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twophase.h File Reference
#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
GlobalTransactionData
GlobalTransaction
 

Functions

Size TwoPhaseShmemSize (void)
 
void TwoPhaseShmemInit (void)
 
void AtAbort_Twophase (void)
 
void PostPrepare_Twophase (void)
 
PGPROCTwoPhaseGetDummyProc (TransactionId xid)
 
BackendId TwoPhaseGetDummyBackendId (TransactionId xid)
 
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 (bool overwriteOK)
 
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)
 
void PrepareRedoRemove (TransactionId xid, bool giveWarning)
 
void restoreTwoPhaseData (void)
 

Variables

int max_prepared_xacts
 

Typedef Documentation

Definition at line 25 of file twophase.h.

Function Documentation

void AtAbort_Twophase ( void  )

Definition at line 317 of file twophase.c.

References InvalidBackendId, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), NULL, 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  if (!MyLockedGxact->valid)
343  {
345  }
346  else
347  {
348  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
349 
351 
352  LWLockRelease(TwoPhaseStateLock);
353  }
355 }
BackendId locking_backend
Definition: twophase.c:172
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
#define InvalidBackendId
Definition: backendid.h:23
#define NULL
Definition: c.h:229
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
static GlobalTransaction MyLockedGxact
Definition: twophase.c:200
void CheckPointTwoPhase ( XLogRecPtr  redo_horizon)

Definition at line 1650 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().

1651 {
1652  int i;
1653  int serialized_xacts = 0;
1654 
1655  if (max_prepared_xacts <= 0)
1656  return; /* nothing to do */
1657 
1658  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1659 
1660  /*
1661  * We are expecting there to be zero GXACTs that need to be copied to
1662  * disk, so we perform all I/O while holding TwoPhaseStateLock for
1663  * simplicity. This prevents any new xacts from preparing while this
1664  * occurs, which shouldn't be a problem since the presence of long-lived
1665  * prepared xacts indicates the transaction manager isn't active.
1666  *
1667  * It's also possible to move I/O out of the lock, but on every error we
1668  * should check whether somebody committed our transaction in different
1669  * backend. Let's leave this optimization for future, if somebody will
1670  * spot that this place cause bottleneck.
1671  *
1672  * Note that it isn't possible for there to be a GXACT with a
1673  * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1674  * because of the efforts with delayChkpt.
1675  */
1676  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1677  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1678  {
1679  /* Note that we are using gxact not pgxact so this works in recovery also */
1681 
1682  if ((gxact->valid || gxact->inredo) &&
1683  !gxact->ondisk &&
1684  gxact->prepare_end_lsn <= redo_horizon)
1685  {
1686  char *buf;
1687  int len;
1688 
1689  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, &len);
1690  RecreateTwoPhaseFile(gxact->xid, buf, len);
1691  gxact->ondisk = true;
1694  pfree(buf);
1695  serialized_xacts++;
1696  }
1697  }
1698  LWLockRelease(TwoPhaseStateLock);
1699 
1700  /*
1701  * Flush unconditionally the parent directory to make any information
1702  * durable on disk. Two-phase files could have been removed and those
1703  * removals need to be made persistent as well as any files newly created
1704  * previously since the last checkpoint.
1705  */
1706  fsync_fname(TWOPHASE_DIR, true);
1707 
1708  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1709 
1710  if (log_checkpoints && serialized_xacts > 0)
1711  ereport(LOG,
1712  (errmsg_plural("%u two-phase state file was written "
1713  "for a long-running prepared transaction",
1714  "%u two-phase state files were written "
1715  "for long-running prepared transactions",
1716  serialized_xacts,
1717  serialized_xacts)));
1718 }
bool log_checkpoints
Definition: xlog.c:102
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:850
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:567
#define LOG
Definition: elog.h:26
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
int max_prepared_xacts
Definition: twophase.c:117
static char * buf
Definition: pg_test_fsync.c:66
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
static void RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
Definition: twophase.c:1568
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
#define TWOPHASE_DIR
Definition: twophase.c:114
TransactionId xid
Definition: twophase.c:169
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1297
int i
XLogRecPtr prepare_end_lsn
Definition: twophase.c:168
void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1065 of file twophase.c.

References Assert, StateFileChunk::data, PGXACT::delayChkpt, END_CRIT_SECTION, ereport, errcode(), errmsg(), ERROR, xllist::head, StateFileChunk::len, TwoPhaseFileHeader::magic, MarkAsPrepared(), MaxAllocSize, MyPgXact, StateFileChunk::next, NULL, xllist::num_chunks, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, ProcLastRecPtr, records, RegisterTwoPhaseRecord(), START_CRIT_SECTION, SyncRepWaitForLSN(), xllist::tail, TwoPhaseFileHeader::total_len, xllist::total_len, TWOPHASE_MAGIC, TWOPHASE_RM_END_ID, XLOG_XACT_PREPARE, XLogBeginInsert(), XLogEnsureRecordSpace(), XLogFlush(), XLogInsert(), and XLogRegisterData().

Referenced by PrepareTransaction().

