PostgreSQL Source Code git master
twophase.h File Reference
#include "access/xact.h"
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
Include dependency graph for twophase.h:
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Go to the source code of this file.

Typedefs

typedef struct GlobalTransactionDataGlobalTransaction
 

Functions

Size TwoPhaseShmemSize (void)
 
void TwoPhaseShmemInit (void)
 
void AtAbort_Twophase (void)
 
void PostPrepare_Twophase (void)
 
TransactionId TwoPhaseGetXidByVirtualXID (VirtualTransactionId vxid, bool *have_more)
 
PGPROCTwoPhaseGetDummyProc (TransactionId xid, bool lock_held)
 
int TwoPhaseGetDummyProcNumber (TransactionId xid, bool lock_held)
 
GlobalTransaction MarkAsPreparing (TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
 
void StartPrepare (GlobalTransaction gxact)
 
void EndPrepare (GlobalTransaction gxact)
 
bool StandbyTransactionIdIsPrepared (TransactionId xid)
 
TransactionId PrescanPreparedTransactions (TransactionId **xids_p, int *nxids_p)
 
void StandbyRecoverPreparedTransactions (void)
 
void RecoverPreparedTransactions (void)
 
void CheckPointTwoPhase (XLogRecPtr redo_horizon)
 
void FinishPreparedTransaction (const char *gid, bool isCommit)
 
void PrepareRedoAdd (char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn, RepOriginId origin_id)
 
void PrepareRedoRemove (TransactionId xid, bool giveWarning)
 
void restoreTwoPhaseData (void)
 
bool LookupGXact (const char *gid, XLogRecPtr prepare_end_lsn, TimestampTz origin_prepare_timestamp)
 
void TwoPhaseTransactionGid (Oid subid, TransactionId xid, char *gid_res, int szgid)
 
bool LookupGXactBySubid (Oid subid)
 

Variables

PGDLLIMPORT int max_prepared_xacts
 

Typedef Documentation

◆ GlobalTransaction

Definition at line 26 of file twophase.h.

Function Documentation

◆ AtAbort_Twophase()

void AtAbort_Twophase ( void  )

Definition at line 304 of file twophase.c.

305{
306 if (MyLockedGxact == NULL)
307 return;
308
309 /*
310 * What to do with the locked global transaction entry? If we were in the
311 * process of preparing the transaction, but haven't written the WAL
312 * record and state file yet, the transaction must not be considered as
313 * prepared. Likewise, if we are in the process of finishing an
314 * already-prepared transaction, and fail after having already written the
315 * 2nd phase commit or rollback record to the WAL, the transaction should
316 * not be considered as prepared anymore. In those cases, just remove the
317 * entry from shared memory.
318 *
319 * Otherwise, the entry must be left in place so that the transaction can
320 * be finished later, so just unlock it.
321 *
322 * If we abort during prepare, after having written the WAL record, we
323 * might not have transferred all locks and other state to the prepared
324 * transaction yet. Likewise, if we abort during commit or rollback,
325 * after having written the WAL record, we might not have released all the
326 * resources held by the transaction yet. In those cases, the in-memory
327 * state can be wrong, but it's too late to back out.
328 */
329 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
330 if (!MyLockedGxact->valid)
332 else
334 LWLockRelease(TwoPhaseStateLock);
335
336 MyLockedGxact = NULL;
337}
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1168
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1781
@ LW_EXCLUSIVE
Definition: lwlock.h:114
#define INVALID_PROC_NUMBER
Definition: procnumber.h:26
ProcNumber locking_backend
Definition: twophase.c:165
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:628
static GlobalTransaction MyLockedGxact
Definition: twophase.c:196

References INVALID_PROC_NUMBER, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyLockedGxact, RemoveGXact(), and GlobalTransactionData::valid.

Referenced by AbortTransaction(), and AtProcExit_Twophase().

◆ CheckPointTwoPhase()

void CheckPointTwoPhase ( XLogRecPtr  redo_horizon)

Definition at line 1806 of file twophase.c.

1807{
1808 int i;
1809 int serialized_xacts = 0;
1810
1811 if (max_prepared_xacts <= 0)
1812 return; /* nothing to do */
1813
1814 TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1815
1816 /*
1817 * We are expecting there to be zero GXACTs that need to be copied to
1818 * disk, so we perform all I/O while holding TwoPhaseStateLock for
1819 * simplicity. This prevents any new xacts from preparing while this
1820 * occurs, which shouldn't be a problem since the presence of long-lived
1821 * prepared xacts indicates the transaction manager isn't active.
1822 *
1823 * It's also possible to move I/O out of the lock, but on every error we
1824 * should check whether somebody committed our transaction in different
1825 * backend. Let's leave this optimization for future, if somebody will
1826 * spot that this place cause bottleneck.
1827 *
1828 * Note that it isn't possible for there to be a GXACT with a
1829 * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1830 * because of the efforts with delayChkptFlags.
1831 */
1832 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1833 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1834 {
1835 /*
1836 * Note that we are using gxact not PGPROC so this works in recovery
1837 * also
1838 */
1840
1841 if ((gxact->valid || gxact->inredo) &&
1842 !gxact->ondisk &&
1843 gxact->prepare_end_lsn <= redo_horizon)
1844 {
1845 char *buf;
1846 int len;
1847
1849 RecreateTwoPhaseFile(gxact->xid, buf, len);
1850 gxact->ondisk = true;
1853 pfree(buf);
1854 serialized_xacts++;
1855 }
1856 }
1857 LWLockRelease(TwoPhaseStateLock);
1858
1859 /*
1860 * Flush unconditionally the parent directory to make any information
1861 * durable on disk. Two-phase files could have been removed and those
1862 * removals need to be made persistent as well as any files newly created
1863 * previously since the last checkpoint.
1864 */
1866
1867 TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1868
1869 if (log_checkpoints && serialized_xacts > 0)
1870 ereport(LOG,
1871 (errmsg_plural("%u two-phase state file was written "
1872 "for a long-running prepared transaction",
1873 "%u two-phase state files were written "
1874 "for long-running prepared transactions",
1875 serialized_xacts,
1876 serialized_xacts)));
1877}
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1180
#define LOG
Definition: elog.h:31
#define ereport(elevel,...)
Definition: elog.h:149
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:755
int i
Definition: isn.c:72
@ LW_SHARED
Definition: lwlock.h:115
void pfree(void *pointer)
Definition: mcxt.c:1521
const void size_t len
static char * buf
Definition: pg_test_fsync.c:72
TransactionId xid
Definition: twophase.c:162
XLogRecPtr prepare_start_lsn
Definition: twophase.c:160
XLogRecPtr prepare_end_lsn
Definition: twophase.c:161
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:185
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1404
#define TWOPHASE_DIR
Definition: twophase.c:112
int max_prepared_xacts
Definition: twophase.c:115
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:188
static void RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
Definition: twophase.c:1726
bool log_checkpoints
Definition: xlog.c:129
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28

References buf, ereport, errmsg_plural(), fsync_fname(), i, GlobalTransactionData::inredo, InvalidXLogRecPtr, len, LOG, log_checkpoints, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_prepared_xacts, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, TwoPhaseStateData::prepXacts, RecreateTwoPhaseFile(), TWOPHASE_DIR, TwoPhaseState, GlobalTransactionData::valid, GlobalTransactionData::xid, and XlogReadTwoPhaseData().

