add SpawnPartitionsWorker to backend's locking group

funbringer · funbringer · commit 7986446bb255 · 2016-10-21T16:49:35.000+03:00
diff --git a/src/pathman_workers.c b/src/pathman_workers.c
@@ -29,6 +29,7 @@
 #include "storage/dsm.h"
 #include "storage/ipc.h"
 #include "storage/latch.h"
+#include "storage/proc.h"
 #include "utils/builtins.h"
 #include "utils/datum.h"
 #include "utils/memutils.h"
@@ -256,6 +257,12 @@ create_partitions_bg_worker_segment(Oid relid, Datum value, Oid value_type)
 	args->dbid = MyDatabaseId;
 	args->partitioned_table = relid;
 
+#if PG_VERSION_NUM >= 90600
+	/* Initialize args for BecomeLockGroupMember() */
+	args->parallel_master_pgproc = MyProc;
+	args->parallel_master_pid = MyProcPid;
+#endif
+
 	/* Write value-related stuff */
 	args->value_type = value_type;
 	args->value_size = datum_size;
@@ -286,6 +293,11 @@ create_partitions_bg_worker(Oid relid, Datum value, Oid value_type)
 	segment_handle = dsm_segment_handle(segment);
 	bgw_args = (SpawnPartitionArgs *) dsm_segment_address(segment);
 
+#if PG_VERSION_NUM >= 90600
+	/* Become locking group leader */
+	BecomeLockGroupLeader();
+#endif
+
 	/* Start worker and wait for it to finish */
 	start_bg_worker(spawn_partitions_bgw,
 					bgw_main_spawn_partitions,
@@ -337,6 +349,13 @@ bgw_main_spawn_partitions(Datum main_arg)
 			 spawn_partitions_bgw, MyProcPid);
 	args = dsm_segment_address(segment);
 
+#if PG_VERSION_NUM >= 90600
+	/* Join locking group. If we can't join the group, quit */
+	if (!BecomeLockGroupMember(args->parallel_master_pgproc,
+							   args->parallel_master_pid))
+		return;
+#endif
+
 	/* Establish connection and start transaction */
 	BackgroundWorkerInitializeConnectionByOid(args->dbid, args->userid);
 
diff --git a/src/pathman_workers.h b/src/pathman_workers.h
@@ -20,6 +20,10 @@
 #include "postgres.h"
 #include "storage/spin.h"
 
+#if PG_VERSION_NUM >= 90600
+#include "storage/lock.h"
+#endif
+
 
 /*
  * Store args, result and execution status of CreatePartitionsWorker.
@@ -32,6 +36,12 @@ typedef struct
 	Oid		dbid;			/* database which stores 'partitioned_table' */
 	Oid		partitioned_table;
 
+#if PG_VERSION_NUM >= 90600
+	/* Args for BecomeLockGroupMember() function */
+	PGPROC *parallel_master_pgproc;
+	pid_t	parallel_master_pid;
+#endif
+
 	/* Needed to decode Datum from 'values' */
 	Oid		value_type;
 	Size	value_size;