1066 {
1067  TwoPhaseFileHeader *hdr;
1068  StateFileChunk *record;
1069 
1070  /* Add the end sentinel to the list of 2PC records */
1072  NULL, 0);
1073 
1074  /* Go back and fill in total_len in the file header record */
1075  hdr = (TwoPhaseFileHeader *) records.head->data;
1076  Assert(hdr->magic == TWOPHASE_MAGIC);
1077  hdr->total_len = records.total_len + sizeof(pg_crc32c);
1078 
1079  /*
1080  * If the data size exceeds MaxAllocSize, we won't be able to read it in
1081  * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1082  * where we write data to file and then re-read at commit time.
1083  */
1084  if (hdr->total_len > MaxAllocSize)
1085  ereport(ERROR,
1086  (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1087  errmsg("two-phase state file maximum length exceeded")));
1088 
1089  /*
1090  * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1091  * cover us, so no need to calculate a separate CRC.
1092  *
1093  * We have to set delayChkpt here, too; otherwise a checkpoint starting
1094  * immediately after the WAL record is inserted could complete without
1095  * fsync'ing our state file. (This is essentially the same kind of race
1096  * condition as the COMMIT-to-clog-write case that RecordTransactionCommit
1097  * uses delayChkpt for; see notes there.)
1098  *
1099  * We save the PREPARE record's location in the gxact for later use by
1100  * CheckPointTwoPhase.
1101  */
1103 
1105 
1106  MyPgXact->delayChkpt = true;
1107 
1108  XLogBeginInsert();
1109  for (record = records.head; record != NULL; record = record->next)
1110  XLogRegisterData(record->data, record->len);
1111  gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1112  XLogFlush(gxact->prepare_end_lsn);
1113 
1114  /* If we crash now, we have prepared: WAL replay will fix things */
1115 
1116  /* Store record's start location to read that later on Commit */
1118 
1119  /*
1120  * Mark the prepared transaction as valid. As soon as xact.c marks
1121  * MyPgXact as not running our XID (which it will do immediately after
1122  * this function returns), others can commit/rollback the xact.
1123  *
1124  * NB: a side effect of this is to make a dummy ProcArray entry for the
1125  * prepared XID. This must happen before we clear the XID from MyPgXact,
1126  * else there is a window where the XID is not running according to
1127  * TransactionIdIsInProgress, and onlookers would be entitled to assume
1128  * the xact crashed. Instead we have a window where the same XID appears
1129  * twice in ProcArray, which is OK.
1130  */
1131  MarkAsPrepared(gxact);
1132 
1133  /*
1134  * Now we can mark ourselves as out of the commit critical section: a
1135  * checkpoint starting after this will certainly see the gxact as a
1136  * candidate for fsyncing.
1137  */
1138  MyPgXact->delayChkpt = false;
1139 
1140  /*
1141  * Remember that we have this GlobalTransaction entry locked for us. If
1142  * we crash after this point, it's too late to abort, but we must unlock
1143  * it so that the prepared transaction can be committed or rolled back.
1144  */
1145  MyLockedGxact = gxact;
1146 
1147  END_CRIT_SECTION();
1148 
1149  /*
1150  * Wait for synchronous replication, if required.
1151  *
1152  * Note that at this stage we have marked the prepare, but still show as
1153  * running in the procarray (twice!) and continue to hold locks.
1154  */
1155  SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1156 
1158  records.num_chunks = 0;
1159 }
#define XLOG_XACT_PREPARE
Definition: xact.h:135
StateFileChunk * tail
Definition: twophase.c:948
uint32 pg_crc32c
Definition: pg_crc32c.h:38
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:336
void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
Definition: syncrep.c:146
#define END_CRIT_SECTION()
Definition: miscadmin.h:132
#define START_CRIT_SECTION()
Definition: miscadmin.h:130
int errcode(int sqlerrcode)
Definition: elog.c:575
#define TWOPHASE_RM_END_ID
Definition: twophase_rmgr.h:24
uint32 num_chunks
Definition: twophase.c:949
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2758
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1165
PGXACT * MyPgXact
Definition: proc.c:68
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
char * data
Definition: twophase.c:940
#define ERROR
Definition: elog.h:43
uint32 len
Definition: twophase.c:941
#define ereport(elevel, rest)
Definition: elog.h:122
bool delayChkpt
Definition: proc.h:220
uint32 total_len
Definition: twophase.c:951
#define MaxAllocSize
Definition: memutils.h:40
struct StateFileChunk * next
Definition: twophase.c:942
void XLogRegisterData(char *data, int len)
Definition: xloginsert.c:323
XLogRecPtr XLogInsert(RmgrId rmid, uint8 info)
Definition: xloginsert.c:415
#define TWOPHASE_MAGIC
Definition: twophase.c:902
StateFileChunk * head
Definition: twophase.c:947
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void MarkAsPrepared(GlobalTransaction gxact)
Definition: twophase.c:536
void XLogEnsureRecordSpace(int max_block_id, int ndatas)
Definition: xloginsert.c:146
int errmsg(const char *fmt,...)
Definition: elog.c:797
static GlobalTransaction MyLockedGxact
Definition: twophase.c:200
static struct xllist records
void XLogBeginInsert(void)
Definition: xloginsert.c:120
XLogRecPtr prepare_end_lsn
Definition: twophase.c:168
void FinishPreparedTransaction ( const char *  gid,
bool  isCommit 
)

Definition at line 1368 of file twophase.c.

