From 59f71a0d0b56b2df48db4bf1738aece5551f7a47 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Wed, 14 Jan 2015 18:45:22 +0100 Subject: Add a default local latch for use in signal handlers. To do so, move InitializeLatchSupport() into the new common process initialization functions, and add a new global variable MyLatch. MyLatch is usable as soon InitPostmasterChild() has been called (i.e. very early during startup). Initially it points to a process local latch that exists in all processes. InitProcess/InitAuxiliaryProcess then replaces that local latch with PGPROC->procLatch. During shutdown the reverse happens. This is primarily advantageous for two reasons: For one it simplifies dealing with the shared process latch, especially in signal handlers, because instead of having to check for MyProc, MyLatch can be used unconditionally. For another, a later patch that makes FEs/BE communication use latches, now can rely on the existence of a latch, even before having gone through InitProcess. Discussion: 20140927191243.GD5423@alap3.anarazel.de --- src/backend/tcop/postgres.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'src/backend/tcop/postgres.c') diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index f805368899a..8f743536cff 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -2607,8 +2607,7 @@ die(SIGNAL_ARGS) } /* If we're still here, waken anything waiting on the process latch */ - if (MyProc) - SetLatch(&MyProc->procLatch); + SetLatch(MyLatch); errno = save_errno; } @@ -2649,8 +2648,7 @@ StatementCancelHandler(SIGNAL_ARGS) } /* If we're still here, waken anything waiting on the process latch */ - if (MyProc) - SetLatch(&MyProc->procLatch); + SetLatch(MyLatch); errno = save_errno; } @@ -2675,8 +2673,7 @@ SigHupHandler(SIGNAL_ARGS) int save_errno = errno; got_SIGHUP = true; - if (MyProc) - SetLatch(&MyProc->procLatch); + SetLatch(MyLatch); errno = save_errno; } @@ -2814,8 +2811,7 @@ RecoveryConflictInterrupt(ProcSignalReason reason) * waiting on that latch, expecting to get interrupted by query cancels et * al., would also need to set set_latch_on_sigusr1. */ - if (MyProc) - SetLatch(&MyProc->procLatch); + SetLatch(MyLatch); errno = save_errno; } -- cgit v1.2.3