Horton
Menu

fix_slot_xmin_race_condition.patch

application/octet-stream

Download
Filename: fix_slot_xmin_race_condition.patch
Type: application/octet-stream
Part: 0
Message: Re: Assertion failure in SnapBuildInitialSnapshot()

Patch

Same data as JSON: GET /api/v1/attachments/:id/patch the parsed metadata as JSON — format, series position, per-file stats; never the diff bytes. API reference →
Format: unified
File+−
src/backend/replication/slot.c 7 1
src/backend/storage/ipc/procarray.c 2 9
src/include/storage/procarray.h 1 1 
diff --git a/src/backend/replication/slot.c b/src/backend/replication/slot.c
index 899acfd912..b781d2ea81 100644
--- a/src/backend/replication/slot.c
+++ b/src/backend/replication/slot.c
@@ -840,6 +840,9 @@ ReplicationSlotsComputeRequiredXmin(bool already_locked)
 
 	Assert(ReplicationSlotCtl != NULL);
 
+	if (!already_locked)
+		LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
+
 	LWLockAcquire(ReplicationSlotControlLock, LW_SHARED);
 
 	for (i = 0; i < max_replication_slots; i++)
@@ -878,7 +881,10 @@ ReplicationSlotsComputeRequiredXmin(bool already_locked)
 
 	LWLockRelease(ReplicationSlotControlLock);
 
-	ProcArraySetReplicationSlotXmin(agg_xmin, agg_catalog_xmin, already_locked);
+	ProcArraySetReplicationSlotXmin(agg_xmin, agg_catalog_xmin);
+
+	if (!already_locked)
+		LWLockRelease(ProcArrayLock);
 }
 
 /*
diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c
index 0176f30270..eb74c34dbc 100644
--- a/src/backend/storage/ipc/procarray.c
+++ b/src/backend/storage/ipc/procarray.c
@@ -3899,20 +3899,13 @@ TerminateOtherDBBackends(Oid databaseId)
  * replication slots.
  */
 void
-ProcArraySetReplicationSlotXmin(TransactionId xmin, TransactionId catalog_xmin,
-								bool already_locked)
+ProcArraySetReplicationSlotXmin(TransactionId xmin, TransactionId catalog_xmin)
 {
-	Assert(!already_locked || LWLockHeldByMe(ProcArrayLock));
-
-	if (!already_locked)
-		LWLockAcquire(ProcArrayLock, LW_EXCLUSIVE);
+	Assert(LWLockHeldByMe(ProcArrayLock));
 
 	procArray->replication_slot_xmin = xmin;
 	procArray->replication_slot_catalog_xmin = catalog_xmin;
 
-	if (!already_locked)
-		LWLockRelease(ProcArrayLock);
-
 	elog(DEBUG1, "xmin required by slots: data %u, catalog %u",
 		 xmin, catalog_xmin);
 }
diff --git a/src/include/storage/procarray.h b/src/include/storage/procarray.h
index 99a58fb162..f25b8c1be3 100644
--- a/src/include/storage/procarray.h
+++ b/src/include/storage/procarray.h
@@ -91,7 +91,7 @@ extern void XidCacheRemoveRunningXids(TransactionId xid,
 									  TransactionId latestXid);
 
 extern void ProcArraySetReplicationSlotXmin(TransactionId xmin,
-											TransactionId catalog_xmin, bool already_locked);
+											TransactionId catalog_xmin);
 
 extern void ProcArrayGetReplicationSlotXmin(TransactionId *xmin,
 											TransactionId *catalog_xmin);