References PROC_HDR::allPgXact, PROC_HDR::allProcs, Assert, AtEOXact_PgStat(), buf, GetUserId(), TwoPhaseFileHeader::gidlen, i, TwoPhaseFileHeader::initfileinval, InvalidBackendId, LockGXact(), MAXALIGN, TwoPhaseFileHeader::nabortrels, TwoPhaseFileHeader::ncommitrels, TwoPhaseFileHeader::ninvalmsgs, TwoPhaseFileHeader::nsubxacts, NULL, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::pgprocno, PredicateLockTwoPhaseFinish(), GlobalTransactionData::prepare_start_lsn, ProcArrayRemove(), ProcessRecords(), ProcGlobal, ReadTwoPhaseFile(), RecordTransactionAbortPrepared(), RecordTransactionCommitPrepared(), RelationCacheInitFilePostInvalidate(), RelationCacheInitFilePreInvalidate(), RemoveGXact(), RemoveTwoPhaseFile(), SendSharedInvalidMessages(), smgrclose(), smgrdounlink(), smgropen(), TransactionIdEquals, TransactionIdLatest(), twophase_postabort_callbacks, twophase_postcommit_callbacks, GlobalTransactionData::valid, PGXACT::xid, TwoPhaseFileHeader::xid, and XlogReadTwoPhaseData().

Referenced by standard_ProcessUtility().

1369 {
1370  GlobalTransaction gxact;
1371  PGPROC *proc;
1372  PGXACT *pgxact;
1373  TransactionId xid;
1374  char *buf;
1375  char *bufptr;
1376  TwoPhaseFileHeader *hdr;
1377  TransactionId latestXid;
1378  TransactionId *children;
1379  RelFileNode *commitrels;
1380  RelFileNode *abortrels;
1381  RelFileNode *delrels;
1382  int ndelrels;
1383  SharedInvalidationMessage *invalmsgs;
1384  int i;
1385 
1386  /*
1387  * Validate the GID, and lock the GXACT to ensure that two backends do not
1388  * try to commit the same GID at once.
1389  */
1390  gxact = LockGXact(gid, GetUserId());
1391  proc = &ProcGlobal->allProcs[gxact->pgprocno];
1392  pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
1393  xid = pgxact->xid;
1394 
1395  /*
1396  * Read and validate 2PC state data. State data will typically be stored
1397  * in WAL files if the LSN is after the last checkpoint record, or moved
1398  * to disk if for some reason they have lived for a long time.
1399  */
1400  if (gxact->ondisk)
1401  buf = ReadTwoPhaseFile(xid, true);
1402  else
1404 
1405 
1406  /*
1407  * Disassemble the header area
1408  */
1409  hdr = (TwoPhaseFileHeader *) buf;
1410  Assert(TransactionIdEquals(hdr->xid, xid));
1411  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1412  bufptr += MAXALIGN(hdr->gidlen);
1413  children = (TransactionId *) bufptr;
1414  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1415  commitrels = (RelFileNode *) bufptr;
1416  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1417  abortrels = (RelFileNode *) bufptr;
1418  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1419  invalmsgs = (SharedInvalidationMessage *) bufptr;
1420  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1421 
1422  /* compute latestXid among all children */
1423  latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1424 
1425  /*
1426  * The order of operations here is critical: make the XLOG entry for
1427  * commit or abort, then mark the transaction committed or aborted in
1428  * pg_xact, then remove its PGPROC from the global ProcArray (which means
1429  * TransactionIdIsInProgress will stop saying the prepared xact is in
1430  * progress), then run the post-commit or post-abort callbacks. The
1431  * callbacks will release the locks the transaction held.
1432  */
1433  if (isCommit)
1435  hdr->nsubxacts, children,
1436  hdr->ncommitrels, commitrels,
1437  hdr->ninvalmsgs, invalmsgs,
1438  hdr->initfileinval);
1439  else
1441  hdr->nsubxacts, children,
1442  hdr->nabortrels, abortrels);
1443 
1444  ProcArrayRemove(proc, latestXid);
1445 
1446  /*
1447  * In case we fail while running the callbacks, mark the gxact invalid so
1448  * no one else will try to commit/rollback, and so it will be recycled if
1449  * we fail after this point. It is still locked by our backend so it
1450  * won't go away yet.
1451  *
1452  * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1453  */
1454  gxact->valid = false;
1455 
1456  /*
1457  * We have to remove any files that were supposed to be dropped. For
1458  * consistency with the regular xact.c code paths, must do this before
1459  * releasing locks, so do it before running the callbacks.
1460  *
1461  * NB: this code knows that we couldn't be dropping any temp rels ...
1462  */
1463  if (isCommit)
1464  {
1465  delrels = commitrels;
1466  ndelrels = hdr->ncommitrels;
1467  }
1468  else
1469  {
1470  delrels = abortrels;
1471  ndelrels = hdr->nabortrels;
1472  }
1473  for (i = 0; i < ndelrels; i++)
1474  {
1475  SMgrRelation srel = smgropen(delrels[i], InvalidBackendId);
1476 
1477  smgrdounlink(srel, false);
1478  smgrclose(srel);
1479  }
1480 
1481  /*
1482  * Handle cache invalidation messages.
1483  *
1484  * Relcache init file invalidation requires processing both before and
1485  * after we send the SI messages. See AtEOXact_Inval()
1486  */
1487  if (hdr->initfileinval)
1489  SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1490  if (hdr->initfileinval)
1492 
1493  /* And now do the callbacks */
1494  if (isCommit)
1496  else
1498 
1499  PredicateLockTwoPhaseFinish(xid, isCommit);
1500 
1501  /* Count the prepared xact as committed or aborted */
1502  AtEOXact_PgStat(isCommit);
1503 
1504  /*
1505  * And now we can clean up any files we may have left.
1506  */
1507  if (gxact->ondisk)
1508  RemoveTwoPhaseFile(xid, true);
1509 
1510  RemoveGXact(gxact);
1511  MyLockedGxact = NULL;
1512 
1513  pfree(buf);
1514 }
void smgrclose(SMgrRelation reln)
Definition: smgr.c:296
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
uint32 TransactionId
Definition: c.h:397
Definition: proc.h:207
Oid GetUserId(void)
Definition: miscinit.c:283
static void RecordTransactionAbortPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileNode *rels)
Definition: twophase.c:2255
PGXACT * allPgXact
Definition: proc.h:234
TransactionId xid
Definition: proc.h:209
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:1520
void smgrdounlink(SMgrRelation reln, bool isRedo)
Definition: smgr.c:414
const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:33
PROC_HDR * ProcGlobal
Definition: proc.c:80
TransactionId xid
Definition: twophase.c:908
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void pfree(void *pointer)
Definition: mcxt.c:950
static GlobalTransaction LockGXact(const char *gid, Oid user)
Definition: twophase.c:556
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:332
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
void PredicateLockTwoPhaseFinish(TransactionId xid, bool isCommit)
Definition: predicate.c:4877
static char * buf
Definition: pg_test_fsync.c:66
SMgrRelation smgropen(RelFileNode rnode, BackendId backend)
Definition: smgr.c:137
static void RecordTransactionCommitPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileNode *rels, int ninvalmsgs, SharedInvalidationMessage *invalmsgs, bool initfileinval)
Definition: twophase.c:2163
#define InvalidBackendId
Definition: backendid.h:23
const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:42
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1186
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6057
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1548
#define NULL
Definition: c.h:229
void RelationCacheInitFilePreInvalidate(void)
Definition: relcache.c:6031
#define Assert(condition)
Definition: c.h:675
#define MAXALIGN(LEN)
Definition: c.h:588
void SendSharedInvalidMessages(const SharedInvalidationMessage *msgs, int n)
Definition: sinval.c:49
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1297
static GlobalTransaction MyLockedGxact
Definition: twophase.c:200
int i
PGPROC * allProcs
Definition: proc.h:232
Definition: proc.h:94
void AtEOXact_PgStat(bool isCommit)
Definition: pgstat.c:2017
GlobalTransaction MarkAsPreparing ( TransactionId  xid,
const char *  gid,
TimestampTz  prepared_at,
Oid  owner,
Oid  databaseid 
)

