core: send out "Reloading" signal before and after doing a full reload/reexec of PID 1

Since we'll unload all units/job during a reload, and then readd them it
is really useful for clients to be aware of this phase hence sent a
signal out before and after. This signal is called "Reloading" (despite
the fact that it is also sent out during reexecution, which we consider
a special case in this context) and has one boolean parameter which is
true for the signal sent before the reload, and false for the signal
after the reload. The UnitRemoved/JobRremoved and UnitNew/JobNew due to
the reloading are guranteed to be between the pair of Reloading
messages.

1 files changed, 4 insertions, 3 deletions

diff --git a/src/core/main.c b/src/core/main.c
index 1d188e0bfe..efc5791bbc 100644
--- a/src/core/main.c
+++ b/src/core/main.c
@@ -1055,15 +1055,16 @@ static int prepare_reexecute(Manager *m, FILE **_f, FDSet **_fds, bool switching
         assert(_f);
         assert(_fds);
 
-        /* Make sure nothing is really destructed when we shut down */
-        m->n_reloading ++;
-
         r = manager_open_serialization(m, &f);
         if (r < 0) {
                 log_error("Failed to create serialization file: %s", strerror(-r));
                 goto fail;
         }
 
+        /* Make sure nothing is really destructed when we shut down */
+        m->n_reloading ++;
+        bus_broadcast_reloading(m, true);
+
         fds = fdset_new();
         if (!fds) {
                 r = -ENOMEM;