PostgreSQL Source Code  git master
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros
twophase.h File Reference
#include "access/xlogdefs.h"
#include "datatype/timestamp.h"
#include "storage/lock.h"
Include dependency graph for twophase.h:
This graph shows which files directly or indirectly include this file:

Go to the source code of this file.

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 (void)
 
void RecoverPreparedTransactions (void)
 
void CheckPointTwoPhase (XLogRecPtr redo_horizon)
 
void FinishPreparedTransaction (const char *gid, bool isCommit)
 
void PrepareRedoAdd (char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn)
 
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 316 of file twophase.c.

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

Referenced by AbortTransaction(), and AtProcExit_Twophase().

317 {
318  if (MyLockedGxact == NULL)
319  return;
320 
321  /*
322  * What to do with the locked global transaction entry? If we were in the
323  * process of preparing the transaction, but haven't written the WAL
324  * record and state file yet, the transaction must not be considered as
325  * prepared. Likewise, if we are in the process of finishing an
326  * already-prepared transaction, and fail after having already written the
327  * 2nd phase commit or rollback record to the WAL, the transaction should
328  * not be considered as prepared anymore. In those cases, just remove the
329  * entry from shared memory.
330  *
331  * Otherwise, the entry must be left in place so that the transaction can
332  * be finished later, so just unlock it.
333  *
334  * If we abort during prepare, after having written the WAL record, we
335  * might not have transferred all locks and other state to the prepared
336  * transaction yet. Likewise, if we abort during commit or rollback,
337  * after having written the WAL record, we might not have released all the
338  * resources held by the transaction yet. In those cases, the in-memory
339  * state can be wrong, but it's too late to back out.
340  */
341  if (!MyLockedGxact->valid)
342  {
344  }
345  else
346  {
347  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
348 
350 
351  LWLockRelease(TwoPhaseStateLock);
352  }
354 }
BackendId locking_backend
Definition: twophase.c:172
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:631
#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 1649 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().

1650 {
1651  int i;
1652  int serialized_xacts = 0;
1653 
1654  if (max_prepared_xacts <= 0)
1655  return; /* nothing to do */
1656 
1657  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1658 
1659  /*
1660  * We are expecting there to be zero GXACTs that need to be copied to
1661  * disk, so we perform all I/O while holding TwoPhaseStateLock for
1662  * simplicity. This prevents any new xacts from preparing while this
1663  * occurs, which shouldn't be a problem since the presence of long-lived
1664  * prepared xacts indicates the transaction manager isn't active.
1665  *
1666  * It's also possible to move I/O out of the lock, but on every error we
1667  * should check whether somebody committed our transaction in different
1668  * backend. Let's leave this optimization for future, if somebody will
1669  * spot that this place cause bottleneck.
1670  *
1671  * Note that it isn't possible for there to be a GXACT with a
1672  * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1673  * because of the efforts with delayChkpt.
1674  */
1675  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1676  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1677  {
1678  /*
1679  * Note that we are using gxact not pgxact so this works in recovery
1680  * also
1681  */
1683 
1684  if ((gxact->valid || gxact->inredo) &&
1685  !gxact->ondisk &&
1686  gxact->prepare_end_lsn <= redo_horizon)
1687  {
1688  char *buf;
1689  int len;
1690 
1691  XlogReadTwoPhaseData(gxact->prepare_start_lsn, &buf, &len);
1692  RecreateTwoPhaseFile(gxact->xid, buf, len);
1693  gxact->ondisk = true;
1696  pfree(buf);
1697  serialized_xacts++;
1698  }
1699  }
1700  LWLockRelease(TwoPhaseStateLock);
1701 
1702  /*
1703  * Flush unconditionally the parent directory to make any information
1704  * durable on disk. Two-phase files could have been removed and those
1705  * removals need to be made persistent as well as any files newly created
1706  * previously since the last checkpoint.
1707  */
1708  fsync_fname(TWOPHASE_DIR, true);
1709 
1710  TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1711 
1712  if (log_checkpoints && serialized_xacts > 0)
1713  ereport(LOG,
1714  (errmsg_plural("%u two-phase state file was written "
1715  "for a long-running prepared transaction",
1716  "%u two-phase state files were written "
1717  "for long-running prepared transactions",
1718  serialized_xacts,
1719  serialized_xacts)));
1720 }
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:1567
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:1296
int i
XLogRecPtr prepare_end_lsn
Definition: twophase.c:168
void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1064 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().

