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twophase.c File Reference
#include "postgres.h"
#include <fcntl.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>
#include "access/commit_ts.h"
#include "access/htup_details.h"
#include "access/subtrans.h"
#include "access/transam.h"
#include "access/twophase.h"
#include "access/twophase_rmgr.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "access/xloginsert.h"
#include "access/xlogreader.h"
#include "access/xlogrecovery.h"
#include "access/xlogutils.h"
#include "catalog/pg_type.h"
#include "catalog/storage.h"
#include "funcapi.h"
#include "miscadmin.h"
#include "pg_trace.h"
#include "pgstat.h"
#include "replication/origin.h"
#include "replication/syncrep.h"
#include "storage/fd.h"
#include "storage/ipc.h"
#include "storage/md.h"
#include "storage/predicate.h"
#include "storage/proc.h"
#include "storage/procarray.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/timestamp.h"
Include dependency graph for twophase.c:

Go to the source code of this file.

Data Structures

struct  GlobalTransactionData
 
struct  TwoPhaseStateData
 
struct  Working_State
 
struct  TwoPhaseRecordOnDisk
 
struct  StateFileChunk
 
struct  xllist
 

Macros

#define TWOPHASE_DIR   "pg_twophase"
 
#define TWOPHASE_MAGIC   0x57F94534 /* format identifier */
 

Typedefs

typedef struct GlobalTransactionData GlobalTransactionData
 
typedef struct TwoPhaseStateData TwoPhaseStateData
 
typedef xl_xact_prepare TwoPhaseFileHeader
 
typedef struct TwoPhaseRecordOnDisk TwoPhaseRecordOnDisk
 
typedef struct StateFileChunk StateFileChunk
 

Functions

static void RecordTransactionCommitPrepared (TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, int ninvalmsgs, SharedInvalidationMessage *invalmsgs, bool initfileinval, const char *gid)
 
static void RecordTransactionAbortPrepared (TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, const char *gid)
 
static void ProcessRecords (char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
 
static void RemoveGXact (GlobalTransaction gxact)
 
static void XlogReadTwoPhaseData (XLogRecPtr lsn, char **buf, int *len)
 
static char * ProcessTwoPhaseBuffer (FullTransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
 
static void MarkAsPreparingGuts (GlobalTransaction gxact, TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
 
static void RemoveTwoPhaseFile (FullTransactionId fxid, bool giveWarning)
 
static void RecreateTwoPhaseFile (TransactionId xid, void *content, int len)
 
Size TwoPhaseShmemSize (void)
 
void TwoPhaseShmemInit (void)
 
static void AtProcExit_Twophase (int code, Datum arg)
 
void AtAbort_Twophase (void)
 
void PostPrepare_Twophase (void)
 
GlobalTransaction MarkAsPreparing (TransactionId xid, const char *gid, TimestampTz prepared_at, Oid owner, Oid databaseid)
 
static void GXactLoadSubxactData (GlobalTransaction gxact, int nsubxacts, TransactionId *children)
 
static void MarkAsPrepared (GlobalTransaction gxact, bool lock_held)
 
static GlobalTransaction LockGXact (const char *gid, Oid user)
 
static int GetPreparedTransactionList (GlobalTransaction *gxacts)
 
Datum pg_prepared_xact (PG_FUNCTION_ARGS)
 
static GlobalTransaction TwoPhaseGetGXact (TransactionId xid, bool lock_held)
 
TransactionId TwoPhaseGetXidByVirtualXID (VirtualTransactionId vxid, bool *have_more)
 
ProcNumber TwoPhaseGetDummyProcNumber (TransactionId xid, bool lock_held)
 
PGPROCTwoPhaseGetDummyProc (TransactionId xid, bool lock_held)
 
static FullTransactionId FullTransactionIdFromCurrentEpoch (TransactionId xid)
 
static int TwoPhaseFilePath (char *path, FullTransactionId fxid)
 
static void save_state_data (const void *data, uint32 len)
 
void StartPrepare (GlobalTransaction gxact)
 
void EndPrepare (GlobalTransaction gxact)
 
void RegisterTwoPhaseRecord (TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
 
static char * ReadTwoPhaseFile (TransactionId xid, bool missing_ok)
 
bool StandbyTransactionIdIsPrepared (TransactionId xid)
 
void FinishPreparedTransaction (const char *gid, bool isCommit)
 
void CheckPointTwoPhase (XLogRecPtr redo_horizon)
 
void restoreTwoPhaseData (void)
 
TransactionId PrescanPreparedTransactions (TransactionId **xids_p, int *nxids_p)
 
void StandbyRecoverPreparedTransactions (void)
 
void RecoverPreparedTransactions (void)
 
void PrepareRedoAdd (char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn, RepOriginId origin_id)
 
void PrepareRedoRemove (TransactionId xid, bool giveWarning)
 
bool LookupGXact (const char *gid, XLogRecPtr prepare_end_lsn, TimestampTz origin_prepare_timestamp)
 
void TwoPhaseTransactionGid (Oid subid, TransactionId xid, char *gid_res, int szgid)
 
static bool IsTwoPhaseTransactionGidForSubid (Oid subid, char *gid)
 
bool LookupGXactBySubid (Oid subid)
 

Variables

int max_prepared_xacts = 0
 
static TwoPhaseStateDataTwoPhaseState
 
static GlobalTransaction MyLockedGxact = NULL
 
static bool twophaseExitRegistered = false
 
static struct xllist records
 

Macro Definition Documentation

◆ TWOPHASE_DIR

#define TWOPHASE_DIR   "pg_twophase"

Definition at line 112 of file twophase.c.

◆ TWOPHASE_MAGIC

#define TWOPHASE_MAGIC   0x57F94534 /* format identifier */

Definition at line 974 of file twophase.c.

Typedef Documentation

◆ GlobalTransactionData

◆ StateFileChunk

◆ TwoPhaseFileHeader

Definition at line 976 of file twophase.c.

◆ TwoPhaseRecordOnDisk

◆ TwoPhaseStateData

Function Documentation

◆ AtAbort_Twophase()

void AtAbort_Twophase ( void  )

Definition at line 304 of file twophase.c.

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

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

Referenced by AbortTransaction(), and AtProcExit_Twophase().

◆ AtProcExit_Twophase()

static void AtProcExit_Twophase ( int  code,
Datum  arg 
)
static

Definition at line 294 of file twophase.c.

295{
296 /* same logic as abort */
298}
void AtAbort_Twophase(void)
Definition: twophase.c:304

References AtAbort_Twophase().

Referenced by LockGXact(), and MarkAsPreparing().

◆ CheckPointTwoPhase()

void CheckPointTwoPhase ( XLogRecPtr  redo_horizon)

Definition at line 1823 of file twophase.c.

1824{
1825 int i;
1826 int serialized_xacts = 0;
1827
1828 if (max_prepared_xacts <= 0)
1829 return; /* nothing to do */
1830
1831 TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_START();
1832
1833 /*
1834 * We are expecting there to be zero GXACTs that need to be copied to
1835 * disk, so we perform all I/O while holding TwoPhaseStateLock for
1836 * simplicity. This prevents any new xacts from preparing while this
1837 * occurs, which shouldn't be a problem since the presence of long-lived
1838 * prepared xacts indicates the transaction manager isn't active.
1839 *
1840 * It's also possible to move I/O out of the lock, but on every error we
1841 * should check whether somebody committed our transaction in different
1842 * backend. Let's leave this optimization for future, if somebody will
1843 * spot that this place cause bottleneck.
1844 *
1845 * Note that it isn't possible for there to be a GXACT with a
1846 * prepare_end_lsn set prior to the last checkpoint yet is marked invalid,
1847 * because of the efforts with delayChkptFlags.
1848 */
1849 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
1850 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1851 {
1852 /*
1853 * Note that we are using gxact not PGPROC so this works in recovery
1854 * also
1855 */
1857
1858 if ((gxact->valid || gxact->inredo) &&
1859 !gxact->ondisk &&
1860 gxact->prepare_end_lsn <= redo_horizon)
1861 {
1862 char *buf;
1863 int len;
1864
1866 RecreateTwoPhaseFile(gxact->xid, buf, len);
1867 gxact->ondisk = true;
1870 pfree(buf);
1871 serialized_xacts++;
1872 }
1873 }
1874 LWLockRelease(TwoPhaseStateLock);
1875
1876 /*
1877 * Flush unconditionally the parent directory to make any information
1878 * durable on disk. Two-phase files could have been removed and those
1879 * removals need to be made persistent as well as any files newly created
1880 * previously since the last checkpoint.
1881 */
1883
1884 TRACE_POSTGRESQL_TWOPHASE_CHECKPOINT_DONE();
1885
1886 if (log_checkpoints && serialized_xacts > 0)
1887 ereport(LOG,
1888 (errmsg_plural("%u two-phase state file was written "
1889 "for a long-running prepared transaction",
1890 "%u two-phase state files were written "
1891 "for long-running prepared transactions",
1892 serialized_xacts,
1893 serialized_xacts)));
1894}
int errmsg_plural(const char *fmt_singular, const char *fmt_plural, unsigned long n,...)
Definition: elog.c:1180
#define LOG
Definition: elog.h:31
#define ereport(elevel,...)
Definition: elog.h:149
void fsync_fname(const char *fname, bool isdir)
Definition: fd.c:755
int i
Definition: isn.c:72
@ LW_SHARED
Definition: lwlock.h:115
void pfree(void *pointer)
Definition: mcxt.c:1521
const void size_t len
static char * buf
Definition: pg_test_fsync.c:72
TransactionId xid
Definition: twophase.c:162
XLogRecPtr prepare_start_lsn
Definition: twophase.c:160
XLogRecPtr prepare_end_lsn
Definition: twophase.c:161
GlobalTransaction prepXacts[FLEXIBLE_ARRAY_MEMBER]
Definition: twophase.c:185
static void XlogReadTwoPhaseData(XLogRecPtr lsn, char **buf, int *len)
Definition: twophase.c:1408
#define TWOPHASE_DIR
Definition: twophase.c:112
int max_prepared_xacts
Definition: twophase.c:115
static TwoPhaseStateData * TwoPhaseState
Definition: twophase.c:188
static void RecreateTwoPhaseFile(TransactionId xid, void *content, int len)
Definition: twophase.c:1740
bool log_checkpoints
Definition: xlog.c:129
#define InvalidXLogRecPtr
Definition: xlogdefs.h:28

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

Referenced by CheckPointGuts().

◆ EndPrepare()

void EndPrepare ( GlobalTransaction  gxact)

Definition at line 1143 of file twophase.c.

