Motivation:
Due to the complexity of handling deregistration and re-registration of
a channel, we previously decided to remove the deregister() operation
completely to simplify our code. However, we realized that it shouldn't
be that complicated to implement it during our discussion about making
I/O scheduling more flexible and more customizable [1], and thus the
removal of deregistration and re-registration is unnecessary now.
Modification:
- Revert commit c149f4bcc0
- Revert commit e743a27e75
- Make some additional adjustments
Result:
- deregister(), fireChannelUnregistered(), and channelRegistered() were
added back..
- Channel constructors do not require an EventLoop anymore.
[1] https://github.com/netty/netty/issues/2250
Motivation:
When no currentMessage has been set and the channel is inactive, a NPE is raised.
Modification:
Make sure that a currentMessage is available before checking the extras.
Result:
No more NPE raised potentially.
Motivation:
If sun.nio.ch is not optional this will cause troubles in the
OSGi world. The package is not exposed by default in OSGi, so
actually the whole netty framework cannot be used directly.
There are workarounds, but workarounds are ugly. Especially since
the use of sun.nio.ch is optional. So the requirement on the
package should be optional as well.
Modifications:
Make the import of sun.nio.ch optional.
Result:
If the package cannot be imported it will behave as if the package
sun.nio.ch is not present (like with other JVMs). If the package is
exposed in OSGi (e.g. bootclassloader delegation, extension fragment)
it will be used.
Motivation:
I had the NioSocketChannelTest.testFlushCloseReentrance() fail sometimes on one of my linux installation. This change let it pass all the time.
Modification:
Set the SO_SNDBUF to a small value to force split writes
Result:
Test is passing all the time where it was sometimes fail before.
Motivation:
AbstractEpollChannel.clearEpollIn() throws an IllegalStateException if a user tries to change the autoRead configuration for the Channel and the Channel is not registered on an EventLoop yet. This makes it for example impossible to set AUTO_READ to false via the ServerBootstrap as the configuration is modifed before the Channel is registered.
Modification:
Check if the Channel is registered and if not just modify the flags directly so they are respected once the Channel is registered
Result:
It is possible now to configure AUTO_READ via the ServerBootstrap
Motivation:
We are currently try to modify the events via EpollEventLoop even when the channel was closed before and so the fd was set to -1. This fails with a RuntimeException in this case.
Modification:
Always check if the Channel is still open before try to modify the events.
Result:
No more RuntimeException because of a not open channel
Motivation:
At the moment it is not possible to deregister a LocalChannel without close it.
Modification:
Not close the LocalChannel during dergister
Result:
It will be possible in the future to deregister a LocalChannel and register it to another EventLoop
Motivation:
Currently the generics used for TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT are incorrect.
Modifications:
Use Integer as type
Result:
User can use TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT as expected
Motivation:
ThreadLocalRandomTest reveals that ThreadLocalRandom's initial seed generation loop becomes tight if the thread is interrupted.
We currently interrupt ourselves inside the wait loop, which will raise an InterruptedException again in the next iteration, resulting in infinite (up to 3 seconds) exception construction and thread interruptions.
Modification:
- When the initial seed generator thread is interrupted, break out of the wait loop immediately.
- Log properly when the initial seed generation failed due to interruption.
- When failed to generate the initial seed, interrupt the generator thread just in case the SecureRandom implementation handles it properly.
- Make the initial seed generator thread daemon and handle potential exceptions raised due to the interruption.
Result:
No more tight loop on interruption. More robust generator thread termination. Fixes#2412
Motivation:
Some SSLEngine implementations violate the contract and raises an
exception when SslHandler feeds an input buffer that contains multiple
SSL records to SSLEngine.unwrap(), while the expected behavior is to
decode the first record and return.
Modification:
- Modify SslHandler.decode() to keep the lengths of each record and feed
SSLEngine.unwrap() record by record to work around the forementioned
issue.
- Rename unwrap() to unwrapMultiple() and unwrapNonApp()
- Rename unwrap0() to unwrapSingle()
Result:
SslHandler now works OpenSSLEngine from finagle-native. Performance
impact remains unnoticeable. Slightly better readability. Fixes#2116.
Motivation:
The problem with the current snappy implementation is that it does
not comply with framing format definition found on
https://code.google.com/p/snappy/source/browse/trunk/framing_format.txt
The document describes that chunk type of the stream identifier is defined
as 0xff. The current implentation uses 0x80.
Modifications:
This patch replaces the first byte of the chunk type of the stream identifier
with 0xff.
Result:
After this modification the snappy implementation is compliant to the
framing format described at
https://code.google.com/p/snappy/source/browse/trunk/framing_format.txt.
This results in a better compatibility with other implementations.
