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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Typedefs

typedef struct GlobalTransactionDataGlobalTransaction
 

Functions

Size TwoPhaseShmemSize (void)
 
void TwoPhaseShmemInit (void)
 
void AtAbort_Twophase (void)
 
void PostPrepare_Twophase (void)
 
PGPROCTwoPhaseGetDummyProc (TransactionId xid, bool lock_held)
 
BackendId TwoPhaseGetDummyBackendId (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_at_lsn, TimestampTz origin_prepare_timestamp)
 

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 317 of file twophase.c.

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

Referenced by AbortTransaction(), and AtProcExit_Twophase().

318 {
319  if (MyLockedGxact == NULL)
320  return;
321 
322  /*
323  * What to do with the locked global transaction entry? If we were in the
324  * process of preparing the transaction, but haven't written the WAL
325  * record and state file yet, the transaction must not be considered as
326  * prepared. Likewise, if we are in the process of finishing an
327  * already-prepared transaction, and fail after having already written the
328  * 2nd phase commit or rollback record to the WAL, the transaction should
329  * not be considered as prepared anymore. In those cases, just remove the
330  * entry from shared memory.
331  *
332  * Otherwise, the entry must be left in place so that the transaction can
333  * be finished later, so just unlock it.
334  *
335  * If we abort during prepare, after having written the WAL record, we
336  * might not have transferred all locks and other state to the prepared
337  * transaction yet. Likewise, if we abort during commit or rollback,
338  * after having written the WAL record, we might not have released all the
339  * resources held by the transaction yet. In those cases, the in-memory
340  * state can be wrong, but it's too late to back out.
341  */
342  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
343  if (!MyLockedGxact->valid)
345  else
347  LWLockRelease(TwoPhaseStateLock);
348 
349  MyLockedGxact = NULL;
350 }
BackendId locking_backend
Definition: twophase.c:168
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
#define InvalidBackendId
Definition: backendid.h:23
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
static GlobalTransaction MyLockedGxact
Definition: twophase.c:199

◆ CheckPointTwoPhase()

void CheckPointTwoPhase ( XLogRecPtr  redo_horizon)

Definition at line 1707 of file twophase.c.

References buf, ereport, errmsg_plural(), fsync_fname(), i, GlobalTransactionData::inredo, InvalidXLogRecPtr, 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, GlobalTransactionData::valid, GlobalTransactionData::xid, and XlogReadTwoPhaseData().

Referenced by CheckPointGuts().

1708 {
1709  int i;
1710  int serialized_xacts = 0;
1711 
1712  if (max_prepared_xacts <= 0)
1713  return; /* nothing to do */
1714 
1715  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1716 
1717  /*
1718  * We are expecting there to be zero GXACTs that need to be copied to
1719  * disk, so we perform all I/O while holding TwoPhaseStateLock for
1720  * simplicity. This prevents any new xacts from preparing while this
1721  * occurs, which shouldn't be a problem since the presence of long-lived
1722  * prepared xacts indicates the transaction manager isn't active.
1723  *
1724  * It's also possible to move I/O out of the lock, but on every error we
1725  * should check whether somebody committed our transaction in different
1726  * backend. Let's leave this optimization for future, if somebody will
1727  * spot that this place cause bottleneck.
1728  *
1729  * Note that it isn't possible for there to be a GXACT with a
1730  * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1731  * because of the efforts with delayChkpt.
1732  */
1733  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1734  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1735  {
1736  /*
1737  * Note that we are using gxact not PGPROC so this works in recovery
1738  * also
1739  */
1741 
1742  if ((gxact->valid || gxact->inredo) &&
1743  !gxact->ondisk &&
1744  gxact->prepare_end_lsn <= redo_horizon)
1745  {
1746  char *buf;
1747  int len;
1748 
1749  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, &len);
1750  RecreateTwoPhaseFile(gxact->xid, buf, len);
1751  gxact->ondisk = true;
1754  pfree(buf);
1755  serialized_xacts++;
1756  }
1757  }
1758  LWLockRelease(TwoPhaseStateLock);
1759 
1760  /*
1761  * Flush unconditionally the parent directory to make any information
1762  * durable on disk. Two-phase files could have been removed and those
1763  * removals need to be made persistent as well as any files newly created
1764  * previously since the last checkpoint.
1765  */
1766  fsync_fname(TWOPHASE_DIR, true);
1767 
1768  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1769 
1770  if (log_checkpoints && serialized_xacts > 0)
1771  ereport(LOG,
1772  (errmsg_plural("%u two-phase state file was written "
1773  "for a long-running prepared transaction",
1774  "%u two-phase state files were written "
1775  "for long-running prepared transactions",
1776  serialized_xacts,
1777  serialized_xacts)));
1778 }
bool log_checkpoints
Definition: xlog.c:106
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1019
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:671
#define LOG
Definition: elog.h:26
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
void pfree(void *pointer)
Definition: mcxt.c:1169
int max_prepared_xacts
Definition: twophase.c:117
static char * buf
Definition: pg_test_fsync.c:68
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
static void RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
Definition: twophase.c:1627
#define ereport(elevel,...)
Definition: elog.h:157
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
#define TWOPHASE_DIR
Definition: twophase.c:114
TransactionId xid
Definition: twophase.c:165
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1326
int i
XLogRecPtr prepare_end_lsn
Definition: twophase.c:164

◆ EndPrepare()

void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1055 of file twophase.c.

References Assert, StateFileChunk::data, PGPROC::delayChkpt, DoNotReplicateId, END_CRIT_SECTION, ereport, errcode(), errmsg(), ERROR, xllist::head, InvalidRepOriginId, InvalidXLogRecPtr, StateFileChunk::len, xl_xact_prepare::magic, MarkAsPrepared(), MaxAllocSize, 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, xl_xact_prepare::total_len, xllist::total_len, TWOPHASE_MAGIC, TWOPHASE_RM_END_ID, XLOG_INCLUDE_ORIGIN, XLOG_XACT_PREPARE, XLogBeginInsert(), XLogEnsureRecordSpace(), XLogFlush(), XLogInsert(), XLogRegisterData(), and XLogSetRecordFlags().

Referenced by PrepareTransaction().

