Thread: IsUnderPostmaster with shared_preload_libraries on Windows
Is it expected that IsUnderPostmaster is true during postmaster startup in an extension's _PG_init() when preloading under Windows? On Linux it is false at this point AFAICT. Thanks, Joe -- Crunchy Data - http://crunchydata.com PostgreSQL Support for Secure Enterprises Consulting, Training, & Open Source Development
Joe Conway <mail@joeconway.com> writes:
> Is it expected that IsUnderPostmaster is true during postmaster startup
> in an extension's _PG_init() when preloading under Windows? On Linux it
> is false at this point AFAICT.
AFAIK it will be false in the *postmaster's* execution of _PG_init().
But keep in mind that on Windows each exec'd child process will have to
load the shared_preload_libraries again for itself, and those executions
should see IsUnderPostmaster = true. I think what you are seeing is
additional executions in the startup process or other background
processes, which don't happen in a forked-children environment.
You can probably duplicate this behavior for testing purposes on Unix
by compiling with EXEC_BACKEND defined, if that helps.
regards, tom lane
On 06/13/2016 01:57 PM, Tom Lane wrote: > Joe Conway <mail@joeconway.com> writes: >> Is it expected that IsUnderPostmaster is true during postmaster startup >> in an extension's _PG_init() when preloading under Windows? On Linux it >> is false at this point AFAICT. > > AFAIK it will be false in the *postmaster's* execution of _PG_init(). > But keep in mind that on Windows each exec'd child process will have to > load the shared_preload_libraries again for itself, and those executions > should see IsUnderPostmaster = true. I think what you are seeing is > additional executions in the startup process or other background > processes, which don't happen in a forked-children environment. > > You can probably duplicate this behavior for testing purposes on Unix > by compiling with EXEC_BACKEND defined, if that helps. Thanks, definitely easier to debug on Linux. It appears the best answer is to use process_shared_preload_libraries_in_progress rather than trying to derive that information using IsUnderPostmaster. Joe -- Crunchy Data - http://crunchydata.com PostgreSQL Support for Secure Enterprises Consulting, Training, & Open Source Development