1065 {
1066  TwoPhaseFileHeader *hdr;
1067  StateFileChunk *record;
1068 
1069  /* Add the end sentinel to the list of 2PC records */
1071  NULL, 0);
1072 
1073  /* Go back and fill in total_len in the file header record */
1074  hdr = (TwoPhaseFileHeader *) records.head->data;
1075  Assert(hdr->magic == TWOPHASE_MAGIC);
1076  hdr->total_len = records.total_len + sizeof(pg_crc32c);
1077 
1078  /*
1079  * If the data size exceeds MaxAllocSize, we won't be able to read it in
1080  * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1081  * where we write data to file and then re-read at commit time.
1082  */
1083  if (hdr->total_len > MaxAllocSize)
1084  ereport(ERROR,
1085  (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1086  errmsg("two-phase state file maximum length exceeded")));
1087 
1088  /*
1089  * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1090  * cover us, so no need to calculate a separate CRC.
1091  *
1092  * We have to set delayChkpt here, too; otherwise a checkpoint starting
1093  * immediately after the WAL record is inserted could complete without
1094  * fsync'ing our state file. (This is essentially the same kind of race
1095  * condition as the COMMIT-to-clog-write case that RecordTransactionCommit
1096  * uses delayChkpt for; see notes there.)
1097  *
1098  * We save the PREPARE record's location in the gxact for later use by
1099  * CheckPointTwoPhase.
1100  */
1102 
1104 
1105  MyPgXact->delayChkpt = true;
1106 
1107  XLogBeginInsert();
1108  for (record = records.head; record != NULL; record = record->next)
1109  XLogRegisterData(record->data, record->len);
1110  gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1111  XLogFlush(gxact->prepare_end_lsn);
1112 
1113  /* If we crash now, we have prepared: WAL replay will fix things */
1114 
1115  /* Store record's start location to read that later on Commit */
1117 
1118  /*
1119  * Mark the prepared transaction as valid. As soon as xact.c marks
1120  * MyPgXact as not running our XID (which it will do immediately after
1121  * this function returns), others can commit/rollback the xact.
1122  *
1123  * NB: a side effect of this is to make a dummy ProcArray entry for the
1124  * prepared XID. This must happen before we clear the XID from MyPgXact,
1125  * else there is a window where the XID is not running according to
1126  * TransactionIdIsInProgress, and onlookers would be entitled to assume
1127  * the xact crashed. Instead we have a window where the same XID appears
1128  * twice in ProcArray, which is OK.
1129  */
1130  MarkAsPrepared(gxact);
1131 
1132  /*
1133  * Now we can mark ourselves as out of the commit critical section: a
1134  * checkpoint starting after this will certainly see the gxact as a
1135  * candidate for fsyncing.
1136  */
1137  MyPgXact->delayChkpt = false;
1138 
1139  /*
1140  * Remember that we have this GlobalTransaction entry locked for us. If
1141  * we crash after this point, it's too late to abort, but we must unlock
1142  * it so that the prepared transaction can be committed or rolled back.
1143  */
1144  MyLockedGxact = gxact;
1145 
1146  END_CRIT_SECTION();
1147 
1148  /*
1149  * Wait for synchronous replication, if required.
1150  *
1151  * Note that at this stage we have marked the prepare, but still show as
1152  * running in the procarray (twice!) and continue to hold locks.
1153  */
1154  SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1155 
1157  records.num_chunks = 0;
1158 }
#define XLOG_XACT_PREPARE
Definition: xact.h:135
StateFileChunk * tail
Definition: twophase.c:947
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:948
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2758
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1164
PGXACT * MyPgXact
Definition: proc.c:68
XLogRecPtr prepare_start_lsn
Definition: twophase.c:167
char * data
Definition: twophase.c:939
#define ERROR
Definition: elog.h:43
uint32 len
Definition: twophase.c:940
#define ereport(elevel, rest)
Definition: elog.h:122
bool delayChkpt
Definition: proc.h:220
uint32 total_len
Definition: twophase.c:950
#define MaxAllocSize
Definition: memutils.h:40
struct StateFileChunk * next
Definition: twophase.c:941
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:901
StateFileChunk * head
Definition: twophase.c:946
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void MarkAsPrepared(GlobalTransaction gxact)
Definition: twophase.c:535
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 1367 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().

