From 16a4e4aecd47da7a6c4e1ebc20f6dd1a13f9133b Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Thu, 19 Dec 2019 14:56:20 -0500 Subject: Extend the ProcSignal mechanism to support barriers. A new function EmitProcSignalBarrier() can be used to emit a global barrier which all backends that participate in the ProcSignal mechanism must absorb, and a new function WaitForProcSignalBarrier() can be used to wait until all relevant backends have in fact absorbed the barrier. This can be used to coordinate global state changes, such as turning checksums on while the system is running. There's no real client of this mechanism yet, although two are proposed, but an enum has to have at least one element, so this includes a placeholder type (PROCSIGNAL_BARRIER_PLACEHOLDER) which should be replaced by the first real client of this mechanism to get committed. Andres Freund and Robert Haas, reviewed by Daniel Gustafsson and, in earlier versions, by Magnus Hagander. Discussion: http://postgr.es/m/CA+TgmoZwDk=BguVDVa+qdA6SBKef=PKbaKDQALTC_9qoz1mJqg@mail.gmail.com --- doc/src/sgml/monitoring.sgml | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'doc/src') diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index a3c5f86b7e8..dcb58115af7 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1473,7 +1473,7 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser Waiting to apply WAL at recovery because it is delayed. - IO + IO BufFileRead Waiting for a read from a buffered file. @@ -1593,6 +1593,10 @@ postgres 27093 0.0 0.0 30096 2752 ? Ss 11:34 0:00 postgres: ser LogicalRewriteWrite Waiting for a write of logical rewrite mappings. + + ProcSignalBarrier + Waiting for a barrier event to be processed by all backends. + RelationMapRead Waiting for a read of the relation map file. -- cgit v1.2.3