Fix assertion failure by an immediate shutdown.

In PM_WAIT_DEAD_END state, checkpointer process must be dead already.
But an immediate shutdown could make postmaster's state machine
transition to PM_WAIT_DEAD_END state even if checkpointer process is
still running,  and which caused assertion failure. This bug was introduced
in commit 457d6cf049c57cabe9b46ea13f26138040a214ec.

This patch ensures that postmaster's state machine doesn't transition to
PM_WAIT_DEAD_END state in an immediate shutdown while checkpointer
process is running.

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index e6d750d4d3847d33ecb25ba851933813724c4983..5a816a2d3a78e2f5332f75e92f32d2b3db5356f6 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -3328,19 +3328,21 @@ PostmasterStateMachine(void)
                 * PM_WAIT_BACKENDS state ends when we have no regular backends
                 * (including autovac workers), no bgworkers (including unconnected
                 * ones), and no walwriter, autovac launcher or bgwriter.  If we are
-                * doing crash recovery then we expect the checkpointer to exit as
-                * well, otherwise not. The archiver, stats, and syslogger processes
-                * are disregarded since they are not connected to shared memory; we
-                * also disregard dead_end children here. Walsenders are also
-                * disregarded, they will be terminated later after writing the
-                * checkpoint record, like the archiver process.
+                * doing crash recovery or an immediate shutdown then we expect
+                * the checkpointer to exit as well, otherwise not. The archiver,
+                * stats, and syslogger processes are disregarded since
+                * they are not connected to shared memory; we also disregard
+                * dead_end children here. Walsenders are also disregarded,
+                * they will be terminated later after writing the checkpoint record,
+                * like the archiver process.
                 */
                if (CountChildren(BACKEND_TYPE_NORMAL | BACKEND_TYPE_WORKER) == 0 &&
                        CountUnconnectedWorkers() == 0 &&
                        StartupPID == 0 &&
                        WalReceiverPID == 0 &&
                        BgWriterPID == 0 &&
-                       (CheckpointerPID == 0 || !FatalError) &&
+                       (CheckpointerPID == 0 ||
+                        (!FatalError && Shutdown < ImmediateShutdown)) &&
                        WalWriterPID == 0 &&
                        AutoVacPID == 0)
                {