1368 {
1369  GlobalTransaction gxact;
1370  PGPROC *proc;
1371  PGXACT *pgxact;
1372  TransactionId xid;
1373  char *buf;
1374  char *bufptr;
1375  TwoPhaseFileHeader *hdr;
1376  TransactionId latestXid;
1377  TransactionId *children;
1378  RelFileNode *commitrels;
1379  RelFileNode *abortrels;
1380  RelFileNode *delrels;
1381  int ndelrels;
1382  SharedInvalidationMessage *invalmsgs;
1383  int i;
1384 
1385  /*
1386  * Validate the GID, and lock the GXACT to ensure that two backends do not
1387  * try to commit the same GID at once.
1388  */
1389  gxact = LockGXact(gid, GetUserId());
1390  proc = &ProcGlobal->allProcs[gxact->pgprocno];
1391  pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
1392  xid = pgxact->xid;
1393 
1394  /*
1395  * Read and validate 2PC state data. State data will typically be stored
1396  * in WAL files if the LSN is after the last checkpoint record, or moved
1397  * to disk if for some reason they have lived for a long time.
1398  */
1399  if (gxact->ondisk)
1400  buf = ReadTwoPhaseFile(xid, true);
1401  else
1403 
1404 
1405  /*
1406  * Disassemble the header area
1407  */
1408  hdr = (TwoPhaseFileHeader *) buf;
1409  Assert(TransactionIdEquals(hdr->xid, xid));
1410  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1411  bufptr += MAXALIGN(hdr->gidlen);
1412  children = (TransactionId *) bufptr;
1413  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1414  commitrels = (RelFileNode *) bufptr;
1415  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1416  abortrels = (RelFileNode *) bufptr;
1417  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1418  invalmsgs = (SharedInvalidationMessage *) bufptr;
1419  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1420 
1421  /* compute latestXid among all children */
1422  latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1423 
1424  /*
1425  * The order of operations here is critical: make the XLOG entry for
1426  * commit or abort, then mark the transaction committed or aborted in
1427  * pg_xact, then remove its PGPROC from the global ProcArray (which means
1428  * TransactionIdIsInProgress will stop saying the prepared xact is in
1429  * progress), then run the post-commit or post-abort callbacks. The
1430  * callbacks will release the locks the transaction held.
1431  */
1432  if (isCommit)
1434  hdr->nsubxacts, children,
1435  hdr->ncommitrels, commitrels,
1436  hdr->ninvalmsgs, invalmsgs,
1437  hdr->initfileinval);
1438  else
1440  hdr->nsubxacts, children,
1441  hdr->nabortrels, abortrels);
1442 
1443  ProcArrayRemove(proc, latestXid);
1444 
1445  /*
1446  * In case we fail while running the callbacks, mark the gxact invalid so
1447  * no one else will try to commit/rollback, and so it will be recycled if
1448  * we fail after this point. It is still locked by our backend so it
1449  * won't go away yet.
1450  *
1451  * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1452  */
1453  gxact->valid = false;
1454 
1455  /*
1456  * We have to remove any files that were supposed to be dropped. For
1457  * consistency with the regular xact.c code paths, must do this before
1458  * releasing locks, so do it before running the callbacks.
1459  *
1460  * NB: this code knows that we couldn't be dropping any temp rels ...
1461  */
1462  if (isCommit)
1463  {
1464  delrels = commitrels;
1465  ndelrels = hdr->ncommitrels;
1466  }
1467  else
1468  {
1469  delrels = abortrels;
1470  ndelrels = hdr->nabortrels;
1471  }
1472  for (i = 0; i < ndelrels; i++)
1473  {
1474  SMgrRelation srel = smgropen(delrels[i], InvalidBackendId);
1475 
1476  smgrdounlink(srel, false);
1477  smgrclose(srel);
1478  }
1479 
1480  /*
1481  * Handle cache invalidation messages.
1482  *
1483  * Relcache init file invalidation requires processing both before and
1484  * after we send the SI messages. See AtEOXact_Inval()
1485  */
1486  if (hdr->initfileinval)
1488  SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1489  if (hdr->initfileinval)
1491 
1492  /* And now do the callbacks */
1493  if (isCommit)
1495  else
1497 
1498  PredicateLockTwoPhaseFinish(xid, isCommit);
1499 
1500  /* Count the prepared xact as committed or aborted */
1501  AtEOXact_PgStat(isCommit);
1502 
1503  /*
1504  * And now we can clean up any files we may have left.
1505  */
1506  if (gxact->ondisk)
1507  RemoveTwoPhaseFile(xid, true);
1508 
1509  RemoveGXact(gxact);
1510  MyLockedGxact = NULL;
1511 
1512  pfree(buf);
1513 }
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:2246
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:1519
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:907
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:555
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:332
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:631
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:2153
#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:1185
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6069
static void RemoveTwoPhaseFile(TransactionId xid, bool giveWarning)
Definition: twophase.c:1547
#define NULL
Definition: c.h:229
void RelationCacheInitFilePreInvalidate(void)
Definition: relcache.c:6043
#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:1296
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:2053
GlobalTransaction MarkAsPreparing ( TransactionId  xid,
const char *  gid,
TimestampTz  prepared_at,
Oid  owner,
Oid  databaseid 
)