1144{
1145 TwoPhaseFileHeader *hdr;
1146 StateFileChunk *record;
1147 bool replorigin;
1148
1149 /* Add the end sentinel to the list of 2PC records */
1151 NULL, 0);
1152
1153 /* Go back and fill in total_len in the file header record */
1155 Assert(hdr->magic == TWOPHASE_MAGIC);
1156 hdr->total_len = records.total_len + sizeof(pg_crc32c);
1157
1160
1161 if (replorigin)
1162 {
1165 }
1166
1167 /*
1168 * If the data size exceeds MaxAllocSize, we won't be able to read it in
1169 * ReadTwoPhaseFile. Check for that now, rather than fail in the case
1170 * where we write data to file and then re-read at commit time.
1171 */
1172 if (hdr->total_len > MaxAllocSize)
1173 ereport(ERROR,
1174 (errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
1175 errmsg("two-phase state file maximum length exceeded")));
1176
1177 /*
1178 * Now writing 2PC state data to WAL. We let the WAL's CRC protection
1179 * cover us, so no need to calculate a separate CRC.
1180 *
1181 * We have to set DELAY_CHKPT_START here, too; otherwise a checkpoint
1182 * starting immediately after the WAL record is inserted could complete
1183 * without fsync'ing our state file. (This is essentially the same kind
1184 * of race condition as the COMMIT-to-clog-write case that
1185 * RecordTransactionCommit uses DELAY_CHKPT_START for; see notes there.)
1186 *
1187 * We save the PREPARE record's location in the gxact for later use by
1188 * CheckPointTwoPhase.
1189 */
1191
1193
1196
1198 for (record = records.head; record != NULL; record = record->next)
1199 XLogRegisterData(record->data, record->len);
1200
1202
1203 gxact->prepare_end_lsn = XLogInsert(RM_XACT_ID, XLOG_XACT_PREPARE);
1204
1205 if (replorigin)
1206 {
1207 /* Move LSNs forward for this replication origin */
1209 gxact->prepare_end_lsn);
1210 }
1211
1212 XLogFlush(gxact->prepare_end_lsn);
1213
1214 /* If we crash now, we have prepared: WAL replay will fix things */
1215
1216 /* Store record's start location to read that later on Commit */
1218
1219 /*
1220 * Mark the prepared transaction as valid. As soon as xact.c marks MyProc
1221 * as not running our XID (which it will do immediately after this
1222 * function returns), others can commit/rollback the xact.
1223 *
1224 * NB: a side effect of this is to make a dummy ProcArray entry for the
1225 * prepared XID. This must happen before we clear the XID from MyProc /
1226 * ProcGlobal->xids[], else there is a window where the XID is not running
1227 * according to TransactionIdIsInProgress, and onlookers would be entitled
1228 * to assume the xact crashed. Instead we have a window where the same
1229 * XID appears twice in ProcArray, which is OK.
1230 */
1231 MarkAsPrepared(gxact, false);
1232
1233 /*
1234 * Now we can mark ourselves as out of the commit critical section: a
1235 * checkpoint starting after this will certainly see the gxact as a
1236 * candidate for fsyncing.
1237 */
1238 MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
1239
1240 /*
1241 * Remember that we have this GlobalTransaction entry locked for us. If
1242 * we crash after this point, it's too late to abort, but we must unlock
1243 * it so that the prepared transaction can be committed or rolled back.
1244 */
1245 MyLockedGxact = gxact;
1246
1248
1249 /*
1250 * Wait for synchronous replication, if required.
1251 *
1252 * Note that at this stage we have marked the prepare, but still show as
1253 * running in the procarray (twice!) and continue to hold locks.
1254 */
1255 SyncRepWaitForLSN(gxact->prepare_end_lsn, false);
1256
1257 records.tail = records.head = NULL;
1258 records.num_chunks = 0;
1259}
#define Assert(condition)
Definition: c.h:812
int errcode(int sqlerrcode)
Definition: elog.c:853
int errmsg(const char *fmt,...)
Definition: elog.c:1070
#define ERROR
Definition: elog.h:39
#define MaxAllocSize
Definition: fe_memutils.h:22
#define START_CRIT_SECTION()
Definition: miscadmin.h:149
#define END_CRIT_SECTION()
Definition: miscadmin.h:151
TimestampTz replorigin_session_origin_timestamp
Definition: origin.c:161
void replorigin_session_advance(XLogRecPtr remote_commit, XLogRecPtr local_commit)
Definition: origin.c:1223
RepOriginId replorigin_session_origin
Definition: origin.c:159
XLogRecPtr replorigin_session_origin_lsn
Definition: origin.c:160
#define DoNotReplicateId
Definition: origin.h:34
#define InvalidRepOriginId
Definition: origin.h:33
uint32 pg_crc32c
Definition: pg_crc32c.h:38
#define DELAY_CHKPT_START
Definition: proc.h:119
PGPROC * MyProc
Definition: proc.c:66
int delayChkptFlags
Definition: proc.h:240
struct StateFileChunk * next
Definition: twophase.c:1000
uint32 len
Definition: twophase.c:999
char * data
Definition: twophase.c:998
TimestampTz origin_timestamp
Definition: xact.h:369
uint32 total_len
Definition: xact.h:355
XLogRecPtr origin_lsn
Definition: xact.h:368
uint32 magic
Definition: xact.h:354
uint32 total_len
Definition: twophase.c:1009
uint32 num_chunks
Definition: twophase.c:1007
StateFileChunk * head
Definition: twophase.c:1005
StateFileChunk * tail
Definition: twophase.c:1006
void SyncRepWaitForLSN(XLogRecPtr lsn, bool commit)
Definition: syncrep.c:148
void RegisterTwoPhaseRecord(TwoPhaseRmgrId rmid, uint16 info, const void *data, uint32 len)
Definition: twophase.c:1265
#define TWOPHASE_MAGIC
Definition: twophase.c:974
static void MarkAsPrepared(GlobalTransaction gxact, bool lock_held)
Definition: twophase.c:530
static struct xllist records
#define TWOPHASE_RM_END_ID
Definition: twophase_rmgr.h:24
#define XLOG_XACT_PREPARE
Definition: xact.h:170
XLogRecPtr ProcLastRecPtr
Definition: xlog.c:253
void XLogFlush(XLogRecPtr record)
Definition: xlog.c:2802
#define XLOG_INCLUDE_ORIGIN
Definition: xlog.h:154
XLogRecPtr XLogInsert(RmgrId rmid, uint8 info)
Definition: xloginsert.c:474
void XLogSetRecordFlags(uint8 flags)
Definition: xloginsert.c:456
void XLogRegisterData(const char *data, uint32 len)
Definition: xloginsert.c:364
void XLogBeginInsert(void)
Definition: xloginsert.c:149
void XLogEnsureRecordSpace(int max_block_id, int ndatas)
Definition: xloginsert.c:175

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

Referenced by PrepareTransaction().

◆ FinishPreparedTransaction()

void FinishPreparedTransaction ( const char *  gid,
bool  isCommit 
)

Definition at line 1491 of file twophase.c.

1492{
1493 GlobalTransaction gxact;
1494 PGPROC *proc;
1495 TransactionId xid;
1496 bool ondisk;
1497 char *buf;
1498 char *bufptr;
1499 TwoPhaseFileHeader *hdr;
1500 TransactionId latestXid;
1501 TransactionId *children;
1502 RelFileLocator *commitrels;
1503 RelFileLocator *abortrels;
1504 RelFileLocator *delrels;
1505 int ndelrels;
1506 xl_xact_stats_item *commitstats;
1507 xl_xact_stats_item *abortstats;
1508 SharedInvalidationMessage *invalmsgs;
1509
1510 /*
1511 * Validate the GID, and lock the GXACT to ensure that two backends do not
1512 * try to commit the same GID at once.
1513 */
1514 gxact = LockGXact(gid, GetUserId());
1515 proc = GetPGProcByNumber(gxact->pgprocno);
1516 xid = gxact->xid;
1517
1518 /*
1519 * Read and validate 2PC state data. State data will typically be stored
1520 * in WAL files if the LSN is after the last checkpoint record, or moved
1521 * to disk if for some reason they have lived for a long time.
1522 */
1523 if (gxact->ondisk)
1524 buf = ReadTwoPhaseFile(xid, false);
1525 else
1527
1528
1529 /*
1530 * Disassemble the header area
1531 */
1532 hdr = (TwoPhaseFileHeader *) buf;
1533 Assert(TransactionIdEquals(hdr->xid, xid));
1534 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
1535 bufptr += MAXALIGN(hdr->gidlen);
1536 children = (TransactionId *) bufptr;
1537 bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
1538 commitrels = (RelFileLocator *) bufptr;
1539 bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileLocator));
1540 abortrels = (RelFileLocator *) bufptr;
1541 bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileLocator));
1542 commitstats = (xl_xact_stats_item *) bufptr;
1543 bufptr += MAXALIGN(hdr->ncommitstats * sizeof(xl_xact_stats_item));
1544 abortstats = (xl_xact_stats_item *) bufptr;
1545 bufptr += MAXALIGN(hdr->nabortstats * sizeof(xl_xact_stats_item));
1546 invalmsgs = (SharedInvalidationMessage *) bufptr;
1547 bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
1548
1549 /* compute latestXid among all children */
1550 latestXid = TransactionIdLatest(xid, hdr->nsubxacts, children);
1551
1552 /* Prevent cancel/die interrupt while cleaning up */
1554
1555 /*
1556 * The order of operations here is critical: make the XLOG entry for
1557 * commit or abort, then mark the transaction committed or aborted in
1558 * pg_xact, then remove its PGPROC from the global ProcArray (which means
1559 * TransactionIdIsInProgress will stop saying the prepared xact is in
1560 * progress), then run the post-commit or post-abort callbacks. The
1561 * callbacks will release the locks the transaction held.
1562 */
1563 if (isCommit)
1565 hdr->nsubxacts, children,
1566 hdr->ncommitrels, commitrels,
1567 hdr->ncommitstats,
1568 commitstats,
1569 hdr->ninvalmsgs, invalmsgs,
1570 hdr->initfileinval, gid);
1571 else
1573 hdr->nsubxacts, children,
1574 hdr->nabortrels, abortrels,
1575 hdr->nabortstats,
1576 abortstats,
1577 gid);
1578
1579 ProcArrayRemove(proc, latestXid);
1580
1581 /*
1582 * In case we fail while running the callbacks, mark the gxact invalid so
1583 * no one else will try to commit/rollback, and so it will be recycled if
1584 * we fail after this point. It is still locked by our backend so it
1585 * won't go away yet.
1586 *
1587 * (We assume it's safe to do this without taking TwoPhaseStateLock.)
1588 */
1589 gxact->valid = false;
1590
1591 /*
1592 * We have to remove any files that were supposed to be dropped. For
1593 * consistency with the regular xact.c code paths, must do this before
1594 * releasing locks, so do it before running the callbacks.
1595 *
1596 * NB: this code knows that we couldn't be dropping any temp rels ...
1597 */
1598 if (isCommit)
1599 {
1600 delrels = commitrels;
1601 ndelrels = hdr->ncommitrels;
1602 }
1603 else
1604 {
1605 delrels = abortrels;
1606 ndelrels = hdr->nabortrels;
1607 }
1608
1609 /* Make sure files supposed to be dropped are dropped */
1610 DropRelationFiles(delrels, ndelrels, false);
1611
1612 if (isCommit)
1613 pgstat_execute_transactional_drops(hdr->ncommitstats, commitstats, false);
1614 else
1615 pgstat_execute_transactional_drops(hdr->nabortstats, abortstats, false);
1616
1617 /*
1618 * Handle cache invalidation messages.
1619 *
1620 * Relcache init file invalidation requires processing both before and
1621 * after we send the SI messages, only when committing. See
1622 * AtEOXact_Inval().
1623 */
1624 if (isCommit)
1625 {
1626 if (hdr->initfileinval)
1628 SendSharedInvalidMessages(invalmsgs, hdr->ninvalmsgs);
1629 if (hdr->initfileinval)
1631 }
1632
1633 /*
1634 * Acquire the two-phase lock. We want to work on the two-phase callbacks
1635 * while holding it to avoid potential conflicts with other transactions
1636 * attempting to use the same GID, so the lock is released once the shared
1637 * memory state is cleared.
1638 */
1639 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1640
1641 /* And now do the callbacks */
1642 if (isCommit)
1644 else
1646
1647 PredicateLockTwoPhaseFinish(xid, isCommit);
1648
1649 /*
1650 * Read this value while holding the two-phase lock, as the on-disk 2PC
1651 * file is physically removed after the lock is released.
1652 */
1653 ondisk = gxact->ondisk;
1654
1655 /* Clear shared memory state */
1656 RemoveGXact(gxact);
1657
1658 /*
1659 * Release the lock as all callbacks are called and shared memory cleanup
1660 * is done.
1661 */
1662 LWLockRelease(TwoPhaseStateLock);
1663
1664 /* Count the prepared xact as committed or aborted */
1665 AtEOXact_PgStat(isCommit, false);
1666
1667 /*
1668 * And now we can clean up any files we may have left. These should be
1669 * from the current epoch.
1670 */
1671 if (ondisk)
1672 {
1673 FullTransactionId fxid;
1674
1676 RemoveTwoPhaseFile(fxid, true);
1677 }
1678
1679 MyLockedGxact = NULL;
1680
1682
1683 pfree(buf);
1684}
#define MAXALIGN(LEN)
Definition: c.h:765
uint32 TransactionId
Definition: c.h:606
void DropRelationFiles(RelFileLocator *delrels, int ndelrels, bool isRedo)
Definition: md.c:1461
#define RESUME_INTERRUPTS()
Definition: miscadmin.h:135
#define HOLD_INTERRUPTS()
Definition: miscadmin.h:133
Oid GetUserId(void)
Definition: miscinit.c:517
void pgstat_execute_transactional_drops(int ndrops, struct xl_xact_stats_item *items, bool is_redo)
Definition: pgstat_xact.c:314
void AtEOXact_PgStat(bool isCommit, bool parallel)
Definition: pgstat_xact.c:40
void PredicateLockTwoPhaseFinish(TransactionId xid, bool isCommit)
Definition: predicate.c:4872
#define GetPGProcByNumber(n)
Definition: proc.h:423
void ProcArrayRemove(PGPROC *proc, TransactionId latestXid)
Definition: procarray.c:565
void RelationCacheInitFilePostInvalidate(void)
Definition: relcache.c:6804
void RelationCacheInitFilePreInvalidate(void)
Definition: relcache.c:6779
void SendSharedInvalidMessages(const SharedInvalidationMessage *msgs, int n)
Definition: sinval.c:47
Definition: proc.h:162
int32 nabortrels
Definition: xact.h:362
int32 ninvalmsgs
Definition: xact.h:365
bool initfileinval
Definition: xact.h:366
int32 ncommitstats
Definition: xact.h:363
uint16 gidlen
Definition: xact.h:367
int32 nabortstats
Definition: xact.h:364
int32 ncommitrels
Definition: xact.h:361
TransactionId xid
Definition: xact.h:356
int32 nsubxacts
Definition: xact.h:360
TransactionId TransactionIdLatest(TransactionId mainxid, int nxids, const TransactionId *xids)
Definition: transam.c:345
#define TransactionIdEquals(id1, id2)
Definition: transam.h:43
static void RecordTransactionAbortPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, const char *gid)
Definition: twophase.c:2464
static void RecordTransactionCommitPrepared(TransactionId xid, int nchildren, TransactionId *children, int nrels, RelFileLocator *rels, int nstats, xl_xact_stats_item *stats, int ninvalmsgs, SharedInvalidationMessage *invalmsgs, bool initfileinval, const char *gid)
Definition: twophase.c:2366
static void RemoveTwoPhaseFile(FullTransactionId fxid, bool giveWarning)
Definition: twophase.c:1721
static void ProcessRecords(char *bufptr, TransactionId xid, const TwoPhaseCallback callbacks[])
Definition: twophase.c:1690
static char * ReadTwoPhaseFile(TransactionId xid, bool missing_ok)
Definition: twophase.c:1289
static FullTransactionId FullTransactionIdFromCurrentEpoch(TransactionId xid)
Definition: twophase.c:934
static GlobalTransaction LockGXact(const char *gid, Oid user)
Definition: twophase.c:552
const TwoPhaseCallback twophase_postcommit_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:33
const TwoPhaseCallback twophase_postabort_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:42

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

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

◆ FullTransactionIdFromCurrentEpoch()

static FullTransactionId FullTransactionIdFromCurrentEpoch ( TransactionId  xid)
inlinestatic

Definition at line 934 of file twophase.c.

