1 files changed, 11 insertions, 26 deletions

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 234c8d08ebc..5c282002900 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -151,7 +151,6 @@ typedef struct GlobalTransactionData
 {
 	GlobalTransaction next;		/* list link for free list */
 	int			pgprocno;		/* ID of associated dummy PGPROC */
-	BackendId	dummyBackendId; /* similar to backend id for backends */
 	TimestampTz prepared_at;	/* time of preparation */
 
 	/*
@@ -285,20 +284,6 @@ TwoPhaseShmemInit(void)
 
 			/* associate it with a PGPROC assigned by InitProcGlobal */
 			gxacts[i].pgprocno = GetNumberFromPGProc(&PreparedXactProcs[i]);
-
-			/*
-			 * Assign a unique ID for each dummy proc, so that the range of
-			 * dummy backend IDs immediately follows the range of normal
-			 * backend IDs. We don't dare to assign a real backend ID to dummy
-			 * procs, because prepared transactions don't take part in cache
-			 * invalidation like a real backend ID would imply, but having a
-			 * unique ID for them is nevertheless handy. This arrangement
-			 * allows you to allocate an array of size (MaxBackends +
-			 * max_prepared_xacts + 1), and have a slot for every backend and
-			 * prepared transaction. Currently multixact.c uses that
-			 * technique.
-			 */
-			gxacts[i].dummyBackendId = MaxBackends + 1 + i;
 		}
 	}
 	else
@@ -457,24 +442,24 @@ MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid,
 	Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
 
 	Assert(gxact != NULL);
-	proc = &ProcGlobal->allProcs[gxact->pgprocno];
+	proc = GetPGProcByNumber(gxact->pgprocno);
 
 	/* Initialize the PGPROC entry */
 	MemSet(proc, 0, sizeof(PGPROC));
 	dlist_node_init(&proc->links);
 	proc->waitStatus = PROC_WAIT_STATUS_OK;
-	if (LocalTransactionIdIsValid(MyProc->lxid))
+	if (LocalTransactionIdIsValid(MyProc->vxid.lxid))
 	{
 		/* clone VXID, for TwoPhaseGetXidByVirtualXID() to find */
-		proc->lxid = MyProc->lxid;
-		proc->backendId = MyBackendId;
+		proc->vxid.lxid = MyProc->vxid.lxid;
+		proc->vxid.backendId = MyBackendId;
 	}
 	else
 	{
 		Assert(AmStartupProcess() || !IsPostmasterEnvironment);
 		/* GetLockConflicts() uses this to specify a wait on the XID */
-		proc->lxid = xid;
-		proc->backendId = InvalidBackendId;
+		proc->vxid.lxid = xid;
+		proc->vxid.backendId = InvalidBackendId;
 	}
 	proc->xid = xid;
 	Assert(proc->xmin == InvalidTransactionId);
@@ -522,7 +507,7 @@ static void
 GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts,
 					 TransactionId *children)
 {
-	PGPROC	   *proc = &ProcGlobal->allProcs[gxact->pgprocno];
+	PGPROC	   *proc = GetPGProcByNumber(gxact->pgprocno);
 
 	/* We need no extra lock since the GXACT isn't valid yet */
 	if (nsubxacts > PGPROC_MAX_CACHED_SUBXIDS)
@@ -559,7 +544,7 @@ MarkAsPrepared(GlobalTransaction gxact, bool lock_held)
 	 * Put it into the global ProcArray so TransactionIdIsInProgress considers
 	 * the XID as still running.
 	 */
-	ProcArrayAdd(&ProcGlobal->allProcs[gxact->pgprocno]);
+	ProcArrayAdd(GetPGProcByNumber(gxact->pgprocno));
 }
 
 /*
@@ -583,7 +568,7 @@ LockGXact(const char *gid, Oid user)
 	for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
 	{
 		GlobalTransaction gxact = TwoPhaseState->prepXacts[i];
-		PGPROC	   *proc = &ProcGlobal->allProcs[gxact->pgprocno];
+		PGPROC	   *proc = GetPGProcByNumber(gxact->pgprocno);
 
 		/* Ignore not-yet-valid GIDs */
 		if (!gxact->valid)
@@ -884,7 +869,7 @@ TwoPhaseGetXidByVirtualXID(VirtualTransactionId vxid,
 
 		if (!gxact->valid)
 			continue;
-		proc = &ProcGlobal->allProcs[gxact->pgprocno];
+		proc = GetPGProcByNumber(gxact->pgprocno);
 		GET_VXID_FROM_PGPROC(proc_vxid, *proc);
 		if (VirtualTransactionIdEquals(vxid, proc_vxid))
 		{
@@ -919,7 +904,7 @@ TwoPhaseGetDummyBackendId(TransactionId xid, bool lock_held)
 {
 	GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
 
-	return gxact->dummyBackendId;
+	return gxact->pgprocno + 1;
 }
 
 /*