1056 {
1057  TwoPhaseFileHeader *hdr;
1058  StateFileChunk *record;
1059  bool replorigin;
1060 
1061  /* Add the end sentinel to the list of 2PC records */
1063  NULL, 0);
1064 
1065  /* Go back and fill in total_len in the file header record */
1066  hdr = (TwoPhaseFileHeader *) records.head->data;
1067  Assert(hdr->magic == TWOPHASE_MAGIC);
1068  hdr->total_len = records.total_len + sizeof(pg_crc32c);
1069 
1070  replorigin = (replorigin_session_origin != InvalidRepOriginId &&
1072 
1073  if (replorigin)
1074  {
1078  }
1079  else
1080  {
1082  hdr->origin_timestamp = 0;
1083  }
1084 
1085  /*
1086  * If the data size exceeds MaxAllocSize, we won't be able to read it in
1087  * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1088  * where we write data to file and then re-read at commit time.
1089  */
1090  if (hdr->total_len > MaxAllocSize)
1091  ereport(ERROR,
1092  (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1093  errmsg("two-phase state file maximum length exceeded")));
1094 
1095  /*
1096  * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1097  * cover us, so no need to calculate a separate CRC.
1098  *
1099  * We have to set delayChkpt here, too; otherwise a checkpoint starting
1100  * immediately after the WAL record is inserted could complete without
1101  * fsync'ing our state file. (This is essentially the same kind of race
1102  * condition as the COMMIT-to-clog-write case that RecordTransactionCommit
1103  * uses delayChkpt for; see notes there.)
1104  *
1105  * We save the PREPARE record's location in the gxact for later use by
1106  * CheckPointTwoPhase.
1107  */
1109 
1111 
1112  MyProc->delayChkpt = true;
1113 
1114  XLogBeginInsert();
1115  for (record = records.head; record != NULL; record = record->next)
1116  XLogRegisterData(record->data, record->len);
1117 
1119 
1120  gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1121 
1122  if (replorigin)
1123  {
1124  /* Move LSNs forward for this replication origin */
1126  gxact->prepare_end_lsn);
1127  }
1128 
1129  XLogFlush(gxact->prepare_end_lsn);
1130 
1131  /* If we crash now, we have prepared: WAL replay will fix things */
1132 
1133  /* Store record's start location to read that later on Commit */
1135 
1136  /*
1137  * Mark the prepared transaction as valid. As soon as xact.c marks MyProc
1138  * as not running our XID (which it will do immediately after this
1139  * function returns), others can commit/rollback the xact.
1140  *
1141  * NB: a side effect of this is to make a dummy ProcArray entry for the
1142  * prepared XID. This must happen before we clear the XID from MyProc /
1143  * ProcGlobal->xids[], else there is a window where the XID is not running
1144  * according to TransactionIdIsInProgress, and onlookers would be entitled
1145  * to assume the xact crashed. Instead we have a window where the same
1146  * XID appears twice in ProcArray, which is OK.
1147  */
1148  MarkAsPrepared(gxact, false);
1149 
1150  /*
1151  * Now we can mark ourselves as out of the commit critical section: a
1152  * checkpoint starting after this will certainly see the gxact as a
1153  * candidate for fsyncing.
1154  */
1155  MyProc->delayChkpt = false;
1156 
1157  /*
1158  * Remember that we have this GlobalTransaction entry locked for us. If
1159  * we crash after this point, it's too late to abort, but we must unlock
1160  * it so that the prepared transaction can be committed or rolled back.
1161  */
1162  MyLockedGxact = gxact;
1163 
1164  END_CRIT_SECTION();
1165 
1166  /*
1167  * Wait for synchronous replication, if required.
1168  *
1169  * Note that at this stage we have marked the prepare, but still show as
1170  * running in the procarray (twice!) and continue to hold locks.
1171  */
1172  SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1173 
1174  records.tail = records.head = NULL;
1175  records.num_chunks = 0;
1176 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
#define XLOG_XACT_PREPARE
Definition: xact.h:149
#define DoNotReplicateId
Definition: origin.h:34
PGPROC * MyProc
Definition: proc.c:68
StateFileChunk * tail
Definition: twophase.c:939
uint32 pg_crc32c
Definition: pg_crc32c.h:38
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:352
void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
Definition: syncrep.c:148
#define END_CRIT_SECTION()
Definition: miscadmin.h:149
#define START_CRIT_SECTION()
Definition: miscadmin.h:147
int errcode(int sqlerrcode)
Definition: elog.c:698
#define TWOPHASE_RM_END_ID
Definition: twophase_rmgr.h:24
#define XLOG_INCLUDE_ORIGIN
Definition: xlog.h:213
uint32 num_chunks
Definition: twophase.c:940
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2887
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1182
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
char * data
Definition: twophase.c:931
#define ERROR
Definition: elog.h:46
bool delayChkpt
Definition: proc.h:187
XLogRecPtr replorigin_session_origin_lsn
Definition: origin.c:155
TimestampTz replorigin_session_origin_timestamp
Definition: origin.c:156
XLogRecPtr origin_lsn
Definition: xact.h:314
uint32 total_len
Definition: xact.h:303
uint32 len
Definition: twophase.c:932
void XLogSetRecordFlags(uint8 flags)
Definition: xloginsert.c:416
static struct xllist records
uint32 total_len
Definition: twophase.c:942
#define MaxAllocSize
Definition: memutils.h:40
struct StateFileChunk * next
Definition: twophase.c:933
void XLogRegisterData(char *data, int len)
Definition: xloginsert.c:340
XLogRecPtr XLogInsert(RmgrId rmid, uint8 info)
Definition: xloginsert.c:434
#define TWOPHASE_MAGIC
Definition: twophase.c:907
#define ereport(elevel,...)
Definition: elog.h:157
StateFileChunk * head
Definition: twophase.c:938
#define Assert(condition)
Definition: c.h:804
RepOriginId replorigin_session_origin
Definition: origin.c:154
TimestampTz origin_timestamp
Definition: xact.h:315
void XLogEnsureRecordSpace(int max_block_id, int ndatas)
Definition: xloginsert.c:161
void replorigin_session_advance(XLogRecPtr remote_commit, XLogRecPtr local_commit)
Definition: origin.c:1188
static void MarkAsPrepared(GlobalTransaction gxact, bool lock_held)
Definition: twophase.c:534
#define InvalidRepOriginId
Definition: origin.h:33
uint32 magic
Definition: xact.h:302
int errmsg(const char *fmt,...)
Definition: elog.c:909
static GlobalTransaction MyLockedGxact
Definition: twophase.c:199
void XLogBeginInsert(void)
Definition: xloginsert.c:135
XLogRecPtr prepare_end_lsn
Definition: twophase.c:164

◆ FinishPreparedTransaction()

void FinishPreparedTransaction ( const char *  gid,
bool  isCommit 
)

Definition at line 1409 of file twophase.c.

