Hi, Sergey!
08.02.2014 18:50, Sergey Vojtovich пишет:
Hi Sanja,
JFYI: while reporting this bug I came up with two questions that I couldn't
answer quickly. Probably they make sense, if not just ignore them:
1. This code was introduced with https://bugs.launchpad.net/maria/+bug/782223,
revision: [email protected]
<quot>
The callstack leading of "free" containing critical section is:
mysqld!free
my_no_flags_free
Query_cache::free_cache
Query_cache::resize
fix_query_cache_size
set_var::update
sql_set_variables
mysql_execute_command
mysql_parse
<quot>
It means that this code was supposed to be executed exactly by
Query_cache::resize(), where you disable it.
Question: if this code is not supposed to be executed by ::resize(), is it
needed at all?
It makes some other things so probably it is needed (and as can see
stack it was more about whole cache, but of course I can't revise head
of Wlad :)
2. In Query_cache::resize() I can see block-level locks are acquired with the
following comment:
<quot>
Wait for all readers and writers to exit. When the list of all queries
is iterated over with a block level lock, we are done.
</quot>
Isn't it needed in ::free_cache() also?
Free cache used in
1) init (it definitely do not need)
2) unlock with check that there is no requests (when switching cache off)
3) destruction here (as I think) all clients should be disconnected
already because of server shutdown.
4) resize (but here you see that it was locked and unlocked
[skip]
_______________________________________________
Mailing list: https://launchpad.net/~maria-developers
Post to : [email protected]
Unsubscribe : https://launchpad.net/~maria-developers
More help : https://help.launchpad.net/ListHelp
