RFR[9u-dev]: 8151442: jstack doesn't close quotation marks properly with threads' name greater than 1996 characters

[Rainer Jung]

Am 21.03.2016 um 09:18 schrieb Robbin Ehn:
> (I must admit I'm very curious why anyone would have a thread name that
> long)

Since thread dumps are very useful for problem analysis but only contain 
stacks but no data, sometimes people switch the thread name on every new 
workload the thread handles, so that the thread name in the dump 
contains the info, kind of side-channel to tunnel data into the dump.

For example: in a web container one might append the request info (HTTP 
method, URI, query string, time the request began) with a separator to 
the original thread name at the beginning of the request, and strip it 
at the end. So if things hang or get slow and you take a thread dump, 
the info on what type or request each thread is working is present in 
that dump.

I'm not arguing whether this is a good pattern or not, but I have seen 
this pattern in production. Still, 1996 characters isn't easily reached 
even with this pattern.

Regards,

Rainer