References PROC_HDR::allProcs, Assert, AtEOXact_PgStat(), buf, DropRelationFiles(), GetUserId(), xl_xact_prepare::gidlen, HOLD_INTERRUPTS, xl_xact_prepare::initfileinval, LockGXact(), LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAXALIGN, xl_xact_prepare::nabortrels, xl_xact_prepare::ncommitrels, xl_xact_prepare::ninvalmsgs, xl_xact_prepare::nsubxacts, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::pgprocno, PredicateLockTwoPhaseFinish(), GlobalTransactionData::prepare_start_lsn, ProcArrayRemove(), ProcessRecords(), ProcGlobal, 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().

1410 {
1411  GlobalTransaction gxact;
1412  PGPROC *proc;
1413  TransactionId xid;
1414  char *buf;
1415  char *bufptr;
1416  TwoPhaseFileHeader *hdr;
1417  TransactionId latestXid;
1418  TransactionId *children;
1419  RelFileNode *commitrels;
1420  RelFileNode *abortrels;
1421  RelFileNode *delrels;
1422  int ndelrels;
1423  SharedInvalidationMessage *invalmsgs;
1424 
1425  /*
1426  * Validate the GID, and lock the GXACT to ensure that two backends do not
1427  * try to commit the same GID at once.
1428  */
1429  gxact = LockGXact(gid, GetUserId());
1430  proc = &ProcGlobal->allProcs[gxact->pgprocno];
1431  xid = gxact->xid;
1432 
1433  /*
1434  * Read and validate 2PC state data. State data will typically be stored
1435  * in WAL files if the LSN is after the last checkpoint record, or moved
1436  * to disk if for some reason they have lived for a long time.
1437  */
1438  if (gxact->ondisk)
1439  buf = ReadTwoPhaseFile(xid, false);
1440  else
1441  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, NULL);
1442 
1443 
1444  /*
1445  * Disassemble the header area
1446  */
1447  hdr = (TwoPhaseFileHeader *) buf;
1448  Assert(TransactionIdEquals(hdr->xid, xid));
1449  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1450  bufptr += MAXALIGN(hdr->gidlen);
1451  children = (TransactionId *) bufptr;
1452  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1453  commitrels = (RelFileNode *) bufptr;
1454  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1455  abortrels = (RelFileNode *) bufptr;
1456  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1457  invalmsgs = (SharedInvalidationMessage *) bufptr;
1458  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1459 
1460  /* compute latestXid among all children */
1461  latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1462 
1463  /* Prevent cancel/die interrupt while cleaning up */
1464  HOLD_INTERRUPTS();
1465 
1466  /*
1467  * The order of operations here is critical: make the XLOG entry for
1468  * commit or abort, then mark the transaction committed or aborted in
1469  * pg_xact, then remove its PGPROC from the global ProcArray (which means
1470  * TransactionIdIsInProgress will stop saying the prepared xact is in
1471  * progress), then run the post-commit or post-abort callbacks. The
1472  * callbacks will release the locks the transaction held.
1473  */
1474  if (isCommit)
1476  hdr->nsubxacts, children,
1477  hdr->ncommitrels, commitrels,
1478  hdr->ninvalmsgs, invalmsgs,
1479  hdr->initfileinval, gid);
1480  else
1482  hdr->nsubxacts, children,
1483  hdr->nabortrels, abortrels,
1484  gid);
1485 
1486  ProcArrayRemove(proc, latestXid);
1487 
1488  /*
1489  * In case we fail while running the callbacks, mark the gxact invalid so
1490  * no one else will try to commit/rollback, and so it will be recycled if
1491  * we fail after this point. It is still locked by our backend so it
1492  * won't go away yet.
1493  *
1494  * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1495  */
1496  gxact->valid = false;
1497 
1498  /*
1499  * We have to remove any files that were supposed to be dropped. For
1500  * consistency with the regular xact.c code paths, must do this before
1501  * releasing locks, so do it before running the callbacks.
1502  *
1503  * NB: this code knows that we couldn't be dropping any temp rels ...
1504  */
1505  if (isCommit)
1506  {
1507  delrels = commitrels;
1508  ndelrels = hdr->ncommitrels;
1509  }
1510  else
1511  {
1512  delrels = abortrels;
1513  ndelrels = hdr->nabortrels;
1514  }
1515 
1516  /* Make sure files supposed to be dropped are dropped */
1517  DropRelationFiles(delrels, ndelrels, false);
1518 
1519  /*
1520  * Handle cache invalidation messages.
1521  *
1522  * Relcache init file invalidation requires processing both before and
1523  * after we send the SI messages, only when committing. See
1524  * AtEOXact_Inval().
1525  */
1526  if (isCommit)
1527  {
1528  if (hdr->initfileinval)
1530  SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1531  if (hdr->initfileinval)
1533  }
1534 
1535  /*
1536  * Acquire the two-phase lock. We want to work on the two-phase callbacks
1537  * while holding it to avoid potential conflicts with other transactions
1538  * attempting to use the same GID, so the lock is released once the shared
1539  * memory state is cleared.
1540  */
1541  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1542 
1543  /* And now do the callbacks */
1544  if (isCommit)
1546  else
1548 
1549  PredicateLockTwoPhaseFinish(xid, isCommit);
1550 
1551  /* Clear shared memory state */
1552  RemoveGXact(gxact);
1553 
1554  /*
1555  * Release the lock as all callbacks are called and shared memory cleanup
1556  * is done.
1557  */
1558  LWLockRelease(TwoPhaseStateLock);
1559 
1560  /* Count the prepared xact as committed or aborted */
1561  AtEOXact_PgStat(isCommit, false);
1562 
1563  /*
1564  * And now we can clean up any files we may have left.
1565  */
1566  if (gxact->ondisk)
1567  RemoveTwoPhaseFile(xid, true);
1568 
1569  MyLockedGxact = NULL;
1570 
1572 
1573  pfree(buf);
1574 }
int32 ninvalmsgs
Definition: xact.h:311
static void RecordTransactionAbortPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileNode *rels, const char *gid)
Definition: twophase.c:2288
int32 nsubxacts
Definition: xact.h:308
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
uint32 TransactionId
Definition: c.h:587
int32 ncommitrels
Definition: xact.h:309
Oid GetUserId(void)
Definition: miscinit.c:495
TransactionId TransactionIdLatest(TransactionId mainxid, int nxids, const TransactionId *xids)
Definition: transam.c:365
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1580
const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:33
PROC_HDR * ProcGlobal
Definition: proc.c:80
static char * ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
Definition: twophase.c:1205
uint16 gidlen
Definition: xact.h:313
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
int32 nabortrels
Definition: xact.h:310
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:133
void pfree(void *pointer)
Definition: mcxt.c:1169
static GlobalTransaction LockGXact(const char *gid, Oid user)
Definition: twophase.c:556
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:552
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
void DropRelationFiles(RelFileNode *delrels, int ndelrels, bool isRedo)
Definition: md.c:1050
void AtEOXact_PgStat(bool isCommit, bool parallel)
Definition: pgstat.c:2464
void PredicateLockTwoPhaseFinish(TransactionId xid, bool isCommit)
Definition: predicate.c:5023
static char * buf
Definition: pg_test_fsync.c:68
const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:42
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6465
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1608
bool initfileinval
Definition: xact.h:312
void RelationCacheInitFilePreInvalidate(void)
Definition: relcache.c:6440
#define Assert(condition)
Definition: c.h:804
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
#define MAXALIGN(LEN)
Definition: c.h:757
void SendSharedInvalidMessages(const SharedInvalidationMessage *msgs, int n)
Definition: sinval.c:49
TransactionId xid
Definition: xact.h:304
TransactionId xid
Definition: twophase.c:165
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1326
static GlobalTransaction MyLockedGxact
Definition: twophase.c:199
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:131
PGPROC * allProcs
Definition: proc.h:318
Definition: proc.h:121
static void RecordTransactionCommitPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileNode *rels, int ninvalmsgs, SharedInvalidationMessage *invalmsgs, bool initfileinval, const char *gid)
Definition: twophase.c:2194

