deadlock occur in 4/2/locker directory.

[GoogleCodeExporter]

What steps will reproduce the problem?
1. #cd 4/2/locker
2. #make
3. #./dlist_test

What is the expected output? What do you see instead?
The program should exit normal, but the program suspended.

What version of the product are you using? On what operating system?
I checked out in Dec, 16, 2011.

Please provide any additional information below.
Func dlist_insert 调用了 dlist_lock, func dlist_length调用了dlist_lock, 
but dlist_insert 又调用了dlist_length, then deadlock accured.

Thank you very much!

Original issue reported on code.google.com by xuchunxi...@gmail.com on 16 Dec 2011 at 2:20