Definition at line 376 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().

378 {
379  GlobalTransaction gxact;
380  int i;
381 
382  if (strlen(gid) >= GIDSIZE)
383  ereport(ERROR,
384  (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
385  errmsg("transaction identifier \"%s\" is too long",
386  gid)));
387 
388  /* fail immediately if feature is disabled */
389  if (max_prepared_xacts == 0)
390  ereport(ERROR,
391  (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
392  errmsg("prepared transactions are disabled"),
393  errhint("Set max_prepared_transactions to a nonzero value.")));
394 
395  /* on first call, register the exit hook */
397  {
399  twophaseExitRegistered = true;
400  }
401 
402  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
403 
404  /* Check for conflicting GID */
405  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
406  {
407  gxact = TwoPhaseState->prepXacts[i];
408  if (strcmp(gxact->gid, gid) == 0)
409  {
410  ereport(ERROR,
412  errmsg("transaction identifier \"%s\" is already in use",
413  gid)));
414  }
415  }
416 
417  /* Get a free gxact from the freelist */
418  if (TwoPhaseState->freeGXacts == NULL)
419  ereport(ERROR,
420  (errcode(ERRCODE_OUT_OF_MEMORY),
421  errmsg("maximum number of prepared transactions reached"),
422  errhint("Increase max_prepared_transactions (currently %d).",
424  gxact = TwoPhaseState->freeGXacts;
425  TwoPhaseState->freeGXacts = gxact->next;
426 
427  MarkAsPreparingGuts(gxact, xid, gid, prepared_at, owner, databaseid);
428 
429  gxact->ondisk = false;
430 
431  /* And insert it into the active array */
434 
435  LWLockRelease(TwoPhaseStateLock);
436 
437  return gxact;
438 }
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:450
#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:306
#define ERRCODE_DUPLICATE_OBJECT
Definition: streamutil.c:31
void PostPrepare_Twophase ( void  )

Definition at line 361 of file twophase.c.

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

Referenced by PrepareTransaction(), and RecoverPreparedTransactions().

362 {
363  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
365  LWLockRelease(TwoPhaseStateLock);
366 
368 }
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 2304 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().

