Motivation:
readPending is currently only set to false if data is delivered to the application, however this may result in duplicate events being received from the selector in the event that the socket was closed.
Modifications:
- We should set readPending to false before each read attempt for all
transports besides NIO.
- Based upon the Javadocs it is possible that NIO may have spurious
wakeups [1]. In this case we should be more cautious and only set
readPending to false if data was actually read.
[1] https://docs.oracle.com/javase/7/docs/api/java/nio/channels/SelectionKey.html
That a selection key's ready set indicates that its channel is ready for some operation category is a hint, but not a guarantee, that an operation in such a category may be performed by a thread without causing the thread to block.
Result:
Notification from the selector (or simulated events from kqueue/epoll ET) in the event of socket closure.
Fixes#7255
Motivation:
Even if it's a super micro-optimization (most JVM could optimize such
cases in runtime), in theory (and according to some perf tests) it
may help a bit. It also makes a code more clear and allows you to
access such methods in the test scope directly, without instance of
the class.
Modifications:
Add 'static' modifier for all methods, where it possible. Mostly in
test scope.
Result:
Cleaner code with proper 'static' modifiers.
Motivation:
There are 2 motivations, the first depends on the second:
Loading Netty Epoll statically stopped working in 4.1.16, due to
`Native` always loading the arch specific shared object. In a
static binary, there is no arch specific SO.
Second, there are a ton of exceptions that can happen when loading
a native library. When loading native code, Netty tries a bunch of
different paths but a failure in any given may not be fatal.
Additionally: turning on debug logging is not always feasible so
exceptions get silently swallowed.
Modifications:
* Change Epoll and Kqueue to try the static load second
* Modify NativeLibraryLoader to record all the locations where
exceptions occur.
* Attempt to use `addSuppressed` from Java 7 if available.
Alternatives Considered:
An alternative would be to record log messages at each failure. If
all load attempts fail, the log messages are printed as warning,
else as debug. The problem with this is there is no `LogRecord` to
create like in java.util.logging. Buffering the args to
logger.log() at the end of the method loses the call site, and
changes the order of events to be confusing.
Another alternative is to teach NativeLibraryLoader about loading
the SO first, and then the static version. This would consolidate
the code fore Epoll, Kqueue, and TCNative. I think this is the
long term better option, but this PR is changing a lot already.
Someone else can take a crack at it later
Results:
Epoll Still Loads and easier debugging.
Motivation:
When SO_LINGER is used we run doClose() on the GlobalEventExecutor by default so we need to ensure we schedule all code that needs to be run on the EventLoop on the EventLoop in doClose. Beside this there are also threading issues when calling shutdownOutput(...)
Modifications:
- Schedule removal from EventLoop to the EventLoop
- Correctly handle shutdownOutput in respect with threading-model
- Add unit tests
Result:
Fixes [#7159].
Motivation:
We need to ensure we use the correct osname in the Bundle-NativeCode declaration as declared in:
https://www.osgi.org/developer/specifications/reference/
Modifications:
Update osname to match the spec.
Result:
Correct Bundle-NativeCode entry in the MANIFEST
Motivation:
We should only try to load the native artifacts if the architecture we are currently running on is the same as the one the native libraries were compiled for.
Modifications:
Include architecture in native lib name and append the current arch when trying to load these. This will fail then if its not the same as the arch of the compiled arch.
Result:
Fixes [#7150].
Motivation:
PD and PD0 Both try to find and use Unsafe. If unavailable, they
try to log why and continue on. However, it is not always east to
enable this logging. Chaining exceptions together is much easier
to reach, and the original exception is relevant when Unsafe is
needed.
Modifications:
* Make PD log why PD0 could not be loaded with a trace level log
* Make PD0 remember why Unsafe wasn't available
* Expose unavailability cause through PD for higher level use.
* Make Epoll and KQueue include the reason when failing
Result:
Easier debugging in hard to reconfigure environments
Motivation:
If AutoClose is false and there is a IoException then AbstractChannel will not close the channel but instead just fail flushed element in the ChannelOutboundBuffer. AbstractChannel also notifies of writability changes, which may lead to an infinite loop if the peer has closed its read side of the socket because we will keep accepting more data but continuously fail because the peer isn't accepting writes.
Modifications:
- If the transport throws on a write we should acknowledge that the output side of the channel has been shutdown and cleanup. If the channel can't accept more data because it is full, and still healthy it is not expected to throw. However if the channel is not healthy it will throw and is not expected to accept any more writes. In this case we should shutdown the output for Channels that support this feature and otherwise just close.
- Connection-less protocols like UDP can remain the same because the channel may disconnected temporarily.
