diff --git a/contrib/pgrowlocks/pgrowlocks.c b/contrib/pgrowlocks/pgrowlocks.c
index 7b8c9fbb326dfdd0bd9edb0ee79a15a2c987b491..36974f716c4602d69543c37796661a84be76fb34 100644
--- a/contrib/pgrowlocks/pgrowlocks.c
+++ b/contrib/pgrowlocks/pgrowlocks.c
@@ -165,7 +165,8 @@ pgrowlocks(PG_FUNCTION_ARGS)
allow_old = !(infomask & HEAP_LOCK_MASK) &&
(infomask & HEAP_XMAX_LOCK_ONLY);
- nmembers = GetMultiXactIdMembers(xmax, &members, allow_old);
+ nmembers = GetMultiXactIdMembers(xmax, &members, allow_old,
+ false);
if (nmembers == -1)
{
values[Atnum_xids] = "{0}";
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 0524f2efdf3b95c9d8dacd1a8b7214269dbfdae0..21e76d6a2a91edc2fcc836ff2bd4d3f42dc997ad 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -4183,7 +4183,9 @@ l3:
* the case, HeapTupleSatisfiesUpdate would have returned
* MayBeUpdated and we wouldn't be here.
*/
- nmembers = GetMultiXactIdMembers(xwait, &members, false);
+ nmembers =
+ GetMultiXactIdMembers(xwait, &members, false,
+ HEAP_XMAX_IS_LOCKED_ONLY(infomask));
for (i = 0; i < nmembers; i++)
{
@@ -4204,7 +4206,8 @@ l3:
}
}
- pfree(members);
+ if (members)
+ pfree(members);
}
/*
@@ -4353,7 +4356,9 @@ l3:
* been the case, HeapTupleSatisfiesUpdate would have returned
* MayBeUpdated and we wouldn't be here.
*/
- nmembers = GetMultiXactIdMembers(xwait, &members, false);
+ nmembers =
+ GetMultiXactIdMembers(xwait, &members, false,
+ HEAP_XMAX_IS_LOCKED_ONLY(infomask));
if (nmembers <= 0)
{
@@ -4834,7 +4839,7 @@ l5:
* MultiXactIdExpand if we weren't to do this, so this check is not
* incurring extra work anyhow.
*/
- if (!MultiXactIdIsRunning(xmax))
+ if (!MultiXactIdIsRunning(xmax, HEAP_XMAX_IS_LOCKED_ONLY(old_infomask)))
{
if (HEAP_XMAX_IS_LOCKED_ONLY(old_infomask) ||
TransactionIdDidAbort(MultiXactIdGetUpdateXid(xmax,
@@ -5175,7 +5180,8 @@ l4:
int i;
MultiXactMember *members;
- nmembers = GetMultiXactIdMembers(rawxmax, &members, false);
+ nmembers = GetMultiXactIdMembers(rawxmax, &members, false,
+ HEAP_XMAX_IS_LOCKED_ONLY(old_infomask));
for (i = 0; i < nmembers; i++)
{
HTSU_Result res;
@@ -5533,7 +5539,8 @@ FreezeMultiXactId(MultiXactId multi, uint16 t_infomask,
*/
Assert((!(t_infomask & HEAP_LOCK_MASK) &&
HEAP_XMAX_IS_LOCKED_ONLY(t_infomask)) ||
- !MultiXactIdIsRunning(multi));
+ !MultiXactIdIsRunning(multi,
+ HEAP_XMAX_IS_LOCKED_ONLY(t_infomask)));
if (HEAP_XMAX_IS_LOCKED_ONLY(t_infomask))
{
*flags |= FRM_INVALIDATE_XMAX;
@@ -5576,7 +5583,9 @@ FreezeMultiXactId(MultiXactId multi, uint16 t_infomask,
allow_old = !(t_infomask & HEAP_LOCK_MASK) &&
HEAP_XMAX_IS_LOCKED_ONLY(t_infomask);
- nmembers = GetMultiXactIdMembers(multi, &members, allow_old);
+ nmembers =
+ GetMultiXactIdMembers(multi, &members, allow_old,
+ HEAP_XMAX_IS_LOCKED_ONLY(t_infomask));
if (nmembers <= 0)
{
/* Nothing worth keeping */
@@ -5983,7 +5992,7 @@ GetMultiXactIdHintBits(MultiXactId multi, uint16 *new_infomask,
* We only use this in multis we just created, so they cannot be values
* pre-pg_upgrade.
