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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 RecreateTwoPhaseFile (TransactionId xid, void *content, int len)
 
void RemoveTwoPhaseFile (TransactionId xid, bool giveWarning)
 
void CheckPointTwoPhase (XLogRecPtr redo_horizon)
 
void FinishPreparedTransaction (const char *gid, bool isCommit)
 

Variables

int max_prepared_xacts
 

Typedef Documentation

Definition at line 25 of file twophase.h.

Function Documentation

void AtAbort_Twophase ( void  )

Definition at line 287 of file twophase.c.

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

Referenced by AbortTransaction(), and AtProcExit_Twophase().

288 {
289  if (MyLockedGxact == NULL)
290  return;
291 
292  /*
293  * What to do with the locked global transaction entry? If we were in the
294  * process of preparing the transaction, but haven't written the WAL
295  * record and state file yet, the transaction must not be considered as
296  * prepared. Likewise, if we are in the process of finishing an
297  * already-prepared transaction, and fail after having already written the
298  * 2nd phase commit or rollback record to the WAL, the transaction should
299  * not be considered as prepared anymore. In those cases, just remove the
300  * entry from shared memory.
301  *
302  * Otherwise, the entry must be left in place so that the transaction can
303  * be finished later, so just unlock it.
304  *
305  * If we abort during prepare, after having written the WAL record, we
306  * might not have transferred all locks and other state to the prepared
307  * transaction yet. Likewise, if we abort during commit or rollback,
308  * after having written the WAL record, we might not have released all the
309  * resources held by the transaction yet. In those cases, the in-memory
310  * state can be wrong, but it's too late to back out.
311  */
312  if (!MyLockedGxact->valid)
313  {
315  }
316  else
317  {
318  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
319 
321 
322  LWLockRelease(TwoPhaseStateLock);
323  }
325 }
BackendId locking_backend
Definition: twophase.c:152
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:587
#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:179
void CheckPointTwoPhase ( XLogRecPtr  redo_horizon)

Definition at line 1605 of file twophase.c.

References PROC_HDR::allPgXact, buf, ereport, errmsg_plural(), i, LOG, log_checkpoints, LW_SHARED, LWLockAcquire(), LWLockRelease(), max_prepared_xacts, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::ondisk, pfree(), GlobalTransactionData::pgprocno, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, TwoPhaseStateData::prepXacts, ProcGlobal, RecreateTwoPhaseFile(), GlobalTransactionData::valid, PGXACT::xid, and XlogReadTwoPhaseData().

Referenced by CheckPointGuts().

1606 {
1607  int i;
1608  int serialized_xacts = 0;
1609 
1610  if (max_prepared_xacts <= 0)
1611  return; /* nothing to do */
1612 
1613  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1614 
1615  /*
1616  * We are expecting there to be zero GXACTs that need to be copied to
1617  * disk, so we perform all I/O while holding TwoPhaseStateLock for
1618  * simplicity. This prevents any new xacts from preparing while this
1619  * occurs, which shouldn't be a problem since the presence of long-lived
1620  * prepared xacts indicates the transaction manager isn't active.
1621  *
1622  * It's also possible to move I/O out of the lock, but on every error we
1623  * should check whether somebody committed our transaction in different
1624  * backend. Let's leave this optimization for future, if somebody will
1625  * spot that this place cause bottleneck.
1626  *
1627  * Note that it isn't possible for there to be a GXACT with a
1628  * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1629  * because of the efforts with delayChkpt.
1630  */
1631  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1632  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1633  {
1635  PGXACT *pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
1636 
1637  if (gxact->valid &&
1638  !gxact->ondisk &&
1639  gxact->prepare_end_lsn <= redo_horizon)
1640  {
1641  char *buf;
1642  int len;
1643 
1644  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, &len);
1645  RecreateTwoPhaseFile(pgxact->xid, buf, len);
1646  gxact->ondisk = true;
1647  pfree(buf);
1648  serialized_xacts++;
1649  }
1650  }
1651  LWLockRelease(TwoPhaseStateLock);
1652 
1653  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1654 
1655  if (log_checkpoints && serialized_xacts > 0)
1656  ereport(LOG,
1657  (errmsg_plural("%u two-phase state file was written "
1658  "for a long-running prepared transaction",
1659  "%u two-phase state files were written "
1660  "for long-running prepared transactions",
1661  serialized_xacts,
1662  serialized_xacts)));
1663 }
bool log_checkpoints
Definition: xlog.c:102
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:174
Definition: proc.h:207
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:850
void RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
Definition: twophase.c:1525
PGXACT * allPgXact
Definition: proc.h:234
TransactionId xid
Definition: proc.h:209
PROC_HDR * ProcGlobal
Definition: proc.c:80
#define LOG
Definition: elog.h:26
XLogRecPtr prepare_start_lsn
Definition: twophase.c:148
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
int max_prepared_xacts
Definition: twophase.c:98
static char * buf
Definition: pg_test_fsync.c:65
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:171
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1252
int i
XLogRecPtr prepare_end_lsn
Definition: twophase.c:149
void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1020 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().