Motivation:
EpollDatagramChannel produced buffer leaks when tried to read from the channel and nothing was ready to be read.
Modifications:
Correctly release buffer if nothing was read
Result:
No buffer leak
Motivation:
Allow to set TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT in native transport to offer the user with more flexibility.
Modifications:
Expose methods to set these options and write the JNI implementation.
Result:
User can now use TCP_KEEPIDLE, TCP_KEEPINTVL and TCP_KEEPCNT.
Motivation:
Some Android SSLEngine implementations skip FINISHED handshake status
and go straightly into NOT_HANDSHAKING. This behavior blocks SslHandler
from notifying its handshakeFuture, because we do the notification when
SSLEngine enters the FINISHED state.
Modification:
When the current handshake state is NOT_HANDSHAKING and the
handshakeFuture is not fulfilled yet, treat NOT_HANDSHAKING as FINISHED.
Result:
Better Android compatibility - fixes#1823
Motivation:
See: https://github.com/netty/netty/issues/2402
See: https://tools.ietf.org/html/draft-ietf-httpbis-http2-10#section-3.5
Only the client should send the preface string, the server should not.
"The server connection header consists of just a SETTINGS frame (Section 6.5)
that MUST be the first frame the server sends in the HTTP/2 connection."
Modifications:
Split out Http2ClientPrefaceWriter and Http2ServerPrefaceReader from
Http2FrameEncoder and Http2FrameDecoder. The new channel handlers are added
to the pipeline and remove themselves after the preface is written/read.
Result:
HTTP2 client sends preface, server does not, in compliance with spec.
Motivation:
HTTP2 is generally negotiated over SSL, makes more sense to provide an SSL example.
Modifications:
Copy the SDPY example to add SSL and NPN negotiation to the HTTP2 example.
Result:
Http2Server and Http2Client examples use SSL.
Motivation:
Once a user implement a custom ChannelHandlerInvoker it is needed to validate the ChannelPromise. We should expose a utility method for this.
Modifications:
Move validatePromise(...) from DefaultChannelHandlerInvoker to ChannelHandlerInvokerUtil and make it public.
Result:
User is able to reuse code
Motivation:
Make it more clear what the output of HttpObjectAggregator is and that it need to come after the encoder in the pipeline.
Modifications:
Change javadocs to make things more clear.
Result:
Better docs
Motivation:
At the moment it is possible to see a NPE when the LocalSocketChannels doRegister() method is called and the LocalSocketChannels doClose() method is called before the registration was completed.
Modifications:
Make sure we delay the actual close until the registration task was executed.
Result:
No more NPE
Motivation:
With SO_REUSEPORT it is possible to bind multiple sockets to the same port and so handle the processing of packets via multiple threads. This allows to handle DatagramPackets with more then one thread on the same port and so gives better performance.
Modifications:
Expose EpollDatagramChannelConfig.setReusePort(..) and isReusePort()
Result:
Allow to bind multiple times to the same local address and so archive better performance.
Motivation:
At the moment ChanneConfig.setAutoRead(false) only is guaranteer to not have an extra channelRead(...) triggered when used from within the channelRead(...) or channelReadComplete(...) method. This is not the correct behaviour as it should also work from other methods that are triggered from within the EventLoop. For example a valid use case is to have it called from within a ChannelFutureListener, which currently not work as expected.
Beside this there is another bug which is kind of related. Currently Channel.read() will not work as expected for OIO as we will stop try to read even if nothing could be read there after one read operation on the socket (when the SO_TIMEOUT kicks in).
Modifications:
Implement the logic the right way for the NIO/OIO/SCTP and native transport, specific to the transport implementation. Also correctly handle Channel.read() for OIO transport by trigger a new read if SO_TIMEOUT was catched.
Result:
It is now also possible to use ChannelConfig.setAutoRead(false) from other methods that are called from within the EventLoop and have direct effect.
Motivation:
There is currently no epoll based DatagramChannel. We should add one to make the set of provided channels complete and also to be able to offer better performance compared to the NioDatagramChannel once SO_REUSEPORT is implemented.
Modifications:
Add implementation of DatagramChannel which uses epoll. This implementation does currently not support multicast yet which will me implemented later on. As most users will not use multicast anyway I think it is fair to just add the EpollDatagramChannel without the support for now. We shipped NioDatagramChannel without support earlier too ...
Result:
Be able to use EpollDatagramChannel for max. performance on linux
Motivation:
In linux kernel 3.9 a new featured named SO_REUSEPORT was introduced which allows to have multiple sockets bind to the same port and so handle the accept() of new connections with multiple threads. This can greatly improve the performance when you not to accept a lot of connections.
