/*
* Deactivate this module.
*
* This must be called when the track_commit_timestamp parameter is turned off.
* This happens during postmaster or standalone-backend startup, or during WAL
* replay.
*
* Resets CommitTs into invalid state to make sure we don't hand back
* possibly-invalid data; also removes segments of old data.
*/
static void
DeactivateCommitTs(void)
{
/*
* Cleanup the status in the shared memory.
*
* We reset everything in the commitTsShared record to prevent user from
* getting confusing data about last committed transaction on the standby
* when the module was activated repeatedly on the primary.
*/
LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
commitTsShared->commitTsActive = false;
commitTsShared->xidLastCommit = InvalidTransactionId;
TIMESTAMP_NOBEGIN(commitTsShared->dataLastCommit.time);
commitTsShared->dataLastCommit.nodeid = InvalidRepOriginId;
ShmemVariableCache->oldestCommitTsXid = InvalidTransactionId;
ShmemVariableCache->newestCommitTsXid = InvalidTransactionId;
LWLockRelease(CommitTsLock);
/*
* Remove *all* files. This is necessary so that there are no leftover
* files; in the case where this feature is later enabled after running
* with it disabled for some time there may be a gap in the file sequence.
* (We can probably tolerate out-of-sequence files, as they are going to
* be overwritten anyway when we wrap around, but it seems better to be
* tidy.)
*/
LWLockAcquire(CommitTsControlLock, LW_EXCLUSIVE);
(void) SlruScanDirectory(CommitTsCtl, SlruScanDirCbDeleteAll, NULL);
LWLockRelease(CommitTsControlLock);
}
/*
* Initialize CommitTs at system startup (postmaster start or standalone
* backend)
*/
void
CommitTsShmemInit(void)
{
bool found;
CommitTsCtl->PagePrecedes = CommitTsPagePrecedes;
SimpleLruInit(CommitTsCtl, "commit_timestamp", CommitTsShmemBuffers(), 0,
CommitTsControlLock, "pg_commit_ts",
LWTRANCHE_COMMITTS_BUFFERS);
commitTsShared = ShmemInitStruct("CommitTs shared",
sizeof(CommitTimestampShared),
&found);
if (!IsUnderPostmaster)
{
Assert(!found);
commitTsShared->xidLastCommit = InvalidTransactionId;
TIMESTAMP_NOBEGIN(commitTsShared->dataLastCommit.time);
commitTsShared->dataLastCommit.nodeid = InvalidRepOriginId;
commitTsShared->commitTsActive = false;
}
else
Assert(found);
}
/* abstime_timestamptz()
* Convert abstime to timestamp with time zone.
*/
Datum
abstime_timestamptz(PG_FUNCTION_ARGS)
{
AbsoluteTime abstime = PG_GETARG_ABSOLUTETIME(0);
TimestampTz result;
struct pg_tm tt,
*tm = &tt;
int tz;
char zone[MAXDATELEN + 1],
*tzn = zone;
switch (abstime)
{
case INVALID_ABSTIME:
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot convert abstime \"invalid\" to timestamp"),
errOmitLocation(true)));
TIMESTAMP_NOBEGIN(result);
break;
case NOSTART_ABSTIME:
TIMESTAMP_NOBEGIN(result);
break;
case NOEND_ABSTIME:
TIMESTAMP_NOEND(result);
break;
default:
abstime2tm(abstime, &tz, tm, &tzn);
if (tm2timestamp(tm, 0, &tz, &result) != 0)
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range"),
errOmitLocation(true)));
break;
};
PG_RETURN_TIMESTAMP(result);
}
timestamp
PGTYPEStimestamp_from_asc(char *str, char **endptr)
{
timestamp result;
#ifdef HAVE_INT64_TIMESTAMP
int64 noresult = 0;
#else
double noresult = 0.0;
#endif
fsec_t fsec;
struct tm tt,
*tm = &tt;
int dtype;
int nf;
char *field[MAXDATEFIELDS];
int ftype[MAXDATEFIELDS];
char lowstr[MAXDATELEN + MAXDATEFIELDS];
char *realptr;
char **ptr = (endptr != NULL) ? endptr : &realptr;
if (strlen(str) >= sizeof(lowstr))
{
errno = PGTYPES_TS_BAD_TIMESTAMP;
return (noresult);
}
if (ParseDateTime(str, lowstr, field, ftype, &nf, ptr) != 0 ||
DecodeDateTime(field, ftype, nf, &dtype, tm, &fsec, 0) != 0)
{
errno = PGTYPES_TS_BAD_TIMESTAMP;
return (noresult);
}
switch (dtype)
{
case DTK_DATE:
if (tm2timestamp(tm, fsec, NULL, &result) != 0)
{
errno = PGTYPES_TS_BAD_TIMESTAMP;
return (noresult);
}
break;
case DTK_EPOCH:
result = SetEpochTimestamp();
break;
case DTK_LATE:
TIMESTAMP_NOEND(result);
break;
case DTK_EARLY:
TIMESTAMP_NOBEGIN(result);
break;
case DTK_INVALID:
errno = PGTYPES_TS_BAD_TIMESTAMP;
return (noresult);
default:
errno = PGTYPES_TS_BAD_TIMESTAMP;
return (noresult);
}
/* AdjustTimestampForTypmod(&result, typmod); */
/*
* Since it's difficult to test for noresult, make sure errno is 0 if no
* error occured.
