Motivation:
JCTools supports both non-unsafe, unsafe versions of queues and JDK6 which allows us to shade the library in netty-common allowing it to stay "zero dependency".
Modifications:
- Remove copy paste JCTools code and shade the library (dependencies that are shaded should be removed from the <dependencies> section of the generated POM).
- Remove usage of OneTimeTask and remove it all together.
Result:
Less code to maintain and easier to update JCTools and less GC pressure as the queue implementation nt creates so much garbage
Related: #4333#4421#5128
Motivation:
slice(), duplicate() and readSlice() currently create a non-recyclable
derived buffer instance. Under heavy load, an application that creates a
lot of derived buffers can put the garbage collector under pressure.
Modifications:
- Add the following methods which creates a non-recyclable derived buffer
- retainedSlice()
- retainedDuplicate()
- readRetainedSlice()
- Add the new recyclable derived buffer implementations, which has its
own reference count value
- Add ByteBufHolder.retainedDuplicate()
- Add ByteBufHolder.replace(ByteBuf) so that..
- a user can replace the content of the holder in a consistent way
- copy/duplicate/retainedDuplicate() can delegate the holder
construction to replace(ByteBuf)
- Use retainedDuplicate() and retainedSlice() wherever possible
- Miscellaneous:
- Rename DuplicateByteBufTest to DuplicatedByteBufTest (missing 'D')
- Make ReplayingDecoderByteBuf.reject() return an exception instead of
throwing it so that its callers don't need to add dummy return
statement
Result:
Derived buffers are now recycled when created via retainedSlice() and
retainedDuplicate() and derived from a pooled buffer
Motivation:
OIO/NIO use a volatile variable to track if a read is pending. EPOLL does not use a volatile an executes a Runnable on the event loop thread to set readPending to false. These mechansims should be consistent, and not using a volatile variable is preferable because the variable is written to frequently in the event loop thread.
OIO also does not set readPending to false before each fireChannelRead operation and may result in reading more data than the user desires.
Modifications:
- OIO/NIO should not use a volatile variable for readPending
- OIO should set readPending to false before each fireChannelRead
Result:
OIO/NIO/EPOLL are more consistent w.r.t. readPending and volatile variable operations are reduced
Fixes https://github.com/netty/netty/issues/5069
Motivation:
Setting the WRITE_BUFFER_LOW_WATER_MARK before WRITE_BUFFER_HIGH_WATER_MARK results in an internal Exception (appears only in the logs) if the value is larger than the default high water mark value. The WRITE_BUFFER_HIGH_WATER_MARK call appears to have no effect in this context.
Setting the values in the reverse order works.
Modifications:
- deprecated ChannelOption.WRITE_BUFFER_HIGH_WATER_MARK and
ChannelOption.WRITE_BUFFER_LOW_WATER_MARK.
- add one new option called ChannelOption.WRITE_BUFFER_WATER_MARK.
Result:
The high/low water mark values limits caused by default values are removed.
Setting the WRITE_BUFFER_LOW_WATER_MARK before WRITE_BUFFER_HIGH_WATER_MARK results in an internal Exception (appears only in the logs) if the value is larger than the default high water mark value. The WRITE_BUFFER_HIGH_WATER_MARK call appears to have no effect in this context.
Setting the values in the reverse order works.
Motivation:
See https://github.com/netty/netty-build/issues/5
Modifications:
Add xml-maven-plugin to check indentation and fix violations
Result:
pom.xml will be checked in the PR build
Motivation:
A few implementations of OioServerChannel have a default max messages per read set to 16. We should set the default to 1 to prevent blocking on a read before setting a socket that has just been accepted.
Modifications:
- OioSctpServerChannel and OioServerSocketChannel metadata changed to use the default (1) max messages per read
Result:
Oio based servers will complete accepting a socket before potentially blocking waiting to accept other sockets.
Motivation:
Not all fields of SctpMessage which used to check message equality are used
to generate hashcode.
Modifications:
Use value of 'unordered' field in hashCode method.
Result:
Better hash function of SctpMessage.
Motivation:
SctpMessage.duplicate() copied message content that leads to additional buffer
allocation and memory copying.
Modifications:
Duplicate message content instead of copying it.
Result:
Better performace and less memory consumption.
Motivation:
The fix for https://github.com/netty/netty/issues/3884 breaks SctpEchoTest because Selector.select will always return 0 if you do not clear last selectedKeys.
Modifications:
Clear readSelector.selectedKeys() if it is not empty.
Result:
SctpEchoTest is green again.
Motivation:
We should use OneTimeTask where possible to reduce object creation.
Modifications:
Replace Runnable with OneTimeTask
Result:
Less object creation
Motivation:
As toString() is often used while logging we need to ensure this produces no exception.
Modifications:
Ensure we never throw an IllegalReferenceCountException.
Result:
Be able to log without produce exceptions.
Motivation:
OioSctpChannel.doReadMessages is iterating over the selected keys, and ignoring each selected key. It is not known why this is needed and no other channel implementation does this.
Modifications:
- Stop iterating over selected keys, and just read like other channels
Result:
No unnecessary iteration in OioSctpChannel.doReadMessages.
Fixes https://github.com/netty/netty/issues/3884
Motiviation:
The current read loops don't fascilitate reading a maximum amount of bytes. This capability is useful to have more fine grain control over how much data is injested.
Modifications:
- Add a setMaxBytesPerRead(int) and getMaxBytesPerRead() to ChannelConfig
- Add a setMaxBytesPerIndividualRead(int) and getMaxBytesPerIndividualRead to ChannelConfig
- Add methods to RecvByteBufAllocator so that a pluggable scheme can be used to control the behavior of the read loop.
- Modify read loop for all transport types to respect the new RecvByteBufAllocator API
Result:
The ability to control how many bytes are read for each read operation/loop, and a more extensible read loop.
Motivation:
Some SCTP applications require the SCTP unordered flag.
This flag was not exposed by Netty so applications were unable
to use it.
Modifications:
- Add unordered flag to SctpMessage.
- {Nio,Oio}SctpChannel pass unordered flag to MessageInfo on write.
- SctpOutboundByteStreamHandler may optionally request unordered
delivery for all outbound messages.
- Added test case to SctpEchoTest using unordered flag.
Result:
Fixes#3698. New constructors and methods added to SctpMessage and
SctpOutboundByteStreamHandler, but changes are backward compatible.
Motivation:
Each different *ChannelOption did extend ChannelOption in 4.0, which we changed in 4.1. This is a breaking change in terms of the API so we need to ensure we keep the old hierarchy.
Modifications:
- Let all *ChannelOption extend ChannelOption
- Add back constructor and mark it as @deprecated
Result:
No API breakage between 4.0 and 4.1