◆ LookupGXact()

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

Definition at line 2482 of file twophase.c.

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(), GlobalTransactionData::valid, GlobalTransactionData::xid, and XlogReadTwoPhaseData().

Referenced by apply_handle_rollback_prepared().

2484 {
2485  int i;
2486  bool found = false;
2487 
2488  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2489  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2490  {
2492 
2493  /* Ignore not-yet-valid GIDs. */
2494  if (gxact->valid && strcmp(gxact->gid, gid) == 0)
2495  {
2496  char *buf;
2497  TwoPhaseFileHeader *hdr;
2498 
2499  /*
2500  * We are not expecting collisions of GXACTs (same gid) between
2501  * publisher and subscribers, so we perform all I/O while holding
2502  * TwoPhaseStateLock for simplicity.
2503  *
2504  * To move the I/O out of the lock, we need to ensure that no
2505  * other backend commits the prepared xact in the meantime. We can
2506  * do this optimization if we encounter many collisions in GID
2507  * between publisher and subscriber.
2508  */
2509  if (gxact->ondisk)
2510  buf = ReadTwoPhaseFile(gxact->xid, false);
2511  else
2512  {
2513  Assert(gxact->prepare_start_lsn);
2514  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, NULL);
2515  }
2516 
2517  hdr = (TwoPhaseFileHeader *) buf;
2518 
2519  if (hdr->origin_lsn == prepare_end_lsn &&
2520  hdr->origin_timestamp == origin_prepare_timestamp)
2521  {
2522  found = true;
2523  pfree(buf);
2524  break;
2525  }
2526 
2527  pfree(buf);
2528  }
2529  }
2530  LWLockRelease(TwoPhaseStateLock);
2531  return found;
2532 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
static char * ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
Definition: twophase.c:1205
char gid[GIDSIZE]
Definition: twophase.c:172
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
void pfree(void *pointer)
Definition: mcxt.c:1169
static char * buf
Definition: pg_test_fsync.c:68
XLogRecPtr origin_lsn
Definition: xact.h:314
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
#define Assert(condition)
Definition: c.h:804
TimestampTz origin_timestamp
Definition: xact.h:315
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
TransactionId xid
Definition: twophase.c:165
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1326
int i

◆ MarkAsPreparing()

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

Definition at line 372 of file twophase.c.

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, and twophaseExitRegistered.

Referenced by PrepareTransaction().

374 {
375  GlobalTransaction gxact;
376  int i;
377 
378  if (strlen(gid) >= GIDSIZE)
379  ereport(ERROR,
380  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
381  errmsg("transaction identifier \"%s\" is too long",
382  gid)));
383 
384  /* fail immediately if feature is disabled */
385  if (max_prepared_xacts == 0)
386  ereport(ERROR,
387  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
388  errmsg("prepared transactions are disabled"),
389  errhint("Set max_prepared_transactions to a nonzero value.")));
390 
391  /* on first call, register the exit hook */
393  {
395  twophaseExitRegistered = true;
396  }
397 
398  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
399 
400  /* Check for conflicting GID */
401  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
402  {
403  gxact = TwoPhaseState->prepXacts[i];
404  if (strcmp(gxact->gid, gid) == 0)
405  {
406  ereport(ERROR,
408  errmsg("transaction identifier \"%s\" is already in use",
409  gid)));
410  }
411  }
412 
413  /* Get a free gxact from the freelist */
414  if (TwoPhaseState->freeGXacts == NULL)
415  ereport(ERROR,
416  (errcode(ERRCODE_OUT_OF_MEMORY),
417  errmsg("maximum number of prepared transactions reached"),
418  errhint("Increase max_prepared_transactions (currently %d).",
420  gxact = TwoPhaseState->freeGXacts;
421  TwoPhaseState->freeGXacts = gxact->next;
422 
423  MarkAsPreparingGuts(gxact, xid, gid, prepared_at, owner, databaseid);
424 
425  gxact->ondisk = false;
426 
427  /* And insert it into the active array */
430 
431  LWLockRelease(TwoPhaseStateLock);
432 
433  return gxact;
434 }
int errhint(const char *fmt,...)
Definition: elog.c:1156
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
GlobalTransaction freeGXacts
Definition: twophase.c:182
int errcode(int sqlerrcode)
Definition: elog.c:698
static bool twophaseExitRegistered
Definition: twophase.c:201
GlobalTransaction next
Definition: twophase.c:151
char gid[GIDSIZE]
Definition: twophase.c:172
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
static void MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:446
#define ERROR
Definition: elog.h:46
int max_prepared_xacts
Definition: twophase.c:117
#define GIDSIZE
Definition: xact.h:31
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:333
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
#define ereport(elevel,...)
Definition: elog.h:157
#define Assert(condition)
Definition: c.h:804
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
int errmsg(const char *fmt,...)
Definition: elog.c:909
int i
static void AtProcExit_Twophase(int code, Datum arg)
Definition: twophase.c:307
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:32

◆ PostPrepare_Twophase()

void PostPrepare_Twophase ( void  )

Definition at line 357 of file twophase.c.

References InvalidBackendId, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), and LWLockRelease().

