran out of objects and thus its cursor is
null.
- Overall clean-up of scavengeSome() and transfer()
Result:
The capacity of Stack never increases beyond its maximum.
Motivation:
io.netty.util.internal.PlatformDependent.isRoot() depends on the IS_ROOT field which is filled in during class initialization. This spawns processes and consumes resources, which are not generally necessary to the complete functioning of that class.
Modifications:
This switches the class to use lazy initialization this field inside of the isRoot() method using double-checked locking (http://en.wikipedia.org/wiki/Double-checked_locking).
Result:
The first call to isRoot() will be slightly slower, at a tradeoff that class loading is faster, uses fewer resources and platform errors are avoided unless necessary.
- Parameterize DomainNameMapping to make it useful for other use cases
than just mapping to SslContext
- Move DomainNameMapping to io.netty.util
- Clean-up the API documentation
- Make SniHandler.hostname and sslContext volatile because they can be
accessed by non-I/O threads
Motivation:
When we need to host multiple server name with a single IP, it requires
the server to support Server Name Indication extension to serve clients
with proper certificate. So the SniHandler will host multiple
SslContext(s) and append SslHandler for requested hostname.
Modification:
* Added SniHandler to host multiple certifications in a single server
* Test case
Result:
User could use SniHandler to host multiple certifcates at a time.
It's server-side only.
Motivation:
8fbc513 introduced stray warnings in callsites of
PromiseAggregator#add and PromiseNotifier#(...).
Modifications:
This commit adds the @SafeVarargs annotation to PromiseAggregator#add
and PromiseNotifier#(...). As Netty is built with JDK7, this is a
recognized annotation and should not affect runtime VM versions 1.5 and
1.6.
Result:
Building Netty with JDK7 will no longer produce warnings in the
callsites mentioned above.
Motivation:
Although the new IntObjectMap.values() that returns Collection is
useful, the removed values(Class<V>) that returns an array is also
useful. It's also good for backward compatibility.
Modifications:
- Add IntObjectMap.values(Class<V>) back
- Miscellaneous improvements
- Cache the collection returned by IntObjectHashMap.values()
- Inspector warnings
- Update the IntObjectHashMapTest to test both values()
Result:
- Backward compatibility
- Potential performance improvement of values()
Motivation:
Found performance issues via FindBugs and PMD.
Modifications:
- Removed unnecessary boxing/unboxing operations in DefaultTextHeaders.convertToInt(CharSequence) and DefaultTextHeaders.convertToLong(CharSequence). A boxed primitive is created from a string, just to extract the unboxed primitive value.
- Added a static modifier for DefaultHttp2Connection.ParentChangedEvent class. This class is an inner class, but does not use its embedded reference to the object which created it. This reference makes the instances of the class larger, and may keep the reference to the creator object alive longer than necessary.
- Added a static compiled Pattern to avoid compile it each time it is used when we need to replace some part of authority.
- Improved using of StringBuilders.
Result:
Performance improvements.
Motivation:
The outbound flow controller logic does not properly reset the allocated
bytes between successive invocations of the priority algorithm.
Modifications:
Updated the priority algorithm to reset the allocated bytes for each
stream.
Result:
Each call to the priority algorithm now starts with zero allocated bytes
for each stream.
Motivation:
NetUtil.isValidIpV6Address() handles the interface name in IPv6 address
incorrectly. For example, it returns false for the following addresses:
- ::1%lo
- ::1%_%_in_name_
Modifications:
- Strip the square brackets before validation for simplicity
- Strip the part after the percent sign completely before validation for
simplicity
- Simplify and reformat NetUtilTest
Result:
- The interface names in IPv6 addresses are handled correctly.
- NetUtilTest is cleaner
Motivation:
ChannelPromiseAggregator and ChannelPromiseNotifiers only allow
consumers to work with Channels as the result type. Generic versions
of these classes allow consumers to aggregate or broadcast the results
of an asynchronous execution with other result types.
Modifications:
Add PromiseAggregator and PromiseNotifier. Add unit tests for both.
Remove code in ChannelPromiseAggregator and ChannelPromiseNotifier and
modify them to extend the new base classes.
Result:
Consumers can now aggregate or broadcast the results of an asynchronous
execution with results types other than Channel.
Motivation:
CollectionUtils has only one method and it is used only in DefaultHeaders.
Modification:
Move CollectionUtils.equals() to DefaultHeaders and make it private
Result:
One less class to expose in our public API
Motivation:
Headers within netty do not cleanly share a common class hierarchy. As a result some header types support some operations
and don't support others. The consolidation of the class hierarchy will allow for maintenance and scalability for new codec.
The existing hierarchy also has a few short comings such as it is not clear when data conversions are happening. This
could result unintentionally getting back a collection or iterator where a conversion on each entry must happen.
The current headers algorithm also prepends all elements which means to find the first element or return a collection
in insertion order often requires a complete traversal followed by a collections.reverse call.
Modifications:
-Provide a generic base class which provides all the implementation for headers in netty
-Provide an extension to this class which allows for name type conversions to happen (to accommodate legacy CharSequence to String conversions)
-Update the headers interface to clarify when conversions will happen.
-Update the headers data structure so that appends are done to avoid unnecessary iteration or collection reversal.
Result:
-More unified class hierarchy for headers in netty
-Improved headers data structure and algorithms
-headers API more clearly identify when conversions are required.