1021 {
1022  TwoPhaseFileHeader *hdr;
1023  StateFileChunk *record;
1024 
1025  /* Add the end sentinel to the list of 2PC records */
1027  NULL, 0);
1028 
1029  /* Go back and fill in total_len in the file header record */
1030  hdr = (TwoPhaseFileHeader *) records.head->data;
1031  Assert(hdr->magic == TWOPHASE_MAGIC);
1032  hdr->total_len = records.total_len + sizeof(pg_crc32c);
1033 
1034  /*
1035  * If the data size exceeds MaxAllocSize, we won't be able to read it in
1036  * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1037  * where we write data to file and then re-read at commit time.
1038  */
1039  if (hdr->total_len > MaxAllocSize)
1040  ereport(ERROR,
1041  (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1042  errmsg("two-phase state file maximum length exceeded")));
1043 
1044  /*
1045  * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1046  * cover us, so no need to calculate a separate CRC.
1047  *
1048  * We have to set delayChkpt here, too; otherwise a checkpoint starting
1049  * immediately after the WAL record is inserted could complete without
1050  * fsync'ing our state file. (This is essentially the same kind of race
1051  * condition as the COMMIT-to-clog-write case that RecordTransactionCommit
1052  * uses delayChkpt for; see notes there.)
1053  *
1054  * We save the PREPARE record's location in the gxact for later use by
1055  * CheckPointTwoPhase.
1056  */
1058 
1060 
1061  MyPgXact->delayChkpt = true;
1062 
1063  XLogBeginInsert();
1064  for (record = records.head; record != NULL; record = record->next)
1065  XLogRegisterData(record->data, record->len);
1066  gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1067  XLogFlush(gxact->prepare_end_lsn);
1068 
1069  /* If we crash now, we have prepared: WAL replay will fix things */
1070 
1071  /* Store record's start location to read that later on Commit */
1073 
1074  /*
1075  * Mark the prepared transaction as valid. As soon as xact.c marks
1076  * MyPgXact as not running our XID (which it will do immediately after
1077  * this function returns), others can commit/rollback the xact.
1078  *
1079  * NB: a side effect of this is to make a dummy ProcArray entry for the
1080  * prepared XID. This must happen before we clear the XID from MyPgXact,
1081  * else there is a window where the XID is not running according to
1082  * TransactionIdIsInProgress, and onlookers would be entitled to assume
1083  * the xact crashed. Instead we have a window where the same XID appears
1084  * twice in ProcArray, which is OK.
1085  */
1086  MarkAsPrepared(gxact);
1087 
1088  /*
1089  * Now we can mark ourselves as out of the commit critical section: a
1090  * checkpoint starting after this will certainly see the gxact as a
1091  * candidate for fsyncing.
1092  */
1093  MyPgXact->delayChkpt = false;
1094 
1095  /*
1096  * Remember that we have this GlobalTransaction entry locked for us. If
1097  * we crash after this point, it's too late to abort, but we must unlock
1098  * it so that the prepared transaction can be committed or rolled back.
1099  */
1100  MyLockedGxact = gxact;
1101 
1102  END_CRIT_SECTION();
1103 
1104  /*
1105  * Wait for synchronous replication, if required.
1106  *
1107  * Note that at this stage we have marked the prepare, but still show as
1108  * running in the procarray (twice!) and continue to hold locks.
1109  */
1110  SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1111 
1113  records.num_chunks = 0;
1114 }
#define XLOG_XACT_PREPARE
Definition: xact.h:135
StateFileChunk * tail
Definition: twophase.c:903
uint32 pg_crc32c
Definition: pg_crc32c.h:38
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:336
void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
Definition: syncrep.c:142
#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:904
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2754
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1120
PGXACT * MyPgXact
Definition: proc.c:68
XLogRecPtr prepare_start_lsn
Definition: twophase.c:148
char * data
Definition: twophase.c:895
#define ERROR
Definition: elog.h:43
uint32 len
Definition: twophase.c:896
#define ereport(elevel, rest)
Definition: elog.h:122
bool delayChkpt
Definition: proc.h:220
uint32 total_len
Definition: twophase.c:906
#define MaxAllocSize
Definition: memutils.h:40
struct StateFileChunk * next
Definition: twophase.c:897
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:857
StateFileChunk * head
Definition: twophase.c:902
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void MarkAsPrepared(GlobalTransaction gxact)
Definition: twophase.c:491
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:179
static struct xllist records
void XLogBeginInsert(void)
Definition: xloginsert.c:120
XLogRecPtr prepare_end_lsn
Definition: twophase.c:149
void FinishPreparedTransaction ( const char *  gid,
bool  isCommit 
)

Definition at line 1325 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().

1326 {
1327  GlobalTransaction gxact;
1328  PGPROC *proc;
1329  PGXACT *pgxact;
1330  TransactionId xid;
1331  char *buf;
1332  char *bufptr;
1333  TwoPhaseFileHeader *hdr;
1334  TransactionId latestXid;
1335  TransactionId *children;
1336  RelFileNode *commitrels;
1337  RelFileNode *abortrels;
1338  RelFileNode *delrels;
1339  int ndelrels;
1340  SharedInvalidationMessage *invalmsgs;
1341  int i;
1342 
1343  /*
1344  * Validate the GID, and lock the GXACT to ensure that two backends do not
1345  * try to commit the same GID at once.
1346  */
1347  gxact = LockGXact(gid, GetUserId());
1348  proc = &ProcGlobal->allProcs[gxact->pgprocno];
1349  pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
1350  xid = pgxact->xid;
1351 
1352  /*
1353  * Read and validate 2PC state data. State data will typically be stored
1354  * in WAL files if the LSN is after the last checkpoint record, or moved
1355  * to disk if for some reason they have lived for a long time.
1356  */
1357  if (gxact->ondisk)
1358  buf = ReadTwoPhaseFile(xid, true);
1359  else
1361 
1362 
1363  /*
1364  * Disassemble the header area
1365  */
1366  hdr = (TwoPhaseFileHeader *) buf;
1367  Assert(TransactionIdEquals(hdr->xid, xid));
1368  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1369  bufptr += MAXALIGN(hdr->gidlen);
1370  children = (TransactionId *) bufptr;
1371  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1372  commitrels = (RelFileNode *) bufptr;
1373  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1374  abortrels = (RelFileNode *) bufptr;
1375  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1376  invalmsgs = (SharedInvalidationMessage *) bufptr;
1377  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1378 
1379  /* compute latestXid among all children */
1380  latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1381 
1382  /*
1383  * The order of operations here is critical: make the XLOG entry for
1384  * commit or abort, then mark the transaction committed or aborted in
1385  * pg_xact, then remove its PGPROC from the global ProcArray (which means
1386  * TransactionIdIsInProgress will stop saying the prepared xact is in
1387  * progress), then run the post-commit or post-abort callbacks. The
1388  * callbacks will release the locks the transaction held.
1389  */
1390  if (isCommit)
1392  hdr->nsubxacts, children,
1393  hdr->ncommitrels, commitrels,
1394  hdr->ninvalmsgs, invalmsgs,
1395  hdr->initfileinval);
1396  else
1398  hdr->nsubxacts, children,
1399  hdr->nabortrels, abortrels);
1400 
1401  ProcArrayRemove(proc, latestXid);
1402 
1403  /*
1404  * In case we fail while running the callbacks, mark the gxact invalid so
1405  * no one else will try to commit/rollback, and so it will be recycled if
1406  * we fail after this point. It is still locked by our backend so it
1407  * won't go away yet.
1408  *
1409  * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1410  */
1411  gxact->valid = false;
1412 
1413  /*
1414  * We have to remove any files that were supposed to be dropped. For
1415  * consistency with the regular xact.c code paths, must do this before
1416  * releasing locks, so do it before running the callbacks.
1417  *
1418  * NB: this code knows that we couldn't be dropping any temp rels ...
1419  */
1420  if (isCommit)
1421  {
1422  delrels = commitrels;
1423  ndelrels = hdr->ncommitrels;
1424  }
1425  else
1426  {
1427  delrels = abortrels;
1428  ndelrels = hdr->nabortrels;
1429  }
1430  for (i = 0; i < ndelrels; i++)
1431  {
1432  SMgrRelation srel = smgropen(delrels[i], InvalidBackendId);
1433 
1434  smgrdounlink(srel, false);
1435  smgrclose(srel);
1436  }
1437 
1438  /*
1439  * Handle cache invalidation messages.
1440  *
1441  * Relcache init file invalidation requires processing both before and
1442  * after we send the SI messages. See AtEOXact_Inval()
1443  */
1444  if (hdr->initfileinval)
1446  SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1447  if (hdr->initfileinval)
1449 
1450  /* And now do the callbacks */
1451  if (isCommit)
1453  else
1455 
1456  PredicateLockTwoPhaseFinish(xid, isCommit);
1457 
1458  /* Count the prepared xact as committed or aborted */
1459  AtEOXact_PgStat(isCommit);
1460 
1461  /*
1462  * And now we can clean up any files we may have left.
1463  */
1464  if (gxact->ondisk)
1465  RemoveTwoPhaseFile(xid, true);
1466 
1467  RemoveGXact(gxact);
1468  MyLockedGxact = NULL;
1469 
1470  pfree(buf);
1471 }
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:2135
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:1477
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:863
XLogRecPtr prepare_start_lsn
Definition: twophase.c:148
void pfree(void *pointer)
Definition: mcxt.c:950
static GlobalTransaction LockGXact(const char *gid, Oid user)
Definition: twophase.c:511
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:331
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:587
void PredicateLockTwoPhaseFinish(TransactionId xid, bool isCommit)
Definition: predicate.c:4813
static char * buf
Definition: pg_test_fsync.c:65
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:2043
void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1505
#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:1141
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6057
#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:1252
static GlobalTransaction MyLockedGxact
Definition: twophase.c:179
int i
PGPROC * allProcs
Definition: proc.h:232
Definition: proc.h:94
void AtEOXact_PgStat(bool isCommit)
Definition: pgstat.c:1952
GlobalTransaction MarkAsPreparing ( TransactionId  xid,
const char *  gid,
TimestampTz  prepared_at,
Oid  owner,
Oid  databaseid 
)

