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_PP(0);
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
if (rel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is a partitioned table",
RelationGetRelationName(rel)),
errdetail("Partitioned tables do not contain rows.")));
else if (rel->rd_rel->relkind != RELKIND_RELATION)
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
errmsg("\"%s\" is not a table",
RelationGetRelationName(rel))));
/*
* check permissions: must have SELECT on table or be in
* pg_stat_scan_tables
*/
aclresult = pg_class_aclcheck(RelationGetRelid(rel), GetUserId(),
ACL_SELECT);
if (aclresult != ACLCHECK_OK)
aclresult = is_member_of_role(GetUserId(), DEFAULT_ROLE_STAT_SCAN_TABLES) ? ACLCHECK_OK : ACLCHECK_NO_PRIV;
if (aclresult != ACLCHECK_OK)
aclcheck_error(aclresult, get_relkind_objtype(rel->rd_rel->relkind),
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.
*/
if (htsu == HeapTupleBeingUpdated)
{
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 = HEAP_LOCKED_UPGRADED(infomask);
nmembers = GetMultiXactIdMembers(xmax, &members, allow_old,
false);
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);
table_close(mydata->rel, AccessShareLock);
SRF_RETURN_DONE(funcctx);
}
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, SnapshotNow, 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)
{
/* must hold a buffer lock to call HeapTupleSatisfiesUpdate */
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_SHARE);
if (HeapTupleSatisfiesUpdate(rel, tuple->t_data,
GetCurrentCommandId(/*false*/),
scan->rs_cbuf) == HeapTupleBeingUpdated)
{
char **values;
int i;
values = (char **) palloc(mydata->ncolumns * sizeof(char *));
i = 0;
values[i++] = (char *) DirectFunctionCall1(tidout, PointerGetDatum(&tuple->t_self));
if (tuple->t_data->t_infomask & HEAP_XMAX_SHARED_LOCK)
values[i++] = pstrdup("Shared");
else
values[i++] = pstrdup("Exclusive");
values[i] = palloc(NCHARS * sizeof(char));
snprintf(values[i++], NCHARS, "%d", HeapTupleHeaderGetXmax(tuple->t_data));
if (tuple->t_data->t_infomask & HEAP_XMAX_IS_MULTI)
{
TransactionId *xids;
int nxids;
int j;
int isValidXid = 0; /* any valid xid ever exists? */
values[i++] = pstrdup("true");
nxids = GetMultiXactIdMembers(HeapTupleHeaderGetXmax(tuple->t_data), &xids);
if (nxids == -1)
{
elog(ERROR, "GetMultiXactIdMembers returns error");
}
values[i] = palloc(NCHARS * nxids);
values[i + 1] = palloc(NCHARS * nxids);
strcpy(values[i], "{");
strcpy(values[i + 1], "{");
for (j = 0; j < nxids; j++)
{
char buf[NCHARS];
if (TransactionIdIsInProgress(xids[j]))
{
if (isValidXid)
{
strcat(values[i], ",");
strcat(values[i + 1], ",");
}
snprintf(buf, NCHARS, "%d", xids[j]);
strcat(values[i], buf);
snprintf(buf, NCHARS, "%d", BackendXidGetPid(xids[j]));
strcat(values[i + 1], buf);
isValidXid = 1;
}
}
strcat(values[i], "}");
strcat(values[i + 1], "}");
i++;
}
else
{
values[i++] = pstrdup("false");
values[i] = palloc(NCHARS * sizeof(char));
snprintf(values[i++], NCHARS, "{%d}", HeapTupleHeaderGetXmax(tuple->t_data));
values[i] = palloc(NCHARS * sizeof(char));
snprintf(values[i++], NCHARS, "{%d}", BackendXidGetPid(HeapTupleHeaderGetXmax(tuple->t_data)));
}
LockBuffer(scan->rs_cbuf, BUFFER_LOCK_UNLOCK);
/* build a tuple */
tuple = BuildTupleFromCStrings(attinmeta, values);
/* make the tuple into a datum */
result = HeapTupleGetDatum(tuple);
/* Clean up */
for (i = 0; i < mydata->ncolumns; i++)
pfree(values[i]);
pfree(values);
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);
}