2305 {
2307  char *bufptr;
2308  const char *gid;
2309  GlobalTransaction gxact;
2310 
2312 
2313  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2314  gid = (const char *) bufptr;
2315 
2316  /*
2317  * Reserve the GID for the given transaction in the redo code path.
2318  *
2319  * This creates a gxact struct and puts it into the active array.
2320  *
2321  * In redo, this struct is mainly used to track PREPARE/COMMIT entries in
2322  * shared memory. Hence, we only fill up the bare minimum contents here.
2323  * The gxact also gets marked with gxact->inredo set to true to indicate
2324  * that it got added in the redo phase
2325  */
2326 
2327  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2328  /* Get a free gxact from the freelist */
2329  if (TwoPhaseState->freeGXacts == NULL)
2330  ereport(ERROR,
2331  (errcode(ERRCODE_OUT_OF_MEMORY),
2332  errmsg("maximum number of prepared transactions reached"),
2333  errhint("Increase max_prepared_transactions (currently %d).",
2334  max_prepared_xacts)));
2335  gxact = TwoPhaseState->freeGXacts;
2336  TwoPhaseState->freeGXacts = gxact->next;
2337 
2338  gxact->prepared_at = hdr->prepared_at;
2339  gxact->prepare_start_lsn = start_lsn;
2340  gxact->prepare_end_lsn = end_lsn;
2341  gxact->xid = hdr->xid;
2342  gxact->owner = hdr->owner;
2344  gxact->valid = false;
2345  gxact->ondisk = XLogRecPtrIsInvalid(start_lsn);
2346  gxact->inredo = true; /* yes, added in redo */
2347  strcpy(gxact->gid, gid);
2348 
2349  /* And insert it into the active array */
2352 
2353  LWLockRelease(TwoPhaseStateLock);
2354 
2355  elog(DEBUG2, "Adding 2PC data to shared memory %u", gxact->xid);
2356 }
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:907
GlobalTransaction next
Definition: twophase.c:155
bool RecoveryInProgress(void)
Definition: xlog.c:7873
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:909
XLogRecPtr prepare_end_lsn
Definition: twophase.c:168
void PrepareRedoRemove ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 2366 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().

2367 {
2368  GlobalTransaction gxact = NULL;
2369  int i;
2370  bool found = false;
2371 
2373 
2374  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2375  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2376  {
2377  gxact = TwoPhaseState->prepXacts[i];
2378 
2379  if (gxact->xid == xid)
2380  {
2381  Assert(gxact->inredo);
2382  found = true;
2383  break;
2384  }
2385  }
2386  LWLockRelease(TwoPhaseStateLock);
2387 
2388  /*
2389  * Just leave if there is nothing, this is expected during WAL replay.
2390  */
2391  if (!found)
2392  return;
2393 
2394  /*
2395  * And now we can clean up any files we may have left.
2396  */
2397  elog(DEBUG2, "Removing 2PC data from shared memory %u", xid);
2398  if (gxact->ondisk)
2399  RemoveTwoPhaseFile(xid, giveWarning);
2400  RemoveGXact(gxact);
2401 
2402  return;
2403 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
bool RecoveryInProgress(void)
Definition: xlog.c:7873
void LWLockRelease(LWLock *lock)
Definition: lwlock.c:1715
static void RemoveGXact(GlobalTransaction gxact)
Definition: twophase.c:631
#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:1547
#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 1786 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().

1787 {
1788  TransactionId origNextXid = ShmemVariableCache->nextXid;
1789  TransactionId result = origNextXid;
1790  TransactionId *xids = NULL;
1791  int nxids = 0;
1792  int allocsize = 0;
1793  int i;
1794 
1795  LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1796  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1797  {
1798  TransactionId xid;
1799  char *buf;
1801 
1802  Assert(gxact->inredo);
1803 
1804  xid = gxact->xid;
1805 
1806  buf = ProcessTwoPhaseBuffer(xid,
1807  gxact->prepare_start_lsn,
1808  gxact->ondisk, false, 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:1632
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
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2006
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
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 1906 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(), PostPrepare_Twophase(), GlobalTransactionData::prepare_start_lsn, TwoPhaseFileHeader::prepared_at, TwoPhaseStateData::prepXacts, ProcessRecords(), ProcessTwoPhaseBuffer(), StandbyReleaseLockTree(), TransactionIdEquals, twophase_recover_callbacks, GlobalTransactionData::xid, and TwoPhaseFileHeader::xid.

