postmaster: Adjust which processes we expect to have exited

Comments and code stated that we expect checkpointer to have been signalled in
case of immediate shutdown / fatal errors, but didn't treat archiver and
walsenders the same. That doesn't seem right.

I had started digging through the history to see where this oddity was
introduced, but it's not the fault of a single commit.

Instead treat archiver, checkpointer, and walsenders the same.

Reviewed-by: Bertrand Drouvot <bertranddrouvot.pg@gmail.com>
Discussion: https://postgr.es/m/kgng5nrvnlv335evmsuvpnh354rw7qyazl73kdysev2cr2v5zu@m3cfzxicm5kp

diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index 29624fa06bf3d89197836a5fcd0b4c09f42e9fb2..f410600f7a4ed385055fa5a3bd2d18e25a12d047 100644 (file)
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -2919,16 +2919,20 @@ PostmasterStateMachine(void)
 
        /*
         * If we are doing crash recovery or an immediate shutdown then we
-        * expect the checkpointer to exit as well, otherwise not.
+        * expect archiver, checkpointer and walsender to exit as well,
+        * otherwise not.
         */
        if (FatalError || Shutdown >= ImmediateShutdown)
-           targetMask = btmask_add(targetMask, B_CHECKPOINTER);
+           targetMask = btmask_add(targetMask,
+                                   B_CHECKPOINTER,
+                                   B_ARCHIVER,
+                                   B_WAL_SENDER);
 
        /*
-        * Walsenders and archiver will continue running; they will be
-        * terminated later after writing the checkpoint record.  We also let
-        * dead-end children to keep running for now.  The syslogger process
-        * exits last.
+        * Normally walsenders and archiver will continue running; they will
+        * be terminated later after writing the checkpoint record.  We also
+        * let dead-end children to keep running for now.  The syslogger
+        * process exits last.
         *
         * This assertion checks that we have covered all backend types,
         * either by including them in targetMask, or by noting here that they
@@ -2939,13 +2943,17 @@ PostmasterStateMachine(void)
            BackendTypeMask remainMask = BTYPE_MASK_NONE;
 
            remainMask = btmask_add(remainMask,
-                                   B_WAL_SENDER,
-                                   B_ARCHIVER,
                                    B_DEAD_END_BACKEND,
                                    B_LOGGER);
 
-           /* checkpointer may or may not be in targetMask already */
-           remainMask = btmask_add(remainMask, B_CHECKPOINTER);
+           /*
+            * Archiver, checkpointer and walsender may or may not be in
+            * targetMask already.
+            */
+           remainMask = btmask_add(remainMask,
+                                   B_ARCHIVER,
+                                   B_CHECKPOINTER,
+                                   B_WAL_SENDER);
 
            /* these are not real postmaster children */
            remainMask = btmask_add(remainMask,