Referenced by PrepareTransaction(), and RecoverPreparedTransactions().

358 {
359  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
361  LWLockRelease(TwoPhaseStateLock);
362 
363  MyLockedGxact = NULL;
364 }
BackendId locking_backend
Definition: twophase.c:168
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
#define InvalidBackendId
Definition: backendid.h:23
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
static GlobalTransaction MyLockedGxact
Definition: twophase.c:199

◆ PrepareRedoAdd()

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

Definition at line 2360 of file twophase.c.

References Assert, DEBUG2, elog, ereport, errcode(), errhint(), errmsg(), ERROR, TwoPhaseStateData::freeGXacts, GlobalTransactionData::gid, GlobalTransactionData::inredo, InvalidBackendId, InvalidRepOriginId, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockHeldByMeInMode(), max_prepared_xacts, MAXALIGN, 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, RecoveryInProgress(), replorigin_advance(), GlobalTransactionData::valid, GlobalTransactionData::xid, xl_xact_prepare::xid, and XLogRecPtrIsInvalid.

Referenced by restoreTwoPhaseData(), and xact_redo().

2362 {
2364  char *bufptr;
2365  const char *gid;
2366  GlobalTransaction gxact;
2367 
2368  Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2370 
2371  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2372  gid = (const char *) bufptr;
2373 
2374  /*
2375  * Reserve the GID for the given transaction in the redo code path.
2376  *
2377  * This creates a gxact struct and puts it into the active array.
2378  *
2379  * In redo, this struct is mainly used to track PREPARE/COMMIT entries in
2380  * shared memory. Hence, we only fill up the bare minimum contents here.
2381  * The gxact also gets marked with gxact->inredo set to true to indicate
2382  * that it got added in the redo phase
2383  */
2384 
2385  /* Get a free gxact from the freelist */
2386  if (TwoPhaseState->freeGXacts == NULL)
2387  ereport(ERROR,
2388  (errcode(ERRCODE_OUT_OF_MEMORY),
2389  errmsg("maximum number of prepared transactions reached"),
2390  errhint("Increase max_prepared_transactions (currently %d).",
2391  max_prepared_xacts)));
2392  gxact = TwoPhaseState->freeGXacts;
2393  TwoPhaseState->freeGXacts = gxact->next;
2394 
2395  gxact->prepared_at = hdr->prepared_at;
2396  gxact->prepare_start_lsn = start_lsn;
2397  gxact->prepare_end_lsn = end_lsn;
2398  gxact->xid = hdr->xid;
2399  gxact->owner = hdr->owner;
2401  gxact->valid = false;
2402  gxact->ondisk = XLogRecPtrIsInvalid(start_lsn);
2403  gxact->inredo = true; /* yes, added in redo */
2404  strcpy(gxact->gid, gid);
2405 
2406  /* And insert it into the active array */
2409 
2410  if (origin_id != InvalidRepOriginId)
2411  {
2412  /* recover apply progress */
2413  replorigin_advance(origin_id, hdr->origin_lsn, end_lsn,
2414  false /* backward */ , false /* WAL */ );
2415  }
2416 
2417  elog(DEBUG2, "added 2PC data in shared memory for transaction %u", gxact->xid);
2418 }
bool LWLockHeldByMeInMode(LWLock *l, LWLockMode mode)
Definition: lwlock.c:1937
int errhint(const char *fmt,...)
Definition: elog.c:1156
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
GlobalTransaction freeGXacts
Definition: twophase.c:182
int errcode(int sqlerrcode)
Definition: elog.c:698
void replorigin_advance(RepOriginId node, XLogRecPtr remote_commit, XLogRecPtr local_commit, bool go_backward, bool wal_log)
Definition: origin.c:872
GlobalTransaction next
Definition: twophase.c:151
bool RecoveryInProgress(void)
Definition: xlog.c:8328
char gid[GIDSIZE]
Definition: twophase.c:172
BackendId locking_backend
Definition: twophase.c:168
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
#define ERROR
Definition: elog.h:46
int max_prepared_xacts
Definition: twophase.c:117
#define DEBUG2
Definition: elog.h:24
static char * buf
Definition: pg_test_fsync.c:68
XLogRecPtr origin_lsn
Definition: xact.h:314
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
#define InvalidBackendId
Definition: backendid.h:23
#define ereport(elevel,...)
Definition: elog.h:157
#define Assert(condition)
Definition: c.h:804
#define MAXALIGN(LEN)
Definition: c.h:757
TransactionId xid
Definition: xact.h:304
#define InvalidRepOriginId
Definition: origin.h:33
TransactionId xid
Definition: twophase.c:165
TimestampTz prepared_at
Definition: twophase.c:154
int errmsg(const char *fmt,...)
Definition: elog.c:909
#define elog(elevel,...)
Definition: elog.h:232
TimestampTz prepared_at
Definition: xact.h:306
XLogRecPtr prepare_end_lsn
Definition: twophase.c:164

◆ PrepareRedoRemove()

void PrepareRedoRemove ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 2430 of file twophase.c.

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

Referenced by ProcessTwoPhaseBuffer(), and xact_redo().

2431 {
2432  GlobalTransaction gxact = NULL;
2433  int i;
2434  bool found = false;
2435 
2436  Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2438 
2439  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2440  {
2441  gxact = TwoPhaseState->prepXacts[i];
2442 
2443  if (gxact->xid == xid)
2444  {
2445  Assert(gxact->inredo);
2446  found = true;
2447  break;
2448  }
2449  }
2450 
2451  /*
2452  * Just leave if there is nothing, this is expected during WAL replay.
2453  */
2454  if (!found)
2455  return;
2456 
2457  /*
2458  * And now we can clean up any files we may have left.
2459  */
2460  elog(DEBUG2, "removing 2PC data for transaction %u", xid);
2461  if (gxact->ondisk)
2462  RemoveTwoPhaseFile(xid, giveWarning);
2463  RemoveGXact(gxact);
2464 }
bool LWLockHeldByMeInMode(LWLock *l, LWLockMode mode)
Definition: lwlock.c:1937
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
bool RecoveryInProgress(void)
Definition: xlog.c:8328
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
#define DEBUG2
Definition: elog.h:24
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1608
#define Assert(condition)
Definition: c.h:804
TransactionId xid
Definition: twophase.c:165
#define elog(elevel,...)
Definition: elog.h:232
int i

◆ PrescanPreparedTransactions()

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

Definition at line 1851 of file twophase.c.

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

Referenced by StartupXLOG(), and xlog_redo().