Referenced by CheckPointGuts().

◆ EndPrepare()

void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1142 of file twophase.c.

1143{
1144 TwoPhaseFileHeader *hdr;
1145 StateFileChunk *record;
1146 bool replorigin;
1147
1148 /* Add the end sentinel to the list of 2PC records */
1150 NULL, 0);
1151
1152 /* Go back and fill in total_len in the file header record */
1154 Assert(hdr->magic == TWOPHASE_MAGIC);
1155 hdr->total_len = records.total_len + sizeof(pg_crc32c);
1156
1159
1160 if (replorigin)
1161 {
1164 }
1165
1166 /*
1167 * If the data size exceeds MaxAllocSize, we won't be able to read it in
1168 * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1169 * where we write data to file and then re-read at commit time.
1170 */
1171 if (hdr->total_len > MaxAllocSize)
1172 ereport(ERROR,
1173 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1174 errmsg("two-phase state file maximum length exceeded")));
1175
1176 /*
1177 * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1178 * cover us, so no need to calculate a separate CRC.
1179 *
1180 * We have to set DELAY_CHKPT_START here, too; otherwise a checkpoint
1181 * starting immediately after the WAL record is inserted could complete
1182 * without fsync'ing our state file. (This is essentially the same kind
1183 * of race condition as the COMMIT-to-clog-write case that
1184 * RecordTransactionCommit uses DELAY_CHKPT_START for; see notes there.)
1185 *
1186 * We save the PREPARE record's location in the gxact for later use by
1187 * CheckPointTwoPhase.
1188 */
1190
1192
1195
1197 for (record = records.head; record != NULL; record = record->next)
1198 XLogRegisterData(record->data, record->len);
1199
1201
1202 gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1203
1204 if (replorigin)
1205 {
1206 /* Move LSNs forward for this replication origin */
1208 gxact->prepare_end_lsn);
1209 }
1210
1211 XLogFlush(gxact->prepare_end_lsn);
1212
1213 /* If we crash now, we have prepared: WAL replay will fix things */
1214
1215 /* Store record's start location to read that later on Commit */
1217
1218 /*
1219 * Mark the prepared transaction as valid. As soon as xact.c marks MyProc
1220 * as not running our XID (which it will do immediately after this
1221 * function returns), others can commit/rollback the xact.
1222 *
1223 * NB: a side effect of this is to make a dummy ProcArray entry for the
1224 * prepared XID. This must happen before we clear the XID from MyProc /
1225 * ProcGlobal->xids[], else there is a window where the XID is not running
1226 * according to TransactionIdIsInProgress, and onlookers would be entitled
1227 * to assume the xact crashed. Instead we have a window where the same
1228 * XID appears twice in ProcArray, which is OK.
1229 */
1230 MarkAsPrepared(gxact, false);
1231
1232 /*
1233 * Now we can mark ourselves as out of the commit critical section: a
1234 * checkpoint starting after this will certainly see the gxact as a
1235 * candidate for fsyncing.
1236 */
1237 MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
1238
1239 /*
1240 * Remember that we have this GlobalTransaction entry locked for us. If
1241 * we crash after this point, it's too late to abort, but we must unlock
1242 * it so that the prepared transaction can be committed or rolled back.
1243 */
1244 MyLockedGxact = gxact;
1245
1247
1248 /*
1249 * Wait for synchronous replication, if required.
1250 *
1251 * Note that at this stage we have marked the prepare, but still show as
1252 * running in the procarray (twice!) and continue to hold locks.
1253 */
1254 SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1255
1256 records.tail = records.head = NULL;
1257 records.num_chunks = 0;
1258}
#define Assert(condition)
Definition: c.h:815
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ERROR
Definition: elog.h:39
#define MaxAllocSize
Definition: fe_memutils.h:22
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
TimestampTz replorigin_session_origin_timestamp
Definition: origin.c:161
void replorigin_session_advance(XLogRecPtr remote_commit, XLogRecPtr local_commit)
Definition: origin.c:1223
RepOriginId replorigin_session_origin
Definition: origin.c:159
XLogRecPtr replorigin_session_origin_lsn
Definition: origin.c:160
#define DoNotReplicateId
Definition: origin.h:34
#define InvalidRepOriginId
Definition: origin.h:33
uint32 pg_crc32c
Definition: pg_crc32c.h:38
#define DELAY_CHKPT_START
Definition: proc.h:119
PGPROC * MyProc
Definition: proc.c:66
int delayChkptFlags
Definition: proc.h:240
struct StateFileChunk * next
Definition: twophase.c:999
uint32 len
Definition: twophase.c:998
char * data
Definition: twophase.c:997
TimestampTz origin_timestamp
Definition: xact.h:369
uint32 total_len
Definition: xact.h:355
XLogRecPtr origin_lsn
Definition: xact.h:368
uint32 magic
Definition: xact.h:354
uint32 total_len
Definition: twophase.c:1008
uint32 num_chunks
Definition: twophase.c:1006
StateFileChunk * head
Definition: twophase.c:1004
StateFileChunk * tail
Definition: twophase.c:1005
void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
Definition: syncrep.c:148
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1264
#define TWOPHASE_MAGIC
Definition: twophase.c:973
static void MarkAsPrepared(GlobalTransaction gxact, bool lock_held)
Definition: twophase.c:530
static struct xllist records
#define TWOPHASE_RM_END_ID
Definition: twophase_rmgr.h:24
#define XLOG_XACT_PREPARE
Definition: xact.h:170
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:253
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2805
#define XLOG_INCLUDE_ORIGIN
Definition: xlog.h:154
XLogRecPtr XLogInsert(RmgrId rmid, uint8 info)
Definition: xloginsert.c:474
void XLogSetRecordFlags(uint8 flags)
Definition: xloginsert.c:456
void XLogRegisterData(const char *data, uint32 len)
Definition: xloginsert.c:364
void XLogBeginInsert(void)
Definition: xloginsert.c:149
void XLogEnsureRecordSpace(int max_block_id, int ndatas)
Definition: xloginsert.c:175

References Assert, StateFileChunk::data, DELAY_CHKPT_START, PGPROC::delayChkptFlags, DoNotReplicateId, END_CRIT_SECTION, ereport, errcode(), errmsg(), ERROR, xllist::head, InvalidRepOriginId, StateFileChunk::len, xl_xact_prepare::magic, MarkAsPrepared(), MaxAllocSize, MyLockedGxact, MyProc, StateFileChunk::next, xllist::num_chunks, xl_xact_prepare::origin_lsn, xl_xact_prepare::origin_timestamp, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, ProcLastRecPtr, records, RegisterTwoPhaseRecord(), replorigin_session_advance(), replorigin_session_origin, replorigin_session_origin_lsn, replorigin_session_origin_timestamp, START_CRIT_SECTION, SyncRepWaitForLSN(), xllist::tail, xllist::total_len, xl_xact_prepare::total_len, TWOPHASE_MAGIC, TWOPHASE_RM_END_ID, XLOG_INCLUDE_ORIGIN, XLOG_XACT_PREPARE, XLogBeginInsert(), XLogEnsureRecordSpace(), XLogFlush(), XLogInsert(), XLogRegisterData(), and XLogSetRecordFlags().

Referenced by PrepareTransaction().

◆ FinishPreparedTransaction()

void FinishPreparedTransaction ( const char *  gid,
bool  isCommit 
)

Definition at line 1487 of file twophase.c.