Definition at line 351 of file twophase.c.

References PROC_HDR::allPgXact, PROC_HDR::allProcs, Assert, AtProcExit_Twophase(), PGPROC::backendId, before_shmem_exit(), PGPROC::databaseId, PGXACT::delayChkpt, ereport, errcode(), ERRCODE_DUPLICATE_OBJECT, errhint(), errmsg(), ERROR, TwoPhaseStateData::freeGXacts, GlobalTransactionData::gid, GIDSIZE, i, InvalidBackendId, InvalidTransactionId, InvalidXLogRecPtr, PGPROC::isBackgroundWorker, PGPROC::links, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), PGPROC::lwWaiting, PGPROC::lwWaitMode, PGPROC::lxid, max_prepared_xacts, MemSet, MyBackendId, PGPROC::myProcLocks, GlobalTransactionData::next, NULL, NUM_LOCK_PARTITIONS, TwoPhaseStateData::numPrepXacts, PGXACT::nxids, GlobalTransactionData::ondisk, PGXACT::overflowed, GlobalTransactionData::owner, PGPROC::pgprocno, GlobalTransactionData::pgprocno, PGPROC::pid, GlobalTransactionData::prepare_end_lsn, GlobalTransactionData::prepare_start_lsn, GlobalTransactionData::prepared_at, TwoPhaseStateData::prepXacts, ProcGlobal, PGPROC::roleId, SHMQueueElemInit(), SHMQueueInit(), STATUS_OK, twophaseExitRegistered, PGXACT::vacuumFlags, GlobalTransactionData::valid, PGPROC::waitLock, PGPROC::waitProcLock, PGPROC::waitStatus, PGXACT::xid, and PGXACT::xmin.

Referenced by PrepareTransaction(), and RecoverPreparedTransactions().