Definition at line 377 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, NULL, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, TwoPhaseStateData::prepXacts, and twophaseExitRegistered.

Referenced by PrepareTransaction().

379 {
380  GlobalTransaction gxact;
381  int i;
382 
383  if (strlen(gid) >= GIDSIZE)
384  ereport(ERROR,
385  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
386  errmsg("transaction identifier \"%s\" is too long",
387  gid)));
388 
389  /* fail immediately if feature is disabled */
390  if (max_prepared_xacts == 0)
391  ereport(ERROR,
392  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
393  errmsg("prepared transactions are disabled"),
394  errhint("Set max_prepared_transactions to a nonzero value.")));
395 
396  /* on first call, register the exit hook */
398  {
400  twophaseExitRegistered = true;
401  }
402 
403  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
404 
405  /* Check for conflicting GID */
406  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
407  {
408  gxact = TwoPhaseState->prepXacts[i];
409  if (strcmp(gxact->gid, gid) == 0)
410  {
411  ereport(ERROR,
413  errmsg("transaction identifier \"%s\" is already in use",
414  gid)));
415  }
416  }
417 
418  /* Get a free gxact from the freelist */
419  if (TwoPhaseState->freeGXacts == NULL)
420  ereport(ERROR,
421  (errcode(ERRCODE_OUT_OF_MEMORY),
422  errmsg("maximum number of prepared transactions reached"),
423  errhint("Increase max_prepared_transactions (currently %d).",
425  gxact = TwoPhaseState->freeGXacts;
426  TwoPhaseState->freeGXacts = gxact->next;
427 
428  MarkAsPreparingGuts(gxact, xid, gid, prepared_at, owner, databaseid);
429 
430  gxact->ondisk = false;
431 
432  /* And insert it into the active array */
435 
436  LWLockRelease(TwoPhaseStateLock);
437 
438  return gxact;
439 }
int errhint(const char *fmt,...)
Definition: elog.c:987
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
GlobalTransaction freeGXacts
Definition: twophase.c:186
int errcode(int sqlerrcode)
Definition: elog.c:575
static bool twophaseExitRegistered
Definition: twophase.c:202
GlobalTransaction next
Definition: twophase.c:155
char gid[GIDSIZE]
Definition: twophase.c:176
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:451
#define ERROR
Definition: elog.h:43
int max_prepared_xacts
Definition: twophase.c:117
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:320
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
#define GIDSIZE
Definition: twophase.c:151
int errmsg(const char *fmt,...)
Definition: elog.c:797
int i
static void AtProcExit_Twophase(int code, Datum arg)
Definition: twophase.c:307
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:31
void PostPrepare_Twophase ( void  )

Definition at line 362 of file twophase.c.

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

Referenced by PrepareTransaction(), and RecoverPreparedTransactions().

363 {
364  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
366  LWLockRelease(TwoPhaseStateLock);
367 
369 }
BackendId locking_backend
Definition: twophase.c:172
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
#define InvalidBackendId
Definition: backendid.h:23
#define NULL
Definition: c.h:229
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
static GlobalTransaction MyLockedGxact
Definition: twophase.c:200
void PrepareRedoAdd ( char *  buf,
XLogRecPtr  start_lsn,
XLogRecPtr  end_lsn 
)

Definition at line 2312 of file twophase.c.