Modifications:
Implement SO_REUSEPORT via JNI
Result:
Be able to use the SO_REUSEPORT feature when using the EpollServerSocketChannel
Motivation:
Fix leaks reported during running SpdyFrameDecoderTest
Modifications:
Make sure the produced buffers of SpdyFrameDecoder and SpdyFrameDecoderTest are released
Result:
No more leak reports during run the tests.
Motivation:
Fix leaks reported during running SpdyFrameDecoderTest
Modifications:
Make sure the produced buffer of SpdyFrameDecoder is released
Result:
No more leak reports during run the tests.
Motivation:
Fix leaks reported during SPDY test.
Modifications:
Use ReferenceCountUtil.releaseLater(...) to make sure everything is released once the tests are done.
Result:
No more leak reports during run the tests.
Motivation:
The HTTP2 example client logs, and it's useful to show what's
going on. It'd be sweet if the server did too.
Modifications:
Added Http2FrameLogger to example server pipeline.
Result:
HTTP2 example server will log frames.
and initial settings frame were sent.
Motivation:
The current logic for marking the connection header and initial settings
frame is a bit complicated.
Modifications:
- Http2FrameEncoder, Http2ConnectionHandler: removed sent listeners and
set the sent flag immediately.
Result:
Just a code cleanup ... behavior is the same.
Motivation:
Currently, the SPDY frame encoding and decoding code is based upon
the ChannelHandler abstraction. This requires maintaining multiple
versions for 3.x and 4.x (and possibly 5.x moving forward).
Modifications:
The SPDY frame encoding and decoding code is separated from the
ChannelHandler and SpdyFrame abstractions. Also test coverage is
improved.
Result:
SpdyFrameCodec now implements the ChannelHandler abstraction and is
responsible for creating and handling SpdyFrame objects.
Motivation:
PoolArena's 'normalizeCapacity' function was micro-optimized some
time ago to remove a while loop. However, there was a change of
behavior in the function as a result. Capacities passed into it
that are already powers of 2 (and >= 512) are doubled in size. So
if I ask for a buffer with a capacity of 1024, I will get back one
that actually uses 2048 bytes (stored in maxLength).
Aligning to powers of two for book keeping ease is reasonable,
and if someone tries to expand a buffer, you might as well use some
of the previously wasted space. However, since this distinction
between 'easily expanded' and 'costly to expand' space is not
supported at all by the APIs, I cannot imagine this change to
doubling is desirable or intentional.
This is especially costly when using composite buffers. They
frequently allocate components with a capacity that is a power of
2, and they never attempt to expand components themselves. The end
result is that heavy use of pool-backed composite buffers wastes
almost half of the memory pool (the smaller / initial components are
<512 and so are not affected by the off-by-one bug).
Modifications:
Although I find it difficult to believe that such an optimization
is really helpful, I left it in and fixed the off-by-one issue by
decrementing the value at the start.
I also added a simple test to both attempt to verify that the
decrement fixes the issue without introducing any other change, and
to make it easy for a reviewer to test the existing behavior. PoolArena
does not seem to have much testing or testability support though so
the test is kind of a hack and will break for unrelated changes. I
suggest either removing it or factoring out the single non-static
portion of normalizeCapacity so that the fragile dummy PoolArena is
not required.
Result:
Pooled allocators will allocate less resources to the highly
inefficient and undocumented buffer section between length and
maxLength.
Composite buffers of non-trivial size that are backed by pooled
allocators will use about half as much memory.
Motivation:
At the moment we create a HashMap that holds the MembershipKeys for multicast with every NioDatagramChannel even when most people not need it at al
Modifications:
Lazy create the HashMap when needed.
Result:
Less memory usage and less object creation
Motivation:
Currently, there exists no example which shows how to use the memcache binary
protocol.
Modifications:
Add an example client and client handler to show how to utilize the binary
protocol in a memcache client with a simple interactive shell.
Result:
Users looking for an example can now start off with the provided one.
Motivation:
The current HTTP/2 support does not properly comply with the HTTP/2 spec
wrt startup.
Modifications:
Changed the frame codec as well as the connection handler to support
exchange of the connection preface, followed immediately by an initial
settings frame.
Result:
The HTTP/2 initialization handshake will be in compliance with the spec.
Will need more work to support the upgrade protocols, however :)
Motivation:
We sometimes see data corruption when writing to the EpollSocketChannel.
Modifications:
Correctly update the position of the ByteBuffer after something was written.
Result:
Fix data-corruption which could happen on partial writes
Motivation:
At the moment we create new ThreadPoolCache whenever a Thread tries either allocate or release something on the PooledByteBufAllocator. When something is released we put it then in its ThreadPoolCache. The problem is we never check if a Thread is not alive anymore and so we may end up with memory that is never freed again if a user create many short living Threads that use the PooledByteBufAllocator.