353 {
354  GlobalTransaction gxact;
355  PGPROC *proc;
356  PGXACT *pgxact;
357  int i;
358 
359  if (strlen(gid) >= GIDSIZE)
360  ereport(ERROR,
361  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
362  errmsg("transaction identifier \"%s\" is too long",
363  gid)));
364 
365  /* fail immediately if feature is disabled */
366  if (max_prepared_xacts == 0)
367  ereport(ERROR,
368  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
369  errmsg("prepared transactions are disabled"),
370  errhint("Set max_prepared_transactions to a nonzero value.")));
371 
372  /* on first call, register the exit hook */
374  {
376  twophaseExitRegistered = true;
377  }
378 
379  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
380 
381  /* Check for conflicting GID */
382  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
383  {
384  gxact = TwoPhaseState->prepXacts[i];
385  if (strcmp(gxact->gid, gid) == 0)
386  {
387  ereport(ERROR,
389  errmsg("transaction identifier \"%s\" is already in use",
390  gid)));
391  }
392  }
393 
394  /* Get a free gxact from the freelist */
395  if (TwoPhaseState->freeGXacts == NULL)
396  ereport(ERROR,
397  (errcode(ERRCODE_OUT_OF_MEMORY),
398  errmsg("maximum number of prepared transactions reached"),
399  errhint("Increase max_prepared_transactions (currently %d).",
401  gxact = TwoPhaseState->freeGXacts;
402  TwoPhaseState->freeGXacts = gxact->next;
403 
404  proc = &ProcGlobal->allProcs[gxact->pgprocno];
405  pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
406 
407  /* Initialize the PGPROC entry */
408  MemSet(proc, 0, sizeof(PGPROC));
409  proc->pgprocno = gxact->pgprocno;
410  SHMQueueElemInit(&(proc->links));
411  proc->waitStatus = STATUS_OK;
412  /* We set up the gxact's VXID as InvalidBackendId/XID */
413  proc->lxid = (LocalTransactionId) xid;
414  pgxact->xid = xid;
415  pgxact->xmin = InvalidTransactionId;
416  pgxact->delayChkpt = false;
417  pgxact->vacuumFlags = 0;
418  proc->pid = 0;
419  proc->backendId = InvalidBackendId;
420  proc->databaseId = databaseid;
421  proc->roleId = owner;
422  proc->isBackgroundWorker = false;
423  proc->lwWaiting = false;
424  proc->lwWaitMode = 0;
425  proc->waitLock = NULL;
426  proc->waitProcLock = NULL;
427  for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
428  SHMQueueInit(&(proc->myProcLocks[i]));
429  /* subxid data must be filled later by GXactLoadSubxactData */
430  pgxact->overflowed = false;
431  pgxact->nxids = 0;
432 
433  gxact->prepared_at = prepared_at;
434  /* initialize LSN to InvalidXLogRecPtr */
437  gxact->owner = owner;
438  gxact->locking_backend = MyBackendId;
439  gxact->valid = false;
440  gxact->ondisk = false;
441  strcpy(gxact->gid, gid);
442 
443  /* And insert it into the active array */
446 
447  /*
448  * Remember that we have this GlobalTransaction entry locked for us. If we
449  * abort after this, we must release it.
450  */
451  MyLockedGxact = gxact;
452 
453  LWLockRelease(TwoPhaseStateLock);
454 
455  return gxact;
456 }
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28
int errhint(const char *fmt,...)
Definition: elog.c:987
BackendId MyBackendId
Definition: globals.c:72
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:174
BackendId backendId
Definition: proc.h:112
Definition: proc.h:207
TransactionId xmin
Definition: proc.h:213
PGXACT * allPgXact
Definition: proc.h:234
TransactionId xid
Definition: proc.h:209
SHM_QUEUE links
Definition: proc.h:97
bool lwWaiting
Definition: proc.h:126
GlobalTransaction freeGXacts
Definition: twophase.c:165
Oid roleId
Definition: proc.h:114
int errcode(int sqlerrcode)
Definition: elog.c:575
PROC_HDR * ProcGlobal
Definition: proc.c:80
#define MemSet(start, val, len)
Definition: c.h:857
static bool twophaseExitRegistered
Definition: twophase.c:181
uint8 lwWaitMode
Definition: proc.h:127
GlobalTransaction next
Definition: twophase.c:136
char gid[GIDSIZE]
Definition: twophase.c:155
uint8 vacuumFlags
Definition: proc.h:218
BackendId locking_backend
Definition: twophase.c:152
XLogRecPtr prepare_start_lsn
Definition: twophase.c:148
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
bool isBackgroundWorker
Definition: proc.h:116
#define ERROR
Definition: elog.h:43
int max_prepared_xacts
Definition: twophase.c:98
PROCLOCK * waitProcLock
Definition: proc.h:136
uint8 nxids
Definition: proc.h:223
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:320
#define InvalidTransactionId
Definition: transam.h:31
Oid databaseId
Definition: proc.h:113
uint32 LocalTransactionId
Definition: c.h:399
LOCK * waitLock
Definition: proc.h:135
#define ereport(elevel, rest)
Definition: elog.h:122
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:171
#define STATUS_OK
Definition: c.h:975
bool delayChkpt
Definition: proc.h:220
#define InvalidBackendId
Definition: backendid.h:23
bool overflowed
Definition: proc.h:219
int waitStatus
Definition: proc.h:101
#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:132
TimestampTz prepared_at
Definition: twophase.c:139
void SHMQueueElemInit(SHM_QUEUE *queue)
Definition: shmqueue.c:57
int pgprocno
Definition: proc.h:109
int errmsg(const char *fmt,...)
Definition: elog.c:797
void SHMQueueInit(SHM_QUEUE *queue)
Definition: shmqueue.c:36
static GlobalTransaction MyLockedGxact
Definition: twophase.c:179
int i
PGPROC * allProcs
Definition: proc.h:232
SHM_QUEUE myProcLocks[NUM_LOCK_PARTITIONS]
Definition: proc.h:156
static void AtProcExit_Twophase(int code, Datum arg)
Definition: twophase.c:277
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:31
Definition: proc.h:94
int pid
Definition: proc.h:108
XLogRecPtr prepare_end_lsn
Definition: twophase.c:149
#define NUM_LOCK_PARTITIONS
Definition: lwlock.h:117
LocalTransactionId lxid
Definition: proc.h:105
void PostPrepare_Twophase ( void  )

Definition at line 332 of file twophase.c.

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

Referenced by PrepareTransaction(), and RecoverPreparedTransactions().

333 {
334  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
336  LWLockRelease(TwoPhaseStateLock);
337 
339 }
BackendId locking_backend
Definition: twophase.c:152
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:179
TransactionId PrescanPreparedTransactions ( TransactionId **  xids_p,
int *  nxids_p 
)

Definition at line 1693 of file twophase.c.

References AllocateDir(), Assert, buf, dirent::d_name, ereport, errmsg(), FreeDir(), TwoPhaseFileHeader::gidlen, i, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MAXALIGN, VariableCacheData::nextXid, TwoPhaseFileHeader::nsubxacts, NULL, palloc(), pfree(), ReadDir(), ReadTwoPhaseFile(), RemoveTwoPhaseFile(), repalloc(), result, ShmemVariableCache, TransactionIdAdvance, TransactionIdEquals, TransactionIdFollows(), TransactionIdFollowsOrEquals(), TransactionIdPrecedes(), TWOPHASE_DIR, WARNING, and TwoPhaseFileHeader::xid.

Referenced by StartupXLOG(), and xlog_redo().