935{
937 FullTransactionId nextFullXid;
939
940 nextFullXid = ReadNextFullTransactionId();
941 epoch = EpochFromFullTransactionId(nextFullXid);
942
944 return fxid;
945}
uint32_t uint32
Definition: c.h:485
#define EpochFromFullTransactionId(x)
Definition: transam.h:47
static FullTransactionId FullTransactionIdFromEpochAndXid(uint32 epoch, TransactionId xid)
Definition: transam.h:71
FullTransactionId ReadNextFullTransactionId(void)
Definition: varsup.c:288
static const unsigned __int64 epoch

References epoch, EpochFromFullTransactionId, FullTransactionIdFromEpochAndXid(), and ReadNextFullTransactionId().

Referenced by FinishPreparedTransaction(), PrepareRedoAdd(), PrepareRedoRemove(), ReadTwoPhaseFile(), and RecreateTwoPhaseFile().

◆ GetPreparedTransactionList()

static int GetPreparedTransactionList ( GlobalTransaction gxacts)
static

Definition at line 666 of file twophase.c.

667{
668 GlobalTransaction array;
669 int num;
670 int i;
671
672 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
673
674 if (TwoPhaseState->numPrepXacts == 0)
675 {
676 LWLockRelease(TwoPhaseStateLock);
677
678 *gxacts = NULL;
679 return 0;
680 }
681
683 array = (GlobalTransaction) palloc(sizeof(GlobalTransactionData) * num);
684 *gxacts = array;
685 for (i = 0; i < num; i++)
686 memcpy(array + i, TwoPhaseState->prepXacts[i],
687 sizeof(GlobalTransactionData));
688
689 LWLockRelease(TwoPhaseStateLock);
690
691 return num;
692}
void * palloc(Size size)
Definition: mcxt.c:1317
struct GlobalTransactionData * GlobalTransaction
Definition: twophase.h:26

References i, LW_SHARED, LWLockAcquire(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, palloc(), TwoPhaseStateData::prepXacts, and TwoPhaseState.

Referenced by pg_prepared_xact().

◆ GXactLoadSubxactData()

static void GXactLoadSubxactData ( GlobalTransaction  gxact,
int  nsubxacts,
TransactionId children 
)
static

Definition at line 504 of file twophase.c.

506{
507 PGPROC *proc = GetPGProcByNumber(gxact->pgprocno);
508
509 /* We need no extra lock since the GXACT isn't valid yet */
510 if (nsubxacts > PGPROC_MAX_CACHED_SUBXIDS)
511 {
512 proc->subxidStatus.overflowed = true;
513 nsubxacts = PGPROC_MAX_CACHED_SUBXIDS;
514 }
515 if (nsubxacts > 0)
516 {
517 memcpy(proc->subxids.xids, children,
518 nsubxacts * sizeof(TransactionId));
519 proc->subxidStatus.count = nsubxacts;
520 }
521}
#define PGPROC_MAX_CACHED_SUBXIDS
Definition: proc.h:39
XidCacheStatus subxidStatus
Definition: proc.h:263
struct XidCache subxids
Definition: proc.h:265
bool overflowed
Definition: proc.h:46
uint8 count
Definition: proc.h:44
TransactionId xids[PGPROC_MAX_CACHED_SUBXIDS]
Definition: proc.h:51

References XidCacheStatus::count, GetPGProcByNumber, XidCacheStatus::overflowed, PGPROC_MAX_CACHED_SUBXIDS, GlobalTransactionData::pgprocno, PGPROC::subxids, PGPROC::subxidStatus, and XidCache::xids.

Referenced by RecoverPreparedTransactions(), and StartPrepare().

◆ IsTwoPhaseTransactionGidForSubid()

static bool IsTwoPhaseTransactionGidForSubid ( Oid  subid,
char *  gid 
)
static

Definition at line 2781 of file twophase.c.

2782{
2783 int ret;
2784 Oid subid_from_gid;
2785 TransactionId xid_from_gid;
2786 char gid_tmp[GIDSIZE];
2787
2788 /* Extract the subid and xid from the given GID */
2789 ret = sscanf(gid, "pg_gid_%u_%u", &subid_from_gid, &xid_from_gid);
2790
2791 /*
2792 * Check that the given GID has expected format, and at least the subid
2793 * matches.
2794 */
2795 if (ret != 2 || subid != subid_from_gid)
2796 return false;
2797
2798 /*
2799 * Reconstruct a temporary GID based on the subid and xid extracted from
2800 * the given GID and check whether the temporary GID and the given GID
2801 * match.
2802 */
2803 TwoPhaseTransactionGid(subid, xid_from_gid, gid_tmp, sizeof(gid_tmp));
2804
2805 return strcmp(gid, gid_tmp) == 0;
2806}
unsigned int Oid
Definition: postgres_ext.h:31
void TwoPhaseTransactionGid(Oid subid, TransactionId xid, char *gid_res, int szgid)
Definition: twophase.c:2763
#define GIDSIZE
Definition: xact.h:31

References GIDSIZE, and TwoPhaseTransactionGid().

Referenced by LookupGXactBySubid().

◆ LockGXact()

static GlobalTransaction LockGXact ( const char *  gid,
Oid  user 
)
static

Definition at line 552 of file twophase.c.

553{
554 int i;
555
556 /* on first call, register the exit hook */
558 {
561 }
562
563 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
564
565 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
566 {
568 PGPROC *proc = GetPGProcByNumber(gxact->pgprocno);
569
570 /* Ignore not-yet-valid GIDs */
571 if (!gxact->valid)
572 continue;
573 if (strcmp(gxact->gid, gid) != 0)
574 continue;
575
576 /* Found it, but has someone else got it locked? */
579 (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
580 errmsg("prepared transaction with identifier \"%s\" is busy",
581 gid)));
582
583 if (user != gxact->owner && !superuser_arg(user))
585 (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
586 errmsg("permission denied to finish prepared transaction"),
587 errhint("Must be superuser or the user that prepared the transaction.")));
588
589 /*
590 * Note: it probably would be possible to allow committing from
591 * another database; but at the moment NOTIFY is known not to work and
592 * there may be some other issues as well. Hence disallow until
593 * someone gets motivated to make it work.
594 */
595 if (MyDatabaseId != proc->databaseId)
597 (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
598 errmsg("prepared transaction belongs to another database"),
599 errhint("Connect to the database where the transaction was prepared to finish it.")));
600
601 /* OK for me to lock it */
603 MyLockedGxact = gxact;
604
605 LWLockRelease(TwoPhaseStateLock);
606
607 return gxact;
608 }
609
610 LWLockRelease(TwoPhaseStateLock);
611
613 (errcode(ERRCODE_UNDEFINED_OBJECT),
614 errmsg("prepared transaction with identifier \"%s\" does not exist",
615 gid)));
616
617 /* NOTREACHED */
618 return NULL;
619}
int errhint(const char *fmt,...)
Definition: elog.c:1317
ProcNumber MyProcNumber
Definition: globals.c:89
Oid MyDatabaseId
Definition: globals.c:93
void before_shmem_exit(pg_on_exit_callback function, Datum arg)
Definition: ipc.c:337
static char * user
Definition: pg_regress.c:119
char gid[GIDSIZE]
Definition: twophase.c:169
Oid databaseId
Definition: proc.h:207
bool superuser_arg(Oid roleid)
Definition: superuser.c:56
static bool twophaseExitRegistered
Definition: twophase.c:198
static void AtProcExit_Twophase(int code, Datum arg)
Definition: twophase.c:294

References AtProcExit_Twophase(), before_shmem_exit(), PGPROC::databaseId, ereport, errcode(), errhint(), errmsg(), ERROR, GetPGProcByNumber, GlobalTransactionData::gid, i, INVALID_PROC_NUMBER, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyDatabaseId, MyLockedGxact, MyProcNumber, TwoPhaseStateData::numPrepXacts, GlobalTransactionData::owner, GlobalTransactionData::pgprocno, TwoPhaseStateData::prepXacts, superuser_arg(), twophaseExitRegistered, TwoPhaseState, user, and GlobalTransactionData::valid.

Referenced by FinishPreparedTransaction().

◆ LookupGXact()

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

Definition at line 2704 of file twophase.c.

2706{
2707 int i;
2708 bool found = false;
2709
2710 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2711 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2712 {
2714
2715 /* Ignore not-yet-valid GIDs. */
2716 if (gxact->valid && strcmp(gxact->gid, gid) == 0)
2717 {
2718 char *buf;
2719 TwoPhaseFileHeader *hdr;
2720
2721 /*
2722 * We are not expecting collisions of GXACTs (same gid) between
2723 * publisher and subscribers, so we perform all I/O while holding
2724 * TwoPhaseStateLock for simplicity.
2725 *
2726 * To move the I/O out of the lock, we need to ensure that no
2727 * other backend commits the prepared xact in the meantime. We can
2728 * do this optimization if we encounter many collisions in GID
2729 * between publisher and subscriber.
2730 */
2731 if (gxact->ondisk)
2732 buf = ReadTwoPhaseFile(gxact->xid, false);
2733 else
2734 {
2735 Assert(gxact->prepare_start_lsn);
2737 }
2738
2739 hdr = (TwoPhaseFileHeader *) buf;
2740
2741 if (hdr->origin_lsn == prepare_end_lsn &&
2742 hdr->origin_timestamp == origin_prepare_timestamp)
2743 {
2744 found = true;
2745 pfree(buf);
2746 break;
2747 }
2748
2749 pfree(buf);
2750 }
2751 }
2752 LWLockRelease(TwoPhaseStateLock);
2753 return found;
2754}

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

Referenced by apply_handle_rollback_prepared().

◆ LookupGXactBySubid()

bool LookupGXactBySubid ( Oid  subid)

Definition at line 2813 of file twophase.c.

2814{
2815 bool found = false;
2816
2817 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
2818 for (int i = 0; i < TwoPhaseState->numPrepXacts; i++)
2819 {
2821
2822 /* Ignore not-yet-valid GIDs. */
2823 if (gxact->valid &&
2825 {
2826 found = true;
2827 break;
2828 }
2829 }
2830 LWLockRelease(TwoPhaseStateLock);
2831
2832 return found;
2833}
static bool IsTwoPhaseTransactionGidForSubid(Oid subid, char *gid)
Definition: twophase.c:2781

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

Referenced by AlterSubscription().

◆ MarkAsPrepared()

static void MarkAsPrepared ( GlobalTransaction  gxact,
bool  lock_held 
)
static

Definition at line 530 of file twophase.c.

531{
532 /* Lock here may be overkill, but I'm not convinced of that ... */
533 if (!lock_held)
534 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
535 Assert(!gxact->valid);
536 gxact->valid = true;
537 if (!lock_held)
538 LWLockRelease(TwoPhaseStateLock);
539
540 /*
541 * Put it into the global ProcArray so TransactionIdIsInProgress considers
542 * the XID as still running.
543 */
545}
void ProcArrayAdd(PGPROC *proc)
Definition: procarray.c:468

References Assert, GetPGProcByNumber, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), GlobalTransactionData::pgprocno, ProcArrayAdd(), and GlobalTransactionData::valid.

Referenced by EndPrepare(), and RecoverPreparedTransactions().

◆ MarkAsPreparing()

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

Definition at line 359 of file twophase.c.

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

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

Referenced by PrepareTransaction().

◆ MarkAsPreparingGuts()

static void MarkAsPreparingGuts ( GlobalTransaction  gxact,
TransactionId  xid,
const char *  gid,
TimestampTz  prepared_at,
Oid  owner,
Oid  databaseid 
)
static

Definition at line 433 of file twophase.c.

