Motiviation:
Before this change, autoRead was a volatile boolean accessed directly. Any thread that invoked the DefaultChannelConfig#setAutoRead(boolean) method would read the current value of autoRead, and then set a new value. If the old value did not match the new value, some action would be immediately taken as part of the same method call.
As volatile only provides happens-before consistency, there was no guarantee that the calling thread was actually the thread mutating the state of the autoRead variable (such that it should be the one to invoke the follow-up actions). For example, with 3 threads:
* Thread 1: get = false
* Thread 1: set = true
* Thread 1: invokes read()
* Thread 2: get = true
* Thread 3: get = true
* Thread 2: set = false
* Thread 2: invokes autoReadCleared()
* Event Loop receives notification from the Selector that data is available, but as autoRead has been cleared, cancels the operation and removes read interest
* Thread 3: set = true
This results in a livelock - autoRead is set true, but no reads will happen even if data is available (as readyOps). The only way around this livelock currently is to set autoRead to false, and then back to true.
Modifications:
Write access to the autoRead variable is now made using the getAndSet() method of an AtomicIntegerFieldUpdater, AUTOREAD_UPDATER. This also changed the type of the underlying autoRead variable to be an integer, as no AtomicBooleanFieldUpdater class exists. Boolean logic is retained by assuming that 1 is true and 0 is false.
Result:
There is no longer a race condition between retrieving the old value of the autoRead variable and setting a new value.
Motivation:
Websocket clients can request to speak a specific subprotocol. The list of
subprotocols the client understands are sent to the server. The server
should select one of the protocols an reply this with the websocket
handshake response. The added code verifies that the reponded subprotocol
is valid.
Modifications:
Added verification of the subprotocol received from the server against the
subprotocol(s) that the user requests. If the user requests a subprotocol
but the server responds none or a non-requested subprotocol this is an
error and the handshake fails through an exception. If the user requests
no subprotocol but the server responds one this is also marked as an
error.
Addiontionally a getter for the WebSocketClientHandshaker in the
WebSocketClientProtocolHandler is added to enable the user of a
WebSocketClientProtocolHandler to extract the used negotiated subprotocol.
Result:
The subprotocol field which is received from a websocket server is now
properly verified on client side and clients and websocket connection
attempts will now only succeed if both parties can negotiate on a
subprotocol.
If the client sends a list of multiple possible subprotocols it can
extract the negotiated subprotocol through the added handshaker getter (WebSocketClientProtocolHandler.handshaker().actualSubprotocol()).
Motivation:
http://public.dhe.ibm.com/software/dw/webservices/ws-mqtt/mqtt-v3r1.html#connack
In MQTT 3.1, MQTT server must send a CONNACK with return code if CONNECT
request contains an invalid client identifier or an unacceptable protocol
version. The return code is one of MqttConnectReturnCode.
But, MqttDecoder throws DecoderException when CONNECT request contains
invalid value without distinguish situations. This makes it difficult
for codec-mqtt users to send a response with return code to clients.
Modifications:
Added exceptions for client identifier rejected and unacceptable
protocol version. MqttDecoder will throw those exceptions instead of
DecoderException.
Result:
Users of codec-mqtt can distinguish which is invalid when CONNECT
contains invalid client identifier or invalid protocol version. And, users can
send CONNACK with return code to clients.
Motivation:
I was not fully reassured that whether everything works correctly when a websocket client receives the websocket handshake HTTP response and a websocket frame in a single ByteBuf (which can happen when the server sends a response directly or shortly after the connect). In this case some parts of the ByteBuf must be processed by HTTP decoder and the remaining by the websocket decoder.
Modification:
Adding a test that verifies that in this scenaria the handshake and the message are correctly interpreted and delivered by Netty.
Result:
One more test for Netty.
The test succeeds - No problems
Motivation:
In MQTT 3.1 specification, "The Client Identifier (Client ID) is between
1 and 23 characters long, and uniquely identifies the client to the
server". But, current client id validation length is 0~23. It must be
1~23. The empty string is invalid client id in MQTT 3.1
Modifications:
Change isValidClientId method. Add MIN_CLIENT_ID_LENGTH.
Result:
The validation check for client id length is between 1 and 23.
Motivation:
It is often helpful to measure the performance of connections, e.g. the
latency and the throughput. This can be performed through benchmarks.
Modification:
This adds a simple but configurable benchmark for websockets into the
example directory. The Netty WebSocket server will echo all received
websocket frames and will provide an HTML/JS page which serves as the
client for the benchmark.
