LOCK_thd_data was used to protect both THD data and
ensure that the THD is not deleted while it was in use
This patch moves the THD delete protection to LOCK_thd_kill,
which already protects the THD for kill.
The benefits are:
- More well defined what LOCK_thd_data protects
- LOCK_thd_data usage is now much simpler and easier to verify
- Less chance of deadlocks in SHOW PROCESS LIST as there is less
chance of interactions between mutexes
- Remove not needed LOCK_thread_count from
thd_get_error_context_description()
- Fewer mutex taken for thd->awake()
Other things:
- Don't take mysys->var mutex in show processlist to check if thread
is kill marked
- thd->awake() now automatically takes the LOCK_thd_kill mutex
(Simplifies code)
- Apc uses LOCK_thd_kill instead of LOCK_thd_data
Moved Apc_target::destroy(), Apc_target::enable() and Apc_targe::disable()
definitions to my_apc.h so that they can be inlined.
Apc_targe::disable() now calls Apc_target::process_apc_requests() only if
there're APC requests. This saves one pthread_mutex_lock() call.
Overhead change:
Apc_target::disable 0.04% -> out of radar
Apc_target::enable 0.03% -> out of radar
Apc_target::process_apc_requests 0.02% -> out of radar
pthread_mutex_lock 0.43% -> 0.42%
pthread_mutex_unlock 0.26% -> 0.25%
This is port of fix for MySQL BUG#17647863.
revno: 5572
revision-id: jon.hauglid@oracle.com-20131030232243-b0pw98oy72uka2sj
committer: Jon Olav Hauglid <jon.hauglid@oracle.com>
timestamp: Thu 2013-10-31 00:22:43 +0100
message:
Bug#17647863: MYSQL DOES NOT COMPILE ON OSX 10.9 GM
Rename test() macro to MY_TEST() to avoid conflict with libc++.
Fixed the following compilation errors and test failures:
- maria SE: "stage_waiting_for_a_resource" wasn't declared w/o PFS
- sql_repl.h: PSI_mutex_key is not available in non-PFS builds
- mysqld.cc: pfs_param is not available in non-PFS builds
- mysqld.cc: init_show_explain_psi_keys() is not available in non-PFS builds
- mysqld.cc: call net_before_header_psi, net_after_header_psi even if PFS
is not available so that thread enters stage_init at proper time. Fixes
sp-threads and a few tests in funcs_1.
- myisam_file_io.opt: added missing loose prefix
- Fix the year in Monty Program Ab copyrights in the new files.
- Fix permissions handling so that SHOW EXPLAIN's handling is the
same as SHOW PROCESSLIST's.
- Add Monty Program Ab copyright in new files
- Change Apc_target::make_apc_call() to accept a C++-style
functor (instead of C-style function + parameter)
- Implement new approach to testing (the DBUG_EXECUTE_IF variant)
- add an 'evalp' mysqltest command that is like 'eval' except that
it prints the original query.
- Fix select_describe() not to change join_tab[i]->type
- More tests
First code
- "Asynchronous procedure call" system
- new THD::check_killed() that serves APC request is called from within most important loops
- EXPLAIN code is now able to generate EXPLAIN output on-the-fly [incomplete]
Parts that are still missing:
- put THD::check_killed() call into every loop where we could spend significant amount of time
- Make sure EXPLAIN code works for group-by queries that replace JOIN::join_tab with make_simple_join()
and other such cases.
- User interface: what error code to use, where to get timeout settings from, etc.
