Header And Logo
|
#include "access/xlogdefs.h"
Go to the source code of this file.
| #define BootstrapTransactionId ((TransactionId) 1) |
Definition at line 32 of file transam.h.
Referenced by TransactionLogFetch().
| #define FirstBootstrapObjectId 10000 |
Definition at line 88 of file transam.h.
Referenced by GetNewObjectId(), is_builtin(), PredicateLockingNeededForRelation(), and record_plan_function_dependency().
| #define FirstNormalObjectId 16384 |
Definition at line 89 of file transam.h.
Referenced by array_to_json_internal(), composite_to_json(), get_loadable_libraries(), get_rel_infos(), GetNewObjectId(), json_agg_transfn(), selectDumpableExtension(), and to_json().
| #define FirstNormalTransactionId ((TransactionId) 3) |
Definition at line 34 of file transam.h.
Referenced by do_start_worker(), ExtendCLOG(), ExtendSUBTRANS(), main(), OldSerXidAdd(), relation_needs_vacanalyze(), and SetTransactionIdLimit().
| #define FrozenTransactionId ((TransactionId) 2) |
Definition at line 33 of file transam.h.
Referenced by fill_seq_with_data(), heap_freeze_tuple(), heap_prepare_insert(), and TransactionLogFetch().
| #define InvalidTransactionId ((TransactionId) 0) |
Definition at line 31 of file transam.h.
Referenced by asyncQueueAddEntries(), asyncQueueReadAllNotifications(), BackendXidGetPid(), do_analyze_rel(), ExpireAllKnownAssignedTransactionIds(), GetSafeSnapshot(), GetSerializableTransactionSnapshot(), heap_freeze_tuple(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesNow(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesToast(), HeapTupleSatisfiesUpdate(), HeapTupleSatisfiesVacuum(), ImportSnapshot(), index_drop(), index_set_state_flags(), lazy_cleanup_index(), lazy_scan_heap(), MinimumActiveBackends(), MultiXactIdGetUpdateXid(), ProcArrayApplyXidAssignment(), read_seq_tuple(), RegisterPredicateLockingXid(), reindex_index(), RelationSetNewRelfilenode(), ReleaseOneSerializableXact(), RemoveProcFromArray(), ResetSequence(), ResolveRecoveryConflictWithLock(), ResolveRecoveryConflictWithTablespace(), set_status_by_pages(), SetNewSxactGlobalXmin(), SimpleLruFlush(), SlruInternalWritePage(), SubTransSetParent(), swap_relation_files(), and UpdateXmaxHintBits().
| #define MaxTransactionId ((TransactionId) 0xFFFFFFFF) |
Definition at line 35 of file transam.h.
Referenced by SetTransactionIdLimit().
| #define NormalTransactionIdPrecedes | ( | id1, | ||
| id2 | ||||
| ) |
(AssertMacro(TransactionIdIsNormal(id1) && TransactionIdIsNormal(id2)), \ (int32) ((id1) - (id2)) < 0)
Definition at line 62 of file transam.h.
Referenced by GetSnapshotData().
| #define StoreInvalidTransactionId | ( | dest | ) | (*(dest) = InvalidTransactionId) |
| #define TransactionIdAdvance | ( | dest | ) |
do { \ (dest)++; \ if ((dest) < FirstNormalTransactionId) \ (dest) = FirstNormalTransactionId; \ } while(0)
Definition at line 48 of file transam.h.
Referenced by GetNewTransactionId(), GetOldestXmin(), GetSnapshotData(), KnownAssignedXidsAdd(), multixact_redo(), PrescanPreparedTransactions(), ProcArrayApplyRecoveryInfo(), RecordKnownAssignedTransactionIds(), StartupXLOG(), xact_redo_abort(), and xact_redo_commit_internal().
| #define TransactionIdEquals | ( | id1, | ||
| id2 | ||||
| ) | ((id1) == (id2)) |
Definition at line 43 of file transam.h.
Referenced by CheckCachedPlan(), CheckForSerializableConflictOut(), ConditionalXactLockTableWait(), EvalPlanQualFetch(), ExtendCLOG(), ExtendSUBTRANS(), FinishPreparedTransaction(), GetSerializableTransactionSnapshotInt(), heap_delete(), heap_get_latest_tid(), heap_get_root_tuples(), heap_hot_search_buffer(), heap_lock_tuple(), heap_prune_chain(), heap_update(), MultiXactIdCreate(), MultiXactIdExpand(), predicatelock_twophase_recover(), PredicateLockTuple(), PrescanPreparedTransactions(), RecoverPreparedTransactions(), ReleasePredicateLocks(), SetNewSxactGlobalXmin(), StandbyRecoverPreparedTransactions(), StandbyTransactionIdIsPrepared(), TransactionIdGetCommitLSN(), TransactionIdIsActive(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), TransactionIdIsKnownCompleted(), TransactionLogFetch(), UpdateXmaxHintBits(), XactLockTableWait(), XidCacheRemoveRunningXids(), xideq(), XidInMVCCSnapshot(), and XidIsConcurrent().
| #define TransactionIdIsNormal | ( | xid | ) | ((xid) >= FirstNormalTransactionId) |
Definition at line 42 of file transam.h.