The benchmark also provides a verification mode that verifies the sent
against the received data. This can be used for the verification ob
websocket frame encoding and decoding funtionality.
Result:
A benchmark is added in form a further Netty websocket example.
With this benchmark it is easily possible to measure the performance between Netty and a browser
Motivation:
The WebSocketClientProtocolHandshakeHandler never releases the received handshake response.
Modification:
Release the message in a finally block.
Result:
No more leak
Motivation:
The WebSocket08FrameEncoder contains an optimization path for small messages which copies the message content into the header buffer to avoid vectored writes. However this path is in the current implementation never taken because the target buffer is preallocated only for exactly the size of the header.
Modification:
For messages below a certain treshold allocate the buffer so that the message can be directly copied. Thereby the optimized path is taken.
Result:
A speedup of about 25% for 100byte messages. Declines with bigger message sizes. I have currently set the treshold to 1kB which is a point where I could still see a few percent speedup, but we should also avoid burning too many CPU cycles.
Motivation:
Websocket performance is to a large account determined through the masking
and unmasking of frames. The current behavior of this in Netty can be
improved.
Modifications:
Perform the XOR operation not bytewise but in int blocks as long as
possible. This reduces the number of necessary operations by 4. Also don't
read the writerIndex in each iteration.
Added a unit test for websocket decoding and encoding for verifiation.
Result:
A large performance gain (up to 50%) in websocket throughput.
Motivation:
Currently the last read/write throughput is calculated by first division,this will be 0 if the last read/write bytes < interval,change the order will get the correct result
Modifications:
Change the operator order from first do division to multiplication
Result:
Get the correct result instead of 0 when bytes are smaller than interval
Motivation:
According to the websocket specification peers may send a close frame when
they detect a protocol violation (with status code 1002). The current
implementation simply closes the connection. This update should add this
functionality. The functionality is optional - but it might help other
implementations with debugging when they receive such a frame.
Modification:
When a protocol violation in the decoder is detected and a close was not
already initiated by the remote peer a close frame is
sent.
Result:
Remotes which will send an invalid frame will now get a close frame that
indicates the protocol violation instead of only seeing a closed
connection.
Motivation:
We incorrectly used SslContext.newServerContext() in some places where a we needed a client context.
Modifications:
Use SslContext.newClientContext() when using ssl on the client side.
Result:
Working ssl client examples.
Motivation:
We use malloc(1) in the on JNI_OnLoad method but never free the allocated memory. This means we have a tiny memory leak of 1 byte.
Modifications:
Call free(...) on previous allocated memory.
Result:
Fix memory leak
Motivation:
We introduced a PoolThreadCache which is used in our PooledByteBufAllocator to reduce the synchronization overhead on PoolArenas when allocate / deallocate PooledByteBuf instances. This cache is used for both the allocation path and deallocation path by:
- Look for cached memory in the PoolThreadCache for the Thread that tries to allocate a new PooledByteBuf and if one is found return it.
- Add the memory that is used by a PooledByteBuf to the PoolThreadCache of the Thread that release the PooledByteBuf
This works out very well when all allocation / deallocation is done in the EventLoop as the EventLoop will be used for read and write. On the otherside this can lead to surprising side-effects if the user allocate from outside the EventLoop and and pass the ByteBuf over for writing. The problem here is that the memory will be added to the PoolThreadCache that did the actual write on the underlying transport and not on the Thread that previously allocated the buffer.
Modifications:
Don't cache if different Threads are used for allocating/deallocating
Result:
Less confusing behavior for users that allocate PooledByteBufs from outside the EventLoop.
Motivation:
When MemoryRegionCache.trim() is called, some unused cache entries will be freed (started from head). However, in MeoryRegionCache.trim() the head is not updated, which make entry list's head point to an entry whose chunk is null now and following allocate of MeoryRegionCache will return false immediately.
In other word, cache is no longer usable once trim happen.
Modifications:
Update head to correct idx after free entries in trim().
Result:
MemoryRegionCache behaves correctly even after calling trim().
Motivation:
handlerAdded and handlerRemoved were overriden but super was never
called, while it should.
Also add one missing information in the toString method.
Modifications:
Add the super corresponding call, and add checkInterval to the
toString() method
Result;
super method calls are correctly passed to the super implementation
part.
Motivation:
A discovered typo in LzmaFrameEncoder constructor when we check `lc + lp` for better compatibility.
Modifications:
Changed `lc + pb` to `lc + lp`.
Result:
Correct check of `lc + lp` value.
Motivation:
Sometimes it is useful to be able to access the uri that was used to initialize the QueryStringDecoder.
Modifications:
Add method which allows to retrieve the uri.
