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authorunknown <serg@janus.mylan>2007-12-20 22:11:37 +0100
committerunknown <serg@janus.mylan>2007-12-20 22:11:37 +0100
commit295732b580716b6b5a48a4a2ceb112b432c96551 (patch)
tree8e1c37da4cf89e91d901badb1c2e5f100be39ec1 /sql/lock.cc
parent3ab83a2e5efdb64b068243d11b6230ae5b11df29 (diff)
parent9bf488563d948ddc86ccef87ddaebc7d15afe1a4 (diff)
downloadmariadb-git-295732b580716b6b5a48a4a2ceb112b432c96551.tar.gz
Merge bk-internal.mysql.com:/home/bk/mysql-5.1-maint
into janus.mylan:/usr/home/serg/Abk/mysql-5.1 configure.in: Auto merged libmysql/CMakeLists.txt: Auto merged libmysqld/lib_sql.cc: Auto merged mysql-test/mysql-test-run.pl: Auto merged mysql-test/r/information_schema.result: Auto merged mysql-test/t/information_schema.test: Auto merged sql/Makefile.am: Auto merged sql/field.cc: Auto merged sql/handler.cc: Auto merged sql/item.cc: Auto merged sql/item_func.cc: Auto merged sql/item_geofunc.cc: Auto merged sql/item_subselect.cc: Auto merged sql/key.cc: Auto merged sql/lock.cc: Auto merged sql/log.cc: Auto merged sql/log_event.cc: Auto merged sql/mysql_priv.h: Auto merged sql/mysqld.cc: Auto merged sql/net_serv.cc: Auto merged sql/opt_sum.cc: Auto merged sql/protocol.h: Auto merged sql/repl_failsafe.cc: Auto merged sql/set_var.cc: Auto merged sql/set_var.h: Auto merged sql/sp_head.cc: Auto merged sql/sql_base.cc: Auto merged sql/sql_cache.cc: Auto merged sql/sql_class.cc: Auto merged sql/sql_delete.cc: Auto merged sql/sql_insert.cc: Auto merged sql/sql_lex.cc: Auto merged sql/sql_prepare.cc: Auto merged sql/sql_select.cc: Auto merged sql/sql_select.h: Auto merged sql/sql_show.cc: Auto merged sql/sql_table.cc: Auto merged sql/sql_update.cc: Auto merged sql/sql_yacc.yy: Auto merged sql/table.h: Auto merged storage/archive/ha_archive.cc: Auto merged storage/innobase/buf/buf0buf.c: Auto merged storage/innobase/buf/buf0flu.c: Auto merged storage/innobase/buf/buf0lru.c: Auto merged storage/innobase/include/buf0buf.h: Auto merged storage/innobase/include/buf0buf.ic: Auto merged storage/innobase/include/sync0arr.h: Auto merged storage/innobase/include/sync0rw.h: Auto merged storage/innobase/include/sync0rw.ic: Auto merged storage/innobase/include/sync0sync.h: Auto merged storage/innobase/os/os0sync.c: Auto merged storage/innobase/sync/sync0arr.c: Auto merged storage/innobase/sync/sync0rw.c: Auto merged storage/innobase/sync/sync0sync.c: Auto merged storage/myisam/ha_myisam.cc: Auto merged storage/myisam/mi_open.c: Auto merged storage/myisammrg/ha_myisammrg.cc: Auto merged sql/ha_ndbcluster.cc: merged sql/item_cmpfunc.cc: merged sql/protocol.cc: merged sql/slave.cc: merged sql/sql_class.h: merged sql/sql_parse.cc: merged
Diffstat (limited to 'sql/lock.cc')
-rw-r--r--sql/lock.cc20
1 files changed, 17 insertions, 3 deletions
diff --git a/sql/lock.cc b/sql/lock.cc
index 8307e762c62..a0d6faa6604 100644
--- a/sql/lock.cc
+++ b/sql/lock.cc
@@ -845,9 +845,6 @@ static MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count,
locks= locks_buf= sql_lock->locks= (THR_LOCK_DATA**) (sql_lock + 1);
to= table_buf= sql_lock->table= (TABLE**) (locks + tables * 2);
sql_lock->table_count=lock_count;
- sql_lock->lock_count=tables;
- DBUG_PRINT("info", ("sql_lock->table_count %d sql_lock->lock_count %d",
- sql_lock->table_count, sql_lock->lock_count));
for (i=0 ; i < count ; i++)
{
@@ -887,6 +884,23 @@ static MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count,
for ( ; org_locks != locks ; org_locks++)
(*org_locks)->debug_print_param= (void *) table;
}
+ /*
+ We do not use 'tables', because there are cases where store_lock()
+ returns less locks than lock_count() claimed. This can happen when
+ a FLUSH TABLES tries to abort locks from a MERGE table of another
+ thread. When that thread has just opened the table, but not yet
+ attached its children, it cannot return the locks. lock_count()
+ always returns the number of locks that an attached table has.
+ This is done to avoid the reverse situation: If lock_count() would
+ return 0 for a non-attached MERGE table, and that table becomes
+ attached between the calls to lock_count() and store_lock(), then
+ we would have allocated too little memory for the lock data. Now
+ we may allocate too much, but better safe than memory overrun.
+ And in the FLUSH case, the memory is released quickly anyway.
+ */
+ sql_lock->lock_count= locks - locks_buf;
+ DBUG_PRINT("info", ("sql_lock->table_count %d sql_lock->lock_count %d",
+ sql_lock->table_count, sql_lock->lock_count));
DBUG_RETURN(sql_lock);
}