From 9246acbc3fd7ed00de831687c8e504f4d5c46f9e Mon Sep 17 00:00:00 2001 From: Antonin Houska Date: Fri, 5 Jul 2019 16:24:01 +0200 Subject: [PATCH 02/17] Prepare ServerLoop for the next patch. This is only refactoring patch that tries to make the following one easier to read. It simply moves some code from ServerLoop() to ServerLoopCheckTimeouts(). --- src/backend/postmaster/postmaster.c | 110 ++++++++++++++++++++---------------- 1 file changed, 60 insertions(+), 50 deletions(-) diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c index 688ad439ed..e8e3f8a4d3 100644 --- a/src/backend/postmaster/postmaster.c +++ b/src/backend/postmaster/postmaster.c @@ -403,6 +403,7 @@ static void BackendInitialize(Port *port); static void BackendRun(Port *port) pg_attribute_noreturn(); static void ExitPostmaster(int status) pg_attribute_noreturn(); static int ServerLoop(void); +static void ServerLoopCheckTimeouts(void); static int BackendStartup(Port *port); static int ProcessStartupPacket(Port *port, bool secure_done); static void SendNegotiateProtocolVersion(List *unrecognized_protocol_options); @@ -1611,6 +1612,8 @@ DetermineSleepTime(struct timeval *timeout) } } +static time_t last_lockfile_recheck_time, last_touch_time; + /* * Main idle loop of postmaster * @@ -1621,8 +1624,6 @@ ServerLoop(void) { fd_set readmask; int nSockets; - time_t last_lockfile_recheck_time, - last_touch_time; last_lockfile_recheck_time = last_touch_time = time(NULL); @@ -1632,7 +1633,6 @@ ServerLoop(void) { fd_set rmask; int selres; - time_t now; /* * Wait for a connection request to arrive. @@ -1797,58 +1797,68 @@ ServerLoop(void) * us sleep at most that long; except for SIGKILL timeout which has * special-case logic there. */ - now = time(NULL); + ServerLoopCheckTimeouts(); + } +} - /* - * If we already sent SIGQUIT to children and they are slow to shut - * down, it's time to send them SIGKILL. This doesn't happen - * normally, but under certain conditions backends can get stuck while - * shutting down. This is a last measure to get them unwedged. - * - * Note we also do this during recovery from a process crash. - */ - if ((Shutdown >= ImmediateShutdown || (FatalError && !SendStop)) && - AbortStartTime != 0 && - (now - AbortStartTime) >= SIGKILL_CHILDREN_AFTER_SECS) - { - /* We were gentle with them before. Not anymore */ - TerminateChildren(SIGKILL); - /* reset flag so we don't SIGKILL again */ - AbortStartTime = 0; - } +/* + * Subroutine of ServerLoop() that checks if various timeouts elapsed, and if + * so, takes the appropriate action. + */ +static void +ServerLoopCheckTimeouts(void) +{ + time_t now = time(NULL); - /* - * Once a minute, verify that postmaster.pid hasn't been removed or - * overwritten. If it has, we force a shutdown. This avoids having - * postmasters and child processes hanging around after their database - * is gone, and maybe causing problems if a new database cluster is - * created in the same place. It also provides some protection - * against a DBA foolishly removing postmaster.pid and manually - * starting a new postmaster. Data corruption is likely to ensue from - * that anyway, but we can minimize the damage by aborting ASAP. - */ - if (now - last_lockfile_recheck_time >= 1 * SECS_PER_MINUTE) - { - if (!RecheckDataDirLockFile()) - { - ereport(LOG, - (errmsg("performing immediate shutdown because data directory lock file is invalid"))); - kill(MyProcPid, SIGQUIT); - } - last_lockfile_recheck_time = now; - } + /* + * If we already sent SIGQUIT to children and they are slow to shut down, + * it's time to send them SIGKILL. This doesn't happen normally, but + * under certain conditions backends can get stuck while shutting down. + * This is a last measure to get them unwedged. + * + * Note we also do this during recovery from a process crash. + */ + if ((Shutdown >= ImmediateShutdown || (FatalError && !SendStop)) && + AbortStartTime != 0 && + (now - AbortStartTime) >= SIGKILL_CHILDREN_AFTER_SECS) + { + /* We were gentle with them before. Not anymore */ + TerminateChildren(SIGKILL); + /* reset flag so we don't SIGKILL again */ + AbortStartTime = 0; + } - /* - * Touch Unix socket and lock files every 58 minutes, to ensure that - * they are not removed by overzealous /tmp-cleaning tasks. We assume - * no one runs cleaners with cutoff times of less than an hour ... - */ - if (now - last_touch_time >= 58 * SECS_PER_MINUTE) + /* + * Once a minute, verify that postmaster.pid hasn't been removed or + * overwritten. If it has, we force a shutdown. This avoids having + * postmasters and child processes hanging around after their database is + * gone, and maybe causing problems if a new database cluster is created + * in the same place. It also provides some protection against a DBA + * foolishly removing postmaster.pid and manually starting a new + * postmaster. Data corruption is likely to ensue from that anyway, but + * we can minimize the damage by aborting ASAP. + */ + if (now - last_lockfile_recheck_time >= 1 * SECS_PER_MINUTE) + { + if (!RecheckDataDirLockFile()) { - TouchSocketFiles(); - TouchSocketLockFiles(); - last_touch_time = now; + ereport(LOG, + (errmsg("performing immediate shutdown because data directory lock file is invalid"))); + kill(MyProcPid, SIGQUIT); } + last_lockfile_recheck_time = now; + } + + /* + * Touch Unix socket and lock files every 58 minutes, to ensure that they + * are not removed by overzealous /tmp-cleaning tasks. We assume no one + * runs cleaners with cutoff times of less than an hour ... + */ + if (now - last_touch_time >= 58 * SECS_PER_MINUTE) + { + TouchSocketFiles(); + TouchSocketLockFiles(); + last_touch_time = now; } } -- 2.13.7