- Make sure AbstractUnsafe#shutdownOutput is called because the shutdown on the socket may throw an exception.
Result:
More correct handling of write failure when AutoClose is false.
Motivation:
We should try to bind to an ipv6 only socket before we enable ipv6 support in the native transport as it may not work due setup of the platform.
Modifications:
Try to bind to ::1 use IPV6 later on if this works
Result:
Fixes [#7021].
Motivation:
KQueueEventLoop and EpollEventLoop implement different approaches to applying a timeout of their respective poll calls. Epoll attempts to ensure the desired timeout is satisfied at the java layer and at the JNI layer, but it should be sufficient to account for spurious wakups at the JNI layer. Epoll timeout granularity is also limited to milliseconds which may be too large for some latency sensitive applications.
Modifications:
- Make EpollEventLoop wait method look like KQueueEventLoop
- Epoll should support a finer timeout granularity via timerfd_create. We can hide most of these details behind the epollWait0 JNI call to avoid crossing additional JNI boundaries.
Result:
More consistent timeout approach between KQueue and Epoll.
Motivation:
At the moment we try to load the library using multiple names which includes names using - but also _ . We should just use _ all the time.
Modifications:
Replace - with _
Result:
Fixes [#7069]
Motivation:
Implementations of DuplexChannel delegate the shutdownOutput to the underlying transport, but do not take any action on the ChannelOutboundBuffer. In the event of a write failure due to the underlying transport failing and application may attempt to shutdown the output and allow the read side the transport to finish and detect the close. However this may result in an issue where writes are failed, this generates a writability change, we continue to write more data, and this may lead to another writability change, and this loop may continue. Shutting down the output should fail all pending writes and not allow any future writes to avoid this scenario.
Modifications:
- Implementations of DuplexChannel should null out the ChannelOutboundBuffer and fail all pending writes
Result:
More controlled sequencing for shutting down the output side of a channel.
Motivation:
We did not correctly handle connect() and disconnect() in EpollDatagramChannel and so the behavior was different compared to NioDatagramChannel.
Modifications:
- Correct implement connect and disconnect methods
- Share connect and related code
- Add tests
Result:
EpollDatagramChannel also supports correctly connect() and disconnect() methods.
Motivation:
IP_TRANSPARENT support is not complete, the option can currently only be set on EpollServerSocket. Setting the option on an EpollSocket is also requires so as to be able to bind a socket to a non-local address as described in ip(7)
http://man7.org/linux/man-pages/man7/ip.7.html
"TProxy redirection with the iptables TPROXY target also
requires that this option be set on the redirected socket."
Modifications:
Added IP_TRANSPARENT socket option to EpollSocketChannelConfig
Result:
A redirecting socket can be created with a non-local IP address as required for TPROXY
Motivation:
We used an int[] to store all values that are returned in the struct for TCP_INFO which is not good enough as it uses usigned int values.
Modifications:
- Change int[] to long[] and correctly cast values.
Result:
No more truncated values.
Motivation:
`Epoll.ensureAvailability()` is called multiple times, once in
static initialization and in a couple of the constructors. This is
redundant and confusing to read.
Modifications:
Move `Epoll.ensureAvailability()` call into an instance initializer
and remove all other references. This ensures that every EELG
checks availability, while still delaying the check until
construction. This pattern is used when there are multiple ctors,
as in this class.
Result:
Easier to read code.
Motivation:
We should not try to detect a free port in tests put just use 0 when bind so there is no race in which the system my bind something to the port we choosen before.
Modifications:
- Remove the usage of TestUtils.getFreePort() in the testsuite
- Remove hack to workaround bind errors which will not happen anymore now
Result:
Less flacky tests.
Motivation:
When run the current testsuite on docker (mac) it will fail a few tests with:
io.netty.channel.AbstractChannel$AnnotatedConnectException: connect(..) failed: Cannot assign requested address: /0:0:0:0:0:0:0:0%0:46607
Caused by: java.net.ConnectException: connect(..) failed: Cannot assign requested address
Modifications:
Specify host explicit as done in other tests to only use ipv6 when really supported.
Result:
Build pass on docker as well
Motivation:
JCTools 2.0.2 provides an unbounded MPSC linked queue. Before we shaded JCTools we had our own unbounded MPSC linked queue and used it in various places but gave this up because there was no public equivalent available in JCTools at the time.
Modifications:
- Use JCTool's MPSC linked queue when no upper bound is specified
Result:
Fixes https://github.com/netty/netty/issues/5951
Motivation:
An intermediate list is creating in the `EpollEventLoop#closeAll` to prevent ConcurrentModificationException. But this is not the obvious purpose has no comment.
