Fix worker_spi when launching workers without shared_preload_libraries

Currently, the database name to connect is initialized only when the
module is loaded with shared_preload_libraries, causing any call of
worker_spi_launch() to fail if the library is not loaded for a dynamic
bgworker launch.  Rather than making the GUC defining the database to
connect to a PGC_POSTMASTER, this commit switches worker_spi.database to
PGC_SIGHUP, loaded even if the module's library is loaded dynamically
for a worker.

We have been discussing about the integration of more advanced tests in
this module, with and without shared_preload_libraries set, so this
eases a bit the work planned in this area.

No backpatch is done as, while this is a bug, it changes the definition
of worker_spi.database.

Author: Masahiro Ikeda
Reviewed-by: Bharath Rupireddy
Discussion: https://postgr.es/m/d30d3ea7d21cb7c9e1e3cc47e301f1b6@oss.nttdata.com

diff --git a/src/test/modules/worker_spi/worker_spi.c b/src/test/modules/worker_spi/worker_spi.c
index 7227cfaa45c179ab02b6850e1e1303310d66d777..ada0fb8ac73333a063a6a8f5cebd489d939d446f 100644 (file)
--- a/src/test/modules/worker_spi/worker_spi.c
+++ b/src/test/modules/worker_spi/worker_spi.c
@@ -283,6 +283,11 @@ _PG_init(void)
    BackgroundWorker worker;
 
    /* get the configuration */
+
+   /*
+    * These GUCs are defined even if this library is not loaded with
+    * shared_preload_libraries, for worker_spi_launch().
+    */
    DefineCustomIntVariable("worker_spi.naptime",
                            "Duration between each check (in seconds).",
                            NULL,
@@ -296,6 +301,15 @@ _PG_init(void)
                            NULL,
                            NULL);
 
+   DefineCustomStringVariable("worker_spi.database",
+                              "Database to connect to.",
+                              NULL,
+                              &worker_spi_database,
+                              "postgres",
+                              PGC_SIGHUP,
+                              0,
+                              NULL, NULL, NULL);
+
    if (!process_shared_preload_libraries_in_progress)
        return;
 
@@ -312,15 +326,6 @@ _PG_init(void)
                            NULL,
                            NULL);
 
-   DefineCustomStringVariable("worker_spi.database",
-                              "Database to connect to.",
-                              NULL,
-                              &worker_spi_database,
-                              "postgres",
-                              PGC_POSTMASTER,
-                              0,
-                              NULL, NULL, NULL);
-
    MarkGUCPrefixReserved("worker_spi");
 
    /* set up common data for all our workers */