[EXTERNAL] [EXTERNAL] Request For Comment: Asynchronous Logging

[Yasumasa Suenaga]

Hi Xin,

On 2021/04/28 2:17, Liu, Xin wrote:
> Hi,
> 
> I would like to report my current progress. I have finished all pending
> tasks except "hoist async_mode to base class for stdout/err". May I ask
> to defer it after this PR? I will create an issue and work on it
> immediately after this PR.  It's not difficult but I need to modify the
> existing interfaces. I would like to keep this PR almost "added" to ease
> reviewers.
> 
> If Yasumasa allows me to do so, now the only blocker is CSR. it seems
> that Iom and Thomas agree with a global option. Shall we go that way?

I agree with you, but I'm not clear a bit between "async=" in -Xlog and -XX:+AsyncLogging.

CSR says about them in below, but I think they are not same because -XX:AsyncLogging affects global, on the other hand "async=" affects in each log output. Is it right?

-----
Unified Logging framework can define a global option -Xlog:async[=true|false]. The effect is same as -XX:+/-AsyncLogging
-----


Thanks,

Yasumasa


> Meanwhile, I have pushed all my code to github:
> https://github.com/openjdk/jdk/pull/3135
> 
> Could you take a look it?
> 
> -------------------------------------------------------------
> | request                                      | Status     |
> -------------------------------------------------------------
> | independent NonJavaThread                    | done       |
> |-----------------------------------------------------------|
> | pass tier1-test with +AsyncLogging           |  [1]       |
> |-----------------------------------------------------------|
> | inject meta-info to display no. of dropping msg. | done   |
> |-----------------------------------------------------------|
> | support jcmd VM.log                          |  done      |
> |-----------------------------------------------------------|
> | preserve accurate decorations                |            |
> |-----------------------------------------------------------<- progress
> | hoist async_mode to base class for stdout/err|            |
> |-----------------------------------------------------------|
> | CSR                                          |JDK-8264323 |
> |-----------------------------------------------------------<- consensus
> |use string table over malloc                  |            |
> ------------------------------------------------------------|
> |use lock-free data structure.                 |            |
> -------------------------------------------------------------
> 
> 
> [1] the only exception is serviceability/dcmd/gc/RunGCTest.java. it
> emits gclog and checks result right away without any synchronization. if
> we do run jtreg test with async logging, I need to add an flushing api
> in whitebox.
> 
> 
> thanks,
> --lx
>