Referenced by StartupXLOG().

1907 {
1908  int i;
1909 
1910  /*
1911  * Don't need a lock in the recovery phase.
1912  */
1913  for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1914  {
1915  TransactionId xid;
1916  char *buf;
1918  char *bufptr;
1919  TwoPhaseFileHeader *hdr;
1920  TransactionId *subxids;
1921  const char *gid;
1922 
1923  xid = gxact->xid;
1924 
1925  /*
1926  * Reconstruct subtrans state for the transaction --- needed because
1927  * pg_subtrans is not preserved over a restart. Note that we are
1928  * linking all the subtransactions directly to the top-level XID;
1929  * there may originally have been a more complex hierarchy, but
1930  * there's no need to restore that exactly. It's possible that
1931  * SubTransSetParent has been set before, if the prepared transaction
1932  * generated xid assignment records.
1933  */
1934  buf = ProcessTwoPhaseBuffer(xid,
1935  gxact->prepare_start_lsn,
1936  gxact->ondisk, true, false);
1937  if (buf == NULL)
1938  continue;
1939 
1940  ereport(LOG,
1941  (errmsg("recovering prepared transaction %u from shared memory", xid)));
1942 
1943  hdr = (TwoPhaseFileHeader *) buf;
1944  Assert(TransactionIdEquals(hdr->xid, xid));
1945  bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1946  gid = (const char *) bufptr;
1947  bufptr += MAXALIGN(hdr->gidlen);
1948  subxids = (TransactionId *) bufptr;
1949  bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1950  bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileNode));
1951  bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileNode));
1952  bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1953 
1954  /*
1955  * Recreate its GXACT and dummy PGPROC. But, check whether it was
1956  * added in redo and already has a shmem entry for it.
1957  */
1958  LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1959  MarkAsPreparingGuts(gxact, xid, gid,
1960  hdr->prepared_at,
1961  hdr->owner, hdr->database);
1962 
1963  /* recovered, so reset the flag for entries generated by redo */
1964  gxact->inredo = false;
1965 
1966  LWLockRelease(TwoPhaseStateLock);
1967 
1968  GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
1969  MarkAsPrepared(gxact);
1970 
1971  /*
1972  * Recover other state (notably locks) using resource managers
1973  */
1975 
1976  /*
1977  * Release locks held by the standby process after we process each
1978  * prepared transaction. As a result, we don't need too many
1979  * additional locks at any one time.
1980  */
1981  if (InHotStandby)
1982  StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
1983 
1984  /*
1985  * We're done with recovering this transaction. Clear MyLockedGxact,
1986  * like we do in PrepareTransaction() during normal operation.
1987  */
1989 
1990  pfree(buf);
1991  }
1992 }
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:195
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
uint32 TransactionId
Definition: c.h:397
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1519
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:907
#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:450
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:510
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
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2006
#define NULL
Definition: c.h:229
#define Assert(condition)
Definition: c.h:675
static void MarkAsPrepared(GlobalTransaction gxact)
Definition: twophase.c:535
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:361
int i
TimestampTz prepared_at
Definition: twophase.c:909
void restoreTwoPhaseData ( void  )

Definition at line 1731 of file twophase.c.

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

Referenced by StartupXLOG().