435{
436 PGPROC *proc;
437 int i;
438
439 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
440
441 Assert(gxact != NULL);
442 proc = GetPGProcByNumber(gxact->pgprocno);
443
444 /* Initialize the PGPROC entry */
445 MemSet(proc, 0, sizeof(PGPROC));
446 dlist_node_init(&proc->links);
449 {
450 /* clone VXID, for TwoPhaseGetXidByVirtualXID() to find */
451 proc->vxid.lxid = MyProc->vxid.lxid;
453 }
454 else
455 {
457 /* GetLockConflicts() uses this to specify a wait on the XID */
458 proc->vxid.lxid = xid;
460 }
461 proc->xid = xid;
463 proc->delayChkptFlags = 0;
464 proc->statusFlags = 0;
465 proc->pid = 0;
466 proc->databaseId = databaseid;
467 proc->roleId = owner;
469 proc->isRegularBackend = false;
471 proc->lwWaitMode = 0;
472 proc->waitLock = NULL;
473 proc->waitProcLock = NULL;
474 pg_atomic_init_u64(&proc->waitStart, 0);
475 for (i = 0; i < NUM_LOCK_PARTITIONS; i++)
476 dlist_init(&proc->myProcLocks[i]);
477 /* subxid data must be filled later by GXactLoadSubxactData */
478 proc->subxidStatus.overflowed = false;
479 proc->subxidStatus.count = 0;
480
481 gxact->prepared_at = prepared_at;
482 gxact->xid = xid;
483 gxact->owner = owner;
485 gxact->valid = false;
486 gxact->inredo = false;
487 strcpy(gxact->gid, gid);
488
489 /*
490 * Remember that we have this GlobalTransaction entry locked for us. If we
491 * abort after this, we must release it.
492 */
493 MyLockedGxact = gxact;
494}
static void pg_atomic_init_u64(volatile pg_atomic_uint64 *ptr, uint64 val)
Definition: atomics.h:453
#define MemSet(start, val, len)
Definition: c.h:974
bool IsPostmasterEnvironment
Definition: globals.c:118
static void dlist_init(dlist_head *head)
Definition: ilist.h:314
static void dlist_node_init(dlist_node *node)
Definition: ilist.h:325
#define LocalTransactionIdIsValid(lxid)
Definition: lock.h:66
bool LWLockHeldByMeInMode(LWLock *lock, LWLockMode mode)
Definition: lwlock.c:1937
@ LW_WS_NOT_WAITING
Definition: lwlock.h:30
#define NUM_LOCK_PARTITIONS
Definition: lwlock.h:97
#define AmStartupProcess()
Definition: miscadmin.h:388
#define InvalidOid
Definition: postgres_ext.h:36
@ PROC_WAIT_STATUS_OK
Definition: proc.h:124
TimestampTz prepared_at
Definition: twophase.c:151
bool isRegularBackend
Definition: proc.h:213
TransactionId xmin
Definition: proc.h:177
LocalTransactionId lxid
Definition: proc.h:200
PROCLOCK * waitProcLock
Definition: proc.h:233
struct PGPROC::@123 vxid
uint8 lwWaitMode
Definition: proc.h:224
uint8 statusFlags
Definition: proc.h:242
pg_atomic_uint64 waitStart
Definition: proc.h:237
ProcNumber procNumber
Definition: proc.h:195
int pid
Definition: proc.h:182
LOCK * waitLock
Definition: proc.h:232
TransactionId xid
Definition: proc.h:172
dlist_head myProcLocks[NUM_LOCK_PARTITIONS]
Definition: proc.h:261
Oid roleId
Definition: proc.h:208
ProcWaitStatus waitStatus
Definition: proc.h:167
Oid tempNamespaceId
Definition: proc.h:210
dlist_node links
Definition: proc.h:163
uint8 lwWaiting
Definition: proc.h:223
#define InvalidTransactionId
Definition: transam.h:31

References AmStartupProcess, Assert, XidCacheStatus::count, PGPROC::databaseId, PGPROC::delayChkptFlags, dlist_init(), dlist_node_init(), GetPGProcByNumber, GlobalTransactionData::gid, i, GlobalTransactionData::inredo, INVALID_PROC_NUMBER, InvalidOid, InvalidTransactionId, IsPostmasterEnvironment, PGPROC::isRegularBackend, PGPROC::links, LocalTransactionIdIsValid, GlobalTransactionData::locking_backend, LW_EXCLUSIVE, LW_WS_NOT_WAITING, LWLockHeldByMeInMode(), PGPROC::lwWaiting, PGPROC::lwWaitMode, PGPROC::lxid, MemSet, MyLockedGxact, MyProc, PGPROC::myProcLocks, MyProcNumber, NUM_LOCK_PARTITIONS, XidCacheStatus::overflowed, GlobalTransactionData::owner, pg_atomic_init_u64(), GlobalTransactionData::pgprocno, PGPROC::pid, GlobalTransactionData::prepared_at, PROC_WAIT_STATUS_OK, PGPROC::procNumber, PGPROC::roleId, PGPROC::statusFlags, PGPROC::subxidStatus, PGPROC::tempNamespaceId, GlobalTransactionData::valid, PGPROC::vxid, PGPROC::waitLock, PGPROC::waitProcLock, PGPROC::waitStart, PGPROC::waitStatus, GlobalTransactionData::xid, PGPROC::xid, and PGPROC::xmin.

Referenced by MarkAsPreparing(), and RecoverPreparedTransactions().

◆ pg_prepared_xact()

Datum pg_prepared_xact ( PG_FUNCTION_ARGS  )

Definition at line 711 of file twophase.c.

712{
713 FuncCallContext *funcctx;
714 Working_State *status;
715
716 if (SRF_IS_FIRSTCALL())
717 {
718 TupleDesc tupdesc;
719 MemoryContext oldcontext;
720
721 /* create a function context for cross-call persistence */
722 funcctx = SRF_FIRSTCALL_INIT();
723
724 /*
725 * Switch to memory context appropriate for multiple function calls
726 */
727 oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
728
729 /* build tupdesc for result tuples */
730 /* this had better match pg_prepared_xacts view in system_views.sql */
731 tupdesc = CreateTemplateTupleDesc(5);
732 TupleDescInitEntry(tupdesc, (AttrNumber) 1, "transaction",
733 XIDOID, -1, 0);
734 TupleDescInitEntry(tupdesc, (AttrNumber) 2, "gid",
735 TEXTOID, -1, 0);
736 TupleDescInitEntry(tupdesc, (AttrNumber) 3, "prepared",
737 TIMESTAMPTZOID, -1, 0);
738 TupleDescInitEntry(tupdesc, (AttrNumber) 4, "ownerid",
739 OIDOID, -1, 0);
740 TupleDescInitEntry(tupdesc, (AttrNumber) 5, "dbid",
741 OIDOID, -1, 0);
742
743 funcctx->tuple_desc = BlessTupleDesc(tupdesc);
744
745 /*
746 * Collect all the 2PC status information that we will format and send
747 * out as a result set.
748 */
749 status = (Working_State *) palloc(sizeof(Working_State));
750 funcctx->user_fctx = status;
751
752 status->ngxacts = GetPreparedTransactionList(&status->array);
753 status->currIdx = 0;
754
755 MemoryContextSwitchTo(oldcontext);
756 }
757
758 funcctx = SRF_PERCALL_SETUP();
759 status = (Working_State *) funcctx->user_fctx;
760
761 while (status->array != NULL && status->currIdx < status->ngxacts)
762 {
763 GlobalTransaction gxact = &status->array[status->currIdx++];
764 PGPROC *proc = GetPGProcByNumber(gxact->pgprocno);
765 Datum values[5] = {0};
766 bool nulls[5] = {0};
767 HeapTuple tuple;
768 Datum result;
769
770 if (!gxact->valid)
771 continue;
772
773 /*
774 * Form tuple with appropriate data.
775 */
776
777 values[0] = TransactionIdGetDatum(proc->xid);
778 values[1] = CStringGetTextDatum(gxact->gid);
780 values[3] = ObjectIdGetDatum(gxact->owner);
782
783 tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
784 result = HeapTupleGetDatum(tuple);
785 SRF_RETURN_NEXT(funcctx, result);
786 }
787
788 SRF_RETURN_DONE(funcctx);
789}
int16 AttrNumber
Definition: attnum.h:21
static Datum values[MAXATTR]
Definition: bootstrap.c:151
#define CStringGetTextDatum(s)
Definition: builtins.h:97
TupleDesc BlessTupleDesc(TupleDesc tupdesc)
Definition: execTuples.c:2258
#define SRF_IS_FIRSTCALL()
Definition: funcapi.h:304
#define SRF_PERCALL_SETUP()
Definition: funcapi.h:308
#define SRF_RETURN_NEXT(_funcctx, _result)
Definition: funcapi.h:310
#define SRF_FIRSTCALL_INIT()
Definition: funcapi.h:306
static Datum HeapTupleGetDatum(const HeapTupleData *tuple)
Definition: funcapi.h:230
#define SRF_RETURN_DONE(_funcctx)
Definition: funcapi.h:328
HeapTuple heap_form_tuple(TupleDesc tupleDescriptor, const Datum *values, const bool *isnull)
Definition: heaptuple.c:1117
static MemoryContext MemoryContextSwitchTo(MemoryContext context)
Definition: palloc.h:124
while(p+4<=pend)
static Datum TransactionIdGetDatum(TransactionId X)
Definition: postgres.h:272
uintptr_t Datum
Definition: postgres.h:64
static Datum ObjectIdGetDatum(Oid X)
Definition: postgres.h:252
void * user_fctx
Definition: funcapi.h:82
MemoryContext multi_call_memory_ctx
Definition: funcapi.h:101
TupleDesc tuple_desc
Definition: funcapi.h:112
GlobalTransaction array
Definition: twophase.c:698
TupleDesc CreateTemplateTupleDesc(int natts)
Definition: tupdesc.c:165
void TupleDescInitEntry(TupleDesc desc, AttrNumber attributeNumber, const char *attributeName, Oid oidtypeid, int32 typmod, int attdim)
Definition: tupdesc.c:797
static int GetPreparedTransactionList(GlobalTransaction *gxacts)
Definition: twophase.c:666
static Datum TimestampTzGetDatum(TimestampTz X)
Definition: timestamp.h:52

References Working_State::array, BlessTupleDesc(), CreateTemplateTupleDesc(), CStringGetTextDatum, Working_State::currIdx, PGPROC::databaseId, GetPGProcByNumber, GetPreparedTransactionList(), GlobalTransactionData::gid, heap_form_tuple(), HeapTupleGetDatum(), MemoryContextSwitchTo(), FuncCallContext::multi_call_memory_ctx, Working_State::ngxacts, ObjectIdGetDatum(), GlobalTransactionData::owner, palloc(), GlobalTransactionData::pgprocno, GlobalTransactionData::prepared_at, SRF_FIRSTCALL_INIT, SRF_IS_FIRSTCALL, SRF_PERCALL_SETUP, SRF_RETURN_DONE, SRF_RETURN_NEXT, TimestampTzGetDatum(), TransactionIdGetDatum(), FuncCallContext::tuple_desc, TupleDescInitEntry(), FuncCallContext::user_fctx, GlobalTransactionData::valid, values, while(), and PGPROC::xid.

◆ PostPrepare_Twophase()

void PostPrepare_Twophase ( void  )

◆ PrepareRedoAdd()

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

Definition at line 2539 of file twophase.c.

2541{
2543 char *bufptr;
2544 const char *gid;
2545 GlobalTransaction gxact;
2546
2547 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2549
2550 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2551 gid = (const char *) bufptr;
2552
2553 /*
2554 * Reserve the GID for the given transaction in the redo code path.
2555 *
2556 * This creates a gxact struct and puts it into the active array.
2557 *
2558 * In redo, this struct is mainly used to track PREPARE/COMMIT entries in
2559 * shared memory. Hence, we only fill up the bare minimum contents here.
2560 * The gxact also gets marked with gxact->inredo set to true to indicate
2561 * that it got added in the redo phase
2562 */
2563
2564 /*
2565 * In the event of a crash while a checkpoint was running, it may be
2566 * possible that some two-phase data found its way to disk while its
2567 * corresponding record needs to be replayed in the follow-up recovery. As
2568 * the 2PC data was on disk, it has already been restored at the beginning
2569 * of recovery with restoreTwoPhaseData(), so skip this record to avoid
2570 * duplicates in TwoPhaseState. If a consistent state has been reached,
2571 * the record is added to TwoPhaseState and it should have no
2572 * corresponding file in pg_twophase.
2573 */
2574 if (!XLogRecPtrIsInvalid(start_lsn))
2575 {
2576 char path[MAXPGPATH];
2577 FullTransactionId fxid;
2578
2579 /* Use current epoch */
2581 TwoPhaseFilePath(path, fxid);
2582
2583 if (access(path, F_OK) == 0)
2584 {
2586 (errmsg("could not recover two-phase state file for transaction %u",
2587 hdr->xid),
2588 errdetail("Two-phase state file has been found in WAL record %X/%X, but this transaction has already been restored from disk.",
2589 LSN_FORMAT_ARGS(start_lsn))));
2590 return;
2591 }
2592
2593 if (errno != ENOENT)
2594 ereport(ERROR,
2596 errmsg("could not access file \"%s\": %m", path)));
2597 }
2598
2599 /* Get a free gxact from the freelist */
2600 if (TwoPhaseState->freeGXacts == NULL)
2601 ereport(ERROR,
2602 (errcode(ERRCODE_OUT_OF_MEMORY),
2603 errmsg("maximum number of prepared transactions reached"),
2604 errhint("Increase \"max_prepared_transactions\" (currently %d).",
2606 gxact = TwoPhaseState->freeGXacts;
2607 TwoPhaseState->freeGXacts = gxact->next;
2608
2609 gxact->prepared_at = hdr->prepared_at;
2610 gxact->prepare_start_lsn = start_lsn;
2611 gxact->prepare_end_lsn = end_lsn;
2612 gxact->xid = hdr->xid;
2613 gxact->owner = hdr->owner;
2615 gxact->valid = false;
2616 gxact->ondisk = XLogRecPtrIsInvalid(start_lsn);
2617 gxact->inredo = true; /* yes, added in redo */
2618 strcpy(gxact->gid, gid);
2619
2620 /* And insert it into the active array */
2623
2624 if (origin_id != InvalidRepOriginId)
2625 {
2626 /* recover apply progress */
2627 replorigin_advance(origin_id, hdr->origin_lsn, end_lsn,
2628 false /* backward */ , false /* WAL */ );
2629 }
2630
2631 elog(DEBUG2, "added 2PC data in shared memory for transaction %u", gxact->xid);
2632}
int errcode_for_file_access(void)
Definition: elog.c:876
int errdetail(const char *fmt,...)
Definition: elog.c:1203
#define WARNING
Definition: elog.h:36
#define DEBUG2
Definition: elog.h:29
#define elog(elevel,...)
Definition: elog.h:225
void replorigin_advance(RepOriginId node, XLogRecPtr remote_commit, XLogRecPtr local_commit, bool go_backward, bool wal_log)
Definition: origin.c:892
#define MAXPGPATH
short access
Definition: preproc-type.c:36
TimestampTz prepared_at
Definition: xact.h:358
static int TwoPhaseFilePath(char *path, FullTransactionId fxid)
Definition: twophase.c:948
bool RecoveryInProgress(void)
Definition: xlog.c:6334
#define LSN_FORMAT_ARGS(lsn)
Definition: xlogdefs.h:43
#define XLogRecPtrIsInvalid(r)
Definition: xlogdefs.h:29
bool reachedConsistency
Definition: xlogrecovery.c:294