Referenced by BuildCachedPlan(), convert_xid(), ForceTransactionIdLimitUpdate(), GetOldestActiveTransactionId(), GetOldestXmin(), GetRunningTransactionData(), GetSnapshotData(), heap_freeze_tuple(), heap_prune_record_prunable(), heap_tuple_needs_freeze(), ImportSnapshot(), ProcArrayApplyRecoveryInfo(), ProcArrayInstallImportedXmin(), ProcessStandbyHSFeedbackMessage(), relation_needs_vacanalyze(), RelationSetNewRelfilenode(), SetTransactionIdLimit(), StartupXLOG(), SubTransGetParent(), swap_relation_files(), TransactionIdFollows(), TransactionIdFollowsOrEquals(), TransactionIdGetCommitLSN(), TransactionIdIsCurrentTransactionId(), TransactionIdPrecedes(), TransactionIdPrecedesOrEquals(), TransactionLogFetch(), vac_truncate_clog(), vac_update_datfrozenxid(), vac_update_relstats(), vacuum_set_xid_limits(), xid_age(), and xlog_redo().
| #define TransactionIdIsValid | ( | xid | ) | ((xid) != InvalidTransactionId) |
Definition at line 41 of file transam.h.
Referenced by _bt_check_unique(), _bt_doinsert(), AbortSubTransaction(), AssignTransactionId(), bitgetpage(), check_exclusion_constraint(), CheckCachedPlan(), CheckForSerializableConflictOut(), CheckPointPredicate(), CheckTableForSerializableConflictIn(), ClearOldPredicateLocks(), CommitSubTransaction(), ConditionalXactLockTableWait(), DropAllPredicateLocksFromTable(), EvalPlanQualFetch(), ForceTransactionIdLimitUpdate(), GetConflictingVirtualXIDs(), GetCurrentTransactionId(), GetCurrentVirtualXIDs(), GetMultiXactIdMembers(), GetRunningTransactionData(), GetRunningTransactionLocks(), GetSerializableTransactionSnapshotInt(), GetSnapshotData(), GetStableLatestTransactionId(), GetTopTransactionId(), heap_get_latest_tid(), heap_get_root_tuples(), heap_hot_search_buffer(), heap_prune_chain(), heap_prune_record_prunable(), heap_update(), heap_xlog_clean(), heapgetpage(), HeapTupleHeaderIsOnlyLocked(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesNow(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesUpdate(), HeapTupleSatisfiesVacuum(), index_getnext_tid(), KnownAssignedXidExists(), KnownAssignedXidsGetAndSetXmin(), KnownAssignedXidsRemove(), KnownAssignedXidsRemovePreceding(), KnownAssignedXidsRemoveTree(), LockGXact(), MultiXactIdCreate(), MultiXactIdExpand(), OldSerXidAdd(), OldSerXidGetMinConflictCommitSeqNo(), OldSerXidSetActiveSerXmin(), PLy_procedure_argument_valid(), predicatelock_twophase_recover(), PredicateLockPageSplit(), PredicateLockTuple(), ProcArrayApplyRecoveryInfo(), ProcArrayEndTransaction(), ProcArrayRemove(), RecordKnownAssignedTransactionIds(), RecordTransactionAbort(), RecordTransactionCommit(), RegisterPredicateLockingXid(), ResolveRecoveryConflictWithSnapshot(), SetHintBits(), SetNewSxactGlobalXmin(), spgFormDeadTuple(), spgRedoVacuumRedirect(), StandbyAcquireAccessExclusiveLock(), StandbyReleaseLocks(), StandbyReleaseOldLocks(), StandbyTransactionIdIsPrepared(), StartupXLOG(), SubTransGetTopmostTransaction(), SubTransSetParent(), SummarizeOldestCommittedSxact(), TransactionIdDidAbort(), TransactionIdDidCommit(), TransactionIdIsActive(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), TransactionIdSetPageStatus(), vacuum_log_cleanup_info(), vacuumRedirectAndPlaceholder(), XactLockTableWait(), XidCacheRemoveRunningXids(), XidIsConcurrent(), and XLogWalRcvSendHSFeedback().
| #define TransactionIdRetreat | ( | dest | ) |
do { \ (dest)--; \ } while ((dest) < FirstNormalTransactionId)
Definition at line 56 of file transam.h.
Referenced by ProcArrayApplyRecoveryInfo(), StartupXLOG(), and xlog_redo().
| typedef VariableCacheData* VariableCache |
| typedef struct VariableCacheData VariableCacheData |
| bool ForceTransactionIdLimitUpdate | ( | void | ) |
Definition at line 397 of file varsup.c.
References DATABASEOID, LW_SHARED, LWLockAcquire(), LWLockRelease(), VariableCacheData::nextXid, ObjectIdGetDatum, VariableCacheData::oldestXid, VariableCacheData::oldestXidDB, SearchSysCacheExists1, TransactionIdFollowsOrEquals(), TransactionIdIsNormal, TransactionIdIsValid, XidGenLock, and VariableCacheData::xidVacLimit.
Referenced by vac_update_datfrozenxid().
