What's the meaning of `accum` field in hprof's result?

Question

When I running java with option:

-agentlib:hprof=cpu=times

The hprof's result is like:

CPU TIME (ms) BEGIN (total = 3093024) Thu Jan 28 14:57:36 2016
rank   self   accum    count trace  method
1      35.81% 35.81%       6 328434 java.util.concurrent.locks.LockSupport.park
2      28.04% 63.85%      68 330338 java.util.concurrent.locks.LockSupport.park
3      11.04% 74.88%   59675 326270 sun.nio.ch.EPollArrayWrapper.poll

I'am wondering what's the meaning of accum filed?

Thanks.

Answer 1

As mentioned in hprof CPU TIMES:

accum: includes the time for the entries that appear above this one in the list. The last entry will have an accum of 100%