Concurrent execution of statements which require non-table-level
write locks on several instances of the same table (such as
SELECT ... FOR UPDATE which uses same InnoDB table twice or a DML
statement which invokes trigger which tries to update same InnoDB
table directly and through stored function) and statements which
required table-level locks on this table (e.g. LOCK TABLE ... WRITE,
ALTER TABLE, ...) might have resulted in a deadlock.

The problem occured when a thread tried to acquire write lock
(TL_WRITE_ALLOW_WRITE) on the table but had to wait since there was
a pending write lock (TL_WRITE, TL_WRITE_ALLOW_READ) on this table
and we failed to detect that this thread already had another instance
of write lock on it (so in fact we were trying to acquire recursive
lock) because there was also another thread holding write lock on the
table (also TL_WRITE_ALLOW_WRITE). When the latter thread released
its lock neither the first thread nor the thread trying to acquire
TL_WRITE/TL_WRITE_ALLOW_READ were woken up (as table was still write
locked by the first thread) so we ended up with a deadlock.

This patch solves this problem by ensuring that thread which
already has write lock on the table won't wait when it tries
to acquire second write lock on the same table.

mysql-test/r/lock_sync.result:
  Added test case for bug #45143 "All connections hang on concurrent
  ALTER TABLE".
mysql-test/t/lock_sync.test:
  Added test case for bug #45143 "All connections hang on concurrent
  ALTER TABLE".
mysys/thr_lock.c:
  Ensured that thread can acquire write lock on the table without
  waiting if it already has write lock on it even if there are other
  threads holding write locks on this table (this is normal situation
  for, e.g., TL_WRITE_ALLOW_WRITE type of lock).
  
  Adjusted comments to better explain why it is OK to do so and added
  asserts to prevent introduction of scenarios in which this can cause
  problems.

additional fix(Betony)

backport to betony

backport to Betony

Original revision:
------------------------------------------------------------
revno: 2801.10.16
committer: Vladislav Vaintroub <vvaintroub@mysql.com>
branch nick: mysql-azalea-bugfixing
timestamp: Mon 2009-08-10 13:26:23 +0200
message:
  Bug #46267 Shutdown with idle connection crash the server.
  
  The crash happens when mysqld logs a warning. The macro 
  ER() used in sql_print_warning references thread local storage
  variable via current_thd(), to output the warning in "current 
  user language". However, for the shutdown thread, 
  current_thd() will return NULL, and mysqld will crash while 
  derefencing NULL pointer.
  
  Solution: get error mesage text with ER_DEFAULT() macro 
  instead of ER(), this does not current_thd() and will output
  errors in default language.
------------------------------------------------------------

backport to Betony

backport to Betony

instead of making it experimental.

The value was changed from 1024 to 2048,
because 1024 is already used.

Original revision:
------------------------------------------------------------
revno: 2476.657.259
committer: tsmith@bk-internal.mysql.com
timestamp: Tue 2008-01-29 19:32:44 +0100
message:
  WL#4098: Add a status flag for slow queries
  
  Add new result set status flag SERVER_QUERY_WAS_SLOW in mysql_com.h.
  
  There is no server-side implementation to actually set this flag at this
  time.  This patch simply defines the interface so that applications can
  make use of it.  See the worklog for background.
------------------------------------------------------------

```---------------------------------------------------------
revno: 2476.714.9
committer: markleith@medusa.mysql.com
timestamp: Mon 2007-09-03 23:18:50 +0100
message:
  Bug#25822 / WL#3953 - Log Access Denied errors for bad passwords in the error log
  
  Added logging of Access Denied messages on failed new connections to the 
  error log when log-warnings = 2.
  
  This allows a user to log these messages without having to incur the overhead
  of using the general query log on production systems.
```

---------------------------------------------------------

Remove the extra line which try to use the name INNOBASE again. The IF ELSE
loop above declares the library name based on the version of mysql