7e784d1dc1
Up to now, if the DBA issued "pg_ctl stop -m immediate", the message sent to clients was the same as for a crash-and-restart situation. This is confusing, not least because the message claims that the database will soon be up again, something we have no business predicting. Improve things so that we can generate distinct messages for the two cases (and also recognize an ad-hoc SIGQUIT, should somebody try that). To do that, add a field to pmsignal.c's shared memory data structure that the postmaster sets just before broadcasting SIGQUIT to its children. No interlocking seems to be necessary; the intervening signal-sending and signal-receipt should sufficiently serialize accesses to the field. Hence, this isn't any riskier than the existing usages of pmsignal.c. We might in future extend this idea to improve other postmaster-to-children signal scenarios, although none of them currently seem to be as badly overloaded as SIGQUIT. Discussion: https://postgr.es/m/559291.1608587013@sss.pgh.pa.us
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/.