Datum
pgrowlocks(PG_FUNCTION_ARGS)
{
FuncCallContext *funcctx;
HeapScanDesc scan;
HeapTuple tuple;
TupleDesc tupdesc;
AttInMetadata *attinmeta;
Datum result;
MyData *mydata;
Relation rel;
if (SRF_IS_FIRSTCALL())
{
text *relname;
RangeVar *relrv;
MemoryContext oldcontext;
AclResult aclresult;
funcctx = SRF_FIRSTCALL_INIT();
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* Build a tuple descriptor for our result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
attinmeta = TupleDescGetAttInMetadata(tupdesc);
funcctx->attinmeta = attinmeta;
relname = PG_GETARG_TEXT_P(0);
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = heap_openrv(relrv, AccessShareLock);
/* check permissions: must have SELECT on table */
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
ACL_SELECT);
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, ACL_KIND_CLASS,
RelationGetRelationName(rel));
scan = heap_beginscan(rel, GetActiveSnapshot(), 0, NULL);
mydata = palloc(sizeof(*mydata));
mydata->rel = rel;
mydata->scan = scan;
mydata->ncolumns = tupdesc->natts;
funcctx->user_fctx = mydata;
MemoryContextSwitchTo(oldcontext);
}
funcctx = SRF_PERCALL_SETUP();
attinmeta = funcctx->attinmeta;
mydata = (MyData *) funcctx->user_fctx;
scan = mydata->scan;
/* scan the relation */
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
HTSU_Result htsu;
TransactionId xmax;
uint16 infomask;
/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
htsu = HeapTupleSatisfiesUpdate(tuple,
GetCurrentCommandId(false),
scan->rs_cbuf);
xmax = HeapTupleHeaderGetRawXmax(tuple->t_data);
infomask = tuple->t_data->t_infomask;
/*
* a tuple is locked if HTSU returns BeingUpdated, and if it returns
* MayBeUpdated but the Xmax is valid and pointing at us.
*/
if (htsu == HeapTupleBeingUpdated ||
(htsu == HeapTupleMayBeUpdated &&
!(infomask & HEAP_XMAX_INVALID) &&
!(infomask & HEAP_XMAX_IS_MULTI) &&
(xmax == GetCurrentTransactionIdIfAny())))
{
char **values;
values = (char **) palloc(mydata->ncolumns * sizeof(char *));
values[Atnum_tid] = (char *) DirectFunctionCall1(tidout,
PointerGetDatum(&tuple->t_self));
values[Atnum_xmax] = palloc(NCHARS * sizeof(char));
snprintf(values[Atnum_xmax], NCHARS, "%d", xmax);
if (infomask & HEAP_XMAX_IS_MULTI)
{
MultiXactMember *members;
int nmembers;
bool first = true;
bool allow_old;
values[Atnum_ismulti] = pstrdup("true");
allow_old = !(infomask & HEAP_LOCK_MASK) &&
(infomask & HEAP_XMAX_LOCK_ONLY);
nmembers = GetMultiXactIdMembers(xmax, &members, allow_old);
if (nmembers == -1)
{
values[Atnum_xids] = "{0}";
values[Atnum_modes] = "{transient upgrade status}";
values[Atnum_pids] = "{0}";
}
else
{
int j;
values[Atnum_xids] = palloc(NCHARS * nmembers);
values[Atnum_modes] = palloc(NCHARS * nmembers);
values[Atnum_pids] = palloc(NCHARS * nmembers);
strcpy(values[Atnum_xids], "{");
strcpy(values[Atnum_modes], "{");
strcpy(values[Atnum_pids], "{");
for (j = 0; j < nmembers; j++)
{
char buf[NCHARS];
if (!first)
{
strcat(values[Atnum_xids], ",");
strcat(values[Atnum_modes], ",");
strcat(values[Atnum_pids], ",");
}
snprintf(buf, NCHARS, "%d", members[j].xid);
strcat(values[Atnum_xids], buf);
switch (members[j].status)
{
case MultiXactStatusUpdate:
snprintf(buf, NCHARS, "Update");
break;
case MultiXactStatusNoKeyUpdate:
snprintf(buf, NCHARS, "No Key Update");
break;
case MultiXactStatusForUpdate:
snprintf(buf, NCHARS, "For Update");
break;
case MultiXactStatusForNoKeyUpdate:
snprintf(buf, NCHARS, "For No Key Update");
break;
case MultiXactStatusForShare:
snprintf(buf, NCHARS, "Share");
break;
case MultiXactStatusForKeyShare:
snprintf(buf, NCHARS, "Key Share");
break;
}
strcat(values[Atnum_modes], buf);
snprintf(buf, NCHARS, "%d",
BackendXidGetPid(members[j].xid));
strcat(values[Atnum_pids], buf);
first = false;
}
strcat(values[Atnum_xids], "}");
