Have walsenders participate in procsignal infrastructure.

The non-participation in procsignal was a problem for both changes in
master, e.g. parallelism not working for normal statements run in
walsender backends, and older branches, e.g. recovery conflicts and
catchup interrupts not working for logical decoding walsenders.

This commit thus replaces the previous WalSndXLogSendHandler with
procsignal_sigusr1_handler.  In branches since db0f6cad48 that can
lead to additional SetLatch calls, but that only rarely seems to make
a difference.

Author: Andres Freund
Reviewed-By: Michael Paquier
Discussion: https://postgr.es/m/20170421014030.fdzvvvbrz4nckrow@alap3.anarazel.de
Backpatch: 9.4, earlier commits don't seem to benefit sufficiently
This commit is contained in:
Andres Freund 2017-06-05 18:53:42 -07:00
parent b2482ab832
commit e1319f64ec

View File

@ -185,7 +185,6 @@ static XLogRecPtr logical_startptr = InvalidXLogRecPtr;
/* Signal handlers */
static void WalSndSigHupHandler(SIGNAL_ARGS);
static void WalSndXLogSendHandler(SIGNAL_ARGS);
static void WalSndLastCycleHandler(SIGNAL_ARGS);
/* Prototypes for private functions */
@ -2579,17 +2578,6 @@ WalSndSigHupHandler(SIGNAL_ARGS)
errno = save_errno;
}
/* SIGUSR1: set flag to send WAL records */
static void
WalSndXLogSendHandler(SIGNAL_ARGS)
{
int save_errno = errno;
latch_sigusr1_handler();
errno = save_errno;
}
/* SIGUSR2: set flag to do a last cycle and shut down afterwards */
static void
WalSndLastCycleHandler(SIGNAL_ARGS)
@ -2623,7 +2611,7 @@ WalSndSignals(void)
pqsignal(SIGQUIT, quickdie); /* hard crash time */
InitializeTimeouts(); /* establishes SIGALRM handler */
pqsignal(SIGPIPE, SIG_IGN);
pqsignal(SIGUSR1, WalSndXLogSendHandler); /* request WAL sending */
pqsignal(SIGUSR1, procsignal_sigusr1_handler);
pqsignal(SIGUSR2, WalSndLastCycleHandler); /* request a last cycle and
* shutdown */