1694 {
1695  TransactionId origNextXid = ShmemVariableCache->nextXid;
1696  TransactionId result = origNextXid;
1697  DIR *cldir;
1698  struct dirent *clde;
1699  TransactionId *xids = NULL;
1700  int nxids = 0;
1701  int allocsize = 0;
1702 
1703  cldir = AllocateDir(TWOPHASE_DIR);
1704  while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1705  {
1706  if (strlen(clde->d_name) == 8 &&
1707  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1708  {
1709  TransactionId xid;
1710  char *buf;
1711  TwoPhaseFileHeader *hdr;
1712  TransactionId *subxids;
1713  int i;
1714 
1715  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1716 
1717  /* Reject XID if too new */
1718  if (TransactionIdFollowsOrEquals(xid, origNextXid))
1719  {
1720  ereport(WARNING,
1721  (errmsg("removing future two-phase state file \"%s\"",
1722  clde->d_name)));
1723  RemoveTwoPhaseFile(xid, true);
1724  continue;
1725  }
1726 
1727  /*
1728  * Note: we can't check if already processed because clog
1729  * subsystem isn't up yet.
1730  */
1731 
1732  /* Read and validate file */
1733  buf = ReadTwoPhaseFile(xid, true);
1734  if (buf == NULL)
1735  {
1736  ereport(WARNING,
1737  (errmsg("removing corrupt two-phase state file \"%s\"",
1738  clde->d_name)));
1739  RemoveTwoPhaseFile(xid, true);
1740  continue;
1741  }
1742 
1743  /* Deconstruct header */
1744  hdr = (TwoPhaseFileHeader *) buf;
1745  if (!TransactionIdEquals(hdr->xid, xid))
1746  {
1747  ereport(WARNING,
1748  (errmsg("removing corrupt two-phase state file \"%s\"",
1749  clde->d_name)));
1750  RemoveTwoPhaseFile(xid, true);
1751  pfree(buf);
1752  continue;
1753  }
1754 
1755  /*
1756  * OK, we think this file is valid. Incorporate xid into the
1757  * running-minimum result.
1758  */
1759  if (TransactionIdPrecedes(xid, result))
1760  result = xid;
1761 
1762  /*
1763  * Examine subtransaction XIDs ... they should all follow main
1764  * XID, and they may force us to advance nextXid.
1765  *
1766  * We don't expect anyone else to modify nextXid, hence we don't
1767  * need to hold a lock while examining it. We still acquire the
1768  * lock to modify it, though.
1769  */
1770  subxids = (TransactionId *) (buf +
1771  MAXALIGN(sizeof(TwoPhaseFileHeader)) +
1772  MAXALIGN(hdr->gidlen));
1773  for (i = 0; i < hdr->nsubxacts; i++)
1774  {
1775  TransactionId subxid = subxids[i];
1776 
1777  Assert(TransactionIdFollows(subxid, xid));
1778  if (TransactionIdFollowsOrEquals(subxid,
1780  {
1781  LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
1782  ShmemVariableCache->nextXid = subxid;
1784  LWLockRelease(XidGenLock);
1785  }
1786  }
1787 
1788 
1789  if (xids_p)
1790  {
1791  if (nxids == allocsize)
1792  {
1793  if (nxids == 0)
1794  {
1795  allocsize = 10;
1796  xids = palloc(allocsize * sizeof(TransactionId));
1797  }
1798  else
1799  {
1800  allocsize = allocsize * 2;
1801  xids = repalloc(xids, allocsize * sizeof(TransactionId));
1802  }
1803  }
1804  xids[nxids++] = xid;
1805  }
1806 
1807  pfree(buf);
1808  }
1809  }
1810  FreeDir(cldir);
1811 
1812  if (xids_p)
1813  {
1814  *xids_p = xids;
1815  *nxids_p = nxids;
1816  }
1817 
1818  return result;
1819 }
#define TransactionIdAdvance(dest)
Definition: transam.h:48
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
bool TransactionIdFollows(TransactionId id1, TransactionId id2)
Definition: transam.c:334
uint32 TransactionId
Definition: c.h:397
bool TransactionIdFollowsOrEquals(TransactionId id1, TransactionId id2)
Definition: transam.c:349
return result
Definition: formatting.c:1618
TransactionId xid
Definition: twophase.c:863
Definition: dirent.h:9
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
void pfree(void *pointer)
Definition: mcxt.c:950
Definition: dirent.c:25
TransactionId nextXid
Definition: transam.h:117
static char * buf
Definition: pg_test_fsync.c:65
VariableCache ShmemVariableCache
Definition: varsup.c:34
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2298
#define ereport(elevel, rest)
Definition: elog.h:122
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:300
void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1505
#define WARNING
Definition: elog.h:40
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1141
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2364
bool LWLockAcquire(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1111
#define MAXALIGN(LEN)
Definition: c.h:588
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:963
#define TWOPHASE_DIR
Definition: twophase.c:95
void * palloc(Size size)
Definition: mcxt.c:849
int errmsg(const char *fmt,...)
Definition: elog.c:797
int i
char d_name[MAX_PATH]
Definition: dirent.h:14
int FreeDir(DIR *dir)
Definition: fd.c:2407
void RecoverPreparedTransactions ( void  )

Definition at line 1915 of file twophase.c.

References AllocateDir(), Assert, buf, dirent::d_name, TwoPhaseFileHeader::database, ereport, errmsg(), FreeDir(), TwoPhaseFileHeader::gidlen, GXactLoadSubxactData(), i, InHotStandby, LOG, MarkAsPrepared(), MarkAsPreparing(), MAXALIGN, MAXPGPATH, TwoPhaseFileHeader::nabortrels, TwoPhaseFileHeader::ncommitrels, TwoPhaseFileHeader::ninvalmsgs, TwoPhaseFileHeader::nsubxacts, NULL, GlobalTransactionData::ondisk, TwoPhaseFileHeader::owner, pfree(), PGPROC_MAX_CACHED_SUBXIDS, PostPrepare_Twophase(), TwoPhaseFileHeader::prepared_at, ProcessRecords(), ReadDir(), ReadTwoPhaseFile(), RemoveTwoPhaseFile(), snprintf(), StandbyReleaseLockTree(), SubTransSetParent(), TransactionIdDidAbort(), TransactionIdDidCommit(), TransactionIdEquals, TWOPHASE_DIR, twophase_recover_callbacks, WARNING, TwoPhaseFileHeader::xid, and XLogLogicalInfoActive.

Referenced by StartupXLOG().

