From 5db4fdc22472919f97ce83d276fb34b47c794d1f Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Thu, 7 Jan 2021 11:45:09 -0500 Subject: [PATCH] Further second thoughts about idle_session_timeout patch. On reflection, the order of operations in PostgresMain() is wrong. These timeouts ought to be shut down before, not after, we do the post-command-read CHECK_FOR_INTERRUPTS, to guarantee that any timeout error will be detected there rather than at some ill-defined later point (possibly after having wasted a lot of work). This is really an error in the original idle_in_transaction_timeout patch, so back-patch to 9.6 where that was introduced. --- src/backend/tcop/postgres.c | 22 ++++++++++++---------- 1 file changed, 12 insertions(+), 10 deletions(-) diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c index 899723470d..174c72a14b 100644 --- a/src/backend/tcop/postgres.c +++ b/src/backend/tcop/postgres.c @@ -4269,7 +4269,18 @@ PostgresMain(int argc, char *argv[], firstchar = ReadCommand(&input_message); /* - * (4) disable async signal conditions again. + * (4) turn off the idle-in-transaction timeout, if active. We do + * this before step (5) so that any last-moment timeout is certain to + * be detected in step (5). + */ + if (disable_idle_in_transaction_timeout) + { + disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false); + disable_idle_in_transaction_timeout = false; + } + + /* + * (5) disable async signal conditions again. * * Query cancel is supposed to be a no-op when there is no query in * progress, so if a query cancel arrived while we were idle, just @@ -4280,15 +4291,6 @@ PostgresMain(int argc, char *argv[], CHECK_FOR_INTERRUPTS(); DoingCommandRead = false; - /* - * (5) turn off the idle-in-transaction timeout - */ - if (disable_idle_in_transaction_timeout) - { - disable_timeout(IDLE_IN_TRANSACTION_SESSION_TIMEOUT, false); - disable_idle_in_transaction_timeout = false; - } - /* * (6) check for any other interesting events that happened while we * slept.