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

Referenced by restoreTwoPhaseData(), and xact_redo().

◆ PrepareRedoRemove()

void PrepareRedoRemove ( TransactionId  xid,
bool  giveWarning 
)

Definition at line 2644 of file twophase.c.

2645{
2646 GlobalTransaction gxact = NULL;
2647 int i;
2648 bool found = false;
2649
2650 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2652
2653 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2654 {
2655 gxact = TwoPhaseState->prepXacts[i];
2656
2657 if (gxact->xid == xid)
2658 {
2659 Assert(gxact->inredo);
2660 found = true;
2661 break;
2662 }
2663 }
2664
2665 /*
2666 * Just leave if there is nothing, this is expected during WAL replay.
2667 */
2668 if (!found)
2669 return;
2670
2671 /*
2672 * And now we can clean up any files we may have left.
2673 */
2674 elog(DEBUG2, "removing 2PC data for transaction %u", xid);
2675 if (gxact->ondisk)
2676 {
2677 FullTransactionId fxid;
2678
2679 /*
2680 * We should deal with a file at the current epoch here.
2681 */
2683 RemoveTwoPhaseFile(fxid, giveWarning);
2684 }
2685 RemoveGXact(gxact);
2686}

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

Referenced by ProcessTwoPhaseBuffer(), and xact_redo().

◆ PrescanPreparedTransactions()

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

Definition at line 1968 of file twophase.c.

1969{
1971 TransactionId origNextXid = XidFromFullTransactionId(nextXid);
1972 TransactionId result = origNextXid;
1973 TransactionId *xids = NULL;
1975 int nxids = 0;
1976 int allocsize = 0;
1977 int i;
1978
1979 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1980 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
1981 {
1982 TransactionId xid;
1983 FullTransactionId fxid;
1984 char *buf;
1986
1987 Assert(gxact->inredo);
1988
1989 xid = gxact->xid;
1990
1991 /*
1992 * All two-phase files with past and future epoch in pg_twophase are
1993 * gone at this point, so we're OK to rely on only the current epoch.
1994 */
1997 gxact->prepare_start_lsn,
1998 gxact->ondisk, false, true);
1999
2000 if (buf == NULL)
2001 continue;
2002
2003 /*
2004 * OK, we think this file is valid. Incorporate xid into the
2005 * running-minimum result.
2006 */
2007 if (TransactionIdPrecedes(xid, result))
2008 result = xid;
2009
2010 if (xids_p)
2011 {
2012 if (nxids == allocsize)
2013 {
2014 if (nxids == 0)
2015 {
2016 allocsize = 10;
2017 xids = palloc(allocsize * sizeof(TransactionId));
2018 }
2019 else
2020 {
2021 allocsize = allocsize * 2;
2022 xids = repalloc(xids, allocsize * sizeof(TransactionId));
2023 }
2024 }
2025 xids[nxids++] = xid;
2026 }
2027
2028 pfree(buf);
2029 }
2030 LWLockRelease(TwoPhaseStateLock);
2031
2032 if (xids_p)
2033 {
2034 *xids_p = xids;
2035 *nxids_p = nxids;
2036 }
2037
2038 return result;
2039}
void * repalloc(void *pointer, Size size)
Definition: mcxt.c:1541
FullTransactionId nextXid
Definition: transam.h:220
bool TransactionIdPrecedes(TransactionId id1, TransactionId id2)
Definition: transam.c:280
#define XidFromFullTransactionId(x)
Definition: transam.h:48
static char * ProcessTwoPhaseBuffer(FullTransactionId xid, XLogRecPtr prepare_start_lsn, bool fromdisk, bool setParent, bool setNextXid)
Definition: twophase.c:2223
TransamVariablesData * TransamVariables
Definition: varsup.c:34

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

Referenced by StartupXLOG(), and xlog_redo().

◆ ProcessRecords()

static void ProcessRecords ( char *  bufptr,
TransactionId  xid,
const TwoPhaseCallback  callbacks[] 
)
static

Definition at line 1690 of file twophase.c.

1692{
1693 for (;;)
1694 {
1695 TwoPhaseRecordOnDisk *record = (TwoPhaseRecordOnDisk *) bufptr;
1696
1697 Assert(record->rmid <= TWOPHASE_RM_MAX_ID);
1698 if (record->rmid == TWOPHASE_RM_END_ID)
1699 break;
1700
1701 bufptr += MAXALIGN(sizeof(TwoPhaseRecordOnDisk));
1702
1703 if (callbacks[record->rmid] != NULL)
1704 callbacks[record->rmid] (xid, record->info, bufptr, record->len);
1705
1706 bufptr += MAXALIGN(record->len);
1707 }
1708}
TwoPhaseRmgrId rmid
Definition: twophase.c:987
#define TWOPHASE_RM_MAX_ID
Definition: twophase_rmgr.h:29

References Assert, TwoPhaseRecordOnDisk::info, TwoPhaseRecordOnDisk::len, MAXALIGN, TwoPhaseRecordOnDisk::rmid, TWOPHASE_RM_END_ID, and TWOPHASE_RM_MAX_ID.

Referenced by FinishPreparedTransaction(), and RecoverPreparedTransactions().

◆ ProcessTwoPhaseBuffer()

static char * ProcessTwoPhaseBuffer ( FullTransactionId  xid,
XLogRecPtr  prepare_start_lsn,
bool  fromdisk,
bool  setParent,
bool  setNextXid 
)
static

Definition at line 2223 of file twophase.c.

2227{
2229 TransactionId *subxids;
2230 char *buf;
2231 TwoPhaseFileHeader *hdr;
2232 int i;
2234
2235 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
2236
2237 if (!fromdisk)
2238 Assert(prepare_start_lsn != InvalidXLogRecPtr);
2239
2240 /*
2241 * Reject full XID if too new. Note that this discards files from future
2242 * epochs.
2243 */
2244 if (FullTransactionIdFollowsOrEquals(fxid, nextXid))
2245 {
2246 if (fromdisk)
2247 {
2249 (errmsg("removing future two-phase state file of epoch %u for transaction %u",
2250 EpochFromFullTransactionId(fxid), xid)));
2251 RemoveTwoPhaseFile(fxid, true);
2252 }
2253 else
2254 {
2256 (errmsg("removing future two-phase state from memory for transaction %u",
2257 xid)));
2258 PrepareRedoRemove(xid, true);
2259 }
2260 return NULL;
2261 }
2262
2263 /* Discard files from past epochs */
2265 {
2266 if (fromdisk)
2267 {
2269 (errmsg("removing past two-phase state file of epoch %u for transaction %u",
2270 EpochFromFullTransactionId(fxid), xid)));
2271 RemoveTwoPhaseFile(fxid, true);
2272 }
2273 else
2274 {
2276 (errmsg("removing past two-phase state from memory for transaction %u",
2277 xid)));
2278 PrepareRedoRemove(xid, true);
2279 }
2280 return NULL;
2281 }
2282
2283 /* Already processed? */
2285 {
2286 if (fromdisk)
2287 {
2289 (errmsg("removing stale two-phase state file for transaction %u",
2290 xid)));
2291 RemoveTwoPhaseFile(fxid, true);
2292 }
2293 else
2294 {
2296 (errmsg("removing stale two-phase state from memory for transaction %u",
2297 xid)));
2298 PrepareRedoRemove(xid, true);
2299 }
2300 return NULL;
2301 }
2302
2303 if (fromdisk)
2304 {
2305 /* Read and validate file */
2306 buf = ReadTwoPhaseFile(xid, false);
2307 }
2308 else
2309 {
2310 /* Read xlog data */
2311 XlogReadTwoPhaseData(prepare_start_lsn, &buf, NULL);
2312 }
2313
2314 /* Deconstruct header */
2315 hdr = (TwoPhaseFileHeader *) buf;
2316 if (!TransactionIdEquals(hdr->xid, xid))
2317 {
2318 if (fromdisk)
2319 ereport(ERROR,
2321 errmsg("corrupted two-phase state file for transaction %u",
2322 xid)));
2323 else
2324 ereport(ERROR,
2326 errmsg("corrupted two-phase state in memory for transaction %u",
2327 xid)));
2328 }
2329
2330 /*
2331 * Examine subtransaction XIDs ... they should all follow main XID, and
2332 * they may force us to advance nextXid.
2333 */
2334 subxids = (TransactionId *) (buf +
2335 MAXALIGN(sizeof(TwoPhaseFileHeader)) +
2336 MAXALIGN(hdr->gidlen));
2337 for (i = 0; i < hdr->nsubxacts; i++)
2338 {
2339 TransactionId subxid = subxids[i];
2340
2341 Assert(TransactionIdFollows(subxid, xid));
2342
2343 /* update nextXid if needed */
2344 if (setNextXid)
2346
2347 if (setParent)
2348 SubTransSetParent(subxid, xid);
2349 }
2350
2351 return buf;
2352}
#define ERRCODE_DATA_CORRUPTED
Definition: pg_basebackup.c:41
void SubTransSetParent(TransactionId xid, TransactionId parent)
Definition: subtrans.c:85
bool TransactionIdDidCommit(TransactionId transactionId)
Definition: transam.c:126
bool TransactionIdDidAbort(TransactionId transactionId)
Definition: transam.c:188
bool TransactionIdFollows(TransactionId id1, TransactionId id2)
Definition: transam.c:314
#define FullTransactionIdFollowsOrEquals(a, b)
Definition: transam.h:54
void PrepareRedoRemove(TransactionId xid, bool giveWarning)
Definition: twophase.c:2644
void AdvanceNextFullTransactionIdPastXid(TransactionId xid)
Definition: varsup.c:304

References AdvanceNextFullTransactionIdPastXid(), Assert, buf, EpochFromFullTransactionId, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errmsg(), ERROR, FullTransactionIdFollowsOrEquals, xl_xact_prepare::gidlen, i, InvalidXLogRecPtr, LW_EXCLUSIVE, LWLockHeldByMeInMode(), MAXALIGN, TransamVariablesData::nextXid, xl_xact_prepare::nsubxacts, PrepareRedoRemove(), ReadTwoPhaseFile(), RemoveTwoPhaseFile(), SubTransSetParent(), TransactionIdDidAbort(), TransactionIdDidCommit(), TransactionIdEquals, TransactionIdFollows(), TransamVariables, WARNING, xl_xact_prepare::xid, XidFromFullTransactionId, and XlogReadTwoPhaseData().

Referenced by PrescanPreparedTransactions(), RecoverPreparedTransactions(), restoreTwoPhaseData(), and StandbyRecoverPreparedTransactions().

◆ ReadTwoPhaseFile()

static char * ReadTwoPhaseFile ( TransactionId  xid,
bool  missing_ok 
)
static

Definition at line 1289 of file twophase.c.

