/ 
DBIO-MySQL-0.900004
/ DBIO::MySQL::MariaDBForkGuard

NAME

DBIO::MySQL::MariaDBForkGuard - keep a forked child's exit from closing DBD::MariaDB connections it inherited

VERSION

version 0.900004

SYNOPSIS

DBIO::MySQL::MariaDBForkGuard->install;

Nothing calls this by hand: the sync storage and the future_io transport install it after every connect that belongs to DBD::MariaDB.

DESCRIPTION

DBI's END block calls DBI->disconnect_all at every normal exit. DBD::MariaDB (measured with 1.24) carries that out on every connection it lists, whatever InactiveDestroy or AutoInactiveDestroy say. In a forked child that is every connection the child inherited from its parent: the close sends COM_QUIT down the socket both processes share, and the server ends the parent's session. Where a handle had already been destroyed under AutoInactiveDestroy but is still listed, the same call instead dies in a DBI active kids panic and the child's exit status becomes 22. DBD::mysql has no such disconnect_all and is not affected. The report for DBD::MariaDB is drafted in docs/upstream/dbd-mariadb-disconnect-all-after-fork.md and not sent; this class is the workaround (this dist's ADR 0009).

METHODS

install

DBIO::MySQL::MariaDBForkGuard->install;

Load DBD::MariaDB and wrap its disconnect_all. Idempotent: a second call, from any process, changes nothing -- the owner stays the first installer. Returns true when the guard is in place, false when DBD::MariaDB cannot be loaded.

WHAT IT DOES

install wraps DBD::MariaDB::dr::disconnect_all. In the process that installed the guard the wrapper hands over to the original, unchanged. In any other process -- a forked child, however deep -- it does nothing: closing a connection inherited across a fork is never right.

This is process-wide and covers every DBD::MariaDB handle of the process, not only the ones DBIO opened. Two consequences, both deliberate:

  • A connection a child opens itself is not closed by disconnect_all either. Its DESTROY closes it (the handle was created in that process, so AutoInactiveDestroy does not skip it), and so does an explicit disconnect.

  • The guard is installed by the first DBIO connect over DBD::MariaDB, so it must happen before the fork for the child to have it. A process that forks first and only then opens its first DBIO connection is the installer and treats its own pid as the owner.

It changes no @ISA and no connection() hook: the wrapped sub is replaced in the DBD's own package, once.

SEE ALSO

AUTHOR

DBIO & DBIx::Class Authors

COPYRIGHT AND LICENSE

Copyright (C) 2026 DBIO Authors Portions Copyright (C) 2005-2025 DBIx::Class Authors Based on DBIx::Class, heavily modified.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.