improve create_partitions_bg_worker(), introduce drop_triggers()

funbringer · funbringer · commit 32d7514e63d0 · 2016-06-03T16:13:08.000+03:00
diff --git a/init.sql b/init.sql
@@ -119,18 +119,11 @@ LANGUAGE plpgsql;
 CREATE OR REPLACE FUNCTION @extschema@.disable_partitioning(IN relation TEXT)
 RETURNS VOID AS
 $$
-DECLARE
-	parttype INTEGER;
 BEGIN
 	relation := @extschema@.validate_relname(relation);
-	parttype := parttype FROM pathman_config WHERE relname = relation;
 
 	DELETE FROM @extschema@.pathman_config WHERE relname = relation;
-	IF parttype = 1 THEN
-		PERFORM @extschema@.drop_triggers(relation);
-	ELSIF parttype = 2 THEN
-		PERFORM @extschema@.drop_triggers(relation);
-	END IF;
+	PERFORM @extschema@.drop_triggers(relation);
 
 	/* Notify backend about changes */
 	PERFORM on_remove_partitions(relation::regclass::integer);
diff --git a/range.sql b/range.sql
@@ -1194,7 +1194,7 @@ BEGIN
 			RAISE NOTICE 'partition % created', v_part;
 		END LOOP;
 	ELSE
-		RAISE NOTICE 'Not implemented yet';
+		RAISE EXCEPTION 'Could not create partition';
 	END IF;
 
 	IF i > 0 THEN
diff --git a/src/init.c b/src/init.c
@@ -198,11 +198,11 @@ load_relations_hashtable(bool reinitialize)
 		TupleDesc tupdesc = SPI_tuptable->tupdesc;
 		SPITupleTable *tuptable = SPI_tuptable;
 
-		for (i=0; i<proc; i++)
+		for (i = 0; i < proc; i++)
 		{
 			RelationKey key;
 			HeapTuple tuple = tuptable->vals[i];
-			int oid = DatumGetObjectId(SPI_getbinval(tuple, tupdesc, 1, &isnull));
+			Oid oid = DatumGetObjectId(SPI_getbinval(tuple, tupdesc, 1, &isnull));
 
 			key.dbid = MyDatabaseId;
 			key.relid = oid;
diff --git a/src/partition_filter.c b/src/partition_filter.c
@@ -169,8 +169,9 @@ partition_filter_exec(CustomScanState *node)
 			elog(ERROR, "PartitionFilter selected more than one partition");
 		else if (nparts == 0)
 		{
-			selected_partid = add_missing_partition(state->partitioned_table,
-													&state->temp_const);
+			selected_partid = create_partitions_bg_worker(state->partitioned_table,
+														  state->temp_const.constvalue,
+														  state->temp_const.consttype);
 
 			refresh_walker_context_ranges(&state->wcxt);
 		}
diff --git a/src/pathman.h b/src/pathman.h
@@ -229,7 +229,7 @@ search_rangerel_result search_range_partition_eq(const Datum value,
 												 const RangeRelation *rangerel,
 												 RangeEntry *out_rentry);
 char *get_extension_schema(void);
-Oid create_partitions_bg_worker(Oid relid, Datum value, Oid value_type, bool *crashed);
+Oid create_partitions_bg_worker(Oid relid, Datum value, Oid value_type);
 Oid create_partitions(Oid relid, Datum value, Oid value_type, bool *crashed);
 
 void handle_modification_query(Query *parse);
diff --git a/src/pl_funcs.c b/src/pl_funcs.c
@@ -121,13 +121,6 @@ find_or_create_range_partition(PG_FUNCTION_ARGS)
 	else
 	{
 		Oid		child_oid;
-		bool	crashed = false;
-
-		/* Lock config before appending new partitions */
-		LWLockAcquire(pmstate->load_config_lock, LW_EXCLUSIVE);
-
-		/* Restrict concurrent partition creation */
-		LWLockAcquire(pmstate->edit_partitions_lock, LW_EXCLUSIVE);
 
