New Early Access builds

[Cay Horstmann]

Build 16-loom+9-316 had Scoped and LightweightThreadLocal classes, which 
are not present in 17-loom+2-42. Thread.Builder.disallowThreadLocals is 
also gone. What's the latest thinking on thread locals and scoped variables?

Cheers,

Cay

Il 16/01/2021 09:34, Alan Bateman ha scritto:
> 
> We've published new builds on the Project Loom Early Access download 
> page [1]. The new builds are based on jdk-17+5 (JDK 17 build 5) so we 
> are up to date with the main line. The "Getting started" page [1] is up 
> to date.
> 
> There are a few more stability fixes in this build, our testing has been 
> with G1 and ZGC.
> 
> As I mentioned in a previous mail, the debugger support has been work in 
> progress. The implementation of JVM TI (the underlying tools interface) 
> has been significantly updated since the last build. It's enough to get 
> jshell working again. There are still a few issues with some of the low 
> level events around scheduling points and we need to resolve those 
> issues before the IDE debuggers will step correctly.
> 
> We've started to explore serviceability/diagnosability features. JFR has 
> support for virtual threads for some time, it can record socket I/O 
> events on virtual threads that exceed some threshold for example. There 
> is also rudimentary support for thread dumps in this build in the form 
> of a new jcmd command and a new JDK-specific ThreadMXBean operation. Use 
> `jcmd <pid> JavaThread.dump -format=json` to get a thread dump in JSON 
> format.  For now, the thread dump will only include the stack trace of 
> virtual threads when the new thread executors are used, and only when 
> they are used in a structured way. The JSON object has enough to allow 
> tools to reconstitute the structure, de-duplicate stack traces, and 
> other interesting things. We're re-evaulate all this at some point but 
> for now, it's something simple that does not require a stop-the-world 
> operation to find the virtual threads in the heap.
> 
> -Alan
> 
> [1] http://jdk.java.net/loom/
> [2] https://wiki.openjdk.java.net/display/loom/Getting+started

-- 

Cay S. Horstmann | http://horstmann.com | mailto:cay at horstmann.com