Go to file
Norman Maurer 2e68e37025 [#5028] Fix re-entrance issue with channelWritabilityChanged(...) and write(...)
Motivation:

When always triggered fireChannelWritabilityChanged() directly when the update the pending bytes in the ChannelOutboundBuffer was made from within the EventLoop. This is problematic as this can cause some re-entrance issue if the user has a custom ChannelOutboundHandler that does multiple writes from within the write(...) method and also has a handler that will intercept the channelWritabilityChanged event and trigger another write when the Channel is writable. This can also easily happen if the user just use a MessageToMessageEncoder subclass and triggers a write from channelWritabilityChanged().

Beside this we also triggered fireChannelWritabilityChanged() too often when a user did a write from outside the EventLoop. In this case we increased the pending bytes of the outboundbuffer before scheduled the actual write and decreased again before the write then takes place. Both of this may trigger a fireChannelWritabilityChanged() event which then may be re-triggered once the actual write ends again in the ChannelOutboundBuffer.

The third gotcha was that a user may get multiple events even if the writability of the channel not changed.

Modification:

- Always invoke the fireChannelWritabilityChanged() later on the EventLoop.
- Only trigger the fireChannelWritabilityChanged() if the channel is still active and if the writability of the channel changed. No need to cause events that were already triggered without a real writability change.
- when write(...) is called from outside the EventLoop we only increase the pending bytes in the outbound buffer (so that Channel.isWritable() is updated directly) but not cause a fireChannelWritabilityChanged(). The fireChannelWritabilityChanged() is then triggered once the task is picked up by the EventLoop as usual.

Result:

No more re-entrance possible because of writes from within channelWritabilityChanged(...) method and no events without a real writability change.
2016-04-06 10:50:41 +02:00
all [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
buffer Fix PoolChunkList.minUsage() and maxUsage() for head and tail 2016-04-06 10:03:14 +02:00
codec [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
codec-haproxy [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
codec-http [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
codec-socks [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
common Add Log4J2LoggerFactory and Log4J2Logger 2016-04-05 14:07:26 +02:00
example [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
handler fcbeebf6df unit test bug 2016-04-06 00:12:54 -07:00
license Let PoolThreadCache work even if allocation and deallocation Thread are different 2015-05-27 14:35:22 +02:00
microbench [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
tarball [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
testsuite [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
testsuite-osgi [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
transport [#5028] Fix re-entrance issue with channelWritabilityChanged(...) and write(...) 2016-04-06 10:50:41 +02:00
transport-native-epoll [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
transport-rxtx [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
transport-sctp [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
transport-udt [maven-release-plugin] prepare for next development iteration 2016-04-04 16:53:40 +02:00
.fbprefs Updated Find Bugs configuration 2009-03-04 10:33:09 +00:00
.gitignore Add JVM crash logs to .gitignore 2014-05-18 21:37:12 +09:00
.travis.yml Travis CI branch whitelisting 2013-03-11 09:55:43 +09:00
CONTRIBUTING.md Move the pull request guide to the developer guide 2014-03-12 13:18:14 +09:00
LICENSE.txt Relicensed to Apache License v2 2009-08-28 07:15:49 +00:00
NOTICE.txt Let PoolThreadCache work even if allocation and deallocation Thread are different 2015-05-27 14:35:22 +02:00
pom.xml Add Log4J2LoggerFactory and Log4J2Logger 2016-04-05 14:07:26 +02:00
README.md Updating Branches to look section to match the current branching structure of the project 2016-03-10 22:09:30 +01:00
run-example.sh Add logLevel property to enable different log levels for the examples. 2014-11-21 10:48:13 +09:00

Netty Project

Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients.

How to build

For the detailed information about building and developing Netty, please visit the developer guide. This page only gives very basic information.

You require the following to build Netty:

Note that this is build-time requirement. JDK 5 (for 3.x) or 6 (for 4.0+) is enough to run your Netty-based application.

Branches to look

Development of all versions takes place in each branch whose name is identical to <majorVersion>.<minorVersion>. For example, the development of 3.9 and 4.0 resides in the branch '3.9' and the branch '4.0' respectively.