From 3f8753ef00a6026d72c0e12aee2f7b162f6af08e Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Mon, 8 Jul 2024 21:00:20 -0500
Subject: [PATCH v7 07/11] parallelize isn and int8 passing mismatch check in
 pg_upgrade

---
 src/bin/pg_upgrade/check.c | 85 ++++++++++++++++++++------------------
 1 file changed, 44 insertions(+), 41 deletions(-)

diff --git a/src/bin/pg_upgrade/check.c b/src/bin/pg_upgrade/check.c
index 4c78fe0274..311743dd1e 100644
--- a/src/bin/pg_upgrade/check.c
+++ b/src/bin/pg_upgrade/check.c
@@ -1195,6 +1195,44 @@ check_for_prepared_transactions(ClusterInfo *cluster)
 	check_ok();
 }
 
+static char *
+isn_and_int8_passing_mismatch_query(void *arg)
+{
+	return pg_strdup("SELECT n.nspname, p.proname "
+					 "FROM   pg_catalog.pg_proc p, "
+					 "       pg_catalog.pg_namespace n "
+					 "WHERE  p.pronamespace = n.oid AND "
+					 "       p.probin = '$libdir/isn'");
+}
+
+static void
+isn_and_int8_passing_mismatch_process(DbInfo *dbinfo, PGresult *res, void *arg)
+{
+	bool		db_used = false;
+	int			ntups = PQntuples(res);
+	int			i_nspname = PQfnumber(res, "nspname");
+	int			i_proname = PQfnumber(res, "proname");
+	FILE	  **script = (FILE **) arg;
+	char		output_path[MAXPGPATH];
+
+	snprintf(output_path, sizeof(output_path), "%s/%s",
+			 log_opts.basedir,
+			 "contrib_isn_and_int8_pass_by_value.txt");
+
+	for (int rowno = 0; rowno < ntups; rowno++)
+	{
+		if (*script == NULL && (*script = fopen_priv(output_path, "w")) == NULL)
+			pg_fatal("could not open file \"%s\": %m", output_path);
+		if (!db_used)
+		{
+			fprintf(*script, "In database: %s\n", dbinfo->db_name);
+			db_used = true;
+		}
+		fprintf(*script, "  %s.%s\n",
+				PQgetvalue(res, rowno, i_nspname),
+				PQgetvalue(res, rowno, i_proname));
+	}
+}
 
 /*
  *	check_for_isn_and_int8_passing_mismatch()
@@ -1206,8 +1244,8 @@ check_for_prepared_transactions(ClusterInfo *cluster)
 static void
 check_for_isn_and_int8_passing_mismatch(ClusterInfo *cluster)
 {
-	int			dbnum;
 	FILE	   *script = NULL;
+	AsyncTask  *task;
 	char		output_path[MAXPGPATH];
 
 	prep_status("Checking for contrib/isn with bigint-passing mismatch");
@@ -1224,46 +1262,11 @@ check_for_isn_and_int8_passing_mismatch(ClusterInfo *cluster)
 			 log_opts.basedir,
 			 "contrib_isn_and_int8_pass_by_value.txt");
 
-	for (dbnum = 0; dbnum < cluster->dbarr.ndbs; dbnum++)
-	{
-		PGresult   *res;
-		bool		db_used = false;
-		int			ntups;
-		int			rowno;
-		int			i_nspname,
-					i_proname;
-		DbInfo	   *active_db = &cluster->dbarr.dbs[dbnum];
-		PGconn	   *conn = connectToServer(cluster, active_db->db_name);
-
-		/* Find any functions coming from contrib/isn */
-		res = executeQueryOrDie(conn,
-								"SELECT n.nspname, p.proname "
-								"FROM	pg_catalog.pg_proc p, "
-								"		pg_catalog.pg_namespace n "
-								"WHERE	p.pronamespace = n.oid AND "
-								"		p.probin = '$libdir/isn'");
-
-		ntups = PQntuples(res);
-		i_nspname = PQfnumber(res, "nspname");
-		i_proname = PQfnumber(res, "proname");
-		for (rowno = 0; rowno < ntups; rowno++)
-		{
-			if (script == NULL && (script = fopen_priv(output_path, "w")) == NULL)
-				pg_fatal("could not open file \"%s\": %m", output_path);
-			if (!db_used)
-			{
-				fprintf(script, "In database: %s\n", active_db->db_name);
-				db_used = true;
-			}
-			fprintf(script, "  %s.%s\n",
-					PQgetvalue(res, rowno, i_nspname),
-					PQgetvalue(res, rowno, i_proname));
-		}
-
-		PQclear(res);
-
-		PQfinish(conn);
-	}
+	task = async_task_create();
+	async_task_add_step(task, isn_and_int8_passing_mismatch_query,
+						isn_and_int8_passing_mismatch_process, true, &script);
+	async_task_run(task, cluster);
+	async_task_free(task);
 
 	if (script)
 	{
-- 
2.39.3 (Apple Git-146)