1488{
1489 GlobalTransaction gxact;
1490 PGPROC *proc;
1491 TransactionId xid;
1492 bool ondisk;
1493 char *buf;
1494 char *bufptr;
1495 TwoPhaseFileHeader *hdr;
1496 TransactionId latestXid;
1497 TransactionId *children;
1498 RelFileLocator *commitrels;
1499 RelFileLocator *abortrels;
1500 RelFileLocator *delrels;
1501 int ndelrels;
1502 xl_xact_stats_item *commitstats;
1503 xl_xact_stats_item *abortstats;
1504 SharedInvalidationMessage *invalmsgs;
1505
1506 /*
1507 * Validate the GID, and lock the GXACT to ensure that two backends do not
1508 * try to commit the same GID at once.
1509 */
1510 gxact = LockGXact(gid, GetUserId());
1511 proc = GetPGProcByNumber(gxact->pgprocno);
1512 xid = gxact->xid;
1513
1514 /*
1515 * Read and validate 2PC state data. State data will typically be stored
1516 * in WAL files if the LSN is after the last checkpoint record, or moved
1517 * to disk if for some reason they have lived for a long time.
1518 */
1519 if (gxact->ondisk)
1520 buf = ReadTwoPhaseFile(xid, false);
1521 else
1523
1524
1525 /*
1526 * Disassemble the header area
1527 */
1528 hdr = (TwoPhaseFileHeader *) buf;
1529 Assert(TransactionIdEquals(hdr->xid, xid));
1530 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1531 bufptr += MAXALIGN(hdr->gidlen);
1532 children = (TransactionId *) bufptr;
1533 bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1534 commitrels = (RelFileLocator *) bufptr;
1535 bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileLocator));
1536 abortrels = (RelFileLocator *) bufptr;
1537 bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileLocator));
1538 commitstats = (xl_xact_stats_item *) bufptr;
1539 bufptr += MAXALIGN(hdr->ncommitstats * sizeof(xl_xact_stats_item));
1540 abortstats = (xl_xact_stats_item *) bufptr;
1541 bufptr += MAXALIGN(hdr->nabortstats * sizeof(xl_xact_stats_item));
1542 invalmsgs = (SharedInvalidationMessage *) bufptr;
1543 bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1544
1545 /* compute latestXid among all children */
1546 latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1547
1548 /* Prevent cancel/die interrupt while cleaning up */
1550
1551 /*
1552 * The order of operations here is critical: make the XLOG entry for
1553 * commit or abort, then mark the transaction committed or aborted in
1554 * pg_xact, then remove its PGPROC from the global ProcArray (which means
1555 * TransactionIdIsInProgress will stop saying the prepared xact is in
1556 * progress), then run the post-commit or post-abort callbacks. The
1557 * callbacks will release the locks the transaction held.
1558 */
1559 if (isCommit)
1561 hdr->nsubxacts, children,
1562 hdr->ncommitrels, commitrels,
1563 hdr->ncommitstats,
1564 commitstats,
1565 hdr->ninvalmsgs, invalmsgs,
1566 hdr->initfileinval, gid);
1567 else
1569 hdr->nsubxacts, children,
1570 hdr->nabortrels, abortrels,
1571 hdr->nabortstats,
1572 abortstats,
1573 gid);
1574
1575 ProcArrayRemove(proc, latestXid);
1576
1577 /*
1578 * In case we fail while running the callbacks, mark the gxact invalid so
1579 * no one else will try to commit/rollback, and so it will be recycled if
1580 * we fail after this point. It is still locked by our backend so it
1581 * won't go away yet.
1582 *
1583 * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1584 */
1585 gxact->valid = false;
1586
1587 /*
1588 * We have to remove any files that were supposed to be dropped. For
1589 * consistency with the regular xact.c code paths, must do this before
1590 * releasing locks, so do it before running the callbacks.
1591 *
1592 * NB: this code knows that we couldn't be dropping any temp rels ...
1593 */
1594 if (isCommit)
1595 {
1596 delrels = commitrels;
1597 ndelrels = hdr->ncommitrels;
1598 }
1599 else
1600 {
1601 delrels = abortrels;
1602 ndelrels = hdr->nabortrels;
1603 }
1604
1605 /* Make sure files supposed to be dropped are dropped */
1606 DropRelationFiles(delrels, ndelrels, false);
1607
1608 if (isCommit)
1609 pgstat_execute_transactional_drops(hdr->ncommitstats, commitstats, false);
1610 else
1611 pgstat_execute_transactional_drops(hdr->nabortstats, abortstats, false);
1612
1613 /*
1614 * Handle cache invalidation messages.
1615 *
1616 * Relcache init file invalidation requires processing both before and
1617 * after we send the SI messages, only when committing. See
1618 * AtEOXact_Inval().
1619 */
1620 if (isCommit)
1621 {
1622 if (hdr->initfileinval)
1624 SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1625 if (hdr->initfileinval)
1627 }
1628
1629 /*
1630 * Acquire the two-phase lock. We want to work on the two-phase callbacks
1631 * while holding it to avoid potential conflicts with other transactions
1632 * attempting to use the same GID, so the lock is released once the shared
1633 * memory state is cleared.
1634 */
1635 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1636
1637 /* And now do the callbacks */
1638 if (isCommit)
1640 else
1642
1643 PredicateLockTwoPhaseFinish(xid, isCommit);
1644
1645 /*
1646 * Read this value while holding the two-phase lock, as the on-disk 2PC
1647 * file is physically removed after the lock is released.
1648 */
1649 ondisk = gxact->ondisk;
1650
1651 /* Clear shared memory state */
1652 RemoveGXact(gxact);
1653
1654 /*
1655 * Release the lock as all callbacks are called and shared memory cleanup
1656 * is done.
1657 */
1658 LWLockRelease(TwoPhaseStateLock);
1659
1660 /* Count the prepared xact as committed or aborted */
1661 AtEOXact_PgStat(isCommit, false);
1662
1663 /*
1664 * And now we can clean up any files we may have left.
1665 */
1666 if (ondisk)
1667 RemoveTwoPhaseFile(xid, true);
1668
1669 MyLockedGxact = NULL;
1670
1672
1673 pfree(buf);
1674}
#define MAXALIGN(LEN)
Definition: c.h:768
uint32 TransactionId
Definition: c.h:609
void DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
Definition: md.c:1461
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:135
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:133
Oid GetUserId(void)
Definition: miscinit.c:517
void pgstat_execute_transactional_drops(int ndrops, struct xl_xact_stats_item *items, bool is_redo)
Definition: pgstat_xact.c:314
void AtEOXact_PgStat(bool isCommit, bool parallel)
Definition: pgstat_xact.c:40
void PredicateLockTwoPhaseFinish(TransactionId xid, bool isCommit)
Definition: predicate.c:4872
#define GetPGProcByNumber(n)
Definition: proc.h:423
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:565
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6808
void RelationCacheInitFilePreInvalidate(void)
Definition: relcache.c:6783
void SendSharedInvalidMessages(const SharedInvalidationMessage *msgs, int n)
Definition: sinval.c:47
Definition: proc.h:162
int32 nabortrels
Definition: xact.h:362
int32 ninvalmsgs
Definition: xact.h:365
bool initfileinval
Definition: xact.h:366
int32 ncommitstats
Definition: xact.h:363
uint16 gidlen
Definition: xact.h:367
int32 nabortstats
Definition: xact.h:364
int32 ncommitrels
Definition: xact.h:361
TransactionId xid
Definition: xact.h:356
int32 nsubxacts
Definition: xact.h:360
TransactionId TransactionIdLatest(TransactionId mainxid, int nxids, const TransactionId *xids)
Definition: transam.c:345
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
static void RecordTransactionAbortPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, const char *gid)
Definition: twophase.c:2394
static void RecordTransactionCommitPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, int ninvalmsgs, SharedInvalidationMessage *invalmsgs, bool initfileinval, const char *gid)
Definition: twophase.c:2296
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1680
static char * ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
Definition: twophase.c:1287
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1707
static GlobalTransaction LockGXact(const char *gid, Oid user)
Definition: twophase.c:552
const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:33
const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:42

