Commit 4646cc58 authored by unknown's avatar unknown
Browse files

BUG#5390 - problems with merge tables 

This fix is necessary because thr_multi_lock()
reorderes the lock data references array.
parent 15ecf922

sql/lock.cc

+16 −4
Original line number Diff line number Diff line
@@ -141,7 +141,12 @@ MYSQL_LOCK *mysql_lock_tables(THD *thd, TABLE **tables, uint count, uint flags) 
    }

    thd->proc_info="Table lock";

    thd->locked=1;

    if (thr_multi_lock(sql_lock->locks,sql_lock->lock_count))

    /* Copy the lock data array. thr_multi_lock() reorders its contens. */

    memcpy(sql_lock->locks + sql_lock->lock_count, sql_lock->locks,

           sql_lock->lock_count * sizeof(*sql_lock->locks));

    /* Lock on the copied half of the lock data array. */

    if (thr_multi_lock(sql_lock->locks + sql_lock->lock_count,

                       sql_lock->lock_count))

    {

      thd->some_tables_deleted=1;		// Try again

      sql_lock->lock_count=0;			// Locks are alread freed
@@ -602,13 +607,20 @@ static MYSQL_LOCK *get_lock_data(THD *thd, TABLE **table_ptr, uint count, 
    }

  }



  /*

    Allocating twice the number of pointers for lock data for use in

    thr_mulit_lock(). This function reorders the lock data, but cannot

    update the table values. So the second part of the array is copied

    from the first part immediately before calling thr_multi_lock().

  */

  if (!(sql_lock= (MYSQL_LOCK*)

	my_malloc(sizeof(*sql_lock) +

		  sizeof(THR_LOCK_DATA*)*tables+sizeof(table_ptr)*lock_count,

		  sizeof(THR_LOCK_DATA*) * tables * 2 +

                  sizeof(table_ptr) * lock_count,

		  MYF(0))))

    DBUG_RETURN(0);

  locks= locks_buf= sql_lock->locks= (THR_LOCK_DATA**) (sql_lock + 1);

  to= table_buf= sql_lock->table= (TABLE**) (locks + tables);

  to= table_buf= sql_lock->table= (TABLE**) (locks + tables * 2);

  sql_lock->table_count=lock_count;

  sql_lock->lock_count=tables;