 		/*
 		 * Check if someone else has already created partition.
@@ -136,26 +129,12 @@ find_or_create_range_partition(PG_FUNCTION_ARGS)
 												 rangerel, &found_re);
 		if (search_state == SEARCH_RANGEREL_FOUND)
 		{
-			LWLockRelease(pmstate->edit_partitions_lock);
-			LWLockRelease(pmstate->load_config_lock);
 			PG_RETURN_OID(found_re.child_oid);
 		}
-		else
-			Assert(search_state != SEARCH_RANGEREL_GAP);
 
 		/* Start background worker to create new partitions */
-		child_oid = create_partitions_bg_worker(relid, value, value_type, &crashed);
-
-		/* Release locks */
-		if (!crashed)
-		{
-			LWLockRelease(pmstate->edit_partitions_lock);
-			LWLockRelease(pmstate->load_config_lock);
-		}
+		child_oid = create_partitions_bg_worker(relid, value, value_type);
 
-		/* Repeat binary search */
-		Assert(SEARCH_RANGEREL_FOUND == search_range_partition_eq(value, &cmp_func,
-																  rangerel, NULL));
 		PG_RETURN_OID(child_oid);
 	}
 }
diff --git a/src/utils.c b/src/utils.c
@@ -153,7 +153,7 @@ check_rinfo_for_partitioned_attr(List *rinfo, Index varno, AttrNumber varattno)
 }
 
 /*
- * Append trigger info contained in 'more' to 'src'.
+ * Append trigger info contained in 'more' to 'src', both remain unmodified.
  *
  * This allows us to execute some of main table's triggers on children.
  * See ExecInsert() for more details.
@@ -227,28 +227,6 @@ append_trigger_descs(TriggerDesc *src, TriggerDesc *more, bool *grown_up)
 	return new_desc;
 }
 
-Oid
-add_missing_partition(Oid partitioned_table, Const *value)
-{
-	bool	crashed;
-	Oid		result = InvalidOid;
-
-	SPI_connect();
-	PushActiveSnapshot(GetTransactionSnapshot());
-
-	/* Create partitions */
-	result = create_partitions(partitioned_table,
-							   value->constvalue,
-							   value->consttype,
-							   &crashed);
-
-	/* Cleanup */
-	SPI_finish();
-	PopActiveSnapshot();
-
-	return result;
-}
-
 /*
  * Get BTORDER_PROC for two types described by Oids
  */
diff --git a/src/utils.h b/src/utils.h
@@ -31,8 +31,6 @@ TriggerDesc * append_trigger_descs(TriggerDesc *src,
 								   TriggerDesc *more,
 								   bool *grown_up);
 
-Oid add_missing_partition(Oid partitioned_table, Const *value);
-
 void fill_type_cmp_fmgr_info(FmgrInfo *finfo,
 							 Oid type1,
 							 Oid type2);
diff --git a/src/worker.c b/src/worker.c
@@ -45,17 +45,31 @@ typedef struct PartitionArgs
  * waits till it finishes the job and returns the result (new partition oid)
  */
 Oid
-create_partitions_bg_worker(Oid relid, Datum value, Oid value_type, bool *crashed)
+create_partitions_bg_worker(Oid relid, Datum value, Oid value_type)
 {
+#define HandleError(condition, new_state) \
+	if (condition) { exec_state = (new_state); goto handle_exec_state; }
+
+	/* Execution state to be checked */
+	enum
+	{
+		BGW_OK = 0,				/* everything is fine (default) */
+		BGW_COULD_NOT_START,	/* could not start worker */
+		BGW_PM_DIED,			/* postmaster died */
+		BGW_CRASHED				/* worker crashed */
+	}						exec_state = BGW_OK;
+
 	BackgroundWorker		worker;
-	BackgroundWorkerHandle *worker_handle;
-	BgwHandleStatus			status;
-	dsm_segment	   *segment;
-	dsm_handle		segment_handle;
-	pid_t 			pid;
-	PartitionArgs  *args;
-	Oid 			child_oid;
-	TypeCacheEntry *tce;
+	BackgroundWorkerHandle *bgw_handle;
+	BgwHandleStatus			bgw_status;
+	bool					bgw_started;
+	dsm_segment			   *segment;
+	dsm_handle				segment_handle;
+	pid_t					pid;
+	PartitionArgs		   *args;
+	TypeCacheEntry		   *tce;
+	Oid						child_oid = InvalidOid;
+
 