References Assert, AtEOXact_PgStat(), buf, DropRelationFiles(), GetPGProcByNumber, GetUserId(), xl_xact_prepare::gidlen, HOLD_INTERRUPTS, xl_xact_prepare::initfileinval, LockGXact(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAXALIGN, MyLockedGxact, xl_xact_prepare::nabortrels, xl_xact_prepare::nabortstats, xl_xact_prepare::ncommitrels, xl_xact_prepare::ncommitstats, xl_xact_prepare::ninvalmsgs, xl_xact_prepare::nsubxacts, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::pgprocno, pgstat_execute_transactional_drops(), PredicateLockTwoPhaseFinish(), GlobalTransactionData::prepare_start_lsn, ProcArrayRemove(), ProcessRecords(), ReadTwoPhaseFile(), RecordTransactionAbortPrepared(), RecordTransactionCommitPrepared(), RelationCacheInitFilePostInvalidate(), RelationCacheInitFilePreInvalidate(), RemoveGXact(), RemoveTwoPhaseFile(), RESUME_INTERRUPTS, SendSharedInvalidMessages(), TransactionIdEquals, TransactionIdLatest(), twophase_postabort_callbacks, twophase_postcommit_callbacks, GlobalTransactionData::valid, GlobalTransactionData::xid, xl_xact_prepare::xid, and XlogReadTwoPhaseData().

Referenced by apply_handle_commit_prepared(), apply_handle_rollback_prepared(), and standard_ProcessUtility().

◆ LookupGXact()

bool LookupGXact ( const char *  gid,
XLogRecPtr  prepare_end_lsn,
TimestampTz  origin_prepare_timestamp 
)

Definition at line 2623 of file twophase.c.

2625{
2626 int i;
2627 bool found = false;
2628
2629 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2630 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2631 {
2633
2634 /* Ignore not-yet-valid GIDs. */
2635 if (gxact->valid && strcmp(gxact->gid, gid) == 0)
2636 {
2637 char *buf;
2638 TwoPhaseFileHeader *hdr;
2639
2640 /*
2641 * We are not expecting collisions of GXACTs (same gid) between
2642 * publisher and subscribers, so we perform all I/O while holding
2643 * TwoPhaseStateLock for simplicity.
2644 *
2645 * To move the I/O out of the lock, we need to ensure that no
2646 * other backend commits the prepared xact in the meantime. We can
2647 * do this optimization if we encounter many collisions in GID
2648 * between publisher and subscriber.
2649 */
2650 if (gxact->ondisk)
2651 buf = ReadTwoPhaseFile(gxact->xid, false);
2652 else
2653 {
2654 Assert(gxact->prepare_start_lsn);
2656 }
2657
2658 hdr = (TwoPhaseFileHeader *) buf;
2659
2660 if (hdr->origin_lsn == prepare_end_lsn &&
2661 hdr->origin_timestamp == origin_prepare_timestamp)
2662 {
2663 found = true;
2664 pfree(buf);
2665 break;
2666 }
2667
2668 pfree(buf);
2669 }
2670 }
2671 LWLockRelease(TwoPhaseStateLock);
2672 return found;
2673}
char gid[GIDSIZE]
Definition: twophase.c:169

References Assert, buf, GlobalTransactionData::gid, i, LW_SHARED, LWLockAcquire(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, xl_xact_prepare::origin_lsn, xl_xact_prepare::origin_timestamp, pfree(), GlobalTransactionData::prepare_start_lsn, TwoPhaseStateData::prepXacts, ReadTwoPhaseFile(), TwoPhaseState, GlobalTransactionData::valid, GlobalTransactionData::xid, and XlogReadTwoPhaseData().

Referenced by apply_handle_rollback_prepared().

◆ LookupGXactBySubid()

bool LookupGXactBySubid ( Oid  subid)

Definition at line 2732 of file twophase.c.

2733{
2734 bool found = false;
2735
2736 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2737 for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
2738 {
2740
2741 /* Ignore not-yet-valid GIDs. */
2742 if (gxact->valid &&
2744 {
2745 found = true;
2746 break;
2747 }
2748 }
2749 LWLockRelease(TwoPhaseStateLock);
2750
2751 return found;
2752}
static bool IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
Definition: twophase.c:2700

References GlobalTransactionData::gid, i, IsTwoPhaseTransactionGidForSubid(), LW_SHARED, LWLockAcquire(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, TwoPhaseStateData::prepXacts, TwoPhaseState, and GlobalTransactionData::valid.

Referenced by AlterSubscription().

◆ MarkAsPreparing()

GlobalTransaction MarkAsPreparing ( TransactionId  xid,
const char *  gid,
TimestampTz  prepared_at,
Oid  owner,
Oid  databaseid 
)

Definition at line 359 of file twophase.c.

361{
362 GlobalTransaction gxact;
363 int i;
364
365 if (strlen(gid) >= GIDSIZE)
367 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
368 errmsg("transaction identifier \"%s\" is too long",
369 gid)));
370
371 /* fail immediately if feature is disabled */
372 if (max_prepared_xacts == 0)
374 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
375 errmsg("prepared transactions are disabled"),
376 errhint("Set \"max_prepared_transactions\" to a nonzero value.")));
377
378 /* on first call, register the exit hook */
380 {
383 }
384
385 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
386
387 /* Check for conflicting GID */
388 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
389 {
390 gxact = TwoPhaseState->prepXacts[i];
391 if (strcmp(gxact->gid, gid) == 0)
392 {
395 errmsg("transaction identifier \"%s\" is already in use",
396 gid)));
397 }
398 }
399
400 /* Get a free gxact from the freelist */
401 if (TwoPhaseState->freeGXacts == NULL)
403 (errcode(ERRCODE_OUT_OF_MEMORY),
404 errmsg("maximum number of prepared transactions reached"),
405 errhint("Increase \"max_prepared_transactions\" (currently %d).",
407 gxact = TwoPhaseState->freeGXacts;
408 TwoPhaseState->freeGXacts = gxact->next;
409
410 MarkAsPreparingGuts(gxact, xid, gid, prepared_at, owner, databaseid);
411
412 gxact->ondisk = false;
413
414 /* And insert it into the active array */
417
418 LWLockRelease(TwoPhaseStateLock);
419
420 return gxact;
421}
int errhint(const char *fmt,...)
Definition: elog.c:1317
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:337
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:30
GlobalTransaction next
Definition: twophase.c:149
GlobalTransaction freeGXacts
Definition: twophase.c:179
static bool twophaseExitRegistered
Definition: twophase.c:198
static void MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:433
static void AtProcExit_Twophase(int code, Datum arg)
Definition: twophase.c:294
#define GIDSIZE
Definition: xact.h:31

References Assert, AtProcExit_Twophase(), before_shmem_exit(), ereport, errcode(), ERRCODE_DUPLICATE_OBJECT, errhint(), errmsg(), ERROR, TwoPhaseStateData::freeGXacts, GlobalTransactionData::gid, GIDSIZE, i, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MarkAsPreparingGuts(), max_prepared_xacts, GlobalTransactionData::next, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, TwoPhaseStateData::prepXacts, twophaseExitRegistered, and TwoPhaseState.