1290{
1291 char path[MAXPGPATH];
1292 char *buf;
1293 TwoPhaseFileHeader *hdr;
1294 int fd;
1295 struct stat stat;
1296 uint32 crc_offset;
1297 pg_crc32c calc_crc,
1298 file_crc;
1299 int r;
1300 FullTransactionId fxid;
1301
1303 TwoPhaseFilePath(path, fxid);
1304
1305 fd = OpenTransientFile(path, O_RDONLY | PG_BINARY);
1306 if (fd < 0)
1307 {
1308 if (missing_ok && errno == ENOENT)
1309 return NULL;
1310
1311 ereport(ERROR,
1313 errmsg("could not open file \"%s\": %m", path)));
1314 }
1315
1316 /*
1317 * Check file length. We can determine a lower bound pretty easily. We
1318 * set an upper bound to avoid palloc() failure on a corrupt file, though
1319 * we can't guarantee that we won't get an out of memory error anyway,
1320 * even on a valid file.
1321 */
1322 if (fstat(fd, &stat))
1323 ereport(ERROR,
1325 errmsg("could not stat file \"%s\": %m", path)));
1326
1327 if (stat.st_size < (MAXALIGN(sizeof(TwoPhaseFileHeader)) +
1329 sizeof(pg_crc32c)) ||
1331 ereport(ERROR,
1333 errmsg_plural("incorrect size of file \"%s\": %lld byte",
1334 "incorrect size of file \"%s\": %lld bytes",
1335 (long long int) stat.st_size, path,
1336 (long long int) stat.st_size)));
1337
1338 crc_offset = stat.st_size - sizeof(pg_crc32c);
1339 if (crc_offset != MAXALIGN(crc_offset))
1340 ereport(ERROR,
1342 errmsg("incorrect alignment of CRC offset for file \"%s\"",
1343 path)));
1344
1345 /*
1346 * OK, slurp in the file.
1347 */
1348 buf = (char *) palloc(stat.st_size);
1349
1350 pgstat_report_wait_start(WAIT_EVENT_TWOPHASE_FILE_READ);
1351 r = read(fd, buf, stat.st_size);
1352 if (r != stat.st_size)
1353 {
1354 if (r < 0)
1355 ereport(ERROR,
1357 errmsg("could not read file \"%s\": %m", path)));
1358 else
1359 ereport(ERROR,
1360 (errmsg("could not read file \"%s\": read %d of %lld",
1361 path, r, (long long int) stat.st_size)));
1362 }
1363
1365
1366 if (CloseTransientFile(fd) != 0)
1367 ereport(ERROR,
1369 errmsg("could not close file \"%s\": %m", path)));
1370
1371 hdr = (TwoPhaseFileHeader *) buf;
1372 if (hdr->magic != TWOPHASE_MAGIC)
1373 ereport(ERROR,
1375 errmsg("invalid magic number stored in file \"%s\"",
1376 path)));
1377
1378 if (hdr->total_len != stat.st_size)
1379 ereport(ERROR,
1381 errmsg("invalid size stored in file \"%s\"",
1382 path)));
1383
1384 INIT_CRC32C(calc_crc);
1385 COMP_CRC32C(calc_crc, buf, crc_offset);
1386 FIN_CRC32C(calc_crc);
1387
1388 file_crc = *((pg_crc32c *) (buf + crc_offset));
1389
1390 if (!EQ_CRC32C(calc_crc, file_crc))
1391 ereport(ERROR,
1393 errmsg("calculated CRC checksum does not match value stored in file \"%s\"",
1394 path)));
1395
1396 return buf;
1397}
#define PG_BINARY
Definition: c.h:1227
int CloseTransientFile(int fd)
Definition: fd.c:2831
int OpenTransientFile(const char *fileName, int fileFlags)
Definition: fd.c:2655
#define read(a, b, c)
Definition: win32.h:13
#define COMP_CRC32C(crc, data, len)
Definition: pg_crc32c.h:98
#define EQ_CRC32C(c1, c2)
Definition: pg_crc32c.h:42
#define INIT_CRC32C(crc)
Definition: pg_crc32c.h:41
#define FIN_CRC32C(crc)
Definition: pg_crc32c.h:103
static int fd(const char *x, int i)
Definition: preproc-init.c:105
__int64 st_size
Definition: win32_port.h:273
static void pgstat_report_wait_start(uint32 wait_event_info)
Definition: wait_event.h:85
static void pgstat_report_wait_end(void)
Definition: wait_event.h:101
#define fstat
Definition: win32_port.h:283

References buf, CloseTransientFile(), COMP_CRC32C, EQ_CRC32C, ereport, errcode(), ERRCODE_DATA_CORRUPTED, errcode_for_file_access(), errmsg(), errmsg_plural(), ERROR, fd(), FIN_CRC32C, fstat, FullTransactionIdFromCurrentEpoch(), INIT_CRC32C, xl_xact_prepare::magic, MAXALIGN, MaxAllocSize, MAXPGPATH, OpenTransientFile(), palloc(), PG_BINARY, pgstat_report_wait_end(), pgstat_report_wait_start(), read, stat::st_size, xl_xact_prepare::total_len, TWOPHASE_MAGIC, and TwoPhaseFilePath().

Referenced by FinishPreparedTransaction(), LookupGXact(), ProcessTwoPhaseBuffer(), and StandbyTransactionIdIsPrepared().

◆ RecordTransactionAbortPrepared()

static void RecordTransactionAbortPrepared ( TransactionId  xid,
int  nchildren,
TransactionId children,
int  nrels,
RelFileLocator rels,
int  nstats,
xl_xact_stats_item stats,
const char *  gid 
)
static

Definition at line 2464 of file twophase.c.

2472{
2473 XLogRecPtr recptr;
2474 bool replorigin;
2475
2476 /*
2477 * Are we using the replication origins feature? Or, in other words, are
2478 * we replaying remote actions?
2479 */
2482
2483 /*
2484 * Catch the scenario where we aborted partway through
2485 * RecordTransactionCommitPrepared ...
2486 */
2487 if (TransactionIdDidCommit(xid))
2488 elog(PANIC, "cannot abort transaction %u, it was already committed",
2489 xid);
2490
2492
2493 /*
2494 * Emit the XLOG commit record. Note that we mark 2PC aborts as
2495 * potentially having AccessExclusiveLocks since we don't know whether or
2496 * not they do.
2497 */
2499 nchildren, children,
2500 nrels, rels,
2501 nstats, stats,
2503 xid, gid);
2504
2505 if (replorigin)
2506 /* Move LSNs forward for this replication origin */
2509
2510 /* Always flush, since we're about to remove the 2PC state file */
2511 XLogFlush(recptr);
2512
2513 /*
2514 * Mark the transaction aborted in clog. This is not absolutely necessary
2515 * but we may as well do it while we are here.
2516 */
2517 TransactionIdAbortTree(xid, nchildren, children);
2518
2520
2521 /*
2522 * Wait for synchronous replication, if required.
2523 *
2524 * Note that at this stage we have marked clog, but still show as running
2525 * in the procarray and continue to hold locks.
2526 */
2527 SyncRepWaitForLSN(recptr, false);
2528}
TimestampTz GetCurrentTimestamp(void)
Definition: timestamp.c:1644
#define PANIC
Definition: elog.h:42
void TransactionIdAbortTree(TransactionId xid, int nxids, TransactionId *xids)
Definition: transam.c:270
int MyXactFlags
Definition: xact.c:135
XLogRecPtr XactLogAbortRecord(TimestampTz abort_time, int nsubxacts, TransactionId *subxacts, int nrels, RelFileLocator *rels, int ndroppedstats, xl_xact_stats_item *droppedstats, int xactflags, TransactionId twophase_xid, const char *twophase_gid)
Definition: xact.c:5974
#define XACT_FLAGS_ACQUIREDACCESSEXCLUSIVELOCK
Definition: xact.h:108
XLogRecPtr XactLastRecEnd
Definition: xlog.c:254
uint64 XLogRecPtr
Definition: xlogdefs.h:21

References DoNotReplicateId, elog, END_CRIT_SECTION, GetCurrentTimestamp(), InvalidRepOriginId, MyXactFlags, PANIC, replorigin_session_advance(), replorigin_session_origin, replorigin_session_origin_lsn, START_CRIT_SECTION, SyncRepWaitForLSN(), TransactionIdAbortTree(), TransactionIdDidCommit(), XACT_FLAGS_ACQUIREDACCESSEXCLUSIVELOCK, XactLastRecEnd, XactLogAbortRecord(), and XLogFlush().

Referenced by FinishPreparedTransaction().

◆ RecordTransactionCommitPrepared()

static void RecordTransactionCommitPrepared ( TransactionId  xid,
int  nchildren,
TransactionId children,
int  nrels,
RelFileLocator rels,
int  nstats,
xl_xact_stats_item stats,
int  ninvalmsgs,
SharedInvalidationMessage invalmsgs,
bool  initfileinval,
const char *  gid 
)
static

Definition at line 2366 of file twophase.c.

2377{
2378 XLogRecPtr recptr;
2379 TimestampTz committs = GetCurrentTimestamp();
2380 bool replorigin;
2381
2382 /*
2383 * Are we using the replication origins feature? Or, in other words, are
2384 * we replaying remote actions?
2385 */
2388
2390
2391 /* See notes in RecordTransactionCommit */
2394
2395 /*
2396 * Emit the XLOG commit record. Note that we mark 2PC commits as
2397 * potentially having AccessExclusiveLocks since we don't know whether or
2398 * not they do.
2399 */
2400 recptr = XactLogCommitRecord(committs,
2401 nchildren, children, nrels, rels,
2402 nstats, stats,
2403 ninvalmsgs, invalmsgs,
2404 initfileinval,
2406 xid, gid);
2407
2408
2409 if (replorigin)
2410 /* Move LSNs forward for this replication origin */
2413
2414 /*
2415 * Record commit timestamp. The value comes from plain commit timestamp
2416 * if replorigin is not enabled, or replorigin already set a value for us
2417 * in replorigin_session_origin_timestamp otherwise.
2418 *
2419 * We don't need to WAL-log anything here, as the commit record written
2420 * above already contains the data.
2421 */
2422 if (!replorigin || replorigin_session_origin_timestamp == 0)
2424
2425 TransactionTreeSetCommitTsData(xid, nchildren, children,
2428
2429 /*
2430 * We don't currently try to sleep before flush here ... nor is there any
2431 * support for async commit of a prepared xact (the very idea is probably
2432 * a contradiction)
2433 */
2434
2435 /* Flush XLOG to disk */
2436 XLogFlush(recptr);
2437
2438 /* Mark the transaction committed in pg_xact */
2439 TransactionIdCommitTree(xid, nchildren, children);
2440
2441 /* Checkpoint can proceed now */
2442 MyProc->delayChkptFlags &= ~DELAY_CHKPT_START;
2443
2445
2446 /*
2447 * Wait for synchronous replication, if required.
2448 *
2449 * Note that at this stage we have marked clog, but still show as running
2450 * in the procarray and continue to hold locks.
2451 */
2452 SyncRepWaitForLSN(recptr, true);
2453}
void TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids, TransactionId *subxids, TimestampTz timestamp, RepOriginId nodeid)
Definition: commit_ts.c:141
int64 TimestampTz
Definition: timestamp.h:39
void TransactionIdCommitTree(TransactionId xid, int nxids, TransactionId *xids)
Definition: transam.c:240
XLogRecPtr XactLogCommitRecord(TimestampTz commit_time, int nsubxacts, TransactionId *subxacts, int nrels, RelFileLocator *rels, int ndroppedstats, xl_xact_stats_item *droppedstats, int nmsgs, SharedInvalidationMessage *msgs, bool relcacheInval, int xactflags, TransactionId twophase_xid, const char *twophase_gid)
Definition: xact.c:5802

References Assert, DELAY_CHKPT_START, PGPROC::delayChkptFlags, DoNotReplicateId, END_CRIT_SECTION, GetCurrentTimestamp(), InvalidRepOriginId, MyProc, MyXactFlags, replorigin_session_advance(), replorigin_session_origin, replorigin_session_origin_lsn, replorigin_session_origin_timestamp, START_CRIT_SECTION, SyncRepWaitForLSN(), TransactionIdCommitTree(), TransactionTreeSetCommitTsData(), XACT_FLAGS_ACQUIREDACCESSEXCLUSIVELOCK, XactLastRecEnd, XactLogCommitRecord(), and XLogFlush().

Referenced by FinishPreparedTransaction().

◆ RecoverPreparedTransactions()

void RecoverPreparedTransactions ( void  )

Definition at line 2108 of file twophase.c.

