64b2e7ad91
Up until now, the total amount of data that could be passed to a background worker at startup was one datum, which can be a small as 4 bytes on some systems. That's enough to pass a dsm_handle or an array index, but not much else. Add a bgw_extra flag to the BackgroundWorker struct, allowing up to 128 bytes to be passed to a new worker on any platform. Use this to fix a problem I recently discovered with the parallel context machinery added in 9.5: the master assigns each worker an array index, and each worker subsequently assigns itself an array index, and there's nothing to guarantee that the two sets of indexes match, leading to chaos. Normally, I would not back-patch the change to add bgw_extra, since it is basically a feature addition. However, since 9.5 is still in beta and there seems to be no other sensible way to repair the broken parallel context machinery, back-patch to 9.5. Existing background worker code can ignore the bgw_extra field without a problem, but might need to be recompiled since the structure size has changed. Report and patch by me. Review by Amit Kapila.
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. PostgreSQL has many language interfaces, many of which are listed here: http://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.