RFR(S): 8200720: Print additional information in thread dump (times, allocated bytes etc.)

[Haug, Gunter]

Hi,

this is an update to an RFR I posted on hotspot-dev, but it is probably more suitable to post it here. Can I please have a review and a sponsor for the following enhancement:

http://cr.openjdk.java.net/~ghaug/webrevs/8200720.v1
https://bugs.openjdk.java.net/browse/JDK-8200720

We at SAP have extended the thread dumps (obtained by jstack or jcmd) by several fields providing thread specific information. These extensions are quite popular with our support team. With some knowledge of the architecture of the application, they often allow for quick and simple diagnosis of a running system. Therefore we would like to contribute these enhancements. 

I took a few simple examples here, namely cpu time, elapsed time since thread creation, bytes allocated and classes defined by the thread and the pthread-id or equivalent on platforms where it makes sense. Provided it is known how the application should behave, a misbehaving thread can identified easily. 

There is no measurable overhead for this enhancement. However, it may be a problem that the format of the output is changed. Tools parsing the output may have to be changed. 

Here is an example of the output generated:

------------------------------------------------------
 
"main" #1 prio=5 os_prio=31 cpu=6300.65ms elapsed=123.28s allocated=242236760B defined_classes=1725 tid=0x00007fa13a806000 nid=0x1c03 pthread-id=0x109708000 waiting on condition [0x0000000109707000] 
   java.lang.Thread.State: TIMED_WAITING (sleeping) 
   JavaThread state: _thread_blocked 
Thread: 0x00007fa13a806000 [0x1c03] State: _at_safepoint _has_called_back 0 _at_poll_safepoint 0 
   JavaThread state: _thread_blocked 
at java.lang.Thread.sleep(java.base/Native Method) 
           ...
------------------------------------------------------

As mentioned above, we have a whole bunch of other enhancements to the thread dump similar to this one and would be willing to contribute them if there is any interest.

Thanks and best regards,
Gunter