*/
- nmembers = GetMultiXactIdMembers(multi, &members, false);
+ nmembers = GetMultiXactIdMembers(multi, &members, false, false);
for (i = 0; i < nmembers; i++)
{
@@ -6062,7 +6071,7 @@ MultiXactIdGetUpdateXid(TransactionId xmax, uint16 t_infomask)
* Since we know the LOCK_ONLY bit is not set, this cannot be a multi from
* pre-pg_upgrade.
*/
- nmembers = GetMultiXactIdMembers(xmax, &members, false);
+ nmembers = GetMultiXactIdMembers(xmax, &members, false, false);
if (nmembers > 0)
{
@@ -6148,7 +6157,8 @@ Do_MultiXactIdWait(MultiXactId multi, MultiXactStatus status,
int remain = 0;
allow_old = !(infomask & HEAP_LOCK_MASK) && HEAP_XMAX_IS_LOCKED_ONLY(infomask);
- nmembers = GetMultiXactIdMembers(multi, &members, allow_old);
+ nmembers = GetMultiXactIdMembers(multi, &members, allow_old,
+ HEAP_XMAX_IS_LOCKED_ONLY(infomask));
if (nmembers >= 0)
{
@@ -6294,7 +6304,8 @@ heap_tuple_needs_freeze(HeapTupleHeader tuple, TransactionId cutoff_xid,
allow_old = !(tuple->t_infomask & HEAP_LOCK_MASK) &&
HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask);
- nmembers = GetMultiXactIdMembers(multi, &members, allow_old);
+ nmembers = GetMultiXactIdMembers(multi, &members, allow_old,
+ HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
for (i = 0; i < nmembers; i++)
{
diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c
index 9f259bb54ebb22ec6d941a4105d3c7fceb855aee..33346c76643dd91eda9096f1af666bfae6eef6f2 100644
--- a/src/backend/access/transam/multixact.c
+++ b/src/backend/access/transam/multixact.c
@@ -428,7 +428,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status)
* caller of this function does a check that the multixact is no longer
* running.
*/
- nmembers = GetMultiXactIdMembers(multi, &members, false);
+ nmembers = GetMultiXactIdMembers(multi, &members, false, false);
if (nmembers < 0)
{
@@ -517,7 +517,7 @@ MultiXactIdExpand(MultiXactId multi, TransactionId xid, MultiXactStatus status)
* a pg_upgraded share-locked tuple.
*/
bool
-MultiXactIdIsRunning(MultiXactId multi)
+MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly)
{
MultiXactMember *members;
int nmembers;
@@ -529,7 +529,7 @@ MultiXactIdIsRunning(MultiXactId multi)
* "false" here means we assume our callers have checked that the given
* multi cannot possibly come from a pg_upgraded database.
*/
- nmembers = GetMultiXactIdMembers(multi, &members, false);
+ nmembers = GetMultiXactIdMembers(multi, &members, false, isLockOnly);
if (nmembers < 0)
{
@@ -1095,10 +1095,15 @@ GetNewMultiXactId(int nmembers, MultiXactOffset *offset)
* the value currently known as the next to assign, raise an error. Previously
* these also returned -1, but since this can lead to the wrong visibility
* results, it is dangerous to do that.
+ *
+ * onlyLock must be set to true if caller is certain that the given multi
+ * is used only to lock tuples; can be false without loss of correctness,
+ * but passing a true means we can return quickly without checking for
+ * old updates.
*/
int
GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members,
- bool allow_old)
+ bool allow_old, bool onlyLock)
{
int pageno;
int prev_pageno;
@@ -1132,6 +1137,19 @@ GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **members,
/* Set our OldestVisibleMXactId[] entry if we didn't already */
MultiXactIdSetOldestVisible();
+ /*
+ * If we know the multi is used only for locking and not for updates,
+ * then we can skip checking if the value is older than our oldest
+ * visible multi. It cannot possibly still be running.
