Make the FileRegion comments about which transports are supported more accurate.
Also, eleminate any outstanding references to FileRegion.transfered as the method was renamed for spelling.
Modifications:
Class-level comment on FileRegion, can call renamed method.
Result:
More accurate documentation and less calls to deprecated methods.
Motivation:
Exceptions generated from transport-native-epoll may include duplicate error string description or inconsistent usage of the method name in the string description.
Modifications:
- Ensure the method name from static exceptions and dynamic exceptions is of the same format
- Remove duplicate string rational from the exception messages
Result:
More consistent error messages with no duplicate error description.
Motivation:
We missed some stuff in 5728e0eb2c and so the build failed on java9
Modifications:
- Add extra cmdline args when needed
- skip the autobahntestsuite as jython not works with java9
- skip the osgi testsuite as the maven plugin not works with java9
Result:
Build finally passed on java9
Motivation:
EpollDatagramChannel uses getOption in the isActive method. getOption is backed by a relatively large conditional if/else if block and this conditional checking can be avoided in the epoll transport.
Modifications:
- Add EpollDatagramChannelConfig#getActiveOnOpen and use this in EpollDatagramChannel
Result:
Conditional checking due to getOption is removed from EpollDatagramChannel.
Motivation:
When the EPOLLRDHUP event is received we assume that the read side of the FD is no longer functional and force the input state to be shutdown. However if the channel is still active we should rely upon EPOLLIN and read to indicate there is no more data before we update the shutdown state. If we do not do this we may not read all pending data in the FD if the RecvByteBufAllocator doesn't want to consume it all in a single read operation.
Modifications:
- AbstractEpollChannel#epollRdHupReady() shouldn't force shutdown the input if the channel is active
Result:
All data can be read even if the RecvByteBufAllocator doesn't read it all in the current read loop.
Fixes https://github.com/netty/netty/issues/6303
Motivation:
We need to pass special arguments to run with jdk9 as otherwise some tests will not be able to run.
Modifications:
Allow to define extra arguments when running with jdk9
Result:
Tests pass with jdk9
Motivation:
EPOLL annotates some exceptions to provide the remote address, but the original exception is not preserved. This may make determining a root cause more difficult. The static EPOLL exceptions references the native method that failed, but does not provide a description of the actual error number. Without the description users have to know intimate details about the native calls and how they may fail to debug issues.
Modifications:
- annotated exceptions should preserve the original exception
- static exceptions should include the string description of the expected errno
Result:
EPOLL exceptions provide more context and are more useful to end users.
Motivation:
EpollRecvByteAllocatorHandle intends to override the meaning of "maybe more data to read" which is a concept also used in all existing implementations of RecvByteBufAllocator$Handle but the interface doesn't support overriding. Because the interfaces lack the ability to propagate this computation EpollRecvByteAllocatorHandle attempts to implement a heuristic on top of the delegate which may lead to reading when we shouldn't or not reading data.
Modifications:
- Create a new interface ExtendedRecvByteBufAllocator and ExtendedHandle which allows the "maybe more data to read" between interfaces
- Deprecate RecvByteBufAllocator and change all existing implementations to extend ExtendedRecvByteBufAllocator
- transport-native-epoll should require ExtendedRecvByteBufAllocator so the "maybe more data to read" can be propagated to the ExtendedHandle
Result:
Fixes https://github.com/netty/netty/issues/6303.
Motivation:
We should call Epoll.ensureAvailability() when init EpollEventLoopGroup to fail fast and with a proper exception.
Modifications:
Call Epoll.ensureAvailability() during EpollEventLoopGroup init.
Result:
Fail fast if epoll is not availability (for whatever reason).
Motivation:
EpollRecvByteAllocatorHandle will read unconditionally if EPOLLRDHUP has been received. However we can just treat this the same was we do as data maybe pending in ET mode, and let LT mode notify us if we haven't read all data.
Modifications:
- EpollRecvByteAllocatorHandle should not always force a read just because EPOLLRDHUP has been received, but just treated as an indicator that there maybe more data to read in ET mode
Result:
Fixes https://github.com/netty/netty/issues/6173.
Motivation:
In later Java8 versions our Atomic*FieldUpdater are slower then the JDK implementations so we should not use ours anymore. Even worse the JDK implementations provide for example an optimized version of addAndGet(...) using intrinsics which makes it a lot faster for this use-case.
Modifications:
- Remove methods that return our own Atomic*FieldUpdaters.
- Use the JDK implementations everywhere.
Result:
Faster code.
Motivation:
To keep our code clean we should fail the build when unused c code is detected.
Modifications:
- Add '-Wunused-variable' to build flags
Result:
Cleaner code.
Motivation:
When attempting to flamegraph netty w/ epoll it was noticed the stacks are lost going from
java to epoll lib.
Modifications:
added the -fno-omit-framepointer flag to compiler flags to ensure the fp is kept intact
Result:
Flamegraphs will now show native code in the same stack as java code using perf-java-flames
Motivation:
We missed to set active = true in EpollServerDomainSocketChannel.doBind(...) which also means that channelActive(...) was never triggered.
Modifications:
Correct set active = true in doBind(...)
Result:
EpollServerDomainSocketChannel is correctly set to active when bound.
Motivation:
I had a need to know the user credentials of a connected unix domain socket.
Modifications:
Added a class to encapsulate user credentials (UID, GID, and the PID).
Augemented the Socket class to provide the JNI native interface to return this new class
Augemented the c code to call getSockOpts passing <a href=http://man7.org/linux/man-pages/man7/socket.7.html>SO_PEERCRED</a>
Then surfaced the ability to get user credentials in the EpollDomainSocketChannel
Result:
The EpollDomainSocketChannel now has a the following function signature:
public PeerCredentials peerCredentials() throws IOException allowing a caller to get the UID, GID, and PID of the linux process
connected to the unix domain socket.