References Assert, DEBUG2, elog, ereport, errcode(), errhint(), errmsg(), ERROR, TwoPhaseStateData::freeGXacts, GlobalTransactionData::gid, GlobalTransactionData::inredo, InvalidBackendId, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), max_prepared_xacts, MAXALIGN, GlobalTransactionData::next, NULL, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, GlobalTransactionData::owner, TwoPhaseFileHeader::owner, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, GlobalTransactionData::prepared_at, TwoPhaseFileHeader::prepared_at, TwoPhaseStateData::prepXacts, RecoveryInProgress(), GlobalTransactionData::valid, GlobalTransactionData::xid, TwoPhaseFileHeader::xid, and XLogRecPtrIsInvalid.

Referenced by restoreTwoPhaseData(), and xact_redo().

2313 {
2315  char *bufptr;
2316  const char *gid;
2317  GlobalTransaction gxact;
2318 
2320 
2321  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2322  gid = (const char *) bufptr;
2323 
2324  /*
2325  * Reserve the GID for the given transaction in the redo code path.
2326  *
2327  * This creates a gxact struct and puts it into the active array.
2328  *
2329  * In redo, this struct is mainly used to track PREPARE/COMMIT entries
2330  * in shared memory. Hence, we only fill up the bare minimum contents here.
2331  * The gxact also gets marked with gxact->inredo set to true to indicate
2332  * that it got added in the redo phase
2333  */
2334 
2335  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2336  /* Get a free gxact from the freelist */
2337  if (TwoPhaseState->freeGXacts == NULL)
2338  ereport(ERROR,
2339  (errcode(ERRCODE_OUT_OF_MEMORY),
2340  errmsg("maximum number of prepared transactions reached"),
2341  errhint("Increase max_prepared_transactions (currently %d).",
2342  max_prepared_xacts)));
2343  gxact = TwoPhaseState->freeGXacts;
2344  TwoPhaseState->freeGXacts = gxact->next;
2345 
2346  gxact->prepared_at = hdr->prepared_at;
2347  gxact->prepare_start_lsn = start_lsn;
2348  gxact->prepare_end_lsn = end_lsn;
2349  gxact->xid = hdr->xid;
2350  gxact->owner = hdr->owner;
2352  gxact->valid = false;
2353  gxact->ondisk = XLogRecPtrIsInvalid(start_lsn);
2354  gxact->inredo = true; /* yes, added in redo */
2355  strcpy(gxact->gid, gid);
2356 
2357  /* And insert it into the active array */
2360 
2361  LWLockRelease(TwoPhaseStateLock);
2362 
2363  elog(DEBUG2, "Adding 2PC data to shared memory %u", gxact->xid);
2364 }
int errhint(const char *fmt,...)
Definition: elog.c:987
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
GlobalTransaction freeGXacts
Definition: twophase.c:186
int errcode(int sqlerrcode)
Definition: elog.c:575
TransactionId xid
Definition: twophase.c:908
GlobalTransaction next
Definition: twophase.c:155
bool RecoveryInProgress(void)
Definition: xlog.c:7874
char gid[GIDSIZE]
Definition: twophase.c:176
BackendId locking_backend
Definition: twophase.c:172
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
#define ERROR
Definition: elog.h:43
int max_prepared_xacts
Definition: twophase.c:117
#define DEBUG2
Definition: elog.h:24
static char * buf
Definition: pg_test_fsync.c:66
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
#define InvalidBackendId
Definition: backendid.h:23
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
#define MAXALIGN(LEN)
Definition: c.h:588
TransactionId xid
Definition: twophase.c:169
TimestampTz prepared_at
Definition: twophase.c:158
int errmsg(const char *fmt,...)
Definition: elog.c:797
#define elog
Definition: elog.h:219
TimestampTz prepared_at
Definition: twophase.c:910
XLogRecPtr prepare_end_lsn
Definition: twophase.c:168
void PrepareRedoRemove ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 2374 of file twophase.c.

References Assert, DEBUG2, elog, i, GlobalTransactionData::inredo, LW_SHARED, LWLockAcquire(), LWLockRelease(), NULL, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, TwoPhaseStateData::prepXacts, RecoveryInProgress(), RemoveGXact(), RemoveTwoPhaseFile(), and GlobalTransactionData::xid.

Referenced by ProcessTwoPhaseBuffer(), and xact_redo().

2375 {
2376  GlobalTransaction gxact = NULL;
2377  int i;
2378  bool found = false;
2379 
2381 
2382  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2383  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2384  {
2385  gxact = TwoPhaseState->prepXacts[i];
2386 
2387  if (gxact->xid == xid)
2388  {
2389  Assert(gxact->inredo);
2390  found = true;
2391  break;
2392  }
2393  }
2394  LWLockRelease(TwoPhaseStateLock);
2395 
2396  /*
2397  * Just leave if there is nothing, this is expected during WAL replay.
2398  */
2399  if (!found)
2400  return;
2401 
2402  /*
2403  * And now we can clean up any files we may have left.
2404  */
2405  elog(DEBUG2, "Removing 2PC data from shared memory %u", xid);
2406  if (gxact->ondisk)
2407  RemoveTwoPhaseFile(xid, giveWarning);
2408  RemoveGXact(gxact);
2409 
2410  return;
2411 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
bool RecoveryInProgress(void)
Definition: xlog.c:7874
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:632
#define DEBUG2
Definition: elog.h:24
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1548
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
TransactionId xid
Definition: twophase.c:169
int i
#define elog
Definition: elog.h:219
TransactionId PrescanPreparedTransactions ( TransactionId **  xids_p,
int *  nxids_p 
)

Definition at line 1785 of file twophase.c.