1732 {
1733  DIR *cldir;
1734  struct dirent *clde;
1735 
1736  cldir = AllocateDir(TWOPHASE_DIR);
1737  while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1738  {
1739  if (strlen(clde->d_name) == 8 &&
1740  strspn(clde->d_name, "0123456789ABCDEF") == 8)
1741  {
1742  TransactionId xid;
1743  char *buf;
1744 
1745  xid = (TransactionId) strtoul(clde->d_name, NULL, 16);
1746 
1748  true, false, false);
1749  if (buf == NULL)
1750  continue;
1751 
1753  }
1754  }
1755  FreeDir(cldir);
1756 }
#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:2304
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2006
#define NULL
Definition: c.h:229
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2401
#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 ( void  )

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, false, false);
1884  if (buf != NULL)
1885  pfree(buf);
1886  }
1887  LWLockRelease(TwoPhaseStateLock);
1888 }
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
static char * ProcessTwoPhaseBuffer(TransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2006
#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
bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1339 of file twophase.c.

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

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

1340 {
1341  char *buf;
1342  TwoPhaseFileHeader *hdr;
1343  bool result;
1344 
1346 
1347  if (max_prepared_xacts <= 0)
1348  return false; /* nothing to do */
1349 
1350  /* Read and validate file */
1351  buf = ReadTwoPhaseFile(xid, false);
1352  if (buf == NULL)
1353  return false;
1354 
1355  /* Check header also */
1356  hdr = (TwoPhaseFileHeader *) buf;
1357  result = TransactionIdEquals(hdr->xid, xid);
1358  pfree(buf);
1359 
1360  return result;
1361 }
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
return result
Definition: formatting.c:1632
TransactionId xid
Definition: twophase.c:907
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:1185
#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 991 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().

992 {
993  PGPROC *proc = &ProcGlobal->allProcs[gxact->pgprocno];
994  PGXACT *pgxact = &ProcGlobal->allPgXact[gxact->pgprocno];
995  TransactionId xid = pgxact->xid;
996  TwoPhaseFileHeader hdr;
997  TransactionId *children;
998  RelFileNode *commitrels;
999  RelFileNode *abortrels;
1000  SharedInvalidationMessage *invalmsgs;
1001 
1002  /* Initialize linked list */
1003  records.head = palloc0(sizeof(StateFileChunk));
1004  records.head->len = 0;
1005  records.head->next = NULL;
1006 
1007  records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
1009 
1011  records.num_chunks = 1;
1012 
1013  records.total_len = 0;
1014 
1015  /* Create header */
1016  hdr.magic = TWOPHASE_MAGIC;
1017  hdr.total_len = 0; /* EndPrepare will fill this in */
1018  hdr.xid = xid;
1019  hdr.database = proc->databaseId;
1020  hdr.prepared_at = gxact->prepared_at;
1021  hdr.owner = gxact->owner;
1022  hdr.nsubxacts = xactGetCommittedChildren(&children);
1023  hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
1024  hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
1026  &hdr.initfileinval);
1027  hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
1028 
1029  save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
1030  save_state_data(gxact->gid, hdr.gidlen);
1031 
1032  /*
1033  * Add the additional info about subxacts, deletable files and cache
1034  * invalidation messages.
1035  */
1036  if (hdr.nsubxacts > 0)
1037  {
1038  save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
1039  /* While we have the child-xact data, stuff it in the gxact too */
1040  GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
1041  }
1042  if (hdr.ncommitrels > 0)
1043  {
1044  save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileNode));
1045  pfree(commitrels);
1046  }
1047  if (hdr.nabortrels > 0)
1048  {
1049  save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileNode));
1050  pfree(abortrels);
1051  }
1052  if (hdr.ninvalmsgs > 0)
1053  {
1054  save_state_data(invalmsgs,
1055  hdr.ninvalmsgs * sizeof(SharedInvalidationMessage));
1056  pfree(invalmsgs);
1057  }
1058 }
int xactGetCommittedChildren(TransactionId **ptr)
Definition: xact.c:5086
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:947
PROC_HDR * ProcGlobal
Definition: proc.c:80
TransactionId xid
Definition: twophase.c:907
uint32 num_chunks
Definition: twophase.c:948
char gid[GIDSIZE]
Definition: twophase.c:176
char * data
Definition: twophase.c:939
void pfree(void *pointer)
Definition: mcxt.c:950
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:510
uint32 bytes_free
Definition: twophase.c:949
int smgrGetPendingDeletes(bool forCommit, RelFileNode **ptr)
Definition: storage.c:389
uint32 len
Definition: twophase.c:940
Oid databaseId
Definition: proc.h:113
uint32 total_len
Definition: twophase.c:950
struct StateFileChunk * next
Definition: twophase.c:941
void * palloc0(Size size)
Definition: mcxt.c:878
#define TWOPHASE_MAGIC
Definition: twophase.c:901
#define Max(x, y)
Definition: c.h:800
StateFileChunk * head
Definition: twophase.c:946
#define NULL
Definition: c.h:229
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:963
TimestampTz prepared_at
Definition: twophase.c:158
void * palloc(Size size)
Definition: mcxt.c:849
int xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs, bool *RelcacheInitFileInval)
Definition: inval.c:816
static struct xllist records
PGPROC * allProcs
Definition: proc.h:232
TimestampTz prepared_at
Definition: twophase.c:909
Definition: proc.h:94
BackendId TwoPhaseGetDummyBackendId ( TransactionId  xid)