strcat(values[Atnum_modes], "}");
strcat(values[Atnum_pids], "}");
}
}
else
{
values[Atnum_ismulti] = pstrdup("false");
values[Atnum_xids] = palloc(NCHARS * sizeof(char));
snprintf(values[Atnum_xids], NCHARS, "{%d}", xmax);
values[Atnum_modes] = palloc(NCHARS);
if (infomask & HEAP_XMAX_LOCK_ONLY)
{
if (HEAP_XMAX_IS_SHR_LOCKED(infomask))
snprintf(values[Atnum_modes], NCHARS, "{For Share}");
else if (HEAP_XMAX_IS_KEYSHR_LOCKED(infomask))
snprintf(values[Atnum_modes], NCHARS, "{For Key Share}");
else if (HEAP_XMAX_IS_EXCL_LOCKED(infomask))
{
if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
snprintf(values[Atnum_modes], NCHARS, "{For Update}");
else
snprintf(values[Atnum_modes], NCHARS, "{For No Key Update}");
}
else
/* neither keyshare nor exclusive bit it set */
snprintf(values[Atnum_modes], NCHARS,
"{transient upgrade status}");
}
else
{
if (tuple->t_data->t_infomask2 & HEAP_KEYS_UPDATED)
snprintf(values[Atnum_modes], NCHARS, "{Update}");
else
snprintf(values[Atnum_modes], NCHARS, "{No Key Update}");
}
values[Atnum_pids] = palloc(NCHARS * sizeof(char));
snprintf(values[Atnum_pids], NCHARS, "{%d}",
BackendXidGetPid(xmax));
}
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
/* build a tuple */
tuple = BuildTupleFromCStrings(attinmeta, values);
/* make the tuple into a datum */
result = HeapTupleGetDatum(tuple);
/*
* no need to pfree what we allocated; it's on a short-lived
* memory context anyway
*/
SRF_RETURN_NEXT(funcctx, result);
}
else
{
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
}
}
heap_endscan(scan);
heap_close(mydata->rel, AccessShareLock);
SRF_RETURN_DONE(funcctx);
}
/*
* Assemble a WAL record from the registered data and buffers into an
* XLogRecData chain, ready for insertion with XLogInsertRecord().
*
* The record header fields are filled in, except for the xl_prev field. The
* calculated CRC does not include the record header yet.
*
* If there are any registered buffers, and a full-page image was not taken
* of all of them, *fpw_lsn is set to the lowest LSN among such pages. This
* signals that the assembled record is only good for insertion on the
* assumption that the RedoRecPtr and doPageWrites values were up-to-date.
*/
static XLogRecData *
XLogRecordAssemble(RmgrId rmid, uint8 info,
XLogRecPtr RedoRecPtr, bool doPageWrites,
XLogRecPtr *fpw_lsn)
{
XLogRecData *rdt;
uint32 total_len = 0;
int block_id;
pg_crc32c rdata_crc;
registered_buffer *prev_regbuf = NULL;
XLogRecData *rdt_datas_last;
XLogRecord *rechdr;
char *scratch = hdr_scratch;
/*
* Note: this function can be called multiple times for the same record.
* All the modifications we do to the rdata chains below must handle that.
*/
/* The record begins with the fixed-size header */
rechdr = (XLogRecord *) scratch;
scratch += SizeOfXLogRecord;
hdr_rdt.next = NULL;
rdt_datas_last = &hdr_rdt;
hdr_rdt.data = hdr_scratch;
/*
* Make an rdata chain containing all the data portions of all block
* references. This includes the data for full-page images. Also append
* the headers for the block references in the scratch buffer.
*/
*fpw_lsn = InvalidXLogRecPtr;
for (block_id = 0; block_id < max_registered_block_id; block_id++)
{
registered_buffer *regbuf = ®istered_buffers[block_id];
bool needs_backup;
bool needs_data;
XLogRecordBlockHeader bkpb;
XLogRecordBlockImageHeader bimg;
XLogRecordBlockCompressHeader cbimg = {0};
bool samerel;
bool is_compressed = false;
if (!regbuf->in_use)
continue;
/* Determine if this block needs to be backed up */
if (regbuf->flags & REGBUF_FORCE_IMAGE)
needs_backup = true;
else if (regbuf->flags & REGBUF_NO_IMAGE)
needs_backup = false;
else if (!doPageWrites)
needs_backup = false;
else
{
/*
* We assume page LSN is first data on *every* page that can be
* passed to XLogInsert, whether it has the standard page layout
* or not.