2109{
2110 int i;
2111 uint32 epoch;
2112 FullTransactionId nextFullXid;
2113
2114 /* get current epoch */
2115 nextFullXid = ReadNextFullTransactionId();
2116 epoch = EpochFromFullTransactionId(nextFullXid);
2117
2118 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2119 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2120 {
2121 TransactionId xid;
2122 FullTransactionId fxid;
2123 char *buf;
2125 char *bufptr;
2126 TwoPhaseFileHeader *hdr;
2127 TransactionId *subxids;
2128 const char *gid;
2129
2130 /*
2131 * At this stage, we're OK to work with the current epoch as all past
2132 * and future files have been already discarded.
2133 */
2134 xid = gxact->xid;
2135
2136 /*
2137 * Reconstruct subtrans state for the transaction --- needed because
2138 * pg_subtrans is not preserved over a restart. Note that we are
2139 * linking all the subtransactions directly to the top-level XID;
2140 * there may originally have been a more complex hierarchy, but
2141 * there's no need to restore that exactly. It's possible that
2142 * SubTransSetParent has been set before, if the prepared transaction
2143 * generated xid assignment records.
2144 */
2147 gxact->prepare_start_lsn,
2148 gxact->ondisk, true, false);
2149 if (buf == NULL)
2150 continue;
2151
2152 ereport(LOG,
2153 (errmsg("recovering prepared transaction %u from shared memory", xid)));
2154
2155 hdr = (TwoPhaseFileHeader *) buf;
2156 Assert(TransactionIdEquals(hdr->xid, xid));
2157 bufptr = buf + MAXALIGN(sizeof(TwoPhaseFileHeader));
2158 gid = (const char *) bufptr;
2159 bufptr += MAXALIGN(hdr->gidlen);
2160 subxids = (TransactionId *) bufptr;
2161 bufptr += MAXALIGN(hdr->nsubxacts * sizeof(TransactionId));
2162 bufptr += MAXALIGN(hdr->ncommitrels * sizeof(RelFileLocator));
2163 bufptr += MAXALIGN(hdr->nabortrels * sizeof(RelFileLocator));
2164 bufptr += MAXALIGN(hdr->ncommitstats * sizeof(xl_xact_stats_item));
2165 bufptr += MAXALIGN(hdr->nabortstats * sizeof(xl_xact_stats_item));
2166 bufptr += MAXALIGN(hdr->ninvalmsgs * sizeof(SharedInvalidationMessage));
2167
2168 /*
2169 * Recreate its GXACT and dummy PGPROC. But, check whether it was
2170 * added in redo and already has a shmem entry for it.
2171 */
2172 MarkAsPreparingGuts(gxact, xid, gid,
2173 hdr->prepared_at,
2174 hdr->owner, hdr->database);
2175
2176 /* recovered, so reset the flag for entries generated by redo */
2177 gxact->inredo = false;
2178
2179 GXactLoadSubxactData(gxact, hdr->nsubxacts, subxids);
2180 MarkAsPrepared(gxact, true);
2181
2182 LWLockRelease(TwoPhaseStateLock);
2183
2184 /*
2185 * Recover other state (notably locks) using resource managers.
2186 */
2188
2189 /*
2190 * Release locks held by the standby process after we process each
2191 * prepared transaction. As a result, we don't need too many
2192 * additional locks at any one time.
2193 */
2194 if (InHotStandby)
2195 StandbyReleaseLockTree(xid, hdr->nsubxacts, subxids);
2196
2197 /*
2198 * We're done with recovering this transaction. Clear MyLockedGxact,
2199 * like we do in PrepareTransaction() during normal operation.
2200 */
2202
2203 pfree(buf);
2204
2205 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2206 }
2207
2208 LWLockRelease(TwoPhaseStateLock);
2209}
void StandbyReleaseLockTree(TransactionId xid, int nsubxids, TransactionId *subxids)
Definition: standby.c:1091
Oid database
Definition: xact.h:357
static void GXactLoadSubxactData(GlobalTransaction gxact, int nsubxacts, TransactionId *children)
Definition: twophase.c:504
void PostPrepare_Twophase(void)
Definition: twophase.c:344
const TwoPhaseCallback twophase_recover_callbacks[TWOPHASE_RM_MAX_ID+1]
Definition: twophase_rmgr.c:24
#define InHotStandby
Definition: xlogutils.h:60

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

Referenced by StartupXLOG().

◆ RecreateTwoPhaseFile()

static void RecreateTwoPhaseFile ( TransactionId  xid,
void *  content,
int  len 
)
static

Definition at line 1740 of file twophase.c.

1741{
1742 char path[MAXPGPATH];
1743 pg_crc32c statefile_crc;
1744 int fd;
1745 FullTransactionId fxid;
1746
1747 /* Recompute CRC */
1748 INIT_CRC32C(statefile_crc);
1749 COMP_CRC32C(statefile_crc, content, len);
1750 FIN_CRC32C(statefile_crc);
1751
1752 /* Use current epoch */
1754 TwoPhaseFilePath(path, fxid);
1755
1756 fd = OpenTransientFile(path,
1757 O_CREAT | O_TRUNC | O_WRONLY | PG_BINARY);
1758 if (fd < 0)
1759 ereport(ERROR,
1761 errmsg("could not recreate file \"%s\": %m", path)));
1762
1763 /* Write content and CRC */
1764 errno = 0;
1765 pgstat_report_wait_start(WAIT_EVENT_TWOPHASE_FILE_WRITE);
1766 if (write(fd, content, len) != len)
1767 {
1768 /* if write didn't set errno, assume problem is no disk space */
1769 if (errno == 0)
1770 errno = ENOSPC;
1771 ereport(ERROR,
1773 errmsg("could not write file \"%s\": %m", path)));
1774 }
1775 if (write(fd, &statefile_crc, sizeof(pg_crc32c)) != sizeof(pg_crc32c))
1776 {
1777 /* if write didn't set errno, assume problem is no disk space */
1778 if (errno == 0)
1779 errno = ENOSPC;
1780 ereport(ERROR,
1782 errmsg("could not write file \"%s\": %m", path)));
1783 }
1785
1786 /*
1787 * We must fsync the file because the end-of-replay checkpoint will not do
1788 * so, there being no GXACT in shared memory yet to tell it to.
1789 */
1790 pgstat_report_wait_start(WAIT_EVENT_TWOPHASE_FILE_SYNC);
1791 if (pg_fsync(fd) != 0)
1792 ereport(ERROR,
1794 errmsg("could not fsync file \"%s\": %m", path)));
1796
1797 if (CloseTransientFile(fd) != 0)
1798 ereport(ERROR,
1800 errmsg("could not close file \"%s\": %m", path)));
1801}
int pg_fsync(int fd)
Definition: fd.c:385
#define write(a, b, c)
Definition: win32.h:14

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

Referenced by CheckPointTwoPhase().

◆ RegisterTwoPhaseRecord()

void RegisterTwoPhaseRecord ( TwoPhaseRmgrId  rmid,
uint16  info,
const void *  data,
uint32  len 
)

Definition at line 1265 of file twophase.c.

1267{
1268 TwoPhaseRecordOnDisk record;
1269
1270 record.rmid = rmid;
1271 record.info = info;
1272 record.len = len;
1273 save_state_data(&record, sizeof(TwoPhaseRecordOnDisk));
1274 if (len > 0)
1276}
const void * data
static void save_state_data(const void *data, uint32 len)
Definition: twophase.c:1022

References data, TwoPhaseRecordOnDisk::info, TwoPhaseRecordOnDisk::len, len, TwoPhaseRecordOnDisk::rmid, and save_state_data().

Referenced by AtPrepare_Locks(), AtPrepare_MultiXact(), AtPrepare_PgStat_Relations(), AtPrepare_PredicateLocks(), and EndPrepare().

◆ RemoveGXact()

static void RemoveGXact ( GlobalTransaction  gxact)
static

Definition at line 628 of file twophase.c.

629{
630 int i;
631
632 Assert(LWLockHeldByMeInMode(TwoPhaseStateLock, LW_EXCLUSIVE));
633
634 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
635 {
636 if (gxact == TwoPhaseState->prepXacts[i])
637 {
638 /* remove from the active array */
641
642 /* and put it back in the freelist */
643 gxact->next = TwoPhaseState->freeGXacts;
644 TwoPhaseState->freeGXacts = gxact;
645
646 return;
647 }
648 }
649
650 elog(ERROR, "failed to find %p in GlobalTransaction array", gxact);
651}

References Assert, elog, ERROR, TwoPhaseStateData::freeGXacts, i, LW_EXCLUSIVE, LWLockHeldByMeInMode(), GlobalTransactionData::next, TwoPhaseStateData::numPrepXacts, TwoPhaseStateData::prepXacts, and TwoPhaseState.

Referenced by AtAbort_Twophase(), FinishPreparedTransaction(), and PrepareRedoRemove().

◆ RemoveTwoPhaseFile()

static void RemoveTwoPhaseFile ( FullTransactionId  fxid,
bool  giveWarning 
)
static

Definition at line 1721 of file twophase.c.

1722{
1723 char path[MAXPGPATH];
1724
1725 TwoPhaseFilePath(path, fxid);
1726 if (unlink(path))
1727 if (errno != ENOENT || giveWarning)
1730 errmsg("could not remove file \"%s\": %m", path)));
1731}

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

Referenced by FinishPreparedTransaction(), PrepareRedoRemove(), and ProcessTwoPhaseBuffer().

◆ restoreTwoPhaseData()

void restoreTwoPhaseData ( void  )

Definition at line 1907 of file twophase.c.

1908{
1909 DIR *cldir;
1910 struct dirent *clde;
1911
1912 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
1913 cldir = AllocateDir(TWOPHASE_DIR);
1914 while ((clde = ReadDir(cldir, TWOPHASE_DIR)) != NULL)
1915 {
1916 if (strlen(clde->d_name) == 16 &&
1917 strspn(clde->d_name, "0123456789ABCDEF") == 16)
1918 {
1919 FullTransactionId fxid;
1920 char *buf;
1921
1922 fxid = FullTransactionIdFromU64(strtou64(clde->d_name, NULL, 16));
1924 true, false, false);
1925 if (buf == NULL)
1926 continue;
1927
1930 }
1931 }
1932 LWLockRelease(TwoPhaseStateLock);
1933 FreeDir(cldir);
1934}
int FreeDir(DIR *dir)
Definition: fd.c:2983
DIR * AllocateDir(const char *dirname)
Definition: fd.c:2865
struct dirent * ReadDir(DIR *dir, const char *dirname)
Definition: fd.c:2931
Definition: dirent.c:26
Definition: dirent.h:10
char d_name[MAX_PATH]
Definition: dirent.h:15
static FullTransactionId FullTransactionIdFromU64(uint64 value)
Definition: transam.h:81
void PrepareRedoAdd(char *buf, XLogRecPtr start_lsn, XLogRecPtr end_lsn, RepOriginId origin_id)
Definition: twophase.c:2539

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

Referenced by StartupXLOG().

◆ save_state_data()

static void save_state_data ( const void *  data,
uint32  len 
)
static

Definition at line 1022 of file twophase.c.

1023{
1024 uint32 padlen = MAXALIGN(len);
1025
1026 if (padlen > records.bytes_free)
1027 {
1030 records.tail->len = 0;
1031 records.tail->next = NULL;
1033
1034 records.bytes_free = Max(padlen, 512);
1036 }
1037
1038 memcpy(((char *) records.tail->data) + records.tail->len, data, len);
1039 records.tail->len += padlen;
1040 records.bytes_free -= padlen;
1041 records.total_len += padlen;
1042}
#define Max(x, y)
Definition: c.h:952
void * palloc0(Size size)
Definition: mcxt.c:1347
uint32 bytes_free
Definition: twophase.c:1008

References xllist::bytes_free, StateFileChunk::data, data, StateFileChunk::len, len, Max, MAXALIGN, StateFileChunk::next, xllist::num_chunks, palloc(), palloc0(), records, xllist::tail, and xllist::total_len.

Referenced by RegisterTwoPhaseRecord(), and StartPrepare().

◆ StandbyRecoverPreparedTransactions()

void StandbyRecoverPreparedTransactions ( void  )

Definition at line 2055 of file twophase.c.

2056{
2057 int i;
2058 uint32 epoch;
2059 FullTransactionId nextFullXid;
2060
2061 /* get current epoch */
2062 nextFullXid = ReadNextFullTransactionId();
2063 epoch = EpochFromFullTransactionId(nextFullXid);
2064
2065 LWLockAcquire(TwoPhaseStateLock, LW_EXCLUSIVE);
2066 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
2067 {
2068 TransactionId xid;
2069 FullTransactionId fxid;
2070 char *buf;
2072
2073 Assert(gxact->inredo);
2074
2075 xid = gxact->xid;
2076
2077 /*
2078 * At this stage, we're OK to work with the current epoch as all past
2079 * and future files have been already discarded.
2080 */
2083 gxact->prepare_start_lsn,
2084 gxact->ondisk, true, false);
2085 if (buf != NULL)
2086 pfree(buf);
2087 }
2088 LWLockRelease(TwoPhaseStateLock);
2089}

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

Referenced by StartupXLOG(), and xlog_redo().

◆ StandbyTransactionIdIsPrepared()

bool StandbyTransactionIdIsPrepared ( TransactionId  xid)

Definition at line 1463 of file twophase.c.

1464{
1465 char *buf;
1466 TwoPhaseFileHeader *hdr;
1467 bool result;
1468
1470
1471 if (max_prepared_xacts <= 0)
1472 return false; /* nothing to do */
1473
1474 /* Read and validate file */
1475 buf = ReadTwoPhaseFile(xid, true);
1476 if (buf == NULL)
1477 return false;
1478
1479 /* Check header also */
1480 hdr = (TwoPhaseFileHeader *) buf;
1481 result = TransactionIdEquals(hdr->xid, xid);
1482 pfree(buf);
1483
1484 return result;
1485}
#define TransactionIdIsValid(xid)
Definition: transam.h:41

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

Referenced by KnownAssignedXidsRemovePreceding(), and StandbyReleaseOldLocks().