{
TransactionId nextXid;
TransactionId xidVacLimit;
TransactionId oldestXid;
Oid oldestXidDB;
/* Locking is probably not really necessary, but let's be careful */
LWLockAcquire(XidGenLock, LW_SHARED);
nextXid = ShmemVariableCache->nextXid;
xidVacLimit = ShmemVariableCache->xidVacLimit;
oldestXid = ShmemVariableCache->oldestXid;
oldestXidDB = ShmemVariableCache->oldestXidDB;
LWLockRelease(XidGenLock);
if (!TransactionIdIsNormal(oldestXid))
return true; /* shouldn't happen, but just in case */
if (!TransactionIdIsValid(xidVacLimit))
return true; /* this shouldn't happen anymore either */
if (TransactionIdFollowsOrEquals(nextXid, xidVacLimit))
return true; /* past VacLimit, don't delay updating */
if (!SearchSysCacheExists1(DATABASEOID, ObjectIdGetDatum(oldestXidDB)))
return true; /* could happen, per comments above */
return false;
}
| Oid GetNewObjectId | ( | void | ) |
Definition at line 435 of file varsup.c.
References elog, ERROR, FirstBootstrapObjectId, FirstNormalObjectId, IsPostmasterEnvironment, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), VariableCacheData::nextOid, VariableCacheData::oidCount, OidGenLock, RecoveryInProgress(), VAR_OID_PREFETCH, and XLogPutNextOid().
Referenced by GetNewOid(), GetNewOidWithIndex(), and GetNewRelFileNode().
{
Oid result;
/* safety check, we should never get this far in a HS slave */
if (RecoveryInProgress())
elog(ERROR, "cannot assign OIDs during recovery");
LWLockAcquire(OidGenLock, LW_EXCLUSIVE);
/*
* Check for wraparound of the OID counter. We *must* not return 0
* (InvalidOid); and as long as we have to check that, it seems a good
* idea to skip over everything below FirstNormalObjectId too. (This
* basically just avoids lots of collisions with bootstrap-assigned OIDs
* right after a wrap occurs, so as to avoid a possibly large number of
* iterations in GetNewOid.) Note we are relying on unsigned comparison.
*
* During initdb, we start the OID generator at FirstBootstrapObjectId, so
* we only enforce wrapping to that point when in bootstrap or standalone
* mode. The first time through this routine after normal postmaster
* start, the counter will be forced up to FirstNormalObjectId. This
* mechanism leaves the OIDs between FirstBootstrapObjectId and
* FirstNormalObjectId available for automatic assignment during initdb,
* while ensuring they will never conflict with user-assigned OIDs.
*/
if (ShmemVariableCache->nextOid < ((Oid) FirstNormalObjectId))
{
if (IsPostmasterEnvironment)
{
/* wraparound in normal environment */
ShmemVariableCache->nextOid = FirstNormalObjectId;
ShmemVariableCache->oidCount = 0;
}
else
{
/* we may be bootstrapping, so don't enforce the full range */
if (ShmemVariableCache->nextOid < ((Oid) FirstBootstrapObjectId))
{
/* wraparound in standalone environment? */
ShmemVariableCache->nextOid = FirstBootstrapObjectId;
ShmemVariableCache->oidCount = 0;
}
}
}
/* If we run out of logged for use oids then we must log more */
if (ShmemVariableCache->oidCount == 0)
{
XLogPutNextOid(ShmemVariableCache->nextOid + VAR_OID_PREFETCH);
ShmemVariableCache->oidCount = VAR_OID_PREFETCH;
}
result = ShmemVariableCache->nextOid;
(ShmemVariableCache->nextOid)++;
(ShmemVariableCache->oidCount)--;
LWLockRelease(OidGenLock);
return result;
}
| TransactionId GetNewTransactionId | ( | bool | isSubXact | ) |
Definition at line 46 of file varsup.c.
References Assert, elog, ereport, errcode(), errhint(), errmsg(), ERROR, ExtendCLOG(), ExtendSUBTRANS(), get_database_name(), IsBootstrapProcessingMode, IsUnderPostmaster, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MyPgXact, MyProc, VariableCacheData::nextXid, PGXACT::nxids, VariableCacheData::oldestXidDB, PGXACT::overflowed, PGPROC_MAX_CACHED_SUBXIDS, PMSIGNAL_START_AUTOVAC_LAUNCHER, RecoveryInProgress(), SendPostmasterSignal(), PGPROC::subxids, TransactionIdAdvance, TransactionIdFollowsOrEquals(), WARNING, PGXACT::xid, XidGenLock, XidCache::xids, VariableCacheData::xidStopLimit, VariableCacheData::xidVacLimit, VariableCacheData::xidWarnLimit, and VariableCacheData::xidWrapLimit.
Referenced by AssignTransactionId().
{
TransactionId xid;
/*
* During bootstrap initialization, we return the special bootstrap
* transaction id.
*/
if (IsBootstrapProcessingMode())
{
Assert(!isSubXact);
MyPgXact->xid = BootstrapTransactionId;
return BootstrapTransactionId;
}
/* safety check, we should never get this far in a HS slave */
if (RecoveryInProgress())
elog(ERROR, "cannot assign TransactionIds during recovery");
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
xid = ShmemVariableCache->nextXid;
/*----------
* Check to see if it's safe to assign another XID. This protects against
* catastrophic data loss due to XID wraparound. The basic rules are:
*
* If we're past xidVacLimit, start trying to force autovacuum cycles.
* If we're past xidWarnLimit, start issuing warnings.
* If we're past xidStopLimit, refuse to execute transactions, unless
* we are running in a standalone backend (which gives an escape hatch
* to the DBA who somehow got past the earlier defenses).
*
* Note that this coding also appears in GetNewMultiXactId.
