The function trx_purge_stop() was calling os_event_reset(purge_sys->event)
before calling rw_lock_x_lock(&purge_sys->latch). The os_event_set()
call in srv_purge_coordinator_suspend() is protected by that X-latch.
It would seem a good idea to consistently protect both os_event_set()
and os_event_reset() calls with a common mutex or rw-lock in those
cases where os_event_set() and os_event_reset() are used
like condition variables, tied to changes of shared state.
For each os_event_t, we try to document the mutex or rw-lock that is
being used. For some events, frequent calls to os_event_set() seem to
try to avoid hangs. Some events are never waited for infinitely, only
timed waits, and os_event_set() is used for early termination of these
waits.
os_aio_simulated_put_read_threads_to_sleep(): Define as a null macro
on other systems than Windows. TODO: remove this altogether and disable
innodb_use_native_aio on Windows.
os_aio_segment_wait_events[]: Initialize only if innodb_use_native_aio=0.
Problem was that std::vector was allocated using calloc instead of
new, this caused vector constructor not being called and vector
metadata not initialized.
There is a bug in Visual Studio 2010
Visual Studio has a feature "Checked Iterators". In a debug build, every
iterator operation is checked at runtime for errors, e g, out of range.
Disable this "Checked Iterators" for Windows and Debug if defined.
Problem was that static array was used for storing thread mutex sync levels.
Fixed by using std::vector instead.
Does not contain test case to avoid too big memory/disk space usage
on buildbot VMs.
Re-applied lost in the merge revision:
commit ed313e8a92
Author: Sergey Vojtovich <svoj@mariadb.org>
Date: Mon Dec 1 14:58:29 2014 +0400
MDEV-7148 - Recurring: InnoDB: Failing assertion: !lock->recursive
On PPC64 high-loaded server may crash due to assertion failure in InnoDB
rwlocks code.
This happened because load order between "recursive" and "writer_thread"
wasn't properly enforced.
The bug was that full memory barrier was missing in the code that ensures that
a waiter on an InnoDB mutex will not go to sleep unless it is guaranteed to be
woken up again by another thread currently holding the mutex. This made
possible a race where a thread could get stuck waiting for a mutex that is in
fact no longer locked. If that thread was also holding other critical locks,
this could stall the entire server. There is an error monitor thread than can
break the stall, it runs about once per second. But if the error monitor
thread itself got stuck or was not running, then the entire server could hang
infinitely.
This was introduced on i386/amd64 platforms in 5.5.40 and 10.0.13 by an
incorrect patch that tried to fix the similar problem for PowerPC.
This commit reverts the incorrect PowerPC patch, and instead implements a fix
for PowerPC that does not change i386/amd64 behaviour, making PowerPC work
similarly to i386/amd64.
Merged Facebooks commit 6e06bbfa315ffb97d713dd6e672d6054036ddc21
authored by Inaam Rana from https://github.com/facebook/mysql-5.6.
Fixes MySQL bug http://bugs.mysql.com/bug.php?id=72123
lock_timeout thread works in a tight loop waking up every second
and checking for lock_wait_timeout. In addition, when a mysql
thread is forced to wait on a lock, it signals the lock_timeout thread
as well. This call is not required. In a heavily contended workload
each thread going to wait will signal the lock_timeout thread making
it work all the time. As lock_timeout thread scans the array of
waiting threads under lock_sys::wait_mutex which is already very
hot in contneded loads, these extra scans can cause significanct
performance regression.
Also, in various codepaths lock_timeout thread is signalled where
actual intention was to signal the innodb monitor thread.
MDEV-6483 - Deadlock around rw_lock_debug_mutex on PPC64
This problem affects only debug builds on PPC64.
There are at least two race conditions around
rw_lock_debug_mutex_enter and rw_lock_debug_mutex_exit:
- rw_lock_debug_waiters was loaded/stored without setting
appropriate locks/memory barriers.
- there is a gap between calls to os_event_reset() and
os_event_wait() and in such case we're supposed to pass
return value of the former to the latter.
Fixed by replacing self-cooked spinlocks with system mutexes.
These days system mutexes offer much better performance. OTOH
performance is not that critical for debug builds.
Part of this work is based on Stewart Smitch's memory barrier and lower priori
patches for power8.
- Added memory syncronization for innodb & xtradb for power8.
- Added HAVE_WINDOWS_MM_FENCE to CMakeList.txt
- Added os_isync to fix a syncronization problem on power
- Added log_get_lsn_nowait which is now used srv_error_monitor_thread to ensur
if log mutex is locked.
All changes done both for InnoDB and Xtradb
4229: MDEV-5670: Assertion failure in file buf0lru.c line 2355
Add more status information if repeatable.
4230: MDEV-5673: Crash while parallel dropping multiple tables under heavy load
Improve long semaphore wait output to include all semaphore waits
and try to find out if there is a sequence of waiters.
4233: Fix compiler errors on product build.
4237: Fix too agressive long semaphore wait output and add guard against introducing
compression failures on insert buffer.
4238: Fix test failure caused by simulated compression failure on
IBUF_DUMMY table.
This problem affects only debug builds on PPC64.
There are at least two race conditions around
rw_lock_debug_mutex_enter and rw_lock_debug_mutex_exit:
- rw_lock_debug_waiters was loaded/stored without setting
appropriate locks/memory barriers.
- there is a gap between calls to os_event_reset() and
os_event_wait() and in such case we're supposed to pass
return value of the former to the latter.
Fixed by replacing self-cooked spinlocks with system mutexes.
These days system mutexes offer much better performance. OTOH
performance is not that critical for debug builds.
Update InnoDB to 5.6.14
Apply MySQL-5.6 hack for MySQL Bug#16434374
Move Aria-only HA_RTREE_INDEX from my_base.h to maria_def.h (breaks an assert in InnoDB)
Fix InnoDB memory leak
DEREFERENCING UT_DBG_NULL_PTR
The abort() call is standard C but InnoDB only uses it in GCC
environments. UT_DBG_USE_ABORT is not defined the code crashed
by dereferencing a null pointer instead of calling abort().
Other code throughout MySQL including ndb, sql, mysys and other
places call abort() directly.
This bug also affects innodb.innodb_bug14147491.test which fails
randomly on windows because of this issue.
Approved by marko in http://rb.no.oracle.com/rb/r/1936/
