erts: Add port monitors

* erlang:monitor/2 with port argument is added, erlang:demonitor, using port task API and avoiding locking;
* port_info and process_info support for monitored ports (with named port monitors support);
* Exit signals contain type 'process' or 'port';
* Propagation of port exit signals;
* Self-cleaning when origin process dies with monitor on;
* 8 test cases + testcase for port driver crashing;
* Documentation for all of the above (monitor, demonitor, port_info and process_info) updated

1 files changed, 6 insertions, 0 deletions

diff --git a/erts/emulator/beam/erl_bif_port.c b/erts/emulator/beam/erl_bif_port.c
index 37f4e1de49..208935bed9 100644
--- a/erts/emulator/beam/erl_bif_port.c
+++ b/erts/emulator/beam/erl_bif_port.c
@@ -139,6 +139,12 @@ sig_lookup_port(Process *c_p, Eterm id_or_name)
     return lookup_port(c_p, id_or_name, ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
 }
 
+/* Non-inline copy of sig_lookup_port to be exported */
+Port *erts_sig_lookup_port(Process *c_p, Eterm id_or_name)
+{
+    return lookup_port(c_p, id_or_name, ERTS_PORT_SFLGS_INVALID_DRIVER_LOOKUP);
+}
+
 static ERTS_INLINE Port *
 data_lookup_port(Process *c_p, Eterm id_or_name)
 {