On Fri, Jul 1, 2016 at 8:50 AM, Michael Paquier
<[email protected]> wrote:
> On Fri, Jul 1, 2016 at 8:48 AM, Alvaro Herrera <[email protected]>
> wrote:
>> Michael Paquier wrote:
>>> Yeah, I know. Now my opinion regarding this view is that we should
>>> show information about a currently-working WAL receiver, and that it
>>> has nothing to do with reporting information of its previous startup state.
>>> That's more consistent with the WAL sender.
>>
>> Okay, that argument I buy.
>>
>> I suppose this function/view should report no row at all if there is no
>> wal receiver connected, rather than a view with nulls.
>
> The function returns PG_RETURN_NULL() so as we don't have to use a
> SRF, and the view checks for IS NOT NULL, so there would be no rows
> popping up.
In short, I would just go with the attached and call it a day.
--
Michael
diff --git a/src/backend/replication/walreceiver.c b/src/backend/replication/walreceiver.c
index d552f04..9d858ce 100644
--- a/src/backend/replication/walreceiver.c
+++ b/src/backend/replication/walreceiver.c
@@ -770,6 +770,7 @@ WalRcvDie(int code, Datum arg)
Assert(walrcv->pid == MyProcPid);
walrcv->walRcvState = WALRCV_STOPPED;
walrcv->pid = 0;
+ walrcv->ready_to_display = false;
SpinLockRelease(&walrcv->mutex);
/* Terminate the connection gracefully. */
@@ -1344,24 +1345,9 @@ pg_stat_get_wal_receiver(PG_FUNCTION_ARGS)
char *conninfo;
/* No WAL receiver, just return a tuple with NULL values */
- if (walrcv->pid == 0)
+ if (walrcv->pid == 0 || !walrcv->ready_to_display)
PG_RETURN_NULL();
- /*
- * Users attempting to read this data mustn't be shown security sensitive
- * data, so sleep until everything has been properly obfuscated.
- */
-retry:
- SpinLockAcquire(&walrcv->mutex);
- if (!walrcv->ready_to_display)
- {
- SpinLockRelease(&walrcv->mutex);
- CHECK_FOR_INTERRUPTS();
- pg_usleep(1000);
- goto retry;
- }
- SpinLockRelease(&walrcv->mutex);
-
/* determine result type */
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
--
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