+ */
+ if (onlyLock &&
+ MultiXactIdPrecedes(multi, OldestVisibleMXactId[MyBackendId]))
+ {
+ debug_elog2(DEBUG2, "GetMembers: a locker-only multi is too old");
+ *members = NULL;
+ return -1;
+ }
+
/*
* We check known limits on MultiXact before resorting to the SLRU area.
*
@@ -1335,7 +1353,7 @@ MultiXactHasRunningRemoteMembers(MultiXactId multi)
int nmembers;
int i;
- nmembers = GetMultiXactIdMembers(multi, &members, true);
+ nmembers = GetMultiXactIdMembers(multi, &members, true, false);
if (nmembers <= 0)
return false;
@@ -2807,7 +2825,8 @@ pg_get_multixact_members(PG_FUNCTION_ARGS)
multi = palloc(sizeof(mxact));
/* no need to allow for old values here */
- multi->nmembers = GetMultiXactIdMembers(mxid, &multi->members, false);
+ multi->nmembers = GetMultiXactIdMembers(mxid, &multi->members, false,
+ false);
multi->iter = 0;
tupdesc = CreateTemplateTupleDesc(2, false);
diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index 96874ab80a7882f5869ba514530494ed252af832..5c3f5adb4a7834c13c0ee38e6432d0efa4d8b09e 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -607,7 +607,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
*/
if ((tuple->t_infomask & (HEAP_XMAX_EXCL_LOCK |
HEAP_XMAX_KEYSHR_LOCK)) &&
- MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
+ MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), true))
return HeapTupleBeingUpdated;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
@@ -615,6 +615,11 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
}
xmax = HeapTupleGetUpdateXid(tuple);
+ if (!TransactionIdIsValid(xmax))
+ {
+ if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
+ return HeapTupleBeingUpdated;
+ }
/* not LOCKED_ONLY, so it has to have an xmax */
Assert(TransactionIdIsValid(xmax));
@@ -627,7 +632,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
return HeapTupleInvisible; /* updated before scan started */
}
- if (TransactionIdIsInProgress(xmax))
+ if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
return HeapTupleBeingUpdated;
if (TransactionIdDidCommit(xmax))
@@ -638,7 +643,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
* what about the other members?
*/
- if (!MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
+ if (!MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
{
/*
* There's no member, even just a locker, alive anymore, so we can
@@ -1240,7 +1245,8 @@ HeapTupleSatisfiesVacuum(HeapTuple htup, TransactionId OldestXmin,
*/
if ((tuple->t_infomask & (HEAP_XMAX_EXCL_LOCK |
HEAP_XMAX_KEYSHR_LOCK)) &&
- MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
+ MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple),
+ true))
return HEAPTUPLE_LIVE;
SetHintBits(tuple, buffer, HEAP_XMAX_INVALID, InvalidTransactionId);
@@ -1267,7 +1273,7 @@ HeapTupleSatisfiesVacuum(HeapTuple htup, TransactionId OldestXmin,
{
TransactionId xmax;
- if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple)))
+ if (MultiXactIdIsRunning(HeapTupleHeaderGetRawXmax(tuple), false))
{
/* already checked above */
Assert(!HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask));
diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h
index f6d2e0418b191fad2e0d098062b1e5af3827223f..8db773b1b5860c1d2521beda7ea4a376ef24e362 100644
--- a/src/include/access/multixact.h
+++ b/src/include/access/multixact.h
@@ -91,10 +91,10 @@ extern MultiXactId MultiXactIdCreateFromMembers(int nmembers,
MultiXactMember *members);
extern MultiXactId ReadNextMultiXactId(void);
-extern bool MultiXactIdIsRunning(MultiXactId multi);
+extern bool MultiXactIdIsRunning(MultiXactId multi, bool isLockOnly);
extern void MultiXactIdSetOldestMember(void);
extern int GetMultiXactIdMembers(MultiXactId multi, MultiXactMember **xids,
- bool allow_old);
+ bool allow_old, bool isLockOnly);
extern bool MultiXactHasRunningRemoteMembers(MultiXactId multi);
extern bool MultiXactIdPrecedes(MultiXactId multi1, MultiXactId multi2);
extern bool MultiXactIdPrecedesOrEquals(MultiXactId multi1,