Referenced by PrepareTransaction().

◆ PostPrepare_Twophase()

void PostPrepare_Twophase ( void  )

◆ PrepareRedoAdd()

void PrepareRedoAdd ( char *  buf,
XLogRecPtr  start_lsn,
XLogRecPtr  end_lsn,
RepOriginId  origin_id 
)

Definition at line 2469 of file twophase.c.

2471{
2473 char *bufptr;
2474 const char *gid;
2475 GlobalTransaction gxact;
2476
2477 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2479
2480 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2481 gid = (const char *) bufptr;
2482
2483 /*
2484 * Reserve the GID for the given transaction in the redo code path.
2485 *
2486 * This creates a gxact struct and puts it into the active array.
2487 *
2488 * In redo, this struct is mainly used to track PREPARE/COMMIT entries in
2489 * shared memory. Hence, we only fill up the bare minimum contents here.
2490 * The gxact also gets marked with gxact->inredo set to true to indicate
2491 * that it got added in the redo phase
2492 */
2493
2494 /*
2495 * In the event of a crash while a checkpoint was running, it may be
2496 * possible that some two-phase data found its way to disk while its
2497 * corresponding record needs to be replayed in the follow-up recovery. As
2498 * the 2PC data was on disk, it has already been restored at the beginning
2499 * of recovery with restoreTwoPhaseData(), so skip this record to avoid
2500 * duplicates in TwoPhaseState. If a consistent state has been reached,
2501 * the record is added to TwoPhaseState and it should have no
2502 * corresponding file in pg_twophase.
2503 */
2504 if (!XLogRecPtrIsInvalid(start_lsn))
2505 {
2506 char path[MAXPGPATH];
2507
2508 TwoPhaseFilePath(path, hdr->xid);
2509
2510 if (access(path, F_OK) == 0)
2511 {
2513 (errmsg("could not recover two-phase state file for transaction %u",
2514 hdr->xid),
2515 errdetail("Two-phase state file has been found in WAL record %X/%X, but this transaction has already been restored from disk.",
2516 LSN_FORMAT_ARGS(start_lsn))));
2517 return;
2518 }
2519
2520 if (errno != ENOENT)
2521 ereport(ERROR,
2523 errmsg("could not access file \"%s\": %m", path)));
2524 }
2525
2526 /* Get a free gxact from the freelist */
2527 if (TwoPhaseState->freeGXacts == NULL)
2528 ereport(ERROR,
2529 (errcode(ERRCODE_OUT_OF_MEMORY),
2530 errmsg("maximum number of prepared transactions reached"),
2531 errhint("Increase \"max_prepared_transactions\" (currently %d).",
2533 gxact = TwoPhaseState->freeGXacts;
2534 TwoPhaseState->freeGXacts = gxact->next;
2535
2536 gxact->prepared_at = hdr->prepared_at;
2537 gxact->prepare_start_lsn = start_lsn;
2538 gxact->prepare_end_lsn = end_lsn;
2539 gxact->xid = hdr->xid;
2540 gxact->owner = hdr->owner;
2542 gxact->valid = false;
2543 gxact->ondisk = XLogRecPtrIsInvalid(start_lsn);
2544 gxact->inredo = true; /* yes, added in redo */
2545 strcpy(gxact->gid, gid);
2546
2547 /* And insert it into the active array */
2550
2551 if (origin_id != InvalidRepOriginId)
2552 {
2553 /* recover apply progress */
2554 replorigin_advance(origin_id, hdr->origin_lsn, end_lsn,
2555 false /* backward */ , false /* WAL */ );
2556 }
2557
2558 elog(DEBUG2, "added 2PC data in shared memory for transaction %u", gxact->xid);
2559}
int errcode_for_file_access(void)
Definition: elog.c:876
int errdetail(const char *fmt,...)
Definition: elog.c:1203
#define WARNING
Definition: elog.h:36
#define DEBUG2
Definition: elog.h:29
#define elog(elevel,...)
Definition: elog.h:225
bool LWLockHeldByMeInMode(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1937
void replorigin_advance(RepOriginId node, XLogRecPtr remote_commit, XLogRecPtr local_commit, bool go_backward, bool wal_log)
Definition: origin.c:892
#define MAXPGPATH
short access
Definition: preproc-type.c:36
TimestampTz prepared_at
Definition: twophase.c:151
TimestampTz prepared_at
Definition: xact.h:358
static int TwoPhaseFilePath(char *path, TransactionId xid)
Definition: twophase.c:945
bool RecoveryInProgress(void)
Definition: xlog.c:6355
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
bool reachedConsistency
Definition: xlogrecovery.c:295

References Assert, buf, DEBUG2, elog, ereport, errcode(), errcode_for_file_access(), errdetail(), errhint(), errmsg(), ERROR, TwoPhaseStateData::freeGXacts, GlobalTransactionData::gid, GlobalTransactionData::inredo, INVALID_PROC_NUMBER, InvalidRepOriginId, GlobalTransactionData::locking_backend, LSN_FORMAT_ARGS, LW_EXCLUSIVE, LWLockHeldByMeInMode(), max_prepared_xacts, MAXALIGN, MAXPGPATH, GlobalTransactionData::next, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, xl_xact_prepare::origin_lsn, GlobalTransactionData::owner, xl_xact_prepare::owner, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, GlobalTransactionData::prepared_at, xl_xact_prepare::prepared_at, TwoPhaseStateData::prepXacts, reachedConsistency, RecoveryInProgress(), replorigin_advance(), TwoPhaseFilePath(), TwoPhaseState, GlobalTransactionData::valid, WARNING, GlobalTransactionData::xid, xl_xact_prepare::xid, and XLogRecPtrIsInvalid.

Referenced by restoreTwoPhaseData(), and xact_redo().

◆ PrepareRedoRemove()

void PrepareRedoRemove ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 2571 of file twophase.c.

2572{
2573 GlobalTransaction gxact = NULL;
2574 int i;
2575 bool found = false;
2576
2577 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2579
2580 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2581 {
2582 gxact = TwoPhaseState->prepXacts[i];
2583
2584 if (gxact->xid == xid)
2585 {
2586 Assert(gxact->inredo);
2587 found = true;
2588 break;
2589 }
2590 }
2591
2592 /*
2593 * Just leave if there is nothing, this is expected during WAL replay.
2594 */
2595 if (!found)
2596 return;
2597
2598 /*
2599 * And now we can clean up any files we may have left.
2600 */
2601 elog(DEBUG2, "removing 2PC data for transaction %u", xid);
2602 if (gxact->ondisk)
2603 RemoveTwoPhaseFile(xid, giveWarning);
2604 RemoveGXact(gxact);
2605}

References Assert, DEBUG2, elog, i, GlobalTransactionData::inredo, LW_EXCLUSIVE, LWLockHeldByMeInMode(), TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, TwoPhaseStateData::prepXacts, RecoveryInProgress(), RemoveGXact(), RemoveTwoPhaseFile(), TwoPhaseState, and GlobalTransactionData::xid.

