erts: Avoid heart killing a nicely exiting emulator

Symptom:
Heart kills exiting emulator before is has flushed all ports
and with HEART_KILL_SIGNAL=SIGABRT it may also produce
unnecessary core dumps from doing init:reboot() for example.

Problem:
Heart port is closed together with all the others in handle_reap_ports()
which is detected by heart OS process.

Solution 1:
Leave the heart port alone in handle_reap_ports() and let it be closed
by OS when emulator exists. It doesn't need to be flushed anyway.

Solution 2:
When heart OS process gets EOF on connection let it wait max 5 seconds
for emulator process to self terminate before trying to kill it.

1 files changed, 7 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_process.c b/erts/emulator/beam/erl_process.c
index ffbfbc4e56..a4f312f101 100644
--- a/erts/emulator/beam/erl_process.c
+++ b/erts/emulator/beam/erl_process.c
@@ -2625,6 +2625,13 @@ handle_reap_ports(ErtsAuxWorkData *awdp, erts_aint32_t aux_work, int waiting)
 
 	    erts_smp_port_lock(prt);
 
+            if (prt->common.u.alive.reg &&
+                prt->common.u.alive.reg->name == am_heart_port) {
+                /* Leave heart port to not get killed before flushing is done*/
+                erts_port_release(prt);
+                continue;
+            }
+
 	    state = erts_atomic32_read_nob(&prt->state);
 	    if (!(state & (ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP
 			   | ERTS_PORT_SFLG_HALT))) {