resolve bgw_main_* functions by name (BGW)

funbringer · funbringer · commit f518cf5624a7 · 2016-12-07T17:55:52.000+03:00
diff --git a/src/pathman_workers.c b/src/pathman_workers.c
@@ -47,15 +47,19 @@ PG_FUNCTION_INFO_V1( show_concurrent_part_tasks_internal );
 PG_FUNCTION_INFO_V1( stop_concurrent_part_task );
 
 
+/*
+ * Dynamically resolve functions (for BGW API).
+ */
+extern PGDLLEXPORT void bgw_main_spawn_partitions(Datum main_arg);
+extern PGDLLEXPORT void bgw_main_concurrent_part(Datum main_arg);
+
+
 static void handle_sigterm(SIGNAL_ARGS);
 static void bg_worker_load_config(const char *bgw_name);
 static void start_bg_worker(const char bgworker_name[BGW_MAXLEN],
-							bgworker_main_type bgw_main_func,
+							const char bgworker_proc[BGW_MAXLEN],
 							Datum bgw_arg, bool wait_for_shutdown);
 
-static void bgw_main_spawn_partitions(Datum main_arg);
-static void bgw_main_concurrent_part(Datum main_arg);
-
 
 /*
  * Function context for concurrent_part_tasks_internal() SRF.
@@ -157,7 +161,7 @@ bg_worker_load_config(const char *bgw_name)
  */
 static void
 start_bg_worker(const char bgworker_name[BGW_MAXLEN],
-				bgworker_main_type bgw_main_func,
+				const char bgworker_proc[BGW_MAXLEN],
 				Datum bgw_arg, bool wait_for_shutdown)
 {
 #define HandleError(condition, new_state) \
@@ -179,12 +183,16 @@ start_bg_worker(const char bgworker_name[BGW_MAXLEN],
 
 	/* Initialize worker struct */
 	memcpy(worker.bgw_name, bgworker_name, BGW_MAXLEN);
-	worker.bgw_flags		= BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
-	worker.bgw_start_time	= BgWorkerStart_RecoveryFinished;
-	worker.bgw_restart_time	= BGW_NEVER_RESTART;
-	worker.bgw_main			= bgw_main_func;
-	worker.bgw_main_arg		= bgw_arg;
-	worker.bgw_notify_pid	= MyProcPid;
+	memcpy(worker.bgw_function_name, bgworker_proc, BGW_MAXLEN);
+	memcpy(worker.bgw_library_name, "pg_pathman", BGW_MAXLEN);
+
+	worker.bgw_flags			= BGWORKER_SHMEM_ACCESS |
+									BGWORKER_BACKEND_DATABASE_CONNECTION;
+	worker.bgw_start_time		= BgWorkerStart_RecoveryFinished;
+	worker.bgw_restart_time		= BGW_NEVER_RESTART;
+	worker.bgw_main				= NULL;
+	worker.bgw_main_arg			= bgw_arg;
+	worker.bgw_notify_pid		= MyProcPid;
 
 	/* Start dynamic worker */
 	bgw_started = RegisterDynamicBackgroundWorker(&worker, &bgw_handle);
@@ -301,7 +309,7 @@ create_partitions_for_value_bg_worker(Oid relid, Datum value, Oid value_type)
 
 	/* Start worker and wait for it to finish */
 	start_bg_worker(spawn_partitions_bgw,
-					bgw_main_spawn_partitions,
+					CppAsString(bgw_main_spawn_partitions),
 					UInt32GetDatum(segment_handle),
 					true);
 
@@ -323,7 +331,7 @@ create_partitions_for_value_bg_worker(Oid relid, Datum value, Oid value_type)
 /*
  * Entry point for SpawnPartitionsWorker's process.
  */
-static void
+void
 bgw_main_spawn_partitions(Datum main_arg)
 {
 	dsm_handle				handle = DatumGetUInt32(main_arg);
@@ -403,7 +411,7 @@ bgw_main_spawn_partitions(Datum main_arg)
 /*
  * Entry point for ConcurrentPartWorker's process.
  */
-static void
+void
 bgw_main_concurrent_part(Datum main_arg)
 {
 	int					rows;
@@ -671,7 +679,7 @@ partition_table_concurrently(PG_FUNCTION_ARGS)
 
 	/* Start worker (we should not wait) */
 	start_bg_worker(concurrent_part_bgw,
-					bgw_main_concurrent_part,
+					CppAsString(bgw_main_concurrent_part),
 					Int32GetDatum(empty_slot_idx),
 					false);
 