 	/* Create a dsm segment for the worker to pass arguments */
 	segment = dsm_create(sizeof(PartitionArgs), 0);
@@ -84,34 +98,53 @@ create_partitions_bg_worker(Oid relid, Datum value, Oid value_type, bool *crashe
 	worker.bgw_main_arg = Int32GetDatum(segment_handle);
 	worker.bgw_notify_pid = MyProcPid;
 
+	LWLockAcquire(pmstate->load_config_lock, LW_EXCLUSIVE);
+	LWLockAcquire(pmstate->edit_partitions_lock, LW_EXCLUSIVE);
+
 	/* Start dynamic worker */
-	if (!RegisterDynamicBackgroundWorker(&worker, &worker_handle))
-	{
-		elog(WARNING, "Unable to create background worker for pg_pathman");
-	}
+	bgw_started = RegisterDynamicBackgroundWorker(&worker, &bgw_handle);
+	HandleError(bgw_started == false, BGW_COULD_NOT_START);
 
-	status = WaitForBackgroundWorkerStartup(worker_handle, &pid);
-	if (status == BGWH_POSTMASTER_DIED)
-	{
-		ereport(WARNING,
-                (errmsg("Postmaster died during the pg_pathman background worker process"),
-                 errhint("More details may be available in the server log.")));
-	}
+	/* Wait till the worker starts */
+	bgw_status = WaitForBackgroundWorkerStartup(bgw_handle, &pid);
+	HandleError(bgw_status == BGWH_POSTMASTER_DIED, BGW_PM_DIED);
 
-	/* Wait till the worker finishes its job */
-	status = WaitForBackgroundWorkerShutdown(worker_handle);
-	if (status == BGWH_POSTMASTER_DIED)
-	{
-		ereport(WARNING,
-                (errmsg("Postmaster died during the pg_pathman background worker process"),
-                 errhint("More details may be available in the server log.")));
-	}
-	*crashed = args->crashed;
+	/* Wait till the worker finishes job */
+	bgw_status = WaitForBackgroundWorkerShutdown(bgw_handle);
+	HandleError(bgw_status == BGWH_POSTMASTER_DIED, BGW_PM_DIED);
+
+	/* Save the result (partition Oid) */
 	child_oid = args->result;
 
+
+/* end execution */
+handle_exec_state:
+	LWLockRelease(pmstate->load_config_lock);
+	LWLockRelease(pmstate->edit_partitions_lock);
+
 	/* Free dsm segment */
 	dsm_detach(segment);
 
+	switch (exec_state)
+	{
+		case BGW_COULD_NOT_START:
+			elog(ERROR, "Unable to create background worker for pg_pathman");
+			break;
+
+		case BGW_PM_DIED:
+			ereport(ERROR,
+					(errmsg("Postmaster died during the pg_pathman background worker process"),
+					errhint("More details may be available in the server log.")));
+			break;
+
+		case BGW_CRASHED:
+			elog(ERROR, "Could not create partition due to background worker crash");
+			break;
+
+		default:
+			break;
+	}
+
 	return child_oid;
 }
 
@@ -129,10 +162,8 @@ bg_worker_main(Datum main_arg)
 