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

Referenced by StartupXLOG(), and xlog_redo().

1786 {
1787  TransactionId origNextXid = ShmemVariableCache->nextXid;
1788  TransactionId result = origNextXid;
1789  TransactionId *xids = NULL;
1790  int nxids = 0;
1791  int allocsize = 0;
1792  int i;
1793 
1794  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1795  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1796  {
1797  TransactionId xid;
1798  char *buf;
1800 
1801  Assert(gxact->inredo);
1802 
1803  xid = gxact->xid;
1804 
1805  buf = ProcessTwoPhaseBuffer(xid,
1806  gxact->prepare_start_lsn,
1807  gxact->ondisk, false, false,
1808  true);
1809 
1810  if (buf == NULL)
1811  continue;
1812 
1813  /*
1814  * OK, we think this file is valid. Incorporate xid into the
1815  * running-minimum result.
1816  */
1817  if (TransactionIdPrecedes(xid, result))
1818  result = xid;
1819 
1820  if (xids_p)
1821  {
1822  if (nxids == allocsize)
1823  {
1824  if (nxids == 0)
1825  {
1826  allocsize = 10;
1827  xids = palloc(allocsize * sizeof(TransactionId));
1828  }
1829  else
1830  {
1831  allocsize = allocsize * 2;
1832  xids = repalloc(xids, allocsize * sizeof(TransactionId));
1833  }
1834  }
1835  xids[nxids++] = xid;
1836  }
1837 
1838  pfree(buf);
1839  }
1840  LWLockRelease(TwoPhaseStateLock);
1841 
1842  if (xids_p)
1843  {
1844  *xids_p = xids;
1845  *nxids_p = nxids;
1846  }
1847 
1848  return result;
1849 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
uint32 TransactionId
Definition: c.h:397
return result
Definition: formatting.c:1618
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
TransactionId nextXid
Definition: transam.h:117
static char * buf
Definition: pg_test_fsync.c:66
VariableCache ShmemVariableCache
Definition: varsup.c:34
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool overwriteOK, bool setParent, bool setNextXid)
Definition: twophase.c:2016
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:963
TransactionId xid
Definition: twophase.c:169
void * palloc(Size size)
Definition: mcxt.c:849
int i
void RecoverPreparedTransactions ( void  )

Definition at line 1900 of file twophase.c.

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

Referenced by StartupXLOG().

1901 {
1902  int i;
1903 
1904  /*
1905  * Don't need a lock in the recovery phase.
1906  */
1907  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1908  {
1909  TransactionId xid;
1910  char *buf;
1912  char *bufptr;
1913  TwoPhaseFileHeader *hdr;
1914  TransactionId *subxids;
1915  const char *gid;
1916  bool overwriteOK = false;
1917  int i;
1918 
1919  xid = gxact->xid;
1920 
1921  buf = ProcessTwoPhaseBuffer(xid,
1922  gxact->prepare_start_lsn,
1923  gxact->ondisk, false, false,
1924  false);
1925  if (buf == NULL)
1926  continue;
1927 
1928  ereport(LOG,
1929  (errmsg("recovering prepared transaction %u from shared memory", xid)));
1930 
1931  hdr = (TwoPhaseFileHeader *) buf;
1932  Assert(TransactionIdEquals(hdr->xid, xid));
1933  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1934  gid = (const char *) bufptr;
1935  bufptr += MAXALIGN(hdr->gidlen);
1936  subxids = (TransactionId *) bufptr;
1937  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1938  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1939  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1940  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1941 
1942  /*
1943  * It's possible that SubTransSetParent has been set before, if
1944  * the prepared transaction generated xid assignment records. Test
1945  * here must match one used in AssignTransactionId().
1946  */
1949  overwriteOK = true;
1950 
1951  /*
1952  * Reconstruct subtrans state for the transaction --- needed
1953  * because pg_subtrans is not preserved over a restart. Note that
1954  * we are linking all the subtransactions directly to the
1955  * top-level XID; there may originally have been a more complex
1956  * hierarchy, but there's no need to restore that exactly.
1957  */
1958  for (i = 0; i < hdr->nsubxacts; i++)
1959  SubTransSetParent(subxids[i], xid, true);
1960 
1961  /*
1962  * Recreate its GXACT and dummy PGPROC. But, check whether
1963  * it was added in redo and already has a shmem entry for
1964  * it.
1965  */
1966  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1967  MarkAsPreparingGuts(gxact, xid, gid,
1968  hdr->prepared_at,
1969  hdr->owner, hdr->database);
1970 
1971  /* recovered, so reset the flag for entries generated by redo */
1972  gxact->inredo = false;
1973 
1974  LWLockRelease(TwoPhaseStateLock);
1975 
1976  GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
1977  MarkAsPrepared(gxact);
1978 
1979  /*
1980  * Recover other state (notably locks) using resource managers
1981  */
1983 
1984  /*
1985  * Release locks held by the standby process after we process each
1986  * prepared transaction. As a result, we don't need too many
1987  * additional locks at any one time.
1988  */
1989  if (InHotStandby)
1990  StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
1991 
1992  /*
1993  * We're done with recovering this transaction. Clear
1994  * MyLockedGxact, like we do in PrepareTransaction() during normal
1995  * operation.
1996  */
1998 
1999  pfree(buf);
2000  }
2001 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
uint32 TransactionId
Definition: c.h:397
void SubTransSetParent(TransactionId xid, TransactionId parent, bool overwriteOK)
Definition: subtrans.c:75
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1520
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:24
#define InHotStandby
Definition: xlog.h:74
TransactionId xid
Definition: twophase.c:908
#define LOG
Definition: elog.h:26
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
static void MarkAsPreparingGuts(GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:451
#define XLogLogicalInfoActive()
Definition: xlog.h:162
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:511
static char * buf
Definition: pg_test_fsync.c:66
void StandbyReleaseLockTree(TransactionId xid, int nsubxids, TransactionId *subxids)
Definition: standby.c:676
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
#define PGPROC_MAX_CACHED_SUBXIDS
Definition: proc.h:35
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void MarkAsPrepared(GlobalTransaction gxact)
Definition: twophase.c:536
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool overwriteOK, bool setParent, bool setNextXid)
Definition: twophase.c:2016
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
#define MAXALIGN(LEN)
Definition: c.h:588
TransactionId xid
Definition: twophase.c:169
int errmsg(const char *fmt,...)
Definition: elog.c:797
void PostPrepare_Twophase(void)
Definition: twophase.c:362
int i
TimestampTz prepared_at
Definition: twophase.c:910
void restoreTwoPhaseData ( void  )

