K 10
svn:author
V 3
mjg
K 8
svn:date
V 27
2014-10-28T04:33:57.634404Z
K 7
svn:log
V 185
Change loginclass mutex to an rwlock.

While here reduce nesting in loginclass_free.

Submitted by:	Tiwei Bie <btw mail.ustc.edu.cn>
X-Additional:	JuniorJobs project
MFC after:	2 weeks

END