09bff91b31
On platforms without support for 64bit atomic operations where we also cannot rely on 64bit reads to have single copy atomicity, such atomics are implemented using a spinlock based fallback. That means it's not safe to even read such atomics from within a signal handler (since the signal handler might run when the spinlock already is held). To avoid this issue defer global barrier processing out of the signal handler. Instead of checking local / shared barrier generation to determine whether to set ProcSignalBarrierPending, introduce PROCSIGNAL_BARRIER and always set ProcSignalBarrierPending when receiving such a signal. Additionally avoid redundant work in ProcessProcSignalBarrier if ProcSignalBarrierPending is unnecessarily. Also do a small amount of other polishing. Author: Andres Freund Reviewed-By: Robert Haas Discussion: https://postgr.es/m/20200609193723.eu5ilsjxwdpyxhgz@alap3.anarazel.de Backpatch: 13-, where the code was introduced.
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: https://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 https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.