Definition at line 1729 of file twophase.c.

References AllocateDir(), buf, dirent::d_name, FreeDir(), InvalidXLogRecPtr, NULL, PrepareRedoAdd(), ProcessTwoPhaseBuffer(), ReadDir(), and TWOPHASE_DIR.

Referenced by StartupXLOG().

1730 {
1731  DIR *cldir;
1732  struct dirent *clde;
1733 
1734  cldir = AllocateDir(TWOPHASE_DIR);
1735  while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1736  {
1737  if (strlen(clde->d_name) == 8 &&
1738  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1739  {
1740  TransactionId xid;
1741  char *buf;
1742 
1743  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1744 
1746  true, false, false,
1747  false);
1748  if (buf == NULL)
1749  continue;
1750 
1752  }
1753  }
1754  FreeDir(cldir);
1755 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
uint32 TransactionId
Definition: c.h:397
Definition: dirent.h:9
Definition: dirent.c:25
static char * buf
Definition: pg_test_fsync.c:66
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2335
void PrepareRedoAdd(char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn)
Definition: twophase.c:2312
#define NULL
Definition: c.h:229
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2401
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool overwriteOK, bool setParent, bool setNextXid)
Definition: twophase.c:2016
#define TWOPHASE_DIR
Definition: twophase.c:114
char d_name[MAX_PATH]
Definition: dirent.h:14
int FreeDir(DIR *dir)
Definition: fd.c:2444
void StandbyRecoverPreparedTransactions ( bool  overwriteOK)

Definition at line 1866 of file twophase.c.

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

Referenced by StartupXLOG(), and xlog_redo().

1867 {
1868  int i;
1869 
1870  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1871  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1872  {
1873  TransactionId xid;
1874  char *buf;
1876 
1877  Assert(gxact->inredo);
1878 
1879  xid = gxact->xid;
1880 
1881  buf = ProcessTwoPhaseBuffer(xid,
1882  gxact->prepare_start_lsn,
1883  gxact->ondisk, overwriteOK, true,
1884  false);
1885  if (buf != NULL)
1886  pfree(buf);
1887  }
1888  LWLockRelease(TwoPhaseStateLock);
1889 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
uint32 TransactionId
Definition: c.h:397
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
static char * buf
Definition: pg_test_fsync.c:66
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:192
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool overwriteOK, bool setParent, bool setNextXid)
Definition: twophase.c:2016
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
TransactionId xid
Definition: twophase.c:169
int i
bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1340 of file twophase.c.

References Assert, buf, max_prepared_xacts, NULL, pfree(), ReadTwoPhaseFile(), result, TransactionIdEquals, TransactionIdIsValid, and TwoPhaseFileHeader::xid.

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

1341 {
1342  char *buf;
1343  TwoPhaseFileHeader *hdr;
1344  bool result;
1345 
1347 
1348  if (max_prepared_xacts <= 0)
1349  return false; /* nothing to do */
1350 
1351  /* Read and validate file */
1352  buf = ReadTwoPhaseFile(xid, false);
1353  if (buf == NULL)
1354  return false;
1355 
1356  /* Check header also */
1357  hdr = (TwoPhaseFileHeader *) buf;
1358  result = TransactionIdEquals(hdr->xid, xid);
1359  pfree(buf);
1360 
1361  return result;
1362 }
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
return result
Definition: formatting.c:1618
TransactionId xid
Definition: twophase.c:908
void pfree(void *pointer)
Definition: mcxt.c:950
int max_prepared_xacts
Definition: twophase.c:117
static char * buf
Definition: pg_test_fsync.c:66
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1186
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
#define TransactionIdIsValid(xid)
Definition: transam.h:41
void StartPrepare ( GlobalTransaction  gxact)

Definition at line 992 of file twophase.c.

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

Referenced by PrepareTransaction().