Referenced by ProcessTwoPhaseBuffer(), and xact_redo().

◆ PrescanPreparedTransactions()

TransactionId PrescanPreparedTransactions ( TransactionId **  xids_p,
int *  nxids_p 
)

Definition at line 1952 of file twophase.c.

1953{
1955 TransactionId origNextXid = XidFromFullTransactionId(nextXid);
1956 TransactionId result = origNextXid;
1957 TransactionId *xids = NULL;
1958 int nxids = 0;
1959 int allocsize = 0;
1960 int i;
1961
1962 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1963 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1964 {
1965 TransactionId xid;
1966 char *buf;
1968
1969 Assert(gxact->inredo);
1970
1971 xid = gxact->xid;
1972
1974 gxact->prepare_start_lsn,
1975 gxact->ondisk, false, true);
1976
1977 if (buf == NULL)
1978 continue;
1979
1980 /*
1981 * OK, we think this file is valid. Incorporate xid into the
1982 * running-minimum result.
1983 */
1984 if (TransactionIdPrecedes(xid, result))
1985 result = xid;
1986
1987 if (xids_p)
1988 {
1989 if (nxids == allocsize)
1990 {
1991 if (nxids == 0)
1992 {
1993 allocsize = 10;
1994 xids = palloc(allocsize * sizeof(TransactionId));
1995 }
1996 else
1997 {
1998 allocsize = allocsize * 2;
1999 xids = repalloc(xids, allocsize * sizeof(TransactionId));
2000 }
2001 }
2002 xids[nxids++] = xid;
2003 }
2004
2005 pfree(buf);
2006 }
2007 LWLockRelease(TwoPhaseStateLock);
2008
2009 if (xids_p)
2010 {
2011 *xids_p = xids;
2012 *nxids_p = nxids;
2013 }
2014
2015 return result;
2016}
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1541
void * palloc(Size size)
Definition: mcxt.c:1317
FullTransactionId nextXid
Definition: transam.h:220
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:280
#define XidFromFullTransactionId(x)
Definition: transam.h:48
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2176
TransamVariablesData * TransamVariables
Definition: varsup.c:34

References Assert, buf, i, GlobalTransactionData::inredo, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), TransamVariablesData::nextXid, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, palloc(), pfree(), GlobalTransactionData::prepare_start_lsn, TwoPhaseStateData::prepXacts, ProcessTwoPhaseBuffer(), repalloc(), TransactionIdPrecedes(), TransamVariables, TwoPhaseState, GlobalTransactionData::xid, and XidFromFullTransactionId.

Referenced by StartupXLOG(), and xlog_redo().

◆ RecoverPreparedTransactions()

void RecoverPreparedTransactions ( void  )

Definition at line 2073 of file twophase.c.

2074{
2075 int i;
2076
2077 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2078 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2079 {
2080 TransactionId xid;
2081 char *buf;
2083 char *bufptr;
2084 TwoPhaseFileHeader *hdr;
2085 TransactionId *subxids;
2086 const char *gid;
2087
2088 xid = gxact->xid;
2089
2090 /*
2091 * Reconstruct subtrans state for the transaction --- needed because
2092 * pg_subtrans is not preserved over a restart. Note that we are
2093 * linking all the subtransactions directly to the top-level XID;
2094 * there may originally have been a more complex hierarchy, but
2095 * there's no need to restore that exactly. It's possible that
2096 * SubTransSetParent has been set before, if the prepared transaction
2097 * generated xid assignment records.
2098 */
2100 gxact->prepare_start_lsn,
2101 gxact->ondisk, true, false);
2102 if (buf == NULL)
2103 continue;
2104
2105 ereport(LOG,
2106 (errmsg("recovering prepared transaction %u from shared memory", xid)));
2107
2108 hdr = (TwoPhaseFileHeader *) buf;
2109 Assert(TransactionIdEquals(hdr->xid, xid));
2110 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2111 gid = (const char *) bufptr;
2112 bufptr += MAXALIGN(hdr->gidlen);
2113 subxids = (TransactionId *) bufptr;
2114 bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
2115 bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileLocator));
2116 bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileLocator));
2117 bufptr += MAXALIGN(hdr->ncommitstats * sizeof(xl_xact_stats_item));
2118 bufptr += MAXALIGN(hdr->nabortstats * sizeof(xl_xact_stats_item));
2119 bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
2120
2121 /*
2122 * Recreate its GXACT and dummy PGPROC. But, check whether it was
2123 * added in redo and already has a shmem entry for it.
2124 */
2125 MarkAsPreparingGuts(gxact, xid, gid,
2126 hdr->prepared_at,
2127 hdr->owner, hdr->database);
2128
2129 /* recovered, so reset the flag for entries generated by redo */
2130 gxact->inredo = false;
2131
2132 GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
2133 MarkAsPrepared(gxact, true);
2134
2135 LWLockRelease(TwoPhaseStateLock);
2136
2137 /*
2138 * Recover other state (notably locks) using resource managers.
2139 */
2141
2142 /*
2143 * Release locks held by the standby process after we process each
2144 * prepared transaction. As a result, we don't need too many
2145 * additional locks at any one time.
2146 */
2147 if (InHotStandby)
2148 StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
2149
2150 /*
2151 * We're done with recovering this transaction. Clear MyLockedGxact,
2152 * like we do in PrepareTransaction() during normal operation.
2153 */
2155
2156 pfree(buf);
2157
2158 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2159 }
2160
2161 LWLockRelease(TwoPhaseStateLock);
2162}
void StandbyReleaseLockTree(TransactionId xid, int nsubxids, TransactionId *subxids)
Definition: standby.c:1091
Oid database
Definition: xact.h:357
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:504
void PostPrepare_Twophase(void)
Definition: twophase.c:344
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:24
#define InHotStandby
Definition: xlogutils.h:60

References Assert, buf, xl_xact_prepare::database, ereport, errmsg(), xl_xact_prepare::gidlen, GXactLoadSubxactData(), i, InHotStandby, GlobalTransactionData::inredo, LOG, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MarkAsPrepared(), MarkAsPreparingGuts(), MAXALIGN, xl_xact_prepare::nabortrels, xl_xact_prepare::nabortstats, xl_xact_prepare::ncommitrels, xl_xact_prepare::ncommitstats, xl_xact_prepare::ninvalmsgs, xl_xact_prepare::nsubxacts, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, xl_xact_prepare::owner, pfree(), PostPrepare_Twophase(), GlobalTransactionData::prepare_start_lsn, xl_xact_prepare::prepared_at, TwoPhaseStateData::prepXacts, ProcessRecords(), ProcessTwoPhaseBuffer(), StandbyReleaseLockTree(), TransactionIdEquals, twophase_recover_callbacks, TwoPhaseState, GlobalTransactionData::xid, and xl_xact_prepare::xid.

Referenced by StartupXLOG().

◆ restoreTwoPhaseData()

void restoreTwoPhaseData ( void  )

Definition at line 1888 of file twophase.c.