1916 {
1917  char dir[MAXPGPATH];
1918  DIR *cldir;
1919  struct dirent *clde;
1920  bool overwriteOK = false;
1921 
1922  snprintf(dir, MAXPGPATH, "%s", TWOPHASE_DIR);
1923 
1924  cldir = AllocateDir(dir);
1925  while ((clde = ReadDir(cldir, dir)) != NULL)
1926  {
1927  if (strlen(clde->d_name) == 8 &&
1928  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1929  {
1930  TransactionId xid;
1931  char *buf;
1932  char *bufptr;
1933  TwoPhaseFileHeader *hdr;
1934  TransactionId *subxids;
1935  GlobalTransaction gxact;
1936  const char *gid;
1937  int i;
1938 
1939  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1940 
1941  /* Already processed? */
1943  {
1944  ereport(WARNING,
1945  (errmsg("removing stale two-phase state file \"%s\"",
1946  clde->d_name)));
1947  RemoveTwoPhaseFile(xid, true);
1948  continue;
1949  }
1950 
1951  /* Read and validate file */
1952  buf = ReadTwoPhaseFile(xid, true);
1953  if (buf == NULL)
1954  {
1955  ereport(WARNING,
1956  (errmsg("removing corrupt two-phase state file \"%s\"",
1957  clde->d_name)));
1958  RemoveTwoPhaseFile(xid, true);
1959  continue;
1960  }
1961 
1962  ereport(LOG,
1963  (errmsg("recovering prepared transaction %u", xid)));
1964 
1965  /* Deconstruct header */
1966  hdr = (TwoPhaseFileHeader *) buf;
1967  Assert(TransactionIdEquals(hdr->xid, xid));
1968  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1969  gid = (const char *) bufptr;
1970  bufptr += MAXALIGN(hdr->gidlen);
1971  subxids = (TransactionId *) bufptr;
1972  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1973  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1974  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1975  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1976 
1977  /*
1978  * It's possible that SubTransSetParent has been set before, if
1979  * the prepared transaction generated xid assignment records. Test
1980  * here must match one used in AssignTransactionId().
1981  */
1984  overwriteOK = true;
1985 
1986  /*
1987  * Reconstruct subtrans state for the transaction --- needed
1988  * because pg_subtrans is not preserved over a restart. Note that
1989  * we are linking all the subtransactions directly to the
1990  * top-level XID; there may originally have been a more complex
1991  * hierarchy, but there's no need to restore that exactly.
1992  */
1993  for (i = 0; i < hdr->nsubxacts; i++)
1994  SubTransSetParent(subxids[i], xid, overwriteOK);
1995 
1996  /*
1997  * Recreate its GXACT and dummy PGPROC
1998  */
1999  gxact = MarkAsPreparing(xid, gid,
2000  hdr->prepared_at,
2001  hdr->owner, hdr->database);
2002  gxact->ondisk = true;
2003  GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
2004  MarkAsPrepared(gxact);
2005 
2006  /*
2007  * Recover other state (notably locks) using resource managers
2008  */
2010 
2011  /*
2012  * Release locks held by the standby process after we process each
2013  * prepared transaction. As a result, we don't need too many
2014  * additional locks at any one time.
2015  */
2016  if (InHotStandby)
2017  StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
2018 
2019  /*
2020  * We're done with recovering this transaction. Clear
2021  * MyLockedGxact, like we do in PrepareTransaction() during normal
2022  * operation.
2023  */
2025 
2026  pfree(buf);
2027  }
2028  }
2029  FreeDir(cldir);
2030 }
#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:1477
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:24
#define InHotStandby
Definition: xlog.h:74
int snprintf(char *str, size_t count, const char *fmt,...) pg_attribute_printf(3
TransactionId xid
Definition: twophase.c:863
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:125
#define LOG
Definition: elog.h:26
Definition: dirent.h:9
GlobalTransaction MarkAsPreparing(TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
Definition: twophase.c:351
void pfree(void *pointer)
Definition: mcxt.c:950
Definition: dirent.c:25
#define XLogLogicalInfoActive()
Definition: xlog.h:162
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:466
#define MAXPGPATH
static char * buf
Definition: pg_test_fsync.c:65
void StandbyReleaseLockTree(TransactionId xid, int nsubxids, TransactionId *subxids)
Definition: standby.c:676
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2298
#define ereport(elevel, rest)
Definition: elog.h:122
bool TransactionIdDidAbort(TransactionId transactionId)
Definition: transam.c:181
void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1505
#define WARNING
Definition: elog.h:40
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1141
#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:491
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2364
#define MAXALIGN(LEN)
Definition: c.h:588
#define TWOPHASE_DIR
Definition: twophase.c:95
int errmsg(const char *fmt,...)
Definition: elog.c:797
void PostPrepare_Twophase(void)
Definition: twophase.c:332
int i
char d_name[MAX_PATH]
Definition: dirent.h:14
TimestampTz prepared_at
Definition: twophase.c:865
int FreeDir(DIR *dir)
Definition: fd.c:2407
void RecreateTwoPhaseFile ( TransactionId  xid,
void *  content,
int  len 
)

Definition at line 1525 of file twophase.c.

References CloseTransientFile(), COMP_CRC32C, ereport, errcode_for_file_access(), errmsg(), ERROR, fd(), FIN_CRC32C, INIT_CRC32C, MAXPGPATH, OpenTransientFile(), PG_BINARY, pg_fsync(), pgstat_report_wait_end(), pgstat_report_wait_start(), TwoPhaseFilePath, WAIT_EVENT_TWOPHASE_FILE_SYNC, WAIT_EVENT_TWOPHASE_FILE_WRITE, and write.

Referenced by CheckPointTwoPhase(), and xact_redo().

1526 {
1527  char path[MAXPGPATH];
1528  pg_crc32c statefile_crc;
1529  int fd;
1530 
1531  /* Recompute CRC */
1532  INIT_CRC32C(statefile_crc);
1533  COMP_CRC32C(statefile_crc, content, len);
1534  FIN_CRC32C(statefile_crc);
1535 
1536  TwoPhaseFilePath(path, xid);
1537 
1538  fd = OpenTransientFile(path,
1539  O_CREAT | O_TRUNC | O_WRONLY | PG_BINARY,
1540  S_IRUSR | S_IWUSR);
1541  if (fd < 0)
1542  ereport(ERROR,
1544  errmsg("could not recreate two-phase state file \"%s\": %m",
1545  path)));
1546 
1547  /* Write content and CRC */
1549  if (write(fd, content, len) != len)
1550  {
1552  CloseTransientFile(fd);
1553  ereport(ERROR,
1555  errmsg("could not write two-phase state file: %m")));
1556  }
1557  if (write(fd, &statefile_crc, sizeof(pg_crc32c)) != sizeof(pg_crc32c))
1558  {
1560  CloseTransientFile(fd);
1561  ereport(ERROR,
1563  errmsg("could not write two-phase state file: %m")));
1564  }
1566 
1567  /*
1568  * We must fsync the file because the end-of-replay checkpoint will not do
1569  * so, there being no GXACT in shared memory yet to tell it to.
1570  */
1572  if (pg_fsync(fd) != 0)
1573  {
1574  CloseTransientFile(fd);
1575  ereport(ERROR,
1577  errmsg("could not fsync two-phase state file: %m")));
1578  }
1580 
1581  if (CloseTransientFile(fd) != 0)
1582  ereport(ERROR,
1584  errmsg("could not close two-phase state file: %m")));
1585 }
#define INIT_CRC32C(crc)
Definition: pg_crc32c.h:41
#define write(a, b, c)
Definition: win32.h:19
uint32 pg_crc32c
Definition: pg_crc32c.h:38
static int fd(const char *x, int i)
Definition: preproc-init.c:105
#define PG_BINARY
Definition: c.h:1038
#define TwoPhaseFilePath(path, xid)
Definition: twophase.c:835
#define ERROR
Definition: elog.h:43
#define MAXPGPATH
int OpenTransientFile(FileName fileName, int fileFlags, int fileMode)
Definition: fd.c:2107
int errcode_for_file_access(void)
Definition: elog.c:598
static void pgstat_report_wait_end(void)
Definition: pgstat.h:1205
#define ereport(elevel, rest)
Definition: elog.h:122
int CloseTransientFile(int fd)
Definition: fd.c:2268
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: pgstat.h:1181
int errmsg(const char *fmt,...)
Definition: elog.c:797
int pg_fsync(int fd)
Definition: fd.c:333
#define COMP_CRC32C(crc, data, len)
Definition: pg_crc32c.h:73
#define FIN_CRC32C(crc)
Definition: pg_crc32c.h:78
void RemoveTwoPhaseFile ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 1505 of file twophase.c.