993 {
994  PGPROC *proc = &ProcGlobal->allProcs[gxact->pgprocno];
995  PGXACT *pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
996  TransactionId xid = pgxact->xid;
997  TwoPhaseFileHeader hdr;
998  TransactionId *children;
999  RelFileNode *commitrels;
1000  RelFileNode *abortrels;
1001  SharedInvalidationMessage *invalmsgs;
1002 
1003  /* Initialize linked list */
1004  records.head = palloc0(sizeof(StateFileChunk));
1005  records.head->len = 0;
1006  records.head->next = NULL;
1007 
1008  records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
1010 
1012  records.num_chunks = 1;
1013 
1014  records.total_len = 0;
1015 
1016  /* Create header */
1017  hdr.magic = TWOPHASE_MAGIC;
1018  hdr.total_len = 0; /* EndPrepare will fill this in */
1019  hdr.xid = xid;
1020  hdr.database = proc->databaseId;
1021  hdr.prepared_at = gxact->prepared_at;
1022  hdr.owner = gxact->owner;
1023  hdr.nsubxacts = xactGetCommittedChildren(&children);
1024  hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
1025  hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
1027  &hdr.initfileinval);
1028  hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
1029 
1030  save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
1031  save_state_data(gxact->gid, hdr.gidlen);
1032 
1033  /*
1034  * Add the additional info about subxacts, deletable files and cache
1035  * invalidation messages.
1036  */
1037  if (hdr.nsubxacts > 0)
1038  {
1039  save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
1040  /* While we have the child-xact data, stuff it in the gxact too */
1041  GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
1042  }
1043  if (hdr.ncommitrels > 0)
1044  {
1045  save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileNode));
1046  pfree(commitrels);
1047  }
1048  if (hdr.nabortrels > 0)
1049  {
1050  save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileNode));
1051  pfree(abortrels);
1052  }
1053  if (hdr.ninvalmsgs > 0)
1054  {
1055  save_state_data(invalmsgs,
1056  hdr.ninvalmsgs * sizeof(SharedInvalidationMessage));
1057  pfree(invalmsgs);
1058  }
1059 }
int xactGetCommittedChildren(TransactionId **ptr)
Definition: xact.c:5084
uint32 TransactionId
Definition: c.h:397
Definition: proc.h:207
PGXACT * allPgXact
Definition: proc.h:234
TransactionId xid
Definition: proc.h:209
StateFileChunk * tail
Definition: twophase.c:948
PROC_HDR * ProcGlobal
Definition: proc.c:80
TransactionId xid
Definition: twophase.c:908
uint32 num_chunks
Definition: twophase.c:949
char gid[GIDSIZE]
Definition: twophase.c:176
char * data
Definition: twophase.c:940
void pfree(void *pointer)
Definition: mcxt.c:950
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:511
uint32 bytes_free
Definition: twophase.c:950
int smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr)
Definition: storage.c:389
uint32 len
Definition: twophase.c:941
Oid databaseId
Definition: proc.h:113
uint32 total_len
Definition: twophase.c:951
struct StateFileChunk * next
Definition: twophase.c:942
void * palloc0(Size size)
Definition: mcxt.c:878
#define TWOPHASE_MAGIC
Definition: twophase.c:902
#define Max(x, y)
Definition: c.h:800
StateFileChunk * head
Definition: twophase.c:947
#define NULL
Definition: c.h:229
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:964
TimestampTz prepared_at
Definition: twophase.c:158
void * palloc(Size size)
Definition: mcxt.c:849
int xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs, bool *RelcacheInitFileInval)
Definition: inval.c:809
static struct xllist records
PGPROC * allProcs
Definition: proc.h:232
TimestampTz prepared_at
Definition: twophase.c:910
Definition: proc.h:94
BackendId TwoPhaseGetDummyBackendId ( TransactionId  xid)

Definition at line 857 of file twophase.c.

References GlobalTransactionData::dummyBackendId, and TwoPhaseGetGXact().

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

858 {
859  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
860 
861  return gxact->dummyBackendId;
862 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:808
BackendId dummyBackendId
Definition: twophase.c:157
PGPROC* TwoPhaseGetDummyProc ( TransactionId  xid)

Definition at line 869 of file twophase.c.

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

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

870 {
871  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
872 
873  return &ProcGlobal->allProcs[gxact->pgprocno];
874 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:808
PROC_HDR * ProcGlobal
Definition: proc.c:80
PGPROC * allProcs
Definition: proc.h:232
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, NULL, 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);
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:195
GlobalTransaction freeGXacts
Definition: twophase.c:186
PGPROC * PreparedXactProcs
Definition: proc.c:82
Size TwoPhaseShmemSize(void)
Definition: twophase.c:236
GlobalTransaction next
Definition: twophase.c:155
struct GlobalTransactionData * GlobalTransaction
Definition: twophase.h:25
int max_prepared_xacts
Definition: twophase.c:117
void * ShmemInitStruct(const char *name, Size size, bool *foundPtr)
Definition: shmem.c:372
int MaxBackends
Definition: globals.c:126
bool IsUnderPostmaster
Definition: globals.c:100
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
#define MAXALIGN(LEN)
Definition: c.h:588
int pgprocno
Definition: proc.h:109
int i
#define offsetof(type, field)
Definition: c.h:555
BackendId dummyBackendId
Definition: twophase.c:157
Size TwoPhaseShmemSize ( void  )

Definition at line 236 of file twophase.c.

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

Referenced by CreateSharedMemoryAndSemaphores(), 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:492
Size add_size(Size s1, Size s2)
Definition: shmem.c:475
size_t Size
Definition: c.h:356
#define MAXALIGN(LEN)
Definition: c.h:588
#define offsetof(type, field)
Definition: c.h:555

Variable Documentation