1889{
1890 DIR *cldir;
1891 struct dirent *clde;
1892
1893 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1894 cldir = AllocateDir(TWOPHASE_DIR);
1895 while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1896 {
1897 if (strlen(clde->d_name) == 16 &&
1898 strspn(clde->d_name, "0123456789ABCDEF") == 16)
1899 {
1900 TransactionId xid;
1901 FullTransactionId fxid;
1902 char *buf;
1903
1904 fxid = FullTransactionIdFromU64(strtou64(clde->d_name, NULL, 16));
1905 xid = XidFromFullTransactionId(fxid);
1906
1908 true, false, false);
1909 if (buf == NULL)
1910 continue;
1911
1914 }
1915 }
1916 LWLockRelease(TwoPhaseStateLock);
1917 FreeDir(cldir);
1918}
int FreeDir(DIR *dir)
Definition: fd.c:2983
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2865
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2931
Definition: dirent.c:26
Definition: dirent.h:10
char d_name[MAX_PATH]
Definition: dirent.h:15
static FullTransactionId FullTransactionIdFromU64(uint64 value)
Definition: transam.h:81
void PrepareRedoAdd(char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn, RepOriginId origin_id)
Definition: twophase.c:2469

References AllocateDir(), buf, dirent::d_name, FreeDir(), FullTransactionIdFromU64(), InvalidRepOriginId, InvalidXLogRecPtr, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), PrepareRedoAdd(), ProcessTwoPhaseBuffer(), ReadDir(), TWOPHASE_DIR, and XidFromFullTransactionId.

Referenced by StartupXLOG().

◆ StandbyRecoverPreparedTransactions()

void StandbyRecoverPreparedTransactions ( void  )

Definition at line 2032 of file twophase.c.

2033{
2034 int i;
2035
2036 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2037 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2038 {
2039 TransactionId xid;
2040 char *buf;
2042
2043 Assert(gxact->inredo);
2044
2045 xid = gxact->xid;
2046
2048 gxact->prepare_start_lsn,
2049 gxact->ondisk, true, false);
2050 if (buf != NULL)
2051 pfree(buf);
2052 }
2053 LWLockRelease(TwoPhaseStateLock);
2054}

References Assert, buf, i, GlobalTransactionData::inredo, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::prepare_start_lsn, TwoPhaseStateData::prepXacts, ProcessTwoPhaseBuffer(), TwoPhaseState, and GlobalTransactionData::xid.

Referenced by StartupXLOG(), and xlog_redo().

◆ StandbyTransactionIdIsPrepared()

bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1459 of file twophase.c.

1460{
1461 char *buf;
1462 TwoPhaseFileHeader *hdr;
1463 bool result;
1464
1466
1467 if (max_prepared_xacts <= 0)
1468 return false; /* nothing to do */
1469
1470 /* Read and validate file */
1471 buf = ReadTwoPhaseFile(xid, true);
1472 if (buf == NULL)
1473 return false;
1474
1475 /* Check header also */
1476 hdr = (TwoPhaseFileHeader *) buf;
1477 result = TransactionIdEquals(hdr->xid, xid);
1478 pfree(buf);
1479
1480 return result;
1481}
#define TransactionIdIsValid(xid)
Definition: transam.h:41

References Assert, buf, max_prepared_xacts, pfree(), ReadTwoPhaseFile(), TransactionIdEquals, TransactionIdIsValid, and xl_xact_prepare::xid.

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

◆ StartPrepare()

void StartPrepare ( GlobalTransaction  gxact)

Definition at line 1049 of file twophase.c.

1050{
1051 PGPROC *proc = GetPGProcByNumber(gxact->pgprocno);
1052 TransactionId xid = gxact->xid;
1054 TransactionId *children;
1055 RelFileLocator *commitrels;
1056 RelFileLocator *abortrels;
1057 xl_xact_stats_item *abortstats = NULL;
1058 xl_xact_stats_item *commitstats = NULL;
1059 SharedInvalidationMessage *invalmsgs;
1060
1061 /* Initialize linked list */
1063 records.head->len = 0;
1064 records.head->next = NULL;
1065
1066 records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
1068
1070 records.num_chunks = 1;
1071
1072 records.total_len = 0;
1073
1074 /* Create header */
1075 hdr.magic = TWOPHASE_MAGIC;
1076 hdr.total_len = 0; /* EndPrepare will fill this in */
1077 hdr.xid = xid;
1078 hdr.database = proc->databaseId;
1079 hdr.prepared_at = gxact->prepared_at;
1080 hdr.owner = gxact->owner;
1081 hdr.nsubxacts = xactGetCommittedChildren(&children);
1082 hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
1083 hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
1084 hdr.ncommitstats =
1085 pgstat_get_transactional_drops(true, &commitstats);
1086 hdr.nabortstats =
1087 pgstat_get_transactional_drops(false, &abortstats);
1089 &hdr.initfileinval);
1090 hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
1091 /* EndPrepare will fill the origin data, if necessary */
1093 hdr.origin_timestamp = 0;
1094
1095 save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
1096 save_state_data(gxact->gid, hdr.gidlen);
1097
1098 /*
1099 * Add the additional info about subxacts, deletable files and cache
1100 * invalidation messages.
1101 */
1102 if (hdr.nsubxacts > 0)
1103 {
1104 save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
1105 /* While we have the child-xact data, stuff it in the gxact too */
1106 GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
1107 }
1108 if (hdr.ncommitrels > 0)
1109 {
1110 save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileLocator));
1111 pfree(commitrels);
1112 }
1113 if (hdr.nabortrels > 0)
1114 {
1115 save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileLocator));
1116 pfree(abortrels);
1117 }
1118 if (hdr.ncommitstats > 0)
1119 {
1120 save_state_data(commitstats,
1121 hdr.ncommitstats * sizeof(xl_xact_stats_item));
1122 pfree(commitstats);
1123 }
1124 if (hdr.nabortstats > 0)
1125 {
1126 save_state_data(abortstats,
1127 hdr.nabortstats * sizeof(xl_xact_stats_item));
1128 pfree(abortstats);
1129 }
1130 if (hdr.ninvalmsgs > 0)
1131 {
1132 save_state_data(invalmsgs,
1134 pfree(invalmsgs);
1135 }
1136}
#define Max(x, y)
Definition: c.h:955
int xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs, bool *RelcacheInitFileInval)
Definition: inval.c:940
void * palloc0(Size size)
Definition: mcxt.c:1347
int pgstat_get_transactional_drops(bool isCommit, xl_xact_stats_item **items)
Definition: pgstat_xact.c:272
int smgrGetPendingDeletes(bool forCommit, RelFileLocator **ptr)
Definition: storage.c:877
Oid databaseId
Definition: proc.h:207
uint32 bytes_free
Definition: twophase.c:1007
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:1021
int xactGetCommittedChildren(TransactionId **ptr)
Definition: xact.c:5778

References xllist::bytes_free, StateFileChunk::data, xl_xact_prepare::database, PGPROC::databaseId, GetPGProcByNumber, GlobalTransactionData::gid, xl_xact_prepare::gidlen, GXactLoadSubxactData(), xllist::head, xl_xact_prepare::initfileinval, InvalidXLogRecPtr, StateFileChunk::len, xl_xact_prepare::magic, Max, xl_xact_prepare::nabortrels, xl_xact_prepare::nabortstats, xl_xact_prepare::ncommitrels, xl_xact_prepare::ncommitstats, StateFileChunk::next, xl_xact_prepare::ninvalmsgs, xl_xact_prepare::nsubxacts, xllist::num_chunks, xl_xact_prepare::origin_lsn, xl_xact_prepare::origin_timestamp, GlobalTransactionData::owner, xl_xact_prepare::owner, palloc(), palloc0(), pfree(), GlobalTransactionData::pgprocno, pgstat_get_transactional_drops(), GlobalTransactionData::prepared_at, xl_xact_prepare::prepared_at, records, save_state_data(), smgrGetPendingDeletes(), xllist::tail, xllist::total_len, xl_xact_prepare::total_len, TWOPHASE_MAGIC, xactGetCommittedChildren(), xactGetCommittedInvalidationMessages(), GlobalTransactionData::xid, and xl_xact_prepare::xid.