*----------
*/
if (TransactionIdFollowsOrEquals(xid, ShmemVariableCache->xidVacLimit))
{
/*
* For safety's sake, we release XidGenLock while sending signals,
* warnings, etc. This is not so much because we care about
* preserving concurrency in this situation, as to avoid any
* possibility of deadlock while doing get_database_name(). First,
* copy all the shared values we'll need in this path.
*/
TransactionId xidWarnLimit = ShmemVariableCache->xidWarnLimit;
TransactionId xidStopLimit = ShmemVariableCache->xidStopLimit;
TransactionId xidWrapLimit = ShmemVariableCache->xidWrapLimit;
Oid oldest_datoid = ShmemVariableCache->oldestXidDB;
LWLockRelease(XidGenLock);
/*
* To avoid swamping the postmaster with signals, we issue the autovac
* request only once per 64K transaction starts. This still gives
* plenty of chances before we get into real trouble.
*/
if (IsUnderPostmaster && (xid % 65536) == 0)
SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER);
if (IsUnderPostmaster &&
TransactionIdFollowsOrEquals(xid, xidStopLimit))
{
char *oldest_datname = get_database_name(oldest_datoid);
/* complain even if that DB has disappeared */
if (oldest_datname)
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("database is not accepting commands to avoid wraparound data loss in database \"%s\"",
oldest_datname),
errhint("Stop the postmaster and use a standalone backend to vacuum that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
else
ereport(ERROR,
(errcode(ERRCODE_PROGRAM_LIMIT_EXCEEDED),
errmsg("database is not accepting commands to avoid wraparound data loss in database with OID %u",
oldest_datoid),
errhint("Stop the postmaster and use a standalone backend to vacuum that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
}
else if (TransactionIdFollowsOrEquals(xid, xidWarnLimit))
{
char *oldest_datname = get_database_name(oldest_datoid);
/* complain even if that DB has disappeared */
if (oldest_datname)
ereport(WARNING,
(errmsg("database \"%s\" must be vacuumed within %u transactions",
oldest_datname,
xidWrapLimit - xid),
errhint("To avoid a database shutdown, execute a database-wide VACUUM in that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
else
ereport(WARNING,
(errmsg("database with OID %u must be vacuumed within %u transactions",
oldest_datoid,
xidWrapLimit - xid),
errhint("To avoid a database shutdown, execute a database-wide VACUUM in that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
}
/* Re-acquire lock and start over */
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
xid = ShmemVariableCache->nextXid;
}
/*
* If we are allocating the first XID of a new page of the commit log,
* zero out that commit-log page before returning. We must do this while
* holding XidGenLock, else another xact could acquire and commit a later
* XID before we zero the page. Fortunately, a page of the commit log
* holds 32K or more transactions, so we don't have to do this very often.
*
* Extend pg_subtrans too.
*/
ExtendCLOG(xid);
ExtendSUBTRANS(xid);
/*
* Now advance the nextXid counter. This must not happen until after we
* have successfully completed ExtendCLOG() --- if that routine fails, we
* want the next incoming transaction to try it again. We cannot assign
* more XIDs until there is CLOG space for them.
*/
TransactionIdAdvance(ShmemVariableCache->nextXid);
/*
* We must store the new XID into the shared ProcArray before releasing
* XidGenLock. This ensures that every active XID older than
* latestCompletedXid is present in the ProcArray, which is essential for
* correct OldestXmin tracking; see src/backend/access/transam/README.
*
* XXX by storing xid into MyPgXact without acquiring ProcArrayLock, we
* are relying on fetch/store of an xid to be atomic, else other backends
* might see a partially-set xid here. But holding both locks at once
* would be a nasty concurrency hit. So for now, assume atomicity.
*
* Note that readers of PGXACT xid fields should be careful to fetch the
* value only once, rather than assume they can read a value multiple
* times and get the same answer each time.
*
* The same comments apply to the subxact xid count and overflow fields.
*
* A solution to the atomic-store problem would be to give each PGXACT its
* own spinlock used only for fetching/storing that PGXACT's xid and
* related fields.
*
* If there's no room to fit a subtransaction XID into PGPROC, set the
* cache-overflowed flag instead. This forces readers to look in
* pg_subtrans to map subtransaction XIDs up to top-level XIDs. There is a
* race-condition window, in that the new XID will not appear as running
* until its parent link has been placed into pg_subtrans. However, that
* will happen before anyone could possibly have a reason to inquire about
* the status of the XID, so it seems OK. (Snapshots taken during this
* window *will* include the parent XID, so they will deliver the correct
* answer later on when someone does have a reason to inquire.)
*/
{
/*
* Use volatile pointer to prevent code rearrangement; other backends
* could be examining my subxids info concurrently, and we don't want
* them to see an invalid intermediate state, such as incrementing
* nxids before filling the array entry. Note we are assuming that
* TransactionId and int fetch/store are atomic.
*/
volatile PGPROC *myproc = MyProc;
volatile PGXACT *mypgxact = MyPgXact;
if (!isSubXact)
mypgxact->xid = xid;
else
{
int nxids = mypgxact->nxids;
if (nxids < PGPROC_MAX_CACHED_SUBXIDS)
{
myproc->subxids.xids[nxids] = xid;
mypgxact->nxids = nxids + 1;
}
else
mypgxact->overflowed = true;
}
}
LWLockRelease(XidGenLock);
return xid;
}
| TransactionId ReadNewTransactionId | ( | void | ) |
Definition at line 240 of file varsup.c.
