Dmitry Shulga d0a872c20e MDEV-14959: Fixed memory leak relating with view and IS ...

Fixed memory leak taken place on executing a prepared statement or
a stored routine that querying a view and this view constructed
on an information schema table. For example,

Lets consider the following definition of the view 'v1'
CREATE VIEW v1 AS SELECT table_name FROM information_schema.views
ORDER BY table_name;

Querying this view in PS mode result in hit of assert.
PREPARE stmt FROM "SELECT * FROM v1";
EXECUTE stmt;
EXECUTE stmt; (*)

Running the statement marked with (*) leads to a crash in case
server build with mode to control allocation of a memory from SP/PS
memory root on the second and following executions of PS/SP.

The reason of leaking the memory is that a memory allocated on
processing of FRM file for the view requested from a PS/PS memory
root meaning that this memory be released only when a stored routine
be evicted from SP-cache or a prepared statement be deallocated
that typically happens on termination of a user session.

To fix the issue switch to a memory root specially created for
allocation of short-lived objects that requested on parsing FRM.

2023-09-02 13:00:00 +07:00

354 KiB

Raw Blame History

View Raw