*/
XLogRecPtr page_lsn = PageGetLSN(regbuf->page);
needs_backup = (page_lsn <= RedoRecPtr);
if (!needs_backup)
{
if (*fpw_lsn == InvalidXLogRecPtr || page_lsn < *fpw_lsn)
*fpw_lsn = page_lsn;
}
}
/* Determine if the buffer data needs to included */
if (regbuf->rdata_len == 0)
needs_data = false;
else if ((regbuf->flags & REGBUF_KEEP_DATA) != 0)
needs_data = true;
else
needs_data = !needs_backup;
bkpb.id = block_id;
bkpb.fork_flags = regbuf->forkno;
bkpb.data_length = 0;
if ((regbuf->flags & REGBUF_WILL_INIT) == REGBUF_WILL_INIT)
bkpb.fork_flags |= BKPBLOCK_WILL_INIT;
if (needs_backup)
{
Page page = regbuf->page;
uint16 compressed_len;
/*
* The page needs to be backed up, so calculate its hole length
* and offset.
*/
if (regbuf->flags & REGBUF_STANDARD)
{
/* Assume we can omit data between pd_lower and pd_upper */
uint16 lower = ((PageHeader) page)->pd_lower;
uint16 upper = ((PageHeader) page)->pd_upper;
if (lower >= SizeOfPageHeaderData &&
upper > lower &&
upper <= BLCKSZ)
{
bimg.hole_offset = lower;
cbimg.hole_length = upper - lower;
}
else
{
/* No "hole" to compress out */
bimg.hole_offset = 0;
cbimg.hole_length = 0;
}
}
else
{
/* Not a standard page header, don't try to eliminate "hole" */
bimg.hole_offset = 0;
cbimg.hole_length = 0;
}
/*
* Try to compress a block image if wal_compression is enabled
*/
if (wal_compression)
{
is_compressed =
XLogCompressBackupBlock(page, bimg.hole_offset,
cbimg.hole_length,
regbuf->compressed_page,
&compressed_len);
}
/*
* Fill in the remaining fields in the XLogRecordBlockHeader
* struct
*/
bkpb.fork_flags |= BKPBLOCK_HAS_IMAGE;
/*
* Construct XLogRecData entries for the page content.
*/
rdt_datas_last->next = ®buf->bkp_rdatas[0];
rdt_datas_last = rdt_datas_last->next;
bimg.bimg_info = (cbimg.hole_length == 0) ? 0 : BKPIMAGE_HAS_HOLE;
if (is_compressed)
{
bimg.length = compressed_len;
bimg.bimg_info |= BKPIMAGE_IS_COMPRESSED;
rdt_datas_last->data = regbuf->compressed_page;
rdt_datas_last->len = compressed_len;
}
else
{
bimg.length = BLCKSZ - cbimg.hole_length;
if (cbimg.hole_length == 0)
{
rdt_datas_last->data = page;
rdt_datas_last->len = BLCKSZ;
}
else
{
/* must skip the hole */
rdt_datas_last->data = page;
rdt_datas_last->len = bimg.hole_offset;
rdt_datas_last->next = ®buf->bkp_rdatas[1];
rdt_datas_last = rdt_datas_last->next;
rdt_datas_last->data =
page + (bimg.hole_offset + cbimg.hole_length);
rdt_datas_last->len =
BLCKSZ - (bimg.hole_offset + cbimg.hole_length);
}
}
total_len += bimg.length;
}
if (needs_data)
{
/*
* Link the caller-supplied rdata chain for this buffer to the
* overall list.
*/
bkpb.fork_flags |= BKPBLOCK_HAS_DATA;
bkpb.data_length = regbuf->rdata_len;
total_len += regbuf->rdata_len;
rdt_datas_last->next = regbuf->rdata_head;
rdt_datas_last = regbuf->rdata_tail;
}
if (prev_regbuf && RelFileNodeEquals(regbuf->rnode, prev_regbuf->rnode))
{
samerel = true;
bkpb.fork_flags |= BKPBLOCK_SAME_REL;
}
else
samerel = false;
prev_regbuf = regbuf;
/* Ok, copy the header to the scratch buffer */
memcpy(scratch, &bkpb, SizeOfXLogRecordBlockHeader);
scratch += SizeOfXLogRecordBlockHeader;
if (needs_backup)
{
memcpy(scratch, &bimg, SizeOfXLogRecordBlockImageHeader);
scratch += SizeOfXLogRecordBlockImageHeader;
if (cbimg.hole_length != 0 && is_compressed)
{
memcpy(scratch, &cbimg,
SizeOfXLogRecordBlockCompressHeader);
scratch += SizeOfXLogRecordBlockCompressHeader;
}
}
if (!samerel)
{
memcpy(scratch, ®buf->rnode, sizeof(RelFileNode));
scratch += sizeof(RelFileNode);
}
memcpy(scratch, ®buf->block, sizeof(BlockNumber));
scratch += sizeof(BlockNumber);
}
/* followed by the record's origin, if any */
if (include_origin && replorigin_sesssion_origin != InvalidRepOriginId)
{
*(scratch++) = XLR_BLOCK_ID_ORIGIN;
memcpy(scratch, &replorigin_sesssion_origin, sizeof(replorigin_sesssion_origin));
scratch += sizeof(replorigin_sesssion_origin);
}
/* followed by main data, if any */
if (mainrdata_len > 0)
{
if (mainrdata_len > 255)
{
*(scratch++) = XLR_BLOCK_ID_DATA_LONG;
memcpy(scratch, &mainrdata_len, sizeof(uint32));
scratch += sizeof(uint32);
}
else
{
*(scratch++) = XLR_BLOCK_ID_DATA_SHORT;
*(scratch++) = (uint8) mainrdata_len;
}
rdt_datas_last->next = mainrdata_head;
rdt_datas_last = mainrdata_last;
total_len += mainrdata_len;
}
rdt_datas_last->next = NULL;
hdr_rdt.len = (scratch - hdr_scratch);
total_len += hdr_rdt.len;
/*
* Calculate CRC of the data
*
* Note that the record header isn't added into the CRC initially since we
* don't know the prev-link yet. Thus, the CRC will represent the CRC of
* the whole record in the order: rdata, then backup blocks, then record
* header.