References LW_SHARED, LWLockAcquire(), LWLockRelease(), VariableCacheData::nextXid, and XidGenLock.
Referenced by _bt_pagedel(), AutoVacWorkerMain(), do_start_worker(), GetNextXidAndEpoch(), GetStableLatestTransactionId(), and vacuum_set_xid_limits().
{
TransactionId xid;
LWLockAcquire(XidGenLock, LW_SHARED);
xid = ShmemVariableCache->nextXid;
LWLockRelease(XidGenLock);
return xid;
}
| void SetTransactionIdLimit | ( | TransactionId | oldest_datfrozenxid, | |
| Oid | oldest_datoid | |||
| ) |
Definition at line 257 of file varsup.c.
References Assert, autovacuum_freeze_max_age, DEBUG1, ereport, errhint(), errmsg(), FirstNormalTransactionId, get_database_name(), InRecovery, IsTransactionState(), IsUnderPostmaster, LW_EXCLUSIVE, LWLockAcquire(), LWLockRelease(), MaxTransactionId, VariableCacheData::nextXid, VariableCacheData::oldestXid, VariableCacheData::oldestXidDB, PMSIGNAL_START_AUTOVAC_LAUNCHER, SendPostmasterSignal(), TransactionIdFollowsOrEquals(), TransactionIdIsNormal, WARNING, XidGenLock, VariableCacheData::xidStopLimit, VariableCacheData::xidVacLimit, VariableCacheData::xidWarnLimit, and VariableCacheData::xidWrapLimit.
Referenced by BootStrapXLOG(), StartupXLOG(), vac_truncate_clog(), and xlog_redo().
{
TransactionId xidVacLimit;
TransactionId xidWarnLimit;
TransactionId xidStopLimit;
TransactionId xidWrapLimit;
TransactionId curXid;
Assert(TransactionIdIsNormal(oldest_datfrozenxid));
/*
* The place where we actually get into deep trouble is halfway around
* from the oldest potentially-existing XID. (This calculation is
* probably off by one or two counts, because the special XIDs reduce the
* size of the loop a little bit. But we throw in plenty of slop below,
* so it doesn't matter.)
*/
xidWrapLimit = oldest_datfrozenxid + (MaxTransactionId >> 1);
if (xidWrapLimit < FirstNormalTransactionId)
xidWrapLimit += FirstNormalTransactionId;
/*
* We'll refuse to continue assigning XIDs in interactive mode once we get
* within 1M transactions of data loss. This leaves lots of room for the
* DBA to fool around fixing things in a standalone backend, while not
* being significant compared to total XID space. (Note that since
* vacuuming requires one transaction per table cleaned, we had better be
* sure there's lots of XIDs left...)
*/
xidStopLimit = xidWrapLimit - 1000000;
if (xidStopLimit < FirstNormalTransactionId)
xidStopLimit -= FirstNormalTransactionId;
/*
* We'll start complaining loudly when we get within 10M transactions of
* the stop point. This is kind of arbitrary, but if you let your gas
* gauge get down to 1% of full, would you be looking for the next gas
* station? We need to be fairly liberal about this number because there
* are lots of scenarios where most transactions are done by automatic
* clients that won't pay attention to warnings. (No, we're not gonna make
* this configurable. If you know enough to configure it, you know enough
* to not get in this kind of trouble in the first place.)
*/
xidWarnLimit = xidStopLimit - 10000000;
if (xidWarnLimit < FirstNormalTransactionId)
xidWarnLimit -= FirstNormalTransactionId;
/*
* We'll start trying to force autovacuums when oldest_datfrozenxid gets
* to be more than autovacuum_freeze_max_age transactions old.
*
* Note: guc.c ensures that autovacuum_freeze_max_age is in a sane range,
* so that xidVacLimit will be well before xidWarnLimit.
*
* Note: autovacuum_freeze_max_age is a PGC_POSTMASTER parameter so that
* we don't have to worry about dealing with on-the-fly changes in its
* value. It doesn't look practical to update shared state from a GUC
* assign hook (too many processes would try to execute the hook,
* resulting in race conditions as well as crashes of those not connected
* to shared memory). Perhaps this can be improved someday.
*/
xidVacLimit = oldest_datfrozenxid + autovacuum_freeze_max_age;
if (xidVacLimit < FirstNormalTransactionId)
xidVacLimit += FirstNormalTransactionId;
/* Grab lock for just long enough to set the new limit values */
LWLockAcquire(XidGenLock, LW_EXCLUSIVE);
ShmemVariableCache->oldestXid = oldest_datfrozenxid;
ShmemVariableCache->xidVacLimit = xidVacLimit;
ShmemVariableCache->xidWarnLimit = xidWarnLimit;
ShmemVariableCache->xidStopLimit = xidStopLimit;
ShmemVariableCache->xidWrapLimit = xidWrapLimit;
ShmemVariableCache->oldestXidDB = oldest_datoid;
curXid = ShmemVariableCache->nextXid;
LWLockRelease(XidGenLock);
/* Log the info */
ereport(DEBUG1,
(errmsg("transaction ID wrap limit is %u, limited by database with OID %u",
xidWrapLimit, oldest_datoid)));
/*
* If past the autovacuum force point, immediately signal an autovac
* request. The reason for this is that autovac only processes one
* database per invocation. Once it's finished cleaning up the oldest
* database, it'll call here, and we'll signal the postmaster to start
* another iteration immediately if there are still any old databases.
