Fix race condition which could result in freeing a struct that is
still in use by another thread.


Detailed revision comments:

r2537 | inaam | 2008-07-15 20:46:03 +0300 (Tue, 15 Jul 2008) | 12 lines
branches/5.1   issue# 4

Fixed a timing hole where a thread dropping an index can free the
in-memory index struct while another thread is still using
that structure to remove entries from adaptive hash index belonging
to one of the pages that belongs to the index being dropped.

The fix is to have a reference counter in the index struct and to
wait for this counter to drop to zero beforing freeing the struct.

Reviewed by: Heikki

r2543 | inaam | 2008-07-22 18:57:43 +0300 (Tue, 22 Jul 2008) | 7 lines
branches/5.1:

Removed UNIV_INLINE qualifier from btr_search_info_get_ref_count().
Otherwise compilation failed on non-debug builds.

Pointed by: Vasil