◆ StartPrepare()

void StartPrepare ( GlobalTransaction  gxact)

Definition at line 1050 of file twophase.c.

1051{
1052 PGPROC *proc = GetPGProcByNumber(gxact->pgprocno);
1053 TransactionId xid = gxact->xid;
1055 TransactionId *children;
1056 RelFileLocator *commitrels;
1057 RelFileLocator *abortrels;
1058 xl_xact_stats_item *abortstats = NULL;
1059 xl_xact_stats_item *commitstats = NULL;
1060 SharedInvalidationMessage *invalmsgs;
1061
1062 /* Initialize linked list */
1064 records.head->len = 0;
1065 records.head->next = NULL;
1066
1067 records.bytes_free = Max(sizeof(TwoPhaseFileHeader), 512);
1069
1071 records.num_chunks = 1;
1072
1073 records.total_len = 0;
1074
1075 /* Create header */
1076 hdr.magic = TWOPHASE_MAGIC;
1077 hdr.total_len = 0; /* EndPrepare will fill this in */
1078 hdr.xid = xid;
1079 hdr.database = proc->databaseId;
1080 hdr.prepared_at = gxact->prepared_at;
1081 hdr.owner = gxact->owner;
1082 hdr.nsubxacts = xactGetCommittedChildren(&children);
1083 hdr.ncommitrels = smgrGetPendingDeletes(true, &commitrels);
1084 hdr.nabortrels = smgrGetPendingDeletes(false, &abortrels);
1085 hdr.ncommitstats =
1086 pgstat_get_transactional_drops(true, &commitstats);
1087 hdr.nabortstats =
1088 pgstat_get_transactional_drops(false, &abortstats);
1090 &hdr.initfileinval);
1091 hdr.gidlen = strlen(gxact->gid) + 1; /* Include '\0' */
1092 /* EndPrepare will fill the origin data, if necessary */
1094 hdr.origin_timestamp = 0;
1095
1096 save_state_data(&hdr, sizeof(TwoPhaseFileHeader));
1097 save_state_data(gxact->gid, hdr.gidlen);
1098
1099 /*
1100 * Add the additional info about subxacts, deletable files and cache
1101 * invalidation messages.
1102 */
1103 if (hdr.nsubxacts > 0)
1104 {
1105 save_state_data(children, hdr.nsubxacts * sizeof(TransactionId));
1106 /* While we have the child-xact data, stuff it in the gxact too */
1107 GXactLoadSubxactData(gxact, hdr.nsubxacts, children);
1108 }
1109 if (hdr.ncommitrels > 0)
1110 {
1111 save_state_data(commitrels, hdr.ncommitrels * sizeof(RelFileLocator));
1112 pfree(commitrels);
1113 }
1114 if (hdr.nabortrels > 0)
1115 {
1116 save_state_data(abortrels, hdr.nabortrels * sizeof(RelFileLocator));
1117 pfree(abortrels);
1118 }
1119 if (hdr.ncommitstats > 0)
1120 {
1121 save_state_data(commitstats,
1122 hdr.ncommitstats * sizeof(xl_xact_stats_item));
1123 pfree(commitstats);
1124 }
1125 if (hdr.nabortstats > 0)
1126 {
1127 save_state_data(abortstats,
1128 hdr.nabortstats * sizeof(xl_xact_stats_item));
1129 pfree(abortstats);
1130 }
1131 if (hdr.ninvalmsgs > 0)
1132 {
1133 save_state_data(invalmsgs,
1135 pfree(invalmsgs);
1136 }
1137}
int xactGetCommittedInvalidationMessages(SharedInvalidationMessage **msgs, bool *RelcacheInitFileInval)
Definition: inval.c:939
int pgstat_get_transactional_drops(bool isCommit, xl_xact_stats_item **items)
Definition: pgstat_xact.c:272
int smgrGetPendingDeletes(bool forCommit, RelFileLocator **ptr)
Definition: storage.c:877
int xactGetCommittedChildren(TransactionId **ptr)
Definition: xact.c:5778

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

Referenced by PrepareTransaction().

◆ TwoPhaseFilePath()

static int TwoPhaseFilePath ( char *  path,
FullTransactionId  fxid 
)
inlinestatic

Definition at line 948 of file twophase.c.

949{
950 return snprintf(path, MAXPGPATH, TWOPHASE_DIR "/%08X%08X",
953}
#define snprintf
Definition: port.h:238

References EpochFromFullTransactionId, MAXPGPATH, snprintf, TWOPHASE_DIR, and XidFromFullTransactionId.

Referenced by PrepareRedoAdd(), ReadTwoPhaseFile(), RecreateTwoPhaseFile(), and RemoveTwoPhaseFile().

◆ TwoPhaseGetDummyProc()

PGPROC * TwoPhaseGetDummyProc ( TransactionId  xid,
bool  lock_held 
)

Definition at line 918 of file twophase.c.

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

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

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

◆ TwoPhaseGetDummyProcNumber()

ProcNumber TwoPhaseGetDummyProcNumber ( TransactionId  xid,
bool  lock_held 
)

Definition at line 903 of file twophase.c.

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

References GlobalTransactionData::pgprocno, and TwoPhaseGetGXact().

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

◆ TwoPhaseGetGXact()

static GlobalTransaction TwoPhaseGetGXact ( TransactionId  xid,
bool  lock_held 
)
static

Definition at line 800 of file twophase.c.

801{
802 GlobalTransaction result = NULL;
803 int i;
804
805 static TransactionId cached_xid = InvalidTransactionId;
806 static GlobalTransaction cached_gxact = NULL;
807
808 Assert(!lock_held || LWLockHeldByMe(TwoPhaseStateLock));
809
810 /*
811 * During a recovery, COMMIT PREPARED, or ABORT PREPARED, we'll be called
812 * repeatedly for the same XID. We can save work with a simple cache.
813 */
814 if (xid == cached_xid)
815 return cached_gxact;
816
817 if (!lock_held)
818 LWLockAcquire(TwoPhaseStateLock, LW_SHARED);
819
820 for (i = 0; i < TwoPhaseState->numPrepXacts; i++)
821 {
823
824 if (gxact->xid == xid)
825 {
826 result = gxact;
827 break;
828 }
829 }
830
831 if (!lock_held)
832 LWLockRelease(TwoPhaseStateLock);
833
834 if (result == NULL) /* should not happen */
835 elog(ERROR, "failed to find GlobalTransaction for xid %u", xid);
836
837 cached_xid = xid;
838 cached_gxact = result;
839
840 return result;
841}
bool LWLockHeldByMe(LWLock *lock)
Definition: lwlock.c:1893

References Assert, elog, ERROR, i, InvalidTransactionId, LW_SHARED, LWLockAcquire(), LWLockHeldByMe(), LWLockRelease(), TwoPhaseStateData::numPrepXacts, TwoPhaseStateData::prepXacts, TwoPhaseState, and GlobalTransactionData::xid.

Referenced by TwoPhaseGetDummyProc(), and TwoPhaseGetDummyProcNumber().

◆ TwoPhaseGetXidByVirtualXID()

TransactionId TwoPhaseGetXidByVirtualXID ( VirtualTransactionId  vxid,
bool *  have_more 
)

Definition at line 852 of file twophase.c.

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

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

Referenced by XactLockForVirtualXact().

◆ TwoPhaseShmemInit()

void TwoPhaseShmemInit ( void  )

Definition at line 253 of file twophase.c.

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

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

Referenced by CreateOrAttachShmemStructs().

◆ TwoPhaseShmemSize()

Size TwoPhaseShmemSize ( void  )

Definition at line 237 of file twophase.c.

238{
239 Size size;
240
241 /* Need the fixed struct, the array of pointers, and the GTD structs */
242 size = offsetof(TwoPhaseStateData, prepXacts);
244 sizeof(GlobalTransaction)));
245 size = MAXALIGN(size);
247 sizeof(GlobalTransactionData)));
248
249 return size;
250}
size_t Size
Definition: c.h:559
Size add_size(Size s1, Size s2)
Definition: shmem.c:488
Size mul_size(Size s1, Size s2)
Definition: shmem.c:505
static pg_noinline void Size size
Definition: slab.c:607

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

Referenced by CalculateShmemSize(), and TwoPhaseShmemInit().

◆ TwoPhaseTransactionGid()

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

Definition at line 2763 of file twophase.c.

2764{
2765 Assert(OidIsValid(subid));
2766
2767 if (!TransactionIdIsValid(xid))
2768 ereport(ERROR,
2769 (errcode(ERRCODE_PROTOCOL_VIOLATION),
2770 errmsg_internal("invalid two-phase transaction ID")));
2771
2772 snprintf(gid_res, szgid, "pg_gid_%u_%u", subid, xid);
2773}
#define OidIsValid(objectId)
Definition: c.h:729
int errmsg_internal(const char *fmt,...)
Definition: elog.c:1157

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

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

◆ XlogReadTwoPhaseData()

static void XlogReadTwoPhaseData ( XLogRecPtr  lsn,
char **  buf,
int *  len 
)
static

Definition at line 1408 of file twophase.c.

1409{
1410 XLogRecord *record;
1412 char *errormsg;
1413
1415 XL_ROUTINE(.page_read = &read_local_xlog_page,
1416 .segment_open = &wal_segment_open,
1417 .segment_close = &wal_segment_close),
1418 NULL);
1419 if (!xlogreader)
1420 ereport(ERROR,
1421 (errcode(ERRCODE_OUT_OF_MEMORY),
1422 errmsg("out of memory"),
1423 errdetail("Failed while allocating a WAL reading processor.")));
1424
1426 record = XLogReadRecord(xlogreader, &errormsg);
1427
1428 if (record == NULL)
1429 {
1430 if (errormsg)
1431 ereport(ERROR,
1433 errmsg("could not read two-phase state from WAL at %X/%X: %s",
1434 LSN_FORMAT_ARGS(lsn), errormsg)));
1435 else
1436 ereport(ERROR,
1438 errmsg("could not read two-phase state from WAL at %X/%X",
1439 LSN_FORMAT_ARGS(lsn))));
1440 }
1441
1442 if (XLogRecGetRmid(xlogreader) != RM_XACT_ID ||
1444 ereport(ERROR,
1446 errmsg("expected two-phase state data is not present in WAL at %X/%X",
1447 LSN_FORMAT_ARGS(lsn))));
1448
1449 if (len != NULL)
1451
1452 *buf = palloc(sizeof(char) * XLogRecGetDataLen(xlogreader));
1453 memcpy(*buf, XLogRecGetData(xlogreader), sizeof(char) * XLogRecGetDataLen(xlogreader));
1454
1456}
#define XLOG_XACT_OPMASK
Definition: xact.h:179
int wal_segment_size
Definition: xlog.c:143
XLogReaderState * XLogReaderAllocate(int wal_segment_size, const char *waldir, XLogReaderRoutine *routine, void *private_data)
Definition: xlogreader.c:106
XLogRecord * XLogReadRecord(XLogReaderState *state, char **errormsg)
Definition: xlogreader.c:389
void XLogReaderFree(XLogReaderState *state)
Definition: xlogreader.c:161
void XLogBeginRead(XLogReaderState *state, XLogRecPtr RecPtr)
Definition: xlogreader.c:231
#define XLogRecGetDataLen(decoder)
Definition: xlogreader.h:416
#define XLogRecGetInfo(decoder)
Definition: xlogreader.h:410
#define XLogRecGetRmid(decoder)
Definition: xlogreader.h:411
#define XLogRecGetData(decoder)
Definition: xlogreader.h:415
#define XL_ROUTINE(...)
Definition: xlogreader.h:117
static XLogReaderState * xlogreader
Definition: xlogrecovery.c:188
void wal_segment_close(XLogReaderState *state)
Definition: xlogutils.c:842
void wal_segment_open(XLogReaderState *state, XLogSegNo nextSegNo, TimeLineID *tli_p)
Definition: xlogutils.c:817
int read_local_xlog_page(XLogReaderState *state, XLogRecPtr targetPagePtr, int reqLen, XLogRecPtr targetRecPtr, char *cur_page)
Definition: xlogutils.c:861

References buf, ereport, errcode(), errcode_for_file_access(), errdetail(), errmsg(), ERROR, len, LSN_FORMAT_ARGS, palloc(), read_local_xlog_page(), wal_segment_close(), wal_segment_open(), wal_segment_size, XL_ROUTINE, XLOG_XACT_OPMASK, XLOG_XACT_PREPARE, XLogBeginRead(), xlogreader, XLogReaderAllocate(), XLogReaderFree(), XLogReadRecord(), XLogRecGetData, XLogRecGetDataLen, XLogRecGetInfo, and XLogRecGetRmid.

Referenced by CheckPointTwoPhase(), FinishPreparedTransaction(), LookupGXact(), and ProcessTwoPhaseBuffer().

Variable Documentation

◆ max_prepared_xacts

◆ MyLockedGxact

◆ records

struct xllist records
static

◆ twophaseExitRegistered

bool twophaseExitRegistered = false
static

Definition at line 198 of file twophase.c.

Referenced by LockGXact(), and MarkAsPreparing().

◆ TwoPhaseState