Result:
Allow to retrieve the uri that was used to create the QueryStringDecoder.
Motivation:
When constructing a FingerprintTrustManagerFactory from an Iterable of Strings, the fingerprints were correctly parsed but never added to the result array. The constructed FingerprintTrustManagerFactory consequently fails to validate any certificate.
Modifications:
I added a line to add each converted SHA-1 certificate fingerprint to the result array which then gets passed on to the next constructor.
Result:
Certificate fingerprints passed to the constructor are now correctly added to the array of valid fingerprints. The resulting FingerprintTrustManagerFactory object correctly validates certificates against the list of specified fingerprints.
Motiviation:
If sendmmsg is already defined then the native epoll module failed to build because of conflicting definitions.
The mmsghdr type was also redefined on systems that already supported this structure.
Modifications:
Provide a way so that systems which already define sendmmsg and mmsghdr can build
Provide a way so that systems which don't define sendmmsg and mmsghdr can build
Result:
The native EPOLL module can build in more environments
Motivation:
LZMA compression algorithm has a very good compression ratio.
Modifications:
- Added `lzma-java` library which implements LZMA algorithm.
- Implemented LzmaFrameEncoder which extends MessageToByteEncoder and provides compression of outgoing messages.
- Added tests to verify the LzmaFrameEncoder and how it can compress data for the next uncompression using the original library.
Result:
LZMA encoder which can compress data using LZMA algorithm.
Motivation:
ExtensionRegistry is a subclass of ExtensionRegistryLite. The ProtobufDecoder
doesn't use the registry directly, it simply passes it through to the Protobuf
API. The Protobuf calls in question are themselves written in terms
ExtensionRegistryLite not ExtensionRegistry.
Modifications:
Require ExtensionRegistryLite instead of ExtensionRegistry in ProtobufDecoder.
Result:
Consumers can use ExtensionRegistryLite with ProtobufDecoder.
Motiviation:
The HTTP content decoder's cleanup method is not cleaning up the decoder correctly.
The cleanup method is currently doing a readOutbound on the EmbeddedChannel but
for decoding the call should be readInbound.
Modifications:
-Change readOutbound to readInbound in the cleanup method
Result:
The cleanup method should be correctly releaseing unused resources
Motivation:
In linux it is possible to write more then one buffer withone syscall when sending datagram messages.
Modifications:
Not copy CompositeByteBuf if it only contains direct buffers.
Result:
More performance due less overhead for copy.
Motivation:
Due incorrect usage of CompositeByteBuf a buffer leak was introduced.
Modifications:
Correctly handle tests with CompositeByteBuf.
Result:
No more buffer leaks
Motivation:
On linux with glibc >= 2.14 it is possible to send multiple DatagramPackets with one syscall. This can be a huge performance win and so we should support it in our native transport.
Modification:
- Add support for sendmmsg by reuse IovArray
- Factor out ThreadLocal support of IovArray to IovArrayThreadLocal for better separation as we use IovArray also without ThreadLocal in NativeDatagramPacketArray now
- Introduce NativeDatagramPacketArray which is used for sendmmsg(...)
- Implement sendmmsg(...) via jni
- Expand DatagramUnicastTest to test also sendmmsg(...)
Result:
Netty now automatically use sendmmsg(...) if it is supported and we have more then 1 DatagramPacket in the ChannelOutboundBuffer and flush() is called.
Motivation:
On linux it is possible to use the sendMsg(...) system call to write multiple buffers with one system call when using datagram/udp.
Modifications:
- Implement the needed changes and make use of sendMsg(...) if possible for max performance
- Add tests that test sending datagram packets with all kind of different ByteBuf implementations.
Result:
Performance improvement when using CompoisteByteBuf and EpollDatagramChannel.
Motivation:
InetAddress.getByName(...) uses exceptions for control flow when try to parse IPv4-mapped-on-IPv6 addresses. This is quite expensive.
Modifications:
Detect IPv4-mapped-on-IPv6 addresses in the JNI level and convert to IPv4 addresses before pass to InetAddress.getByName(...) (via InetSocketAddress constructor).
Result:
Eliminate performance problem causes by exception creation when parsing IPv4-mapped-on-IPv6 addresses.
Motivation:
We received a bug-report that the ByteBuf.refCnt() does sometimes not show the correct value when release() and refCnt() is called from different Threads.
Modifications:
Add test-case which shows that all is working like expected
Result:
Test-case added which shows everything is ok.
Motivation:
This fixes bug #2848 which caused Recycler to become unbounded and cache infinite number of objects with maxCapacity that's not a power of two. This can result in general sluggishness of the application and OutOfMemoryError.