1852 {
1854  TransactionId origNextXid = XidFromFullTransactionId(nextXid);
1855  TransactionId result = origNextXid;
1856  TransactionId *xids = NULL;
1857  int nxids = 0;
1858  int allocsize = 0;
1859  int i;
1860 
1861  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1862  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1863  {
1864  TransactionId xid;
1865  char *buf;
1867 
1868  Assert(gxact->inredo);
1869 
1870  xid = gxact->xid;
1871 
1872  buf = ProcessTwoPhaseBuffer(xid,
1873  gxact->prepare_start_lsn,
1874  gxact->ondisk, false, true);
1875 
1876  if (buf == NULL)
1877  continue;
1878 
1879  /*
1880  * OK, we think this file is valid. Incorporate xid into the
1881  * running-minimum result.
1882  */
1883  if (TransactionIdPrecedes(xid, result))
1884  result = xid;
1885 
1886  if (xids_p)
1887  {
1888  if (nxids == allocsize)
1889  {
1890  if (nxids == 0)
1891  {
1892  allocsize = 10;
1893  xids = palloc(allocsize * sizeof(TransactionId));
1894  }
1895  else
1896  {
1897  allocsize = allocsize * 2;
1898  xids = repalloc(xids, allocsize * sizeof(TransactionId));
1899  }
1900  }
1901  xids[nxids++] = xid;
1902  }
1903 
1904  pfree(buf);
1905  }
1906  LWLockRelease(TwoPhaseStateLock);
1907 
1908  if (xids_p)
1909  {
1910  *xids_p = xids;
1911  *nxids_p = nxids;
1912  }
1913 
1914  return result;
1915 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
uint32 TransactionId
Definition: c.h:587
FullTransactionId nextXid
Definition: transam.h:220
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
#define XidFromFullTransactionId(x)
Definition: transam.h:48
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
void pfree(void *pointer)
Definition: mcxt.c:1169
static char * buf
Definition: pg_test_fsync.c:68
VariableCache ShmemVariableCache
Definition: varsup.c:34
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2074
#define Assert(condition)
Definition: c.h:804
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1182
TransactionId xid
Definition: twophase.c:165
void * palloc(Size size)
Definition: mcxt.c:1062
int i

◆ RecoverPreparedTransactions()

void RecoverPreparedTransactions ( void  )

Definition at line 1973 of file twophase.c.

References Assert, buf, xl_xact_prepare::database, ereport, errmsg(), GlobalTransactionData::gid, xl_xact_prepare::gidlen, GXactLoadSubxactData(), i, InHotStandby, GlobalTransactionData::inredo, LOG, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MarkAsPrepared(), MarkAsPreparingGuts(), MAXALIGN, xl_xact_prepare::nabortrels, xl_xact_prepare::ncommitrels, 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, GlobalTransactionData::xid, and xl_xact_prepare::xid.

Referenced by StartupXLOG().

1974 {
1975  int i;
1976 
1977  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1978  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1979  {
1980  TransactionId xid;
1981  char *buf;
1983  char *bufptr;
1984  TwoPhaseFileHeader *hdr;
1985  TransactionId *subxids;
1986  const char *gid;
1987 
1988  xid = gxact->xid;
1989 
1990  /*
1991  * Reconstruct subtrans state for the transaction --- needed because
1992  * pg_subtrans is not preserved over a restart. Note that we are
1993  * linking all the subtransactions directly to the top-level XID;
1994  * there may originally have been a more complex hierarchy, but
1995  * there's no need to restore that exactly. It's possible that
1996  * SubTransSetParent has been set before, if the prepared transaction
1997  * generated xid assignment records.
1998  */
1999  buf = ProcessTwoPhaseBuffer(xid,
2000  gxact->prepare_start_lsn,
2001  gxact->ondisk, true, false);
2002  if (buf == NULL)
2003  continue;
2004 
2005  ereport(LOG,
2006  (errmsg("recovering prepared transaction %u from shared memory", xid)));
2007 
2008  hdr = (TwoPhaseFileHeader *) buf;
2009  Assert(TransactionIdEquals(hdr->xid, xid));
2010  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2011  gid = (const char *) bufptr;
2012  bufptr += MAXALIGN(hdr->gidlen);
2013  subxids = (TransactionId *) bufptr;
2014  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
2015  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
2016  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
2017  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
2018 
2019  /*
2020  * Recreate its GXACT and dummy PGPROC. But, check whether it was
2021  * added in redo and already has a shmem entry for it.
2022  */
2023  MarkAsPreparingGuts(gxact, xid, gid,
2024  hdr->prepared_at,
2025  hdr->owner, hdr->database);
2026 
2027  /* recovered, so reset the flag for entries generated by redo */
2028  gxact->inredo = false;
2029 
2030  GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
2031  MarkAsPrepared(gxact, true);
2032 
2033  LWLockRelease(TwoPhaseStateLock);
2034 
2035  /*
2036  * Recover other state (notably locks) using resource managers.
2037  */
2039 
2040  /*
2041  * Release locks held by the standby process after we process each
2042  * prepared transaction. As a result, we don't need too many
2043  * additional locks at any one time.
2044  */
2045  if (InHotStandby)
2046  StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
2047 
2048  /*
2049  * We're done with recovering this transaction. Clear MyLockedGxact,
2050  * like we do in PrepareTransaction() during normal operation.
2051  */
2053 
2054  pfree(buf);
2055 
2056  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2057  }
2058 
2059  LWLockRelease(TwoPhaseStateLock);
2060 }
int32 ninvalmsgs
Definition: xact.h:311
int32 nsubxacts
Definition: xact.h:308
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
uint32 TransactionId
Definition: c.h:587
int32 ncommitrels
Definition: xact.h:309
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1580
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:24
uint16 gidlen
Definition: xact.h:313
#define LOG
Definition: elog.h:26
Oid database
Definition: xact.h:305
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
int32 nabortrels
Definition: xact.h:310
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
void pfree(void *pointer)
Definition: mcxt.c:1169
static void MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:446
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:508
static char * buf
Definition: pg_test_fsync.c:68
#define InHotStandby
Definition: xlogutils.h:57
void StandbyReleaseLockTree(TransactionId xid, int nsubxids, TransactionId *subxids)
Definition: standby.c:1035
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2074
#define ereport(elevel,...)
Definition: elog.h:157
#define Assert(condition)
Definition: c.h:804
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
#define MAXALIGN(LEN)
Definition: c.h:757
static void MarkAsPrepared(GlobalTransaction gxact, bool lock_held)
Definition: twophase.c:534
TransactionId xid
Definition: xact.h:304
TransactionId xid
Definition: twophase.c:165
int errmsg(const char *fmt,...)
Definition: elog.c:909
void PostPrepare_Twophase(void)
Definition: twophase.c:357
int i
TimestampTz prepared_at
Definition: xact.h:306

◆ restoreTwoPhaseData()

void restoreTwoPhaseData ( void  )

Definition at line 1789 of file twophase.c.

