42fba015ce
Motivation:
ResourceLeakDetector shows two main problems, racy access and heavy lock contention.
Modifications:
This PR fixes this by doing two things:
1. Replace the sampling counter with a ThreadLocalRandom. This has two benefits.
First, it makes the sampling ration no longer have to be a power of two. Second,
it de-noises the continuous races that fight over this single value. Instead,
this change uses slightly more CPU to decide if it should sample by using TLR.
2. DefaultResourceLeaks need to be kept alive in order to catch leaks. The means
by which this happens is by a singular, doubly-linked list. This creates a
large amount of contention when allocating quickly. This is noticeable when
running on a multi core machine.
Instead, this uses a concurrent hash map to keep track of active resources
which has much better contention characteristics.
Results:
Better concurrent hygiene. Running the gRPC QPS benchmark showed RLD taking about
3 CPU seconds for every 1 wall second when runnign with 12 threads.
There are some minor perks to this as well. DefaultResourceLeak accounting is
moved to a central place which probably has better caching behavior.
Netty Project
Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients.
Links
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:
- Latest stable Oracle JDK 7
- Latest stable Apache Maven
- If you are on Linux, you need additional development packages installed on your system, because you'll build the native transport.
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.