*/
if (TransactionIdFollowsOrEquals(curXid, xidVacLimit) &&
IsUnderPostmaster && !InRecovery)
SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER);
/* Give an immediate warning if past the wrap warn point */
if (TransactionIdFollowsOrEquals(curXid, xidWarnLimit) && !InRecovery)
{
char *oldest_datname;
/*
* We can be called when not inside a transaction, for example during
* StartupXLOG(). In such a case we cannot do database access, so we
* must just report the oldest DB's OID.
*
* Note: it's also possible that get_database_name fails and returns
* NULL, for example because the database just got dropped. We'll
* still warn, even though the warning might now be unnecessary.
*/
if (IsTransactionState())
oldest_datname = get_database_name(oldest_datoid);
else
oldest_datname = NULL;
if (oldest_datname)
ereport(WARNING,
(errmsg("database \"%s\" must be vacuumed within %u transactions",
oldest_datname,
xidWrapLimit - curXid),
errhint("To avoid a database shutdown, execute a database-wide VACUUM in that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
else
ereport(WARNING,
(errmsg("database with OID %u must be vacuumed within %u transactions",
oldest_datoid,
xidWrapLimit - curXid),
errhint("To avoid a database shutdown, execute a database-wide VACUUM in that database.\n"
"You might also need to commit or roll back old prepared transactions.")));
}
}
| void TransactionIdAbort | ( | TransactionId | transactionId | ) |
| void TransactionIdAbortTree | ( | TransactionId | xid, | |
| int | nxids, | |||
| TransactionId * | xids | |||
| ) |
Definition at line 290 of file transam.c.
References InvalidXLogRecPtr, TRANSACTION_STATUS_ABORTED, and TransactionIdSetTreeStatus().
Referenced by RecordTransactionAbort(), RecordTransactionAbortPrepared(), and xact_redo_abort().
{
TransactionIdSetTreeStatus(xid, nxids, xids,
TRANSACTION_STATUS_ABORTED, InvalidXLogRecPtr);
}
| void TransactionIdAsyncCommitTree | ( | TransactionId | xid, | |
| int | nxids, | |||
| TransactionId * | xids, | |||
| XLogRecPtr | lsn | |||
| ) |
Definition at line 272 of file transam.c.
References TRANSACTION_STATUS_COMMITTED, and TransactionIdSetTreeStatus().
Referenced by RecordTransactionCommit(), and xact_redo_commit_internal().
{
TransactionIdSetTreeStatus(xid, nxids, xids,
TRANSACTION_STATUS_COMMITTED, lsn);
}
| void TransactionIdCommitTree | ( | TransactionId | xid, | |
| int | nxids, | |||
| TransactionId * | xids | |||
| ) |
Definition at line 260 of file transam.c.
References InvalidXLogRecPtr, TRANSACTION_STATUS_COMMITTED, and TransactionIdSetTreeStatus().
Referenced by RecordTransactionCommit(), RecordTransactionCommitPrepared(), and xact_redo_commit_internal().
{
TransactionIdSetTreeStatus(xid, nxids, xids,
TRANSACTION_STATUS_COMMITTED,
InvalidXLogRecPtr);
}
| bool TransactionIdDidAbort | ( | TransactionId | transactionId | ) |
Definition at line 181 of file transam.c.
References elog, SubTransGetParent(), TRANSACTION_STATUS_ABORTED, TRANSACTION_STATUS_SUB_COMMITTED, TransactionIdDidAbort(), TransactionIdIsValid, TransactionIdPrecedes(), TransactionLogFetch(), TransactionXmin, and WARNING.
Referenced by asyncQueueProcessPageEntries(), compute_new_xmax_infomask(), heap_lock_updated_tuple_rec(), heap_update(), MultiXactIdGetUpdateXid(), ProcArrayApplyRecoveryInfo(), RecoverPreparedTransactions(), StandbyAcquireAccessExclusiveLock(), StandbyRecoverPreparedTransactions(), TransactionIdDidAbort(), and TransactionIdIsInProgress().
{
XidStatus xidstatus;
xidstatus = TransactionLogFetch(transactionId);
/*
* If it's marked aborted, it's aborted.
*/
if (xidstatus == TRANSACTION_STATUS_ABORTED)
return true;
/*
* If it's marked subcommitted, we have to check the parent recursively.
* However, if it's older than TransactionXmin, we can't look at
* pg_subtrans; instead assume that the parent crashed without cleaning up
* its children.
*/
if (xidstatus == TRANSACTION_STATUS_SUB_COMMITTED)
{
TransactionId parentXid;
if (TransactionIdPrecedes(transactionId, TransactionXmin))
return true;
parentXid = SubTransGetParent(transactionId);
if (!TransactionIdIsValid(parentXid))
{
/* see notes in TransactionIdDidCommit */
elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
transactionId);
return true;
}
return TransactionIdDidAbort(parentXid);
}
/*
* It's not aborted.
*/
return false;
}
| bool TransactionIdDidCommit | ( | TransactionId | transactionId | ) |
Definition at line 125 of file transam.c.
