WL#3262 add mutex lock order checking to safemutex (also called safe_mutex_deadlock_detector)

This writes a warning on stderr if one uses mutex in different order,
like if one in one case would lock mutex in the order A,B and in another case
would lock mutex in the order B,A
This is inspired by and loosely based on the LOCKDEP patch by Jonas
Wrong mutex order is either fixed or mutex are marked with MYF_NO_DEADLOCK_DETECTION
if used inconsistently (need to be fixed by server team)

KNOWN_BUGS.txt:
  Added information that one need to dump and restore Maria tables
include/hash.h:
  Added prototype function for walking over all elements in a hash
include/my_pthread.h:
  Added my_pthread_mutex_init() and my_pthread_mutex_lock(); These should be used if one wants to disable mutex order checking.
  Changed names of the nonposix mutex_init functions to not conflict with my_phread_mutex_init()
  Added and extended structures for mutex deadlock detection.
  New arguments to sage_mutex_init() and safe_mutex_lock() to allow one to disable mutex order checking.
  Added variable 'safe_mutex_deadlock_detector' to enable/disable deadlock detection for all pthread_mutex_init()
mysys/Makefile.am:
  Added cleaning of test files
  Added test_thr_mutex
mysys/hash.c:
  Added hash_iterate() to iterate over all elements in a hash
  More comments
mysys/my_init.c:
  Added calls to destory all mutex uses by mysys()
  Added waiting for threads to end before calling TERMINATE() to list not freed memory
mysys/my_pthread.c:
  Changed names to free my_pthread_mutex_init() for mutex-lock-order-checking
mysys/my_sleep.c:
  Fixed too long wait if using 1000000L as argument
mysys/my_thr_init.c:
  Mark THR_LOCK_threads and THR_LOCK_malloc to not have mutex deadlock detection.
  (We can't have it enabled for this as these are internal mutex used by the detector  
  Call my_thread_init() early as we need thread specific variables enabled for the following pthread_mutex_init()
  Move code to wait for threads to end to my_wait_for_other_threads_to_die()
  Don't destroy mutex and conditions unless all threads have died
  Added my_thread_destroy_mutex() to destroy all mutex used by the mysys thread system
  Name the thread specific mutex as "mysys_var->mutex"
  Added my_thread_var_mutex_in_use() to return pointer to mutex in use or 0 if thread variables are not initialized
mysys/mysys_priv.h:
  Added prototypes for functions used internally with mutex-wrong-usage detection
mysys/thr_mutex.c:
  Added runtime detection of mutex used in conflicting order
  See WL#3262 or test_thr_mutex.c for examples
  The base idea is for each mutex have two hashes:
  - mutex->locked_mutex points to all mutex used after this one
  - mutex->used_mutex points to all mutex which has this mutex in it's mutex->locked_mutex
  There is a wrong mutex order if any mutex currently locked before this mutex is in the mutex->locked_mutex hash
sql/event_queue.cc:
  Mark mutex used inconsistently (need to be fixed by server team)
sql/event_scheduler.cc:
  Declare the right order to take the mutex
sql/events.cc:
  Mark mutex used inconsistently (need to be fixed by server team)
sql/ha_ndbcluster_binlog.cc:
  Mark mutex used inconsistently (need to be fixed by server team)
sql/log.cc:
  Mark mutex used inconsistently (need to be fixed by server team)
sql/mysqld.cc:
  Use pthread_mutex_trylock instead of pthread_mutex_unlock() when sending kill signal to thread
  This is needed to avoid wrong mutex order as normally one takes 'current_mutex' before mysys_var->mutex.
  Added call to free sp cache.
  Add destruction of LOCK_server_started and COND_server_started.
  Added register_mutex_order() function to register in which order mutex should be taken
  (to initiailize mutex_deadlock_detector).
  Added option to turn off safe_mutex_deadlock_detector
sql/protocol.cc:
  Fixed wrong argument to DBUG_PRINT (found by valgrind)
sql/rpl_mi.cc:
  Mark mutex used inconsistently (need to be fixed by server team)
sql/set_var.cc:
  Remove wrong locking of LOCK_global_system_variables when reading and setting log variables
  (would cause inconsistent mutex order).
  Update global variables outside of logger.unlock() as LOCK_global_system_variables has to be taken before logger locks
  Reviewed by gluh
sql/sp_cache.cc:
  Added function to destroy mutex used by sp cache
sql/sp_cache.h:
  Added function to destroy mutex used by sp cache
sql/sql_class.cc:
  Use pthread_mutex_trylock instead of pthread_mutex_unlock() when sending kill signal to thread
  This is needed to avoid wrong mutex order as normally one takes 'current_mutex' before mysys_var->mutex.
  Register order in which LOCK_delete and mysys_var->mutex is taken
sql/sql_insert.cc:
  Give a name for Delayed_insert::mutex
  Mark mutex used inconsistently (need to be fixed by server team)
  Move closing of tables outside of di->mutex (to avoid wrong mutex order)
sql/sql_show.cc:
  Don't keep LOCK_global_system_variables locked over value->show_type() as this leads to wrong mutex order
storage/innobase/handler/ha_innodb.cc:
  Disable safe_muted_deadlock_detector for innobase intern mutex (to speed up page cache initialization)
storage/maria/ha_maria.cc:
  Added flag to ha_maria::info() to signal if we need to lock table share or not.
  This is needed to avoid locking mutex in wrong order
storage/maria/ha_maria.h:
  Added flag to ha_maria::info() to signal if we need to lock table share or not.
storage/maria/ma_close.c:
  Destroy key_del_lock
  Simplify freeing ftparser_param
storage/maria/ma_key.c:
  Better comment
storage/maria/ma_loghandler.c:
  Mark mutex used inconsistently (need to be fixed by sanja)
storage/maria/ma_state.c:
  More comments
storage/maria/ma_test1.c:
  Ensure that safe_mutex_deadlock_detector is always on (should be, this is just for safety)
storage/maria/ma_test2.c:
  Ensure that safe_mutex_deadlock_detector is always on (should be, this is just for safety)

1 files changed, 6 insertions, 1 deletions

diff --git a/sql/events.cc b/sql/events.cc
index df49b7db773..73c76688eb7 100644
--- a/sql/events.cc
+++ b/sql/events.cc
@@ -995,7 +995,12 @@ Events::deinit()
 void
 Events::init_mutexes()
 {
-  pthread_mutex_init(&LOCK_event_metadata, MY_MUTEX_INIT_FAST);
+  /*
+    Inconsisent usage between LOCK_event_metadata and LOCK_scheduler_state
+    and LOCK_open
+  */
+  my_pthread_mutex_init(&LOCK_event_metadata, MY_MUTEX_INIT_FAST,
+                        "LOCK_event_metadata", MYF_NO_DEADLOCK_DETECTION);
 }