Motivation:
The previously generated manifest causes a parse exception when loaded into an Apache Felix OSGI container.
Modifications:
Fix parameter delimiter and unbalanced quotes in manifest entry. Suffixed with asterisk so the bundle is resolved on other architectures as well even if native libs won't be loaded.
Result:
Bundle will load properly in OSGI containers.
Motivation:
If an exception is thrown while processing the ready channels in the EventLoop we should still run all tasks as this may allow to recover. For example a OutOfMemoryError may be thrown and runAllTasks() will free up memory again. Beside this we should also ensure we always allow to shutdown even if an exception was thrown.
Modifications:
- Call runAllTasks() in a finally block
- Ensure shutdown is always handles.
Result:
More robust EventLoop implementations for NIO and Epoll.
Motivation:
At the moment only DefaultFileRegion is supported when using the native epoll transport.
Modification:
- Add support for any FileRegion implementation
- Add test case
Result:
Also custom FileRegion implementation are supported when using the epoll transport.
Motivition:
NIO throws ClosedChannelException when a user tries to call shutdown*() on a closed Channel. We should do the same for the EPOLL transport
Modification:
Throw ClosedChannelException when a user tries to call shutdown*() on a closed channel.
Result:
Consistent behavior.
Motivation:
Commit 2c1f17faa2 introduced a regression which could cause NotYetConnectedExceptions when handling RDHUP events.
Modifications:
Correct ignore NotYetConnectedException when handling RDHUP events.
Result:
No more regression.
Motivation:
The NIO transport used an IllegalStateException if a user tried to issue another connect(...) while the connect was still in process. For this case the JDK specified a ConnectPendingException which we should use. The same issues exists in the EPOLL transport. Beside this the EPOLL transport also does not throw the right exceptions for ENETUNREACH and EISCONN errno codes.
Modifications:
- Replace IllegalStateException with ConnectPendingException in NIO and EPOLL transport
- throw correct exceptions for ENETUNREACH and EISCONN in EPOLL transport
- Add test case
Result:
More correct error handling for connect attempts when using NIO and EPOLL transport
Motivation:
We need to ensure we also call fireChannelActive() if the Channel is directly closed in a ChannelFutureListener that is belongs to the promise for the connect. Otherwise we will see missing active events.
Modifications:
Ensure we always call fireChannelActive() if the Channel was active.
Result:
No missing events.
Motivation:
We should throw a NotYetConnectedException when ENOTCONN errno is set. This is also consistent with NIO.
Modification:
Throw correct exception and add test case
Result:
More correct and consistent behavior.
Motivation:
In 4.0 AbstractNioByteChannel has a default of 16 max messages per read. However in 4.1 that constraint was applied at the NioSocketChannel which is not equivalent. In 4.1 AbstractEpollStreamChannel also did not have the default of 16 max messages per read applied.
Modifications:
- Make Nio consistent with 4.0
- Make Epoll consistent with Nio
Result:
Nio and Epoll both have consistent ChannelMetadata and are consistent with 4.0.
Motivation:
The build generates a OSGi bundle with missing Bundle-NativeCode manifest entry.
Modifications:
Add missing manifest entry.
Result:
Be able to use transport-native-epoll in osgi container.
Motivation:
ECONNREFUSED can be a common type of exception when attempting to finish the connection process. Generating a new exception each time can be costly and quickly bloat memory usage.
Modifications:
- Expose ECONNREFUSED from JNI and cache this exception in Socket.finishConnect
Result:
ECONNREFUSED during finish connect doesn't create a new exception each time.
Motiviation:
Sometimes it is useful to allow to specify a custom strategy to handle rejected tasks. For example if someone tries to add tasks from outside the eventloop it may make sense to try to backoff and retries and so give the executor time to recover.
Modification:
Add RejectedEventExecutor interface and implementations and allow to inject it.
Result:
More flexible handling of executor overload.
Motivation:
To restrict the memory usage of a system it is sometimes needed to adjust the number of max pending tasks in the tasks queue.
Modifications:
- Add new constructors to modify the number of allowed pending tasks.
- Add system properties to configure the default values.
Result:
More flexible configuration.
Motivation:
We use pre-instantiated exceptions in various places for performance reasons. These exceptions don't include a stacktrace which makes it hard to know where the exception was thrown. This is especially true as we use the same exception type (for example ChannelClosedException) in different places. Setting some StackTraceElements will provide more context as to where these exceptions original and make debugging easier.
Modifications:
Set a generated StackTraceElement on these pre-instantiated exceptions which at least contains the origin class and method name. The filename and linenumber are specified as unkown (as stated in the javadocs of StackTraceElement).
Result:
Easier to find the origin of a pre-instantiated exception.
Motivation:
Unused methods create warnings on some C compilers. It may not be feasible to selectively turn them off.
Modifications:
Remove createInetSocketAddress as it is unused.
Result:
Less noisy compilation
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
Motivation:
epoll_wait accepts a timeout argument which will specify the maximum amount of time the epoll_wait will wait for an event to occur. If the epoll_wait method returns for any reason that is not fatal (e.g. EINTR) the original timeout value is re-used. This does not honor the timeout interface contract and can lead to unbounded time in epoll_wait.
Modifications:
- The time taken by epoll_wait should be decremented before calling epoll_wait again, and if the remaining time is exhausted we should return 0 according to the epoll_wait interface docs http://man7.org/linux/man-pages/man2/epoll_wait.2.html
- link librt which is needed for some platforms to use clock_gettime
Result:
epoll_wait will wait for at most timeout ms according to the epoll_wait interface contract.
