Java Stack Trace

I'm messing around with Java. Ubuntu has a write up. I choose IcedTea:

apt-get install icedtea-java7-jdk

I also installed mmake. I'm revisiting the Knock Knock server. Doing a SIGQUIT kill (-3) causes it to dump core and keep running:

$ java KKMultiServer > log 
...
$ ps axu | grep java | grep -v grep
user  24050  0.5  0.3 1308620 12740 pts/22  Sl+  15:24   0:00 java KKMultiServer
user  24071  2.0  0.3 1377796 15024 pts/20  Sl+  15:25   0:00 java KnockKnockClient
user  24093  2.4  0.3 1378512 15456 pts/21  Sl+  15:25   0:00 java KnockKnockClient
user  24113  4.3  0.3 1377708 15472 pts/19  Sl+  15:25   0:00 java KnockKnockClient
$ kill -3 24050
$ ps axu | grep 24050 | grep -v grep 
user  24050  0.0  0.3 1308620 12788 pts/22  Sl+  15:24   0:00 java KKMultiServer
$ wc -l log 
117 log

The stack trace output is interesting. It seemed to list each thread that the KKMultiServer had:

"KKMultiServerThread" prio=10 tid=0x00000000006e8400 nid=0x5e43 runnable [0x0000000041412000..0x0000000041412d90]
...
"KKMultiServerThread" prio=10 tid=0x00000000006e6400 nid=0x5e2f runnable [0x0000000041311000..0x0000000041311c10]
...
"KKMultiServerThread" prio=10 tid=0x00000000006d2400 nid=0x5e1b runnable [0x0000000041210000..0x0000000041210c90]

Then I see other runnable threads like the Low Memory Detector, Compiler Thread, Signal Dispatcher, Finalizer, Reference Handler, main, VM Thread and GC tasks. Each was waiting or runnable. It also prints Heap information. I came across PSYoungGen.java when trying to make sense of it. I found two stack trace articles from Sun and [0xCAFEFEED]. It's nice to see that people find this useful.