On 2019-Nov-11, Amit Kapila wrote:
> On Mon, Nov 11, 2019 at 7:53 AM Michael Paquier <[email protected]> wrote:
> > So your suggestion would be to call GetFlushRecPtr() before the first
> > check on RecentFlushPtr and before entering the loop?
>
> No. What I meant was to keep the current code as-is and have an
> additional check on RecentFlushPtr before entering the loop.
I noticed that the "return" at the bottom of the function does a
SetLatch(), but the other returns do not. Isn't that a bug?
Also, what's up with those useless returns?
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
diff --git a/src/backend/replication/walsender.c b/src/backend/replication/walsender.c
index 7f5671504f..771fd353cd 100644
--- a/src/backend/replication/walsender.c
+++ b/src/backend/replication/walsender.c
@@ -1298,22 +1298,31 @@ WalSndWaitForWal(XLogRecPtr loc)
/*
* Fast path to avoid acquiring the spinlock in case we already know we
* have enough WAL available. This is particularly interesting if we're
* far behind.
*/
if (RecentFlushPtr != InvalidXLogRecPtr &&
loc <= RecentFlushPtr)
+ {
+ SetLatch(MyLatch);
return RecentFlushPtr;
+ }
/* Get a more recent flush pointer. */
if (!RecoveryInProgress())
RecentFlushPtr = GetFlushRecPtr();
else
RecentFlushPtr = GetXLogReplayRecPtr(NULL);
+ if (loc <= RecentFlushPtr)
+ {
+ SetLatch(MyLatch);
+ return RecentFlushPtr;
+ }
+
for (;;)
{
long sleeptime;
/* Clear any already-pending wakeups */
ResetLatch(MyLatch);
@@ -2267,15 +2276,14 @@ WalSndLoop(WalSndSendDataCallback send_data)
/* Sleep until something happens or we time out */
(void) WaitLatchOrSocket(MyLatch, wakeEvents,
MyProcPort->sock, sleeptime,
WAIT_EVENT_WAL_SENDER_MAIN);
}
}
- return;
}
/* Initialize a per-walsender data structure for this walsender process */
static void
InitWalSenderSlot(void)
{
int i;
@@ -2797,16 +2805,14 @@ XLogSendPhysical(void)
{
char activitymsg[50];
snprintf(activitymsg, sizeof(activitymsg), "streaming %X/%X",
(uint32) (sentPtr >> 32), (uint32) sentPtr);
set_ps_display(activitymsg, false);
}
-
- return;
}
/*
* Stream out logically decoded data.
*/
static void
XLogSendLogical(void)