References ereport, errcode_for_file_access(), errmsg(), MAXPGPATH, TwoPhaseFilePath, unlink(), and WARNING.

Referenced by FinishPreparedTransaction(), PrescanPreparedTransactions(), RecoverPreparedTransactions(), StandbyRecoverPreparedTransactions(), and xact_redo().

1506 {
1507  char path[MAXPGPATH];
1508 
1509  TwoPhaseFilePath(path, xid);
1510  if (unlink(path))
1511  if (errno != ENOENT || giveWarning)
1512  ereport(WARNING,
1514  errmsg("could not remove two-phase state file \"%s\": %m",
1515  path)));
1516 }
#define TwoPhaseFilePath(path, xid)
Definition: twophase.c:835
#define MAXPGPATH
int errcode_for_file_access(void)
Definition: elog.c:598
int unlink(const char *filename)
#define ereport(elevel, rest)
Definition: elog.h:122
#define WARNING
Definition: elog.h:40
int errmsg(const char *fmt,...)
Definition: elog.c:797
void StandbyRecoverPreparedTransactions ( bool  overwriteOK)

Definition at line 1834 of file twophase.c.

References AllocateDir(), Assert, buf, dirent::d_name, ereport, errmsg(), FreeDir(), TwoPhaseFileHeader::gidlen, i, MAXALIGN, TwoPhaseFileHeader::nsubxacts, NULL, pfree(), ReadDir(), ReadTwoPhaseFile(), RemoveTwoPhaseFile(), SubTransSetParent(), TransactionIdDidAbort(), TransactionIdDidCommit(), TransactionIdEquals, TransactionIdFollows(), TWOPHASE_DIR, WARNING, and TwoPhaseFileHeader::xid.

Referenced by StartupXLOG(), and xlog_redo().

1835 {
1836  DIR *cldir;
1837  struct dirent *clde;
1838 
1839  cldir = AllocateDir(TWOPHASE_DIR);
1840  while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1841  {
1842  if (strlen(clde->d_name) == 8 &&
1843  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1844  {
1845  TransactionId xid;
1846  char *buf;
1847  TwoPhaseFileHeader *hdr;
1848  TransactionId *subxids;
1849  int i;
1850 
1851  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1852 
1853  /* Already processed? */
1855  {
1856  ereport(WARNING,
1857  (errmsg("removing stale two-phase state file \"%s\"",
1858  clde->d_name)));
1859  RemoveTwoPhaseFile(xid, true);
1860  continue;
1861  }
1862 
1863  /* Read and validate file */
1864  buf = ReadTwoPhaseFile(xid, true);
1865  if (buf == NULL)
1866  {
1867  ereport(WARNING,
1868  (errmsg("removing corrupt two-phase state file \"%s\"",
1869  clde->d_name)));
1870  RemoveTwoPhaseFile(xid, true);
1871  continue;
1872  }
1873 
1874  /* Deconstruct header */
1875  hdr = (TwoPhaseFileHeader *) buf;
1876  if (!TransactionIdEquals(hdr->xid, xid))
1877  {
1878  ereport(WARNING,
1879  (errmsg("removing corrupt two-phase state file \"%s\"",
1880  clde->d_name)));
1881  RemoveTwoPhaseFile(xid, true);
1882  pfree(buf);
1883  continue;
1884  }
1885 
1886  /*
1887  * Examine subtransaction XIDs ... they should all follow main
1888  * XID.
1889  */
1890  subxids = (TransactionId *) (buf +
1891  MAXALIGN(sizeof(TwoPhaseFileHeader)) +
1892  MAXALIGN(hdr->gidlen));
1893  for (i = 0; i < hdr->nsubxacts; i++)
1894  {
1895  TransactionId subxid = subxids[i];
1896 
1897  Assert(TransactionIdFollows(subxid, xid));
1898  SubTransSetParent(xid, subxid, overwriteOK);
1899  }
1900 
1901  pfree(buf);
1902  }
1903  }
1904  FreeDir(cldir);
1905 }
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
bool TransactionIdFollows(TransactionId id1, TransactionId id2)
Definition: transam.c:334
uint32 TransactionId
Definition: c.h:397
void SubTransSetParent(TransactionId xid, TransactionId parent, bool overwriteOK)
Definition: subtrans.c:75
TransactionId xid
Definition: twophase.c:863
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:125
Definition: dirent.h:9
void pfree(void *pointer)
Definition: mcxt.c:950
Definition: dirent.c:25
static char * buf
Definition: pg_test_fsync.c:65
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2298
#define ereport(elevel, rest)
Definition: elog.h:122
bool TransactionIdDidAbort(TransactionId transactionId)
Definition: transam.c:181
void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1505
#define WARNING
Definition: elog.h:40
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1141
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2364
#define MAXALIGN(LEN)
Definition: c.h:588
#define TWOPHASE_DIR
Definition: twophase.c:95
int errmsg(const char *fmt,...)
Definition: elog.c:797
int i
char d_name[MAX_PATH]
Definition: dirent.h:14
int FreeDir(DIR *dir)
Definition: fd.c:2407
bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1297 of file twophase.c.

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

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

1298 {
1299  char *buf;
1300  TwoPhaseFileHeader *hdr;
1301  bool result;
1302 
1304 
1305  if (max_prepared_xacts <= 0)
1306  return false; /* nothing to do */
1307 
1308  /* Read and validate file */
1309  buf = ReadTwoPhaseFile(xid, false);
1310  if (buf == NULL)
1311  return false;
1312 
1313  /* Check header also */
1314  hdr = (TwoPhaseFileHeader *) buf;
1315  result = TransactionIdEquals(hdr->xid, xid);
1316  pfree(buf);
1317 
1318  return result;
1319 }
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
return result
Definition: formatting.c:1618
TransactionId xid
Definition: twophase.c:863
void pfree(void *pointer)
Definition: mcxt.c:950
int max_prepared_xacts
Definition: twophase.c:98
static char * buf
Definition: pg_test_fsync.c:65
static char * ReadTwoPhaseFile(TransactionId xid, bool give_warnings)
Definition: twophase.c:1141
#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 947 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().

