erts: Add garbage_collection_info to process_info/2

This info request returns greater details about the current
gc state. This info is not included in the default process_info/1
as it would clutter the default printout with too much information.

1 files changed, 29 insertions, 1 deletions

diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c
index 1eb106a551..855ef8742a 100644
--- a/erts/emulator/beam/erl_bif_info.c
+++ b/erts/emulator/beam/erl_bif_info.c
@@ -589,7 +589,8 @@ static Eterm pi_args[] = {
     am_min_bin_vheap_size,
     am_current_location,
     am_current_stacktrace,
-    am_off_heap_message_queue
+    am_off_heap_message_queue,
+    am_garbage_collection_info
 };
 
 #define ERTS_PI_ARGS ((int) (sizeof(pi_args)/sizeof(Eterm)))
@@ -638,6 +639,7 @@ pi_arg2ix(Eterm arg)
     case am_current_location:			return 29;
     case am_current_stacktrace:			return 30;
     case am_off_heap_message_queue:		return 31;
+    case am_garbage_collection_info:		return 32;
     default:					return -1;
     }
 }
@@ -1395,6 +1397,32 @@ process_info_aux(Process *BIF_P,
 	break;
     }
 
+    case am_garbage_collection_info: {
+        Uint sz = 0, actual_sz = 0;
+
+        if (rp == BIF_P) {
+            sz += ERTS_PROCESS_GC_INFO_MAX_SIZE;
+        } else {
+            erts_process_gc_info(rp, &sz, NULL);
+            sz += 3;
+        }
+
+        hp = HAlloc(BIF_P, sz);
+        res = erts_process_gc_info(rp, &actual_sz, &hp);
+
+        /* We may have some extra space, fill with 0 tuples */
+        if (actual_sz <= sz - 3) {
+            for (; actual_sz < sz - 3; hp++, actual_sz++)
+                hp[0] = make_arityval(0);
+        } else {
+            for (; actual_sz < sz; hp++, actual_sz++)
+                hp[0] = make_arityval(0);
+            hp = HAlloc(BIF_P, 3);
+        }
+
+        break;
+    }
+
     case am_group_leader: {
 	int sz = NC_HEAP_SIZE(rp->group_leader);
 	hp = HAlloc(BIF_P, 3 + sz);