References elog, SubTransGetParent(), TRANSACTION_STATUS_COMMITTED, TRANSACTION_STATUS_SUB_COMMITTED, TransactionIdDidCommit(), TransactionIdIsValid, TransactionIdPrecedes(), TransactionLogFetch(), TransactionXmin, and WARNING.
Referenced by asyncQueueProcessPageEntries(), compute_new_xmax_infomask(), heap_lock_updated_tuple_rec(), HeapTupleHeaderAdvanceLatestRemovedXid(), HeapTupleHeaderIsOnlyLocked(), HeapTupleSatisfiesDirty(), HeapTupleSatisfiesMVCC(), HeapTupleSatisfiesNow(), HeapTupleSatisfiesSelf(), HeapTupleSatisfiesToast(), HeapTupleSatisfiesUpdate(), HeapTupleSatisfiesVacuum(), MultiXactIdExpand(), ProcArrayApplyRecoveryInfo(), RecordTransactionAbort(), RecordTransactionAbortPrepared(), RecoverPreparedTransactions(), StandbyAcquireAccessExclusiveLock(), StandbyRecoverPreparedTransactions(), TransactionIdDidCommit(), and UpdateXmaxHintBits().
{
XidStatus xidstatus;
xidstatus = TransactionLogFetch(transactionId);
/*
* If it's marked committed, it's committed.
*/
if (xidstatus == TRANSACTION_STATUS_COMMITTED)
return true;
/*
* If it's marked subcommitted, we have to check the parent recursively.
* However, if it's older than TransactionXmin, we can't look at
* pg_subtrans; instead assume that the parent crashed without cleaning up
* its children.
*
* Originally we Assert'ed that the result of SubTransGetParent was not
* zero. However with the introduction of prepared transactions, there can
* be a window just after database startup where we do not have complete
* knowledge in pg_subtrans of the transactions after TransactionXmin.
* StartupSUBTRANS() has ensured that any missing information will be
* zeroed. Since this case should not happen under normal conditions, it
* seems reasonable to emit a WARNING for it.
*/
if (xidstatus == TRANSACTION_STATUS_SUB_COMMITTED)
{
TransactionId parentXid;
if (TransactionIdPrecedes(transactionId, TransactionXmin))
return false;
parentXid = SubTransGetParent(transactionId);
if (!TransactionIdIsValid(parentXid))
{
elog(WARNING, "no pg_subtrans entry for subcommitted XID %u",
transactionId);
return false;
}
return TransactionIdDidCommit(parentXid);
}
/*
* It's not committed.
*/
return false;
}
| bool TransactionIdFollows | ( | TransactionId | id1, | |
| TransactionId | id2 | |||
| ) |
Definition at line 334 of file transam.c.
References TransactionIdIsNormal.
Referenced by convert_xid(), GetConflictingVirtualXIDs(), GetSerializableTransactionSnapshotInt(), heap_page_is_all_visible(), HeapTupleHeaderAdvanceLatestRemovedXid(), lazy_scan_heap(), OldSerXidAdd(), OldSerXidGetMinConflictCommitSeqNo(), OldSerXidSetActiveSerXmin(), predicatelock_twophase_recover(), PrescanPreparedTransactions(), ProcArrayApplyRecoveryInfo(), RecordKnownAssignedTransactionIds(), and StandbyRecoverPreparedTransactions().
{
int32 diff;
if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2))
return (id1 > id2);
diff = (int32) (id1 - id2);
return (diff > 0);
}
| bool TransactionIdFollowsOrEquals | ( | TransactionId | id1, | |
| TransactionId | id2 | |||
| ) |
Definition at line 349 of file transam.c.
References TransactionIdIsNormal.
Referenced by CheckForSerializableConflictOut(), ForceTransactionIdLimitUpdate(), GetNewTransactionId(), KnownAssignedXidsAdd(), KnownAssignedXidsGetAndSetXmin(), KnownAssignedXidsRemovePreceding(), multixact_redo(), PredicateLockTuple(), PrescanPreparedTransactions(), SetTransactionIdLimit(), StartupXLOG(), SubTransGetParent(), SubTransGetTopmostTransaction(), vacuumLeafPage(), xact_redo_abort(), xact_redo_commit_internal(), XidInMVCCSnapshot(), and XidIsConcurrent().
{
int32 diff;
if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2))
return (id1 >= id2);
diff = (int32) (id1 - id2);
return (diff >= 0);
}
| XLogRecPtr TransactionIdGetCommitLSN | ( | TransactionId | xid | ) |
Definition at line 402 of file transam.c.
References cachedCommitLSN, cachedFetchXid, TransactionIdEquals, TransactionIdGetStatus(), and TransactionIdIsNormal.
Referenced by SetHintBits().
{
XLogRecPtr result;
/*
* Currently, all uses of this function are for xids that were just
* reported to be committed by TransactionLogFetch, so we expect that
* checking TransactionLogFetch's cache will usually succeed and avoid an
* extra trip to shared memory.
*/
if (TransactionIdEquals(xid, cachedFetchXid))
return cachedCommitLSN;
/* Special XIDs are always known committed */
if (!TransactionIdIsNormal(xid))
return InvalidXLogRecPtr;
/*
* Get the transaction status.
*/
(void) TransactionIdGetStatus(xid, &result);
return result;
}
| bool TransactionIdIsKnownCompleted | ( | TransactionId | transactionId | ) |
Definition at line 238 of file transam.c.
References cachedFetchXid, and TransactionIdEquals.