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

Referenced by StartupXLOG().

1790 {
1791  DIR *cldir;
1792  struct dirent *clde;
1793 
1794  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1795  cldir = AllocateDir(TWOPHASE_DIR);
1796  while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1797  {
1798  if (strlen(clde->d_name) == 8 &&
1799  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1800  {
1801  TransactionId xid;
1802  char *buf;
1803 
1804  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1805 
1807  true, false, false);
1808  if (buf == NULL)
1809  continue;
1810 
1813  }
1814  }
1815  LWLockRelease(TwoPhaseStateLock);
1816  FreeDir(cldir);
1817 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
uint32 TransactionId
Definition: c.h:587
Definition: dirent.h:9
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
Definition: dirent.c:25
static char * buf
Definition: pg_test_fsync.c:68
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2720
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2074
void PrepareRedoAdd(char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn, RepOriginId origin_id)
Definition: twophase.c:2360
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2786
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
#define InvalidRepOriginId
Definition: origin.h:33
#define TWOPHASE_DIR
Definition: twophase.c:114
char d_name[MAX_PATH]
Definition: dirent.h:15
int FreeDir(DIR *dir)
Definition: fd.c:2838

◆ StandbyRecoverPreparedTransactions()

void StandbyRecoverPreparedTransactions ( void  )

Definition at line 1932 of file twophase.c.

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

Referenced by StartupXLOG(), and xlog_redo().

1933 {
1934  int i;
1935 
1936  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1937  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1938  {
1939  TransactionId xid;
1940  char *buf;
1942 
1943  Assert(gxact->inredo);
1944 
1945  xid = gxact->xid;
1946 
1947  buf = ProcessTwoPhaseBuffer(xid,
1948  gxact->prepare_start_lsn,
1949  gxact->ondisk, false, false);
1950  if (buf != NULL)
1951  pfree(buf);
1952  }
1953  LWLockRelease(TwoPhaseStateLock);
1954 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
uint32 TransactionId
Definition: c.h:587
XLogRecPtr prepare_start_lsn
Definition: twophase.c:163
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1803
void pfree(void *pointer)
Definition: mcxt.c:1169
static char * buf
Definition: pg_test_fsync.c:68
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:188
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2074
#define Assert(condition)
Definition: c.h:804
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1199
TransactionId xid
Definition: twophase.c:165
int i

◆ StandbyTransactionIdIsPrepared()

bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1381 of file twophase.c.

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

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

1382 {
1383  char *buf;
1384  TwoPhaseFileHeader *hdr;
1385  bool result;
1386 
1388 
1389  if (max_prepared_xacts <= 0)
1390  return false; /* nothing to do */
1391 
1392  /* Read and validate file */
1393  buf = ReadTwoPhaseFile(xid, true);
1394  if (buf == NULL)
1395  return false;
1396 
1397  /* Check header also */
1398  hdr = (TwoPhaseFileHeader *) buf;
1399  result = TransactionIdEquals(hdr->xid, xid);
1400  pfree(buf);
1401 
1402  return result;
1403 }
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
static char * ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
Definition: twophase.c:1205
void pfree(void *pointer)
Definition: mcxt.c:1169
int max_prepared_xacts
Definition: twophase.c:117
static char * buf
Definition: pg_test_fsync.c:68
#define Assert(condition)
Definition: c.h:804
TransactionId xid
Definition: xact.h:304
#define TransactionIdIsValid(xid)
Definition: transam.h:41

◆ StartPrepare()

void StartPrepare ( GlobalTransaction  gxact)

Definition at line 983 of file twophase.c.

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

Referenced by PrepareTransaction().

984 {
985  PGPROC *proc = &ProcGlobal->allProcs[gxact->pgprocno];
986  TransactionId xid = gxact->xid;
987  TwoPhaseFileHeader hdr;
988  TransactionId *children;
989  RelFileNode *commitrels;
990  RelFileNode *abortrels;
991  SharedInvalidationMessage *invalmsgs;
992 
993  /* Initialize linked list */
994  records.head = palloc0(sizeof(StateFileChunk));
995  records.head->len = 0;
996  records.head->next = NULL;
997 
998  records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
1000 
1002  records.num_chunks = 1;
1003 
1004  records.total_len = 0;
1005 
1006  /* Create header */
1007  hdr.magic = TWOPHASE_MAGIC;
1008  hdr.total_len = 0; /* EndPrepare will fill this in */
1009  hdr.xid = xid;
1010  hdr.database = proc->databaseId;
1011  hdr.prepared_at = gxact->prepared_at;
1012  hdr.owner = gxact->owner;
1013  hdr.nsubxacts = xactGetCommittedChildren(&children);
1014  hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
1015  hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
1017  &hdr.initfileinval);
1018  hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
1019 
1020  save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
1021  save_state_data(gxact->gid, hdr.gidlen);
1022 
1023  /*
1024  * Add the additional info about subxacts, deletable files and cache
1025  * invalidation messages.
1026  */
1027  if (hdr.nsubxacts > 0)
1028  {
1029  save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
1030  /* While we have the child-xact data, stuff it in the gxact too */
1031  GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
1032  }
1033  if (hdr.ncommitrels > 0)
1034  {
1035  save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileNode));
1036  pfree(commitrels);
1037  }
1038  if (hdr.nabortrels > 0)
1039  {
1040  save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileNode));
1041  pfree(abortrels);
1042  }
1043  if (hdr.ninvalmsgs > 0)
1044  {
1045  save_state_data(invalmsgs,
1046  hdr.ninvalmsgs * sizeof(SharedInvalidationMessage));
1047  pfree(invalmsgs);
1048  }
1049 }
int32 ninvalmsgs
Definition: xact.h:311
int xactGetCommittedChildren(TransactionId **ptr)
Definition: xact.c:5493
int32 nsubxacts
Definition: xact.h:308
uint32 TransactionId
Definition: c.h:587
int32 ncommitrels
Definition: xact.h:309
StateFileChunk * tail
Definition: twophase.c:939
PROC_HDR * ProcGlobal
Definition: proc.c:80
uint16 gidlen
Definition: xact.h:313
uint32 num_chunks
Definition: twophase.c:940
char gid[GIDSIZE]
Definition: twophase.c:172
Oid database
Definition: xact.h:305
char * data
Definition: twophase.c:931
int32 nabortrels
Definition: xact.h:310
void pfree(void *pointer)
Definition: mcxt.c:1169
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:508
uint32 bytes_free
Definition: twophase.c:941
int smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr)
Definition: storage.c:832
uint32 total_len
Definition: xact.h:303
uint32 len
Definition: twophase.c:932
Oid databaseId
Definition: proc.h:154
static struct xllist records
uint32 total_len
Definition: twophase.c:942
struct StateFileChunk * next
Definition: twophase.c:933
void * palloc0(Size size)
Definition: mcxt.c:1093
#define TWOPHASE_MAGIC
Definition: twophase.c:907
bool initfileinval
Definition: xact.h:312
#define Max(x, y)
Definition: c.h:980
StateFileChunk * head
Definition: twophase.c:938
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:955
TransactionId xid
Definition: xact.h:304
TransactionId xid
Definition: twophase.c:165
TimestampTz prepared_at
Definition: twophase.c:154
uint32 magic
Definition: xact.h:302
void * palloc(Size size)
Definition: mcxt.c:1062
int xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs, bool *RelcacheInitFileInval)
Definition: inval.c:863
TimestampTz prepared_at
Definition: xact.h:306
PGPROC * allProcs
Definition: proc.h:318
Definition: proc.h:121