Referenced by PrepareTransaction().

◆ TwoPhaseGetDummyProc()

PGPROC * TwoPhaseGetDummyProc ( TransactionId  xid,
bool  lock_held 
)

Definition at line 918 of file twophase.c.

919{
920 GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
921
922 return GetPGProcByNumber(gxact->pgprocno);
923}
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid, bool lock_held)
Definition: twophase.c:800

References GetPGProcByNumber, GlobalTransactionData::pgprocno, and TwoPhaseGetGXact().

Referenced by lock_twophase_postcommit(), lock_twophase_recover(), and PostPrepare_Locks().

◆ TwoPhaseGetDummyProcNumber()

int TwoPhaseGetDummyProcNumber ( TransactionId  xid,
bool  lock_held 
)

Definition at line 903 of file twophase.c.

904{
905 GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
906
907 return gxact->pgprocno;
908}

References GlobalTransactionData::pgprocno, and TwoPhaseGetGXact().

Referenced by multixact_twophase_postcommit(), multixact_twophase_recover(), and PostPrepare_MultiXact().

◆ TwoPhaseGetXidByVirtualXID()

TransactionId TwoPhaseGetXidByVirtualXID ( VirtualTransactionId  vxid,
bool *  have_more 
)

Definition at line 852 of file twophase.c.

854{
855 int i;
857
859 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
860
861 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
862 {
864 PGPROC *proc;
865 VirtualTransactionId proc_vxid;
866
867 if (!gxact->valid)
868 continue;
869 proc = GetPGProcByNumber(gxact->pgprocno);
870 GET_VXID_FROM_PGPROC(proc_vxid, *proc);
871 if (VirtualTransactionIdEquals(vxid, proc_vxid))
872 {
873 /*
874 * Startup process sets proc->vxid.procNumber to
875 * INVALID_PROC_NUMBER.
876 */
877 Assert(!gxact->inredo);
878
879 if (result != InvalidTransactionId)
880 {
881 *have_more = true;
882 break;
883 }
884 result = gxact->xid;
885 }
886 }
887
888 LWLockRelease(TwoPhaseStateLock);
889
890 return result;
891}
#define VirtualTransactionIdIsValid(vxid)
Definition: lock.h:67
#define GET_VXID_FROM_PGPROC(vxid_dst, proc)
Definition: lock.h:77
#define VirtualTransactionIdEquals(vxid1, vxid2)
Definition: lock.h:71
#define InvalidTransactionId
Definition: transam.h:31

References Assert, GET_VXID_FROM_PGPROC, GetPGProcByNumber, i, GlobalTransactionData::inredo, InvalidTransactionId, LW_SHARED, LWLockAcquire(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, GlobalTransactionData::pgprocno, TwoPhaseStateData::prepXacts, TwoPhaseState, GlobalTransactionData::valid, VirtualTransactionIdEquals, VirtualTransactionIdIsValid, and GlobalTransactionData::xid.

Referenced by XactLockForVirtualXact().

◆ TwoPhaseShmemInit()

void TwoPhaseShmemInit ( void  )

Definition at line 253 of file twophase.c.

254{
255 bool found;
256
257 TwoPhaseState = ShmemInitStruct("Prepared Transaction Table",
259 &found);
261 {
262 GlobalTransaction gxacts;
263 int i;
264
265 Assert(!found);
268
269 /*
270 * Initialize the linked list of free GlobalTransactionData structs
271 */
272 gxacts = (GlobalTransaction)
273 ((char *) TwoPhaseState +
274 MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) +
276 for (i = 0; i < max_prepared_xacts; i++)
277 {
278 /* insert into linked list */
279 gxacts[i].next = TwoPhaseState->freeGXacts;
280 TwoPhaseState->freeGXacts = &gxacts[i];
281
282 /* associate it with a PGPROC assigned by InitProcGlobal */
284 }
285 }
286 else
287 Assert(found);
288}
bool IsUnderPostmaster
Definition: globals.c:119
#define GetNumberFromPGProc(proc)
Definition: proc.h:424
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:382
PGPROC * PreparedXactProcs
Definition: proc.c:80
Size TwoPhaseShmemSize(void)
Definition: twophase.c:237
struct GlobalTransactionData * GlobalTransaction
Definition: twophase.h:26

References Assert, TwoPhaseStateData::freeGXacts, GetNumberFromPGProc, i, IsUnderPostmaster, max_prepared_xacts, MAXALIGN, GlobalTransactionData::next, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::pgprocno, PreparedXactProcs, ShmemInitStruct(), TwoPhaseShmemSize(), and TwoPhaseState.

Referenced by CreateOrAttachShmemStructs().

◆ TwoPhaseShmemSize()

Size TwoPhaseShmemSize ( void  )

Definition at line 237 of file twophase.c.

238{
239 Size size;
240
241 /* Need the fixed struct, the array of pointers, and the GTD structs */
242 size = offsetof(TwoPhaseStateData, prepXacts);
244 sizeof(GlobalTransaction)));
245 size = MAXALIGN(size);
247 sizeof(GlobalTransactionData)));
248
249 return size;
250}
size_t Size
Definition: c.h:562
Size add_size(Size s1, Size s2)
Definition: shmem.c:488
Size mul_size(Size s1, Size s2)
Definition: shmem.c:505
static pg_noinline void Size size
Definition: slab.c:607

References add_size(), max_prepared_xacts, MAXALIGN, mul_size(), and size.

Referenced by CalculateShmemSize(), and TwoPhaseShmemInit().

◆ TwoPhaseTransactionGid()

void TwoPhaseTransactionGid ( Oid  subid,
TransactionId  xid,
char *  gid_res,
int  szgid 
)

Definition at line 2682 of file twophase.c.

2683{
2684 Assert(OidIsValid(subid));
2685
2686 if (!TransactionIdIsValid(xid))
2687 ereport(ERROR,
2688 (errcode(ERRCODE_PROTOCOL_VIOLATION),
2689 errmsg_internal("invalid two-phase transaction ID")));
2690
2691 snprintf(gid_res, szgid, "pg_gid_%u_%u", subid, xid);
2692}
#define OidIsValid(objectId)
Definition: c.h:732
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157
#define snprintf
Definition: port.h:239

References Assert, ereport, errcode(), errmsg_internal(), ERROR, OidIsValid, snprintf, and TransactionIdIsValid.

Referenced by apply_handle_commit_prepared(), apply_handle_prepare_internal(), apply_handle_rollback_prepared(), and IsTwoPhaseTransactionGidForSubid().

Variable Documentation

◆ max_prepared_xacts