Modifications:
The test for maxCapacity has been moved out of test to check if the buffer has filled. The buffer is now also capped at maxCapacity and cannot grow over it as it jumps from one power of two to the other.
Additionally, a unit test was added to verify maxCapacity is honored even when it's not a power of two.
Result:
With these changes the user is able to use a custom maxCapacity number and not have it ignored. The unit test assures this bug will not repeat itself.
Motivation:
In EpollSocketchannel.doWriteFileRegion(...) we need to make sure we write until sendFile(...) returns either 0 or all is written. Otherwise we may not get notified once the Channel is writable again.
This is the case as we use EPOLL_ET.
Modifications:
Always write until either sendFile returns 0 or all is written.
Result:
No more hangs when writing DefaultFileRegion can happen.
Related issue: #2821
Motivation:
There's no way for a user to change the default ZlibEncoder
implementation.
It is already possible to change the default ZlibDecoder implementation.
Modification:
Add a new system property 'io.netty.noJdkZlibEncoder'.
Result:
A user can disable JDK ZlibEncoder, just like he or she can disable JDK
ZlibDecoder.
Motivation:
We have some duplicated code that can be reused.
Modifications:
Create package private class called CodecUtil that now contains the shared code / helper method.
Result:
Less code-duplication
Motivation:
ByteToMessageCodec miss to check for @Sharable annotation in one of its constructors.
Modifications:
Ensure we call checkForSharableAnnotation in all constructors.
Result:
After your change, what will change.
Motivation:
Currently we do more memory copies then needed.
Modification:
- Directly use heap buffers to reduce memory copy
- Correctly release buffers to fix buffer leak
Result:
Less memory copies and no leaks
Motivation:
There were no way to efficient write a CompositeByteBuf as we always did a memory copy to a direct buffer in this case. This is not needed as we can just write a CompositeByteBuf as long as all the components are buffers with a memory address.
Modifications:
- Write CompositeByteBuf which contains only direct buffers without memory copy
- Also handle CompositeByteBuf that have more components then 1024.
Result:
More efficient writing of CompositeByteBuf.
Motivation:
There is not need todo redunant reads of head in peakNode as we can just spin on next() until it becomes visible.
Modifications:
Remove redundant reads of head in peakNode. This is based on @nitsanw's patch for akka.
See https://github.com/akka/akka/pull/15596
Result:
Less volatile access.
Motivation:
We used the wrong EventExecutor to notify for bind failures if a late registration was done.
Modifications:
Use the correct EventExecutor to notify and only use the GlobelEventExecutor if the registration fails itself.
Result:
The correct Thread will do the notification.
Motivation:
The unit tests in codec-socks contained redundant casts and empty test classes.
Modifications:
- Remove redundant casts
- Delete empty test classes
Result:
Cleanup
Motivation:
The example mis handle two elements:
1) Last message is a LastHttpContent and is not taken into account by
the server handler
2) The client makes a sync on last write (chunked) but there is no flush
before, therefore the sync is waiting forever.
Modifications:
1) Take into account the message LastHttpContent in simple Get.
2) Removes sync but add flush for each post and multipost parts
Results:
Example is no more blocked after get test.
Should be done also in 4.0 and Master (similar changes)
Motivation:
Recently we changed the default value of SOMAXCONN that is used when we can not determine it by reading /proc/sys/net/core/somaxconn. While doing this we missed to update the javadocs to reflect the new default value that is used.
Modifications:
List correct default value in the javadocs of SOMAXCONN.
Result:
Correct javadocs.
Motivation:
In GitHub issue #2767 a bug was reported that the IPv4
default route leads to the ipfilter package denying
instead of accepting all addresses.
While the issue was reported for Netty 3.9, this bug
also applies to Netty 4 and higher.
Modifications:
When computing the subnet address from the CIDR prefix,
correctly handle the case where the prefix is set to zero.
Result:
Ipfilter accepts all addresses when passed the
IPv4 default route.
Motivation:
The test procedure is unstable when testing quick time (factor less or equal to 1). Changing to default 10ms in this case will force time to be correct and time to be checked only when factor is >= 2.
Modifications:
When factor is <= 1, minimalWaitBetween is 10ms
Result:
Hoping this version is finally stable.
Motivation:
It seems that in certain conditions, the write back from the server is so quick that the handler has no time to compute traffic shaping. So 10ms of wait before acknowledging is added in server side.
Modifications:
Add 10ms waiting before server ackonwledge the client.
Result:
The timing is now suppsed to be stable.
