Create test_case_for_pstree.py
Create test_case_for_pstree.py

Bug caught:
========
$python test.py
Main Process id: 25613
waiting for sub-thread 0
waiting for sub-thread 1
pstree was terminated by signal 11
waiting for sub-thread 2
pstree was terminated by signal 11
waiting for sub-thread 3
pstree was terminated by signal 11
waiting for sub-thread 4
pstree was terminated by signal 11
waiting for sub-thread 5
pstree was terminated by signal 11
pstree was terminated by signal 11
waiting for sub-thread 6
pstree was terminated by signal 11
waiting for sub-thread 7
pstree was terminated by signal 11
waiting for sub-thread 8
waiting for sub-thread 9
pstree was terminated by signal 11
pstree was terminated by signal 11
totally use 22.4255637811 seconds



Bug fixed:
======
$python test.py
Main Process id: 14491
waiting for sub-thread 0
waiting for sub-thread 1
waiting for sub-thread 2
waiting for sub-thread 3
waiting for sub-thread 4
waiting for sub-thread 5
waiting for sub-thread 6
waiting for sub-thread 7
waiting for sub-thread 8
waiting for sub-thread 9
totally use 22.3295838833 seconds
zhangzl2013/CodeSnippets,zhangzl2013/snippets,zhangzl2013/snippets,zhangzl2013/snippets,zhangzl2013/CodeSnippets