*/
errno = 0;
return result;
}
/*
* Start new apply background worker, if possible.
*/
void
logicalrep_worker_launch(Oid dbid, Oid subid, const char *subname, Oid userid,
Oid relid)
{
BackgroundWorker bgw;
BackgroundWorkerHandle *bgw_handle;
uint16 generation;
int i;
int slot = 0;
LogicalRepWorker *worker = NULL;
int nsyncworkers;
TimestampTz now;
ereport(DEBUG1,
(errmsg("starting logical replication worker for subscription \"%s\"",
subname)));
/* Report this after the initial starting message for consistency. */
if (max_replication_slots == 0)
ereport(ERROR,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("cannot start logical replication workers when max_replication_slots = 0")));
/*
* We need to do the modification of the shared memory under lock so that
* we have consistent view.
*/
LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
retry:
/* Find unused worker slot. */
for (i = 0; i < max_logical_replication_workers; i++)
{
LogicalRepWorker *w = &LogicalRepCtx->workers[i];
if (!w->in_use)
{
worker = w;
slot = i;
break;
}
}
nsyncworkers = logicalrep_sync_worker_count(subid);
now = GetCurrentTimestamp();
/*
* If we didn't find a free slot, try to do garbage collection. The
* reason we do this is because if some worker failed to start up and its
* parent has crashed while waiting, the in_use state was never cleared.
*/
if (worker == NULL || nsyncworkers >= max_sync_workers_per_subscription)
{
bool did_cleanup = false;
for (i = 0; i < max_logical_replication_workers; i++)
{
LogicalRepWorker *w = &LogicalRepCtx->workers[i];
/*
* If the worker was marked in use but didn't manage to attach in
* time, clean it up.
*/
if (w->in_use && !w->proc &&
TimestampDifferenceExceeds(w->launch_time, now,
wal_receiver_timeout))
{
elog(WARNING,
"logical replication worker for subscription %u took too long to start; canceled",
w->subid);
logicalrep_worker_cleanup(w);
did_cleanup = true;
}
}
if (did_cleanup)
goto retry;
}
/*
* If we reached the sync worker limit per subscription, just exit
* silently as we might get here because of an otherwise harmless race
* condition.
*/
if (nsyncworkers >= max_sync_workers_per_subscription)
{
LWLockRelease(LogicalRepWorkerLock);
return;
}
/*
* However if there are no more free worker slots, inform user about it
* before exiting.
*/
if (worker == NULL)
{
LWLockRelease(LogicalRepWorkerLock);
ereport(WARNING,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("out of logical replication worker slots"),
errhint("You might need to increase max_logical_replication_workers.")));
return;
}
/* Prepare the worker slot. */
worker->launch_time = now;
worker->in_use = true;
worker->generation++;
worker->proc = NULL;
worker->dbid = dbid;
worker->userid = userid;
worker->subid = subid;
worker->relid = relid;
worker->relstate = SUBREL_STATE_UNKNOWN;
worker->relstate_lsn = InvalidXLogRecPtr;
worker->last_lsn = InvalidXLogRecPtr;
TIMESTAMP_NOBEGIN(worker->last_send_time);
TIMESTAMP_NOBEGIN(worker->last_recv_time);
worker->reply_lsn = InvalidXLogRecPtr;
TIMESTAMP_NOBEGIN(worker->reply_time);
/* Before releasing lock, remember generation for future identification. */
generation = worker->generation;
LWLockRelease(LogicalRepWorkerLock);
/* Register the new dynamic worker. */
memset(&bgw, 0, sizeof(bgw));
bgw.bgw_flags = BGWORKER_SHMEM_ACCESS |
BGWORKER_BACKEND_DATABASE_CONNECTION;
bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ApplyWorkerMain");
if (OidIsValid(relid))
snprintf(bgw.bgw_name, BGW_MAXLEN,
"logical replication worker for subscription %u sync %u", subid, relid);
else
snprintf(bgw.bgw_name, BGW_MAXLEN,
"logical replication worker for subscription %u", subid);
snprintf(bgw.bgw_type, BGW_MAXLEN, "logical replication worker");
bgw.bgw_restart_time = BGW_NEVER_RESTART;
bgw.bgw_notify_pid = MyProcPid;
bgw.bgw_main_arg = Int32GetDatum(slot);
if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
{
/* Failed to start worker, so clean up the worker slot. */
LWLockAcquire(LogicalRepWorkerLock, LW_EXCLUSIVE);
Assert(generation == worker->generation);
logicalrep_worker_cleanup(worker);
LWLockRelease(LogicalRepWorkerLock);
ereport(WARNING,
(errcode(ERRCODE_CONFIGURATION_LIMIT_EXCEEDED),
errmsg("out of background worker slots"),
errhint("You might need to increase max_worker_processes.")));
return;
}
/* Now wait until it attaches. */
WaitForReplicationWorkerAttach(worker, generation, bgw_handle);
}