Modifications:
Add comment to clarify the appointment of the intermediate collection.
Result:
More clear code.
Motivation:
We used an intermediate collection to store the read DatagramPackets and only fired these through the pipeline once wewere done with the reading loop. This is not needed and can also increase memory usage.
Modifications:
Remove intermediate collection
Result:
Less overhead and possible less memory usage during read loop.
Motivation:
We had a typo in the method name of the EpollSocketChannelConfig.
Modifications:
Deprecate old method and introduce a new one.
Result:
Fixes [#6909]
fix not execute unit test in transport-native-unix-common-tests module
Motivation:
- Commit 047da11 introduced an bug for still copy byteBuf for composed of n(n <= IOV_MAX) NIO direct buffers
- Commit 3c4dfed add UnixChannelUtilTest in transport-native-unix-common-tests module, but not execute in maven compile
as issue #6825, #6870
Modifications:
- modified UnixChannelUtil#isBufferCopyNeededForWrite(ByteBuf), and UnixChannelUtilTest
- move UnixChannelUtilTest into transport-native-unix-common module, and add packet scope method UnixChannelUtil#isBufferCopyNeededForWrite(ByteBuf, int)
Result:
- no copy byteBuf for composed of n(n <= IOV_MAX) NIO direct buffers
- auto execute unit tests in UnixChannelUtilTest and it is easier to mock IOV_MAX
The code in question has this comment, but it is *after* the fall
so the static analysis flags it.
This is described in http://errorprone.info/bugpattern/FallThrough
Modifications:
Move fall through comment to where the fall actually occurs
Result:
More compatible with Error Prone tools
Motivation:
Google requires stricter compilation by adding -Werror and enabling many other warnings.
Modification:
* fix warning caused by -Wmissing-braces
* Use the address of `sendmmsg` rather than the function itself when
checking for presence. This resovles the warning caused by
`-Wpointer-bool-conversion`.
More detail:
When compiling on Linux, `sendmmsg` is always present, so the
function is always nonnull. When compiling elsewhere, the
function is defined as `__attribute__((weak))` which means it
may be absent at link time. This is controlled by
`IO_NETTY_SENDMMSG_NOT_FOUND`, which is off by default.
The reason for the error is due to the risk of accidentally not
calling the function. By adding `&` before the function, there
is no ambiguity. (the result of the fn call cannot have its
address taken.)
* use != to check for sendmmsg
Result:
Easier compilation.
Motivation:
We should not force autoconf and compile as this will result in multiple executions and so slow down the build.
Modifications:
Remove force declarations
Result:
Faster build of native modules
Motivation:
Commit 3c4dfed08a introduced a regression in handling buffers that have no memoryAddress.
Modifications:
Fix regression and also add unit tests.
Result:
It's possible again to write buffers without memory address.
Motivation:
We used strstr to find the path to the library, which fails if the library is contained in a directory that also matches the library name.
Modifications:
- Introduce netty_unix_util_strstr_last which will return a pointer which points to the last accourance and so not fails if the direct also matches the library name.
Result:
Be able to load the library in all cases.
Motivation:
1. special handling of ByteBuf with multi nioBuffer rather than type of CompositeByteBuf (eg. DuplicatedByteBuf with CompositeByteBuf)
2. EpollDatagramUnicastTest and passed because CompositeByteBuf is converted to DuplicatedByteBuf before write to channel
3. uninitalized struct msghdr will raise error
Modifications:
1. isBufferCopyNeededForWrite(like isSingleDirectBuffer in NioDatgramChannel) checks wether a new direct buffer is needed
2. special handling of ByteBuf with multi nioBuffer in EpollDatagramChannel, AbstractEpollStreamChannel and IovArray
3. initalize struct msghdr
Result:
handle of ByteBuf with multi nioBuffer in EpollDatagramChannel is ok
Motivation:
We only can call eventLoop() if we are registered on an EventLoop yet. As we just did this without checking we spammed the log with an error that was harmless.
Modifications:
Check if registered on eventLoop before try to deregister on close.
Result:
Fixes [#6770]
Motivation:
For our native libraries in netty we support shading, to have this work on runtime the user needs to set a system property. This code should shared.
Modifications:
Move logic to NativeLbiraryLoader and so share for all native libs.
Result:
Less code duplication and also will work for netty-tcnative out of the box once it support shading
Motivation:
SocketTest should verify that EPOLL is available before running the test.
Modifications:
- Add a @BeforeClass method which assumeTrue if EPOLL is available
Result:
More robust tests than get skipped if EPOLL isn't available