Modifications:
Periodically check if the Thread is still alive that has a ThreadPoolCache assinged and if not free it.
Result:
Memory is freed up correctly even for short living Threads.
Motivation:
When using System.getProperty(...) and various methods to get a ClassLoader it will fail when a SecurityManager is in place.
Modifications:
Use a priveled block if needed. This work is based in the PR #2353 done by @anilsaldhana .
Result:
Code works also when SecurityManager is present
Motivation:
Provide some example code to show how to bootstrap client and server for
use with HTTP/2 framing.
Modifications:
- Fixed Http2ConnectionHandler to allow headers after stream creation.
Needed for response headers.
- Added toString() to all frame classes to help with debugging/logging
- Added example classes for HTTP/2
Result:
HTTP/2 connections now properly support response headers. Examples for
HTTP/2 provided with the distribution of examples module.
After your change, what will change.
Motivation:
At the moment a user can not safetly call slice().retain() or duplicate.retain()in the ByteToMessageDecoder.decode(...) implementation without the risk to see coruption because we may call discardSomeReadBytes() to make room on the buffer once the handling is done.
Modifications:
Check for the refCnt() before call discardSomeReadBytes() and also check before call decode(...) to create a copy if needed.
Result:
The user can safetly call slice().retain() or duplicate.retain() in his/her ByteToMessageDecoder.decode(...) method.
Motivation:
Bring the http2 codec more inline with the rest of Netty's code-base.
Modifications:
- Add null checks in constructors
- Move private static methods into inner-classes where they are used
- Use getBytes(CharsetUtil.UTf8)
Result:
More consistent code-base
Motivation:
The use of the guava library library is fairly superficial and can
easily be removed to reduce the overall dependency list of the module.
Cleaning up the HTTP2 code to use common Netty utilities, etc.
Modifications:
- Various changes to remove use of guava preconditions and collections.
- Changed default charset to use CharsetUtil.UTF_8.
- Changed StreamState to use ArrayDeque instead of LinkedList.
- Changed precondition checks to throw NPE
- Changed implementation of Http2Headers to more closely mirror the SPDY
implementation.
Result:
The behavior of the HTTP2 module will remain unchanged.
Motivation:
Because we not null out the array entry in the SelectionKey[] which is produced by SelectedSelectionKeySet.flip() we may end up with a few SelectionKeyreferences still hanging around here even after the Channel was closed. As these entries may be present at the end of the SelectionKey[] which is never updated for a long time as not enough SelectionKeys are ready.
Modifications:
Once we access the SelectionKey out of the SelectionKey[] we directly null it out.
Result:
Reference can be GC'ed right away once the Channel was closed.
Motivation:
EpollSocketChannel.remoteAddress0() is always null on accepted EpollSocketChannels as we not set it excplicit.
Modifications:
Correctly retrieve the local and remote address when accept new channel and store it
Result:
EpollSocketchannel.remoteAddress0() and EpollSocketChannel.localAddress0() return correct addresses
Motivation:
At the moment we do a Channel.isActive() check in every AbstractChannel.AbstractUnsafe.write(...) call which gives quite some overhead as shown in the profiler when you write fast enough. We can eliminate the check and do something more smart here.
Modifications:
Remove the isActive() check and just check if the ChannelOutboundBuffer was set to null before, which means the Channel was closed. The rest will be handled in flush0() anyway.
Result:
Less overhead when doing many write calls
Motivation:
Native.epollCreate(...) fails on systems using a kernel < 2.6.27 / glibc < 2.9 because it uses epoll_create1(...) without checking if it is present
Modifications:
Check if epoll_create1(...) exists abd if not fall back to use epoll_create(...)
Result:
Works even on systems with kernel < 2.6.27 / glibc < 2.9
Motivation:
In SslHandler.safeClose(...) we attach a ChannelFutureListener to the flushFuture and will notify the ChannelPromise which was used for close(...) in it. The problem here is that we only call ChannelHandlerContext.close(ChannelPromise) if Channel.isActive() is true and otherwise not notify it at all. We should just call ChannelHandlerContext.close(ChannelPromise) in all cases.
Modifications:
Always call ChannelHandlerContext.close(ChannelPromise) in the ChannelFutureListeiner
Result:
ChannelPromise used for close the Channel is notified in all cases
Motivation:
At the moment an IllegalArgumentException will be thrown if a ChannelPromise is cancelled while propagate through the ChannelPipeline. This is not correct, we should just stop to propagate it as it is valid to cancel at any time.
Modifications:
Stop propagate the operation through the ChannelPipeline once a ChannelPromise is cancelled.
Result:
No more IllegalArgumentException when cancel a ChannelPromise while moving through the ChannelPipeline.