 	/* Attach to dynamic shared memory */
 	if (!handle)
-	{
-		ereport(WARNING,
-                (errmsg("pg_pathman worker: invalid dsm_handle")));
-	}
+		ereport(WARNING, (errmsg("pg_pathman worker: invalid dsm_handle")));
+
 	segment = dsm_attach(handle);
 	args = dsm_segment_address(segment);
 
@@ -163,19 +194,16 @@ bg_worker_main(Datum main_arg)
 Oid
 create_partitions(Oid relid, Datum value, Oid value_type, bool *crashed)
 {
-	int					ret;
-	Datum				vals[2];
-	Oid					oids[] = {OIDOID, value_type};
-	bool				nulls[] = {false, false};
+	Oid					oids[]	= { OIDOID,					 value_type };
+	Datum				vals[]	= { ObjectIdGetDatum(relid), value };
+	bool				nulls[]	= { false,					 false };
 	char			   *sql;
 	PartRelationInfo   *prel;
 	RangeRelation	   *rangerel;
 	FmgrInfo			cmp_func;
 	char			   *schema;
-	search_rangerel_result search_state;
-	RangeEntry			found_re;
 
-	*crashed = false;
+	*crashed = true;
 	schema = get_extension_schema();
 
 	prel = get_pathman_relation_info(relid, NULL);
@@ -184,36 +212,39 @@ create_partitions(Oid relid, Datum value, Oid value_type, bool *crashed)
 	/* Comparison function */
 	fill_type_cmp_fmgr_info(&cmp_func, value_type, prel->atttype);
 
-	vals[0] = ObjectIdGetDatum(relid);
-	vals[1] = value;
-
 	/* Perform PL procedure */
 	sql = psprintf("SELECT %s.append_partitions_on_demand_internal($1, $2)",
 				   schema);
 	PG_TRY();
 	{
+		int				ret;
+		Oid				partid = InvalidOid;
+		bool			isnull;
+
 		ret = SPI_execute_with_args(sql, 2, oids, vals, nulls, false, 0);
 		if (ret > 0)
 		{
+			TupleDesc	tupdesc = SPI_tuptable->tupdesc;
+			HeapTuple	tuple = SPI_tuptable->vals[0];
+
+			Assert(SPI_processed == 1);
+
+			partid = DatumGetObjectId(SPI_getbinval(tuple, tupdesc, 1, &isnull));
+
 			/* Update relation info */
 			free_dsm_array(&rangerel->ranges);
 			free_dsm_array(&prel->children);
 			load_check_constraints(relid, GetCatalogSnapshot(relid));
 		}
+
+		*crashed = false;
+		return partid;
 	}
 	PG_CATCH();
 	{
-		elog(WARNING, "Attempt to create new partitions failed");
-		if (crashed != NULL)
-			*crashed = true;
-		return 0;
+		elog(ERROR, "Attempt to create new partitions failed");
+
+		return InvalidOid; /* compiler should be happy */
 	}
 	PG_END_TRY();
-
-	search_state = search_range_partition_eq(value, &cmp_func,
-											 rangerel, &found_re);
-	if (search_state == SEARCH_RANGEREL_FOUND)
-		return found_re.child_oid;
-
-	return 0;
 }

Original file line number	Diff line number	Diff line change
`@@ -169,8 +169,9 @@ partition_filter_exec(CustomScanState *node)`
`169`	`169`	`elog(ERROR, "PartitionFilter selected more than one partition");`
`170`	`170`	`else if (nparts == 0)`
`171`	`171`	`{`
`172`		`- selected_partid = add_missing_partition(state->partitioned_table,`
`173`		`- &state->temp_const);`
	`172`	`+ selected_partid = create_partitions_bg_worker(state->partitioned_table,`
	`173`	`+ state->temp_const.constvalue,`
	`174`	`+ state->temp_const.consttype);`
`174`	`175`
`175`	`176`	`refresh_walker_context_ranges(&state->wcxt);`
`176`	`177`	`}`