9d888cd3f3
If SHMEM_CALLBACKS_ALLOW_AFTER_STARTUP is used to allocate shared memory after startup, but the initialization fails half-way through, the shmem area is left in an indeterminate state. Furthermore, if multiple shmem areas are registered in one RegisterShmemCallbacks() call, some might be allocated while others are not. This commit adds an explicit 'initialized' flag to each shmem area. We still leave behind an uninitialized area on error, but at least they are now clearly marked, and you get a slightly nicer error message if you try to re-register them. It'd be nice to clean up more thoroughly and support actually retrying the allocations, but in practice, the most likely reason for a shmem allocation or initialization to fail is that you are out of shared memory and retrying wouldn't help with that. This isn't exactly a new problem, the old ShmemInitStruct() interface had similar issues if the initialization code failed, or if you allocated multiple structs and some allocations failed. It was just left to the calling code to deal with it. Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Discussion: https://www.postgresql.org/message-id/CAJTYsWVRRWH48=PcuAo_2Y4Ap6M0QRmzxgUfFkNRtdWK74LjBQ@mail.gmail.com Backpatch-through: 19
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/19/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/19/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.