@@ -410,7 +410,7 @@ ReplicationSlotRelease(void)
410410 * Cleanup all temporary slots created in current session.
411411 */
412412void
413- ReplicationSlotCleanup ()
413+ ReplicationSlotCleanup (void )
414414{
415415int i ;
416416
@@ -802,12 +802,12 @@ ReplicationSlotsCountDBSlots(Oid dboid, int *nslots, int *nactive)
802802 * pg_database oid for the database to prevent creation of new slots on the db
803803 * or replay from existing slots.
804804 *
805- * This routine isn't as efficient as it could be - but we don't drop databases
806- * often, especially databases with lots of slots.
807- *
808805 * Another session that concurrently acquires an existing slot on the target DB
809806 * (most likely to drop it) may cause this function to ERROR. If that happens
810807 * it may have dropped some but not all slots.
808+ *
809+ * This routine isn't as efficient as it could be - but we don't drop
810+ * databases often, especially databases with lots of slots.
811811 */
812812void
813813ReplicationSlotsDropDBSlots (Oid dboid )
@@ -822,7 +822,7 @@ ReplicationSlotsDropDBSlots(Oid dboid)
822822for (i = 0 ;i < max_replication_slots ;i ++ )
823823{
824824ReplicationSlot * s ;
825- NameData slotname ;
825+ char * slotname ;
826826int active_pid ;
827827
828828s = & ReplicationSlotCtl -> replication_slots [i ];
@@ -839,10 +839,10 @@ ReplicationSlotsDropDBSlots(Oid dboid)
839839if (s -> data .database != dboid )
840840continue ;
841841
842- /*Claim the slot,as if ReplicationSlotAcquire()ing. */
842+ /*acquire slot,so ReplicationSlotDropAcquired can be reused */
843843SpinLockAcquire (& s -> mutex );
844- strncpy ( NameStr ( slotname ), NameStr ( s -> data . name ), NAMEDATALEN );
845- NameStr ( slotname )[ NAMEDATALEN - 1 ] = '\0' ;
844+ /* can't change while ReplicationSlotControlLock is held */
845+ slotname = NameStr ( s -> data . name ) ;
846846active_pid = s -> active_pid ;
847847if (active_pid == 0 )
848848{
@@ -852,36 +852,32 @@ ReplicationSlotsDropDBSlots(Oid dboid)
852852SpinLockRelease (& s -> mutex );
853853
854854/*
855- * We might fail here if the slot was active. Even though we hold an
856- * exclusive lock on the database object a logical slot for that DB can
857- * still be active if it's being dropped by a backend connected to
858- * another DB or is otherwise acquired.
855+ * Even though we hold an exclusive lock on the database object a
856+ * logical slot for that DB can still be active, e.g. if it's
857+ * concurrently being dropped by a backend connected to another DB.
859858 *
860- * It's an unlikely race that'll only arise from concurrent user action,
861- * so we'll just bail out.
859+ * That's fairly unlikely in practice, so we'll just bail out.
862860 */
863861if (active_pid )
864- elog (ERROR ,"replication slot %s is in use by pid %d" ,
865- NameStr (slotname ),active_pid );
862+ ereport (ERROR ,
863+ (errcode (ERRCODE_OBJECT_IN_USE ),
864+ errmsg ("replication slot \"%s\" is active for PID %d" ,
865+ slotname ,active_pid )));
866866
867867/*
868- * To avoidlargely duplicating ReplicationSlotDropAcquired()or
869- *complicating it with already_locked flags for ProcArrayLock ,
870- * ReplicationSlotControlLock andReplicationSlotAllocationLock, we
871- *just release our ReplicationSlotControlLock to drop the slot .
868+ * To avoid duplicating ReplicationSlotDropAcquired()and to avoid
869+ *holding ReplicationSlotControlLock over filesystem operations ,
870+ *release ReplicationSlotControlLock anduse
871+ *ReplicationSlotDropAcquired .
872872 *
873- *For safety we'll restart our scan from the beginning each
874- * time we release the lock.
873+ *As that means the set of slots could change, restart scan from the
874+ *beginning each time we release the lock.
875875 */
876876LWLockRelease (ReplicationSlotControlLock );
877877ReplicationSlotDropAcquired ();
878878gotorestart ;
879879}
880880LWLockRelease (ReplicationSlotControlLock );
881-
882- /* recompute limits once after all slots are dropped */
883- ReplicationSlotsComputeRequiredXmin (false);
884- ReplicationSlotsComputeRequiredLSN ();
885881}
886882
887883