Definition at line 856 of file twophase.c.

References GlobalTransactionData::dummyBackendId, and TwoPhaseGetGXact().

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

857 {
858  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
859 
860  return gxact->dummyBackendId;
861 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:807
BackendId dummyBackendId
Definition: twophase.c:157
PGPROC* TwoPhaseGetDummyProc ( TransactionId  xid)

Definition at line 868 of file twophase.c.

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

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

869 {
870  GlobalTransaction gxact = TwoPhaseGetGXact(xid);
871 
872  return &ProcGlobal->allProcs[gxact->pgprocno];
873 }
static GlobalTransaction TwoPhaseGetGXact(TransactionId xid)
Definition: twophase.c:807
PROC_HDR * ProcGlobal
Definition: proc.c:80
PGPROC * allProcs
Definition: proc.h:232
void TwoPhaseShmemInit ( void  )

Definition at line 251 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().

252 {
253  bool found;
254 
255  TwoPhaseState = ShmemInitStruct("Prepared Transaction Table",
257  &found);
258  if (!IsUnderPostmaster)
259  {
260  GlobalTransaction gxacts;
261  int i;
262 
263  Assert(!found);
266 
267  /*
268  * Initialize the linked list of free GlobalTransactionData structs
269  */
270  gxacts = (GlobalTransaction)
271  ((char *) TwoPhaseState +
272  MAXALIGN(offsetof(TwoPhaseStateData, prepXacts) +
274  for (i = 0; i < max_prepared_xacts; i++)
275  {
276  /* insert into linked list */
277  gxacts[i].next = TwoPhaseState->freeGXacts;
278  TwoPhaseState->freeGXacts = &gxacts[i];
279 
280  /* associate it with a PGPROC assigned by InitProcGlobal */
282 
283  /*
284  * Assign a unique ID for each dummy proc, so that the range of
285  * dummy backend IDs immediately follows the range of normal
286  * backend IDs. We don't dare to assign a real backend ID to dummy
287  * procs, because prepared transactions don't take part in cache
288  * invalidation like a real backend ID would imply, but having a
289  * unique ID for them is nevertheless handy. This arrangement
290  * allows you to allocate an array of size (MaxBackends +
291  * max_prepared_xacts + 1), and have a slot for every backend and
292  * prepared transaction. Currently multixact.c uses that
293  * technique.
294  */
295  gxacts[i].dummyBackendId = MaxBackends + 1 + i;
296  }
297  }
298  else
299  Assert(found);
300 }
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:235
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 235 of file twophase.c.

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

Referenced by CreateSharedMemoryAndSemaphores(), and TwoPhaseShmemInit().

236 {
237  Size size;
238 
239  /* Need the fixed struct, the array of pointers, and the GTD structs */
240  size = offsetof(TwoPhaseStateData, prepXacts);
241  size = add_size(size, mul_size(max_prepared_xacts,
242  sizeof(GlobalTransaction)));
243  size = MAXALIGN(size);
244  size = add_size(size, mul_size(max_prepared_xacts,
245  sizeof(GlobalTransactionData)));
246 
247  return size;
248 }
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