*/
INIT_CRC32C(rdata_crc);
COMP_CRC32C(rdata_crc, hdr_scratch + SizeOfXLogRecord, hdr_rdt.len - SizeOfXLogRecord);
for (rdt = hdr_rdt.next; rdt != NULL; rdt = rdt->next)
COMP_CRC32C(rdata_crc, rdt->data, rdt->len);
/*
* Fill in the fields in the record header. Prev-link is filled in later,
* once we know where in the WAL the record will be inserted. The CRC does
* not include the record header yet.
*/
rechdr->xl_xid = GetCurrentTransactionIdIfAny();
rechdr->xl_tot_len = total_len;
rechdr->xl_info = info;
rechdr->xl_rmid = rmid;
rechdr->xl_prev = InvalidXLogRecPtr;
rechdr->xl_crc = rdata_crc;
return &hdr_rdt;
}
static void
DtmXactCallback(XactEvent event, void *arg)
{
//XTM_INFO("%d: DtmXactCallbackevent=%d nextxid=%d\n", getpid(), event, DtmNextXid);
switch (event)
{
case XACT_EVENT_START:
//XTM_INFO("%d: normal=%d, initialized=%d, replication=%d, bgw=%d, vacuum=%d\n",
// getpid(), IsNormalProcessingMode(), dtm->initialized, MMDoReplication, IsBackgroundWorker, IsAutoVacuumWorkerProcess());
if (IsNormalProcessingMode() && dtm->initialized && MMDoReplication && !am_walsender && !IsBackgroundWorker && !IsAutoVacuumWorkerProcess()) {
MMBeginTransaction();
}
break;
#if 0
case XACT_EVENT_PRE_COMMIT:
case XACT_EVENT_PARALLEL_PRE_COMMIT:
{
TransactionId xid = GetCurrentTransactionIdIfAny();
if (!MMIsDistributedTrans && TransactionIdIsValid(xid)) {
XTM_INFO("%d: Will ignore transaction %u\n", getpid(), xid);
MMMarkTransAsLocal(xid);
}
break;
}
#endif
case XACT_EVENT_COMMIT:
case XACT_EVENT_ABORT:
if (TransactionIdIsValid(DtmNextXid))
{
if (!DtmVoted) {
ArbiterSetTransStatus(DtmNextXid, TRANSACTION_STATUS_ABORTED, false);
}
if (event == XACT_EVENT_COMMIT)
{
/*
* Now transaction status is already written in CLOG,
* so we can remove information about it from hash table
*/
LWLockAcquire(dtm->hashLock, LW_EXCLUSIVE);
hash_search(xid_in_doubt, &DtmNextXid, HASH_REMOVE, NULL);
LWLockRelease(dtm->hashLock);
}
#if 0 /* should be handled now using DtmVoted flag */
else
{
/*
* Transaction at the node can be aborted because of transaction failure at some other node
* before it starts doing anything and assigned Xid, in this case Postgres is not calling SetTransactionStatus,
* so we have to send report to DTMD here
*/
if (!TransactionIdIsValid(GetCurrentTransactionIdIfAny())) {
XTM_INFO("%d: abort transation on DTMD\n", getpid());
ArbiterSetTransStatus(DtmNextXid, TRANSACTION_STATUS_ABORTED, false);
}
}
#endif
DtmNextXid = InvalidTransactionId;
DtmLastSnapshot = NULL;
}
MMIsDistributedTrans = false;
break;
default:
break;
}
}