◆ TwoPhaseGetDummyBackendId()

BackendId TwoPhaseGetDummyBackendId ( TransactionId  xid,
bool  lock_held 
)

Definition at line 859 of file twophase.c.

References GlobalTransactionData::dummyBackendId, and TwoPhaseGetGXact().

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

860 {
861  GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
862 
863  return gxact->dummyBackendId;
864 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid, bool lock_held)
Definition: twophase.c:806
BackendId dummyBackendId
Definition: twophase.c:153

◆ TwoPhaseGetDummyProc()

PGPROC* TwoPhaseGetDummyProc ( TransactionId  xid,
bool  lock_held 
)

Definition at line 874 of file twophase.c.

References PROC_HDR::allProcs, GlobalTransactionData::pgprocno, ProcGlobal, and TwoPhaseGetGXact().

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

875 {
876  GlobalTransaction gxact = TwoPhaseGetGXact(xid, lock_held);
877 
878  return &ProcGlobal->allProcs[gxact->pgprocno];
879 }
PROC_HDR * ProcGlobal
Definition: proc.c:80
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid, bool lock_held)
Definition: twophase.c:806
PGPROC * allProcs
Definition: proc.h:318

◆ TwoPhaseShmemInit()

void TwoPhaseShmemInit ( void  )

Definition at line 252 of file twophase.c.

References Assert, GlobalTransactionData::dummyBackendId, TwoPhaseStateData::freeGXacts, i, IsUnderPostmaster, max_prepared_xacts, MAXALIGN, MaxBackends, GlobalTransactionData::next, TwoPhaseStateData::numPrepXacts, offsetof, PGPROC::pgprocno, GlobalTransactionData::pgprocno, PreparedXactProcs, ShmemInitStruct(), and TwoPhaseShmemSize().

Referenced by CreateSharedMemoryAndSemaphores().

253 {
254  bool found;
255 
256  TwoPhaseState = ShmemInitStruct("Prepared Transaction Table",
258  &found);
259  if (!IsUnderPostmaster)
260  {
261  GlobalTransaction gxacts;
262  int i;
263 
264  Assert(!found);
265  TwoPhaseState->freeGXacts = NULL;
267 
268  /*
269  * Initialize the linked list of free GlobalTransactionData structs
270  */
271  gxacts = (GlobalTransaction)
272  ((char *) TwoPhaseState +
273  MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) +
275  for (i = 0; i < max_prepared_xacts; i++)
276  {
277  /* insert into linked list */
278  gxacts[i].next = TwoPhaseState->freeGXacts;
279  TwoPhaseState->freeGXacts = &gxacts[i];
280 
281  /* associate it with a PGPROC assigned by InitProcGlobal */
283 
284  /*
285  * Assign a unique ID for each dummy proc, so that the range of
286  * dummy backend IDs immediately follows the range of normal
287  * backend IDs. We don't dare to assign a real backend ID to dummy
288  * procs, because prepared transactions don't take part in cache
289  * invalidation like a real backend ID would imply, but having a
290  * unique ID for them is nevertheless handy. This arrangement
291  * allows you to allocate an array of size (MaxBackends +
292  * max_prepared_xacts + 1), and have a slot for every backend and
293  * prepared transaction. Currently multixact.c uses that
294  * technique.
295  */
296  gxacts[i].dummyBackendId = MaxBackends + 1 + i;
297  }
298  }
299  else
300  Assert(found);
301 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:191
GlobalTransaction freeGXacts
Definition: twophase.c:182
PGPROC * PreparedXactProcs
Definition: proc.c:82
Size TwoPhaseShmemSize(void)
Definition: twophase.c:236
GlobalTransaction next
Definition: twophase.c:151
struct GlobalTransactionData * GlobalTransaction
Definition: twophase.h:26
int max_prepared_xacts
Definition: twophase.c:117
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:396
int MaxBackends
Definition: globals.c:139
bool IsUnderPostmaster
Definition: globals.c:112
#define Assert(condition)
Definition: c.h:804
#define MAXALIGN(LEN)
Definition: c.h:757
int pgprocno
Definition: proc.h:150
int i
#define offsetof(type, field)
Definition: c.h:727
BackendId dummyBackendId
Definition: twophase.c:153

◆ TwoPhaseShmemSize()

Size TwoPhaseShmemSize ( void  )

Definition at line 236 of file twophase.c.

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

Referenced by CalculateShmemSize(), and TwoPhaseShmemInit().

237 {
238  Size size;
239 
240  /* Need the fixed struct, the array of pointers, and the GTD structs */
241  size = offsetof(TwoPhaseStateData, prepXacts);
242  size = add_size(size, mul_size(max_prepared_xacts,
243  sizeof(GlobalTransaction)));
244  size = MAXALIGN(size);
245  size = add_size(size, mul_size(max_prepared_xacts,
246  sizeof(GlobalTransactionData)));
247 
248  return size;
249 }
int max_prepared_xacts
Definition: twophase.c:117
Size mul_size(Size s1, Size s2)
Definition: shmem.c:519
Size add_size(Size s1, Size s2)
Definition: shmem.c:502
size_t Size
Definition: c.h:540
#define MAXALIGN(LEN)
Definition: c.h:757
#define offsetof(type, field)
Definition: c.h:727

Variable Documentation

◆ max_prepared_xacts