Referenced by TransactionIdIsInProgress().
{
if (TransactionIdEquals(transactionId, cachedFetchXid))
{
/* If it's in the cache at all, it must be completed. */
return true;
}
return false;
}
| TransactionId TransactionIdLatest | ( | TransactionId | mainxid, | |
| int | nxids, | |||
| const TransactionId * | xids | |||
| ) |
Definition at line 365 of file transam.c.
References TransactionIdPrecedes().
Referenced by FinishPreparedTransaction(), ProcArrayApplyXidAssignment(), RecordTransactionAbort(), RecordTransactionCommit(), xact_redo_abort(), and xact_redo_commit_internal().
{
TransactionId result;
/*
* In practice it is highly likely that the xids[] array is sorted, and so
* we could save some cycles by just taking the last child XID, but this
* probably isn't so performance-critical that it's worth depending on
* that assumption. But just to show we're not totally stupid, scan the
* array back-to-front to avoid useless assignments.
*/
result = mainxid;
while (--nxids >= 0)
{
if (TransactionIdPrecedes(result, xids[nxids]))
result = xids[nxids];
}
return result;
}
| bool TransactionIdPrecedes | ( | TransactionId | id1, | |
| TransactionId | id2 | |||
| ) |
Definition at line 300 of file transam.c.
References TransactionIdIsNormal.
Referenced by _bt_page_recyclable(), CheckForSerializableConflictOut(), CheckTargetForConflictsIn(), CLOGPagePrecedes(), convert_xid(), copy_heap_data(), do_start_worker(), ExpireTreeKnownAssignedTransactionIds(), ExportSnapshot(), get_relation_info(), GetOldestActiveTransactionId(), GetOldestXmin(), GetRunningTransactionData(), GetSnapshotData(), heap_freeze_tuple(), heap_page_is_all_visible(), heap_prune_record_prunable(), heap_tuple_needs_freeze(), HeapTupleHeaderAdvanceLatestRemovedXid(), HeapTupleIsSurelyDead(), HeapTupleSatisfiesVacuum(), KnownAssignedXidsAdd(), KnownAssignedXidsGetAndSetXmin(), KnownAssignedXidsSearch(), lazy_scan_heap(), multixact_redo(), OldSerXidAdd(), OldSerXidGetMinConflictCommitSeqNo(), OldSerXidSetActiveSerXmin(), PrescanPreparedTransactions(), ProcArrayApplyRecoveryInfo(), ProcArrayApplyXidAssignment(), ProcArrayEndTransaction(), ProcArrayRemove(), relation_needs_vacanalyze(), rewrite_heap_tuple(), SetNewSxactGlobalXmin(), SubTransGetTopmostTransaction(), SubTransPagePrecedes(), TransactionIdDidAbort(), TransactionIdDidCommit(), TransactionIdIsActive(), TransactionIdIsCurrentTransactionId(), TransactionIdIsInProgress(), TransactionIdLatest(), vac_truncate_clog(), vac_update_datfrozenxid(), vac_update_relstats(), vacuum_set_xid_limits(), vacuumRedirectAndPlaceholder(), XidCacheRemoveRunningXids(), XidInMVCCSnapshot(), XidIsConcurrent(), and xlog_redo().
{
/*
* If either ID is a permanent XID then we can just do unsigned
* comparison. If both are normal, do a modulo-2^31 comparison.
*/
int32 diff;
if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2))
return (id1 < id2);
diff = (int32) (id1 - id2);
return (diff < 0);
}
| bool TransactionIdPrecedesOrEquals | ( | TransactionId | id1, | |
| TransactionId | id2 | |||
| ) |
Definition at line 319 of file transam.c.
References TransactionIdIsNormal.
Referenced by ClearOldPredicateLocks(), GetCurrentVirtualXIDs(), GetSnapshotData(), KnownAssignedXidsAdd(), lazy_vacuum_rel(), ProcArrayInstallImportedXmin(), ProcessStandbyHSFeedbackMessage(), RecordKnownAssignedTransactionIds(), and TransactionIdIsInProgress().
{
int32 diff;
if (!TransactionIdIsNormal(id1) || !TransactionIdIsNormal(id2))
return (id1 <= id2);
diff = (int32) (id1 - id2);
return (diff <= 0);
}
| bool TransactionStartedDuringRecovery | ( | void | ) |
Definition at line 749 of file xact.c.
References TransactionStateData::startedInRecovery.
Referenced by RelationGetIndexScan().
{
return CurrentTransactionState->startedInRecovery;
}
| PGDLLIMPORT VariableCache ShmemVariableCache |
Definition at line 32 of file varsup.c.
Referenced by BootStrapXLOG(), CreateCheckPoint(), ExpireTreeKnownAssignedTransactionIds(), GetOldestActiveTransactionId(), GetOldestXmin(), GetRunningTransactionData(), GetSnapshotData(), InitShmemAllocation(), multixact_redo(), PrescanPreparedTransactions(), ProcArrayApplyRecoveryInfo(), ProcArrayEndTransaction(), ProcArrayRemove(), RecordKnownAssignedTransactionIds(), ReleasePredicateLocks(), StartupCLOG(), StartupSUBTRANS(), StartupXLOG(), TransactionIdIsInProgress(), TrimCLOG(), xact_redo_abort(), xact_redo_commit_internal(), XidCacheRemoveRunningXids(), and xlog_redo().
1.7.1