948 {
949  PGPROC *proc = &ProcGlobal->allProcs[gxact->pgprocno];
950  PGXACT *pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
951  TransactionId xid = pgxact->xid;
952  TwoPhaseFileHeader hdr;
953  TransactionId *children;
954  RelFileNode *commitrels;
955  RelFileNode *abortrels;
956  SharedInvalidationMessage *invalmsgs;
957 
958  /* Initialize linked list */
959  records.head = palloc0(sizeof(StateFileChunk));
960  records.head->len = 0;
961  records.head->next = NULL;
962 
963  records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
965 
967  records.num_chunks = 1;
968 
969  records.total_len = 0;
970 
971  /* Create header */
972  hdr.magic = TWOPHASE_MAGIC;
973  hdr.total_len = 0; /* EndPrepare will fill this in */
974  hdr.xid = xid;
975  hdr.database = proc->databaseId;
976  hdr.prepared_at = gxact->prepared_at;
977  hdr.owner = gxact->owner;
978  hdr.nsubxacts = xactGetCommittedChildren(&children);
979  hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
980  hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
982  &hdr.initfileinval);
983  hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
984 
985  save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
986  save_state_data(gxact->gid, hdr.gidlen);
987 
988  /*
989  * Add the additional info about subxacts, deletable files and cache
990  * invalidation messages.
991  */
992  if (hdr.nsubxacts > 0)
993  {
994  save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
995  /* While we have the child-xact data, stuff it in the gxact too */
996  GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
997  }
998  if (hdr.ncommitrels > 0)
999  {
1000  save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileNode));
1001  pfree(commitrels);
1002  }
1003  if (hdr.nabortrels > 0)
1004  {
1005  save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileNode));
1006  pfree(abortrels);
1007  }
1008  if (hdr.ninvalmsgs > 0)
1009  {
1010  save_state_data(invalmsgs,
1011  hdr.ninvalmsgs * sizeof(SharedInvalidationMessage));
1012  pfree(invalmsgs);
1013  }
1014 }
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:903
PROC_HDR * ProcGlobal
Definition: proc.c:80
TransactionId xid
Definition: twophase.c:863
uint32 num_chunks
Definition: twophase.c:904
char gid[GIDSIZE]
Definition: twophase.c:155
char * data
Definition: twophase.c:895
void pfree(void *pointer)
Definition: mcxt.c:950
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:466
uint32 bytes_free
Definition: twophase.c:905
int smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr)
Definition: storage.c:389
uint32 len
Definition: twophase.c:896
Oid databaseId
Definition: proc.h:113
uint32 total_len
Definition: twophase.c:906
struct StateFileChunk * next
Definition: twophase.c:897
void * palloc0(Size size)
Definition: mcxt.c:878
#define TWOPHASE_MAGIC
Definition: twophase.c:857
#define Max(x, y)
Definition: c.h:800
StateFileChunk * head
Definition: twophase.c:902
#define NULL
Definition: c.h:229
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:919
TimestampTz prepared_at
Definition: twophase.c:139
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:865
Definition: proc.h:94
BackendId TwoPhaseGetDummyBackendId ( TransactionId  xid)

Definition at line 812 of file twophase.c.

References GlobalTransactionData::dummyBackendId, and TwoPhaseGetGXact().

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

813 {
814  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
815 
816  return gxact->dummyBackendId;
817 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:763
BackendId dummyBackendId
Definition: twophase.c:138
PGPROC* TwoPhaseGetDummyProc ( TransactionId  xid)

Definition at line 824 of file twophase.c.

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

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

825 {
826  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
827 
828  return &ProcGlobal->allProcs[gxact->pgprocno];
829 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:763
PROC_HDR * ProcGlobal
Definition: proc.c:80
PGPROC * allProcs
Definition: proc.h:232
void TwoPhaseShmemInit ( void  )

Definition at line 222 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().

223 {
224  bool found;
225 
226  TwoPhaseState = ShmemInitStruct("Prepared Transaction Table",
228  &found);
229  if (!IsUnderPostmaster)
230  {
231  GlobalTransaction gxacts;
232  int i;
233 
234  Assert(!found);
237 
238  /*
239  * Initialize the linked list of free GlobalTransactionData structs
240  */
241  gxacts = (GlobalTransaction)
242  ((char *) TwoPhaseState +
243  MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) +
245  for (i = 0; i < max_prepared_xacts; i++)
246  {
247  /* insert into linked list */
248  gxacts[i].next = TwoPhaseState->freeGXacts;
249  TwoPhaseState->freeGXacts = &gxacts[i];
250 
251  /* associate it with a PGPROC assigned by InitProcGlobal */
253 
254  /*
255  * Assign a unique ID for each dummy proc, so that the range of
256  * dummy backend IDs immediately follows the range of normal
257  * backend IDs. We don't dare to assign a real backend ID to dummy
258  * procs, because prepared transactions don't take part in cache
259  * invalidation like a real backend ID would imply, but having a
260  * unique ID for them is nevertheless handy. This arrangement
261  * allows you to allocate an array of size (MaxBackends +
262  * max_prepared_xacts + 1), and have a slot for every backend and
263  * prepared transaction. Currently multixact.c uses that
264  * technique.
265  */
266  gxacts[i].dummyBackendId = MaxBackends + 1 + i;
267  }
268  }
269  else
270  Assert(found);
271 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:174
GlobalTransaction freeGXacts
Definition: twophase.c:165
PGPROC * PreparedXactProcs
Definition: proc.c:82
Size TwoPhaseShmemSize(void)
Definition: twophase.c:206
GlobalTransaction next
Definition: twophase.c:136
struct GlobalTransactionData * GlobalTransaction
Definition: twophase.h:25
int max_prepared_xacts
Definition: twophase.c:98
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:138
Size TwoPhaseShmemSize ( void  )

Definition at line 206 of file twophase.c.

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

Referenced by CreateSharedMemoryAndSemaphores(), and TwoPhaseShmemInit().

207 {
208  Size size;
209 
210  /* Need the fixed struct, the array of pointers, and the GTD structs */
211  size = offsetof(TwoPhaseStateData, prepXacts);
212  size = add_size(size, mul_size(max_prepared_xacts,
213  sizeof(GlobalTransaction)));
214  size = MAXALIGN(size);
215  size = add_size(size, mul_size(max_prepared_xacts,
216  sizeof(GlobalTransactionData)));
217 
218  return size;
219 }
int max_prepared_xacts
Definition: twophase.c:98
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