Motivation:
At the moment we use SocketChannel.open(), ServerSocketChannel.open() and DatagramSocketChannel.open(...) within the constructor of our
NIO channels. This introduces a bottleneck if you create a lot of connections as these calls delegate to SelectorProvider.provider() which
uses synchronized internal. This change removed the bottleneck.
Modifications:
Obtain a static instance of the SelectorProvider and use SelectorProvider.openSocketChannel(), SelectorProvider.openServerSocketChannel() and
SelectorProvider.openDatagramChannel(). This eliminates the bottleneck as SelectorProvider.provider() is not called on every channel creation.
Result:
Less conditions when create new channels.
Motivation:
Remove the synchronization bottleneck and so speed up things
Modifications:
Introduce a ThreadLocal cache that holds mappings between classes of ChannelHandlerAdapater implementations and the result of checking if the @Sharable annotation is present.
This way we only will need to do the real check one time and server the other calls via the cache. A ThreadLocal and WeakHashMap combo is used to implement the cache
as this way we can minimize the conditions while still be sure we not leak class instances in containers.
Result:
Less conditions during adding ChannelHandlerAdapter to the ChannelPipeline
This also does factor out some logic of ChannelOutboundBuffer. Mainly we not need nioBuffers() for many
transports and also not need to copy from heap to direct buffer. So this functionality was moved to
NioSocketChannelOutboundBuffer. Also introduce a EpollChannelOutboundBuffer which makes use of
memory addresses for all the writes to reduce GC pressure
- Inspired by #2214 by @normanmaurer
- Call setUncancellable() before performing an outbound operation
- Add safeSetSuccess/Failure() and use them wherever
- Related: #2163
- Add ResourceLeakHint to allow a user to provide a meaningful information about the leak when touching it
- DefaultChannelHandlerContext now implements ResourceLeakHint to tell where the message is going.
- Cleaner resource leak report by excluding noisy stack trace elements
- Fixes#2060
- Ensure to return a future/promise implementation that does not fail with 'not registered to an event loop' error for registration operations
- If there is no usable event loop available, GlobalEventExecutor.INSTANCE is used as a fallback.
- Add VoidChannel, which is used when an instantiation of a channel fails.
- Fixes#1808
- Move all methods in ChannelInboundHandler and ChannelOutboundHandler up to ChannelHandler
- Remove ChannelInboundHandler and ChannelOutboundHandler
- Deprecate ChannelInboundHandlerAdapter, ChannelOutboundHandlerAdapter, and ChannelDuplexHandler
- Replace CombinedChannelDuplexHandler with ChannelHandlerAppender
because it's not possible to combine two handlers into one easily now
- Introduce 'Skip' annotation to pass events through efficiently
- Remove all references to the deprecated types and update Javadoc
- Fixes#2003 properly
- Instead of using 'bundle' packaging, use 'jar' packaging. This is
more robust because some strict build tools fail to retrieve the
artifacts from a Maven repository unless their packaging is not 'jar'.
- All artifacts now contain META-INF/io.netty.version.properties, which
provides the detailed information about the build and repository.
- Removed OSGi testsuite temporarily because it gives false errors
during split package test and examination.
- Add io.netty.util.Version for easy retrieval of version information
- Fixes#1912
- Add ChannelHandlerInvoker and its default implementation
- Add pipeline manipulation methods that accept ChannelHandlerInvoker
- Rename Channel(Inbound|Outbound)Invoker to
Channel(Inbound|Outbound)Ops to avoid confusion
- Remove the Javadoc references to the package-private interfaces
- Fixes#1810
- Add a new interface ChannelId and its default implementation which generates globally unique channel ID.
- Replace AbstractChannel.hashCode with ChannelId.hashCode() and ChannelId.shortValue()
- Add variants of ByteBuf.hexDump() which accept byte[] instead of ByteBuf.
- Proposed fix for #1824
UniqueName and its subtypes do not allow getting the previously registered instance. For example, let's assume that a user is running his/her application in an OSGi container with Netty bundles and his server bundle. Whenever the server bundle is reloaded, the server will try to create a new AttributeKey instance with the same name. However, Netty bundles were not reloaded at all, so AttributeKey will complain that the name is taken already (by the previously loaded bundle.)
To fix this problem:
- Replaced UniqueName with Constant, AbstractConstant, and ConstantPool. Better name and better design.
- Sctp/Udt/RxtxChannelOption is not a ChannelOption anymore. They are just constant providers and ChannelOption is final now. It's because caching anything that's from outside of netty-transport will lead to ClassCastException on reload, because ChannelOption's constant pool will keep all option objects for reuse.
- Signal implements Constant because we can't ensure its uniqueness anymore by relying on the exception raised by UniqueName's constructor.
Beside this it also helps to reduce CPU usage as nioBufferCount() is quite expensive when used on CompositeByteBuf which are
nested and contains a lot of components
This ChannelOption allows to tell the DatagramChannel implementation to be active as soon as they are registrated to their EventLoop. This can be used to make it possible to write to a not bound DatagramChannel.
The ChannelOption is marked as @deprecated as I'm looking for a better solution in master which breaks default behaviour with 4.0 branch.
The problem with the old way was that we always set the OP_WRITE when the buffer could not be written
until the write-spin-count was reached. This means that in some cases the channel was still be writable
but we just was not able to write out the data quick enough. For this cases we should better break out the
write loop and schedule a write to be picked up later in the EventLoop, when other tasks was executed.
The OP_WRITE will only be set if a write actual returned 0 which means there is no more room for writing data
and this we need to wait for the os to notify us.
