dirty, but working version

Author: kelvich

src/backend/access/transam/twophase.c

@@ -217,7 +217,9 @@ StandbyCheckPointTwoPhase(XLogRecPtr redo_horizon)
 	dlist_mutable_iter miter;
 	int			serialized_xacts = 0;
 
-	Assert(RecoveryInProgress());
+	// Assert(RecoveryInProgress());
+
+	elog(WARNING, "StandbyCheckPointTwoPhase");
 
 	TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
 
@@ -226,11 +228,13 @@ StandbyCheckPointTwoPhase(XLogRecPtr redo_horizon)
 		StandbyPreparedTransaction   *xact = dlist_container(StandbyPreparedTransaction,
 															list_node, miter.cur);
 
-		if (xact->prepare_end_lsn <= redo_horizon)
+		if (redo_horizon == 0 || xact->prepare_end_lsn <= redo_horizon)
+		// if (true)
 		{
 			char	   *buf;
 			int			len;
 
+			fprintf(stderr, "2PC: checkpoint: %x --> %d (horizon: %x)\n", xact->prepare_start_lsn, xact->xid, redo_horizon);
 			XlogReadTwoPhaseData(xact->prepare_start_lsn, &buf, &len);
 			RecreateTwoPhaseFile(xact->xid, buf, len);
 			pfree(buf);
@@ -267,6 +271,7 @@ StandbyAtCommit(TransactionId xid)
 		if (xact->xid == xid)
 		{
 			// pfree(xact);
+			fprintf(stderr, "2PC: commit: %x/%d\n", xact->prepare_start_lsn, xact->xid);
 			dlist_delete(miter.cur);
 			return;
 		}
@@ -1741,6 +1746,8 @@ StandbyAtPrepare(XLogReaderState *record)
 	xact->prepare_start_lsn = record->ReadRecPtr;
 	xact->prepare_end_lsn = record->EndRecPtr;
 
+	fprintf(stderr, "2PC: at_prepare: %x/%d\n", xact->prepare_start_lsn, xact->xid);
+
 	dlist_push_tail(&StandbyTwoPhaseStateData, &xact->list_node);
 }
 
@@ -1782,6 +1789,9 @@ PrescanPreparedTransactions(TransactionId **xids_p, int *nxids_p)
 	int			nxids = 0;
 	int			allocsize = 0;
 
+	fprintf(stderr, "--- PrescanPreparedTransactions\n");
+	StandbyCheckPointTwoPhase(0);
+
 	cldir = AllocateDir(TWOPHASE_DIR);
 	while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
 	{
@@ -1918,6 +1928,8 @@ StandbyRecoverPreparedTransactions(bool overwriteOK)
 	DIR		   *cldir;
 	struct dirent *clde;
 
+	fprintf(stderr, "--- StandbyRecoverPreparedTransactions\n");
+
 	cldir = AllocateDir(TWOPHASE_DIR);
 	while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
 	{
@@ -2001,6 +2013,8 @@ RecoverPreparedTransactions(void)
 	struct dirent *clde;
 	bool		overwriteOK = false;
 
+	fprintf(stderr, "--- RecoverPreparedTransactions\n");
+
 	snprintf(dir, MAXPGPATH, "%s", TWOPHASE_DIR);
 
 	cldir = AllocateDir(dir);

src/backend/access/transam/xact.c

@@ -5635,6 +5635,7 @@ xact_redo(XLogReaderState *record)
 		// elog(WARNING, "2PC: RecreateTwoPhaseFile");
 		// RecreateTwoPhaseFile(XLogRecGetXid(record),
 		// 				  XLogRecGetData(record), XLogRecGetDataLen(record));
+		elog(WARNING, "reading prepared tx");
 		StandbyAtPrepare(record);
 	}
 	else if (info == XLOG_XACT_ASSIGNMENT)

src/backend/access/transam/xlog.c

@@ -6734,6 +6734,7 @@ StartupXLOG(void)
 
 				ProcArrayApplyRecoveryInfo(&running);
 
+				StandbyCheckPointTwoPhase(0);
 				StandbyRecoverPreparedTransactions(false);
 			}
 		}
@@ -8773,6 +8774,7 @@ CreateEndOfRecoveryRecord(void)
 	END_CRIT_SECTION();
 
 	LocalXLogInsertAllowed = -1;	/* return to "check" state */
+	// StandbyCheckPointTwoPhase(0);
 }
 
 /*
@@ -8796,6 +8798,7 @@ CheckPointGuts(XLogRecPtr checkPointRedo, int flags)
 	CheckPointBuffers(flags);	/* performs all required fsyncs */
 	CheckPointReplicationOrigin();
 	/* We deliberately delay 2PC checkpointing as long as possible */
+	StandbyCheckPointTwoPhase(checkPointRedo);
 	CheckPointTwoPhase(checkPointRedo);
 }
 
@@ -9479,6 +9482,8 @@ xlog_redo(XLogReaderState *record)
 
 			ProcArrayApplyRecoveryInfo(&running);
 
+			fprintf(stderr, "--- aaa\n");
+			StandbyCheckPointTwoPhase(0);
 			StandbyRecoverPreparedTransactions(true);
 		}
 
@@ -9571,6 +9576,7 @@ xlog_redo(XLogReaderState *record)
 			ereport(PANIC,
 					(errmsg("unexpected timeline ID %u (should be %u) in checkpoint record",
 							xlrec.ThisTimeLineID, ThisTimeLineID)));
+		// StandbyCheckPointTwoPhase(0);
 	}
 	else if (info == XLOG_NOOP)
 	{

src/test/recovery/t/000_twophase.pl

@@ -10,6 +10,7 @@
 $node_master->init(allows_streaming => 1);
 $node_master->append_conf('postgresql.conf', qq(
 	max_prepared_transactions = 10
+	log_checkpoints = true
 ));
 $node_master->start;
 $node_master->backup('master_backup');
@@ -311,4 +312,4 @@
 
 $node_master->psql('postgres', "select count(*) from t",
 	  stdout => \$psql_out);
-is($psql_out, '6', "Check nextXid handling for prepared subtransactions");
+is($psql_out, '6', "Check nextXid handling for prepared subtransactions");