1 files changed, 47 insertions, 2 deletions
diff --git a/lib/observer/test/crashdump_helper.erl b/lib/observer/test/crashdump_helper.erl
index 145ff56b71..576d112154 100644
--- a/lib/observer/test/crashdump_helper.erl
+++ b/lib/observer/test/crashdump_helper.erl
@@ -21,7 +21,9 @@
 -module(crashdump_helper).
 -export([n1_proc/2,remote_proc/2,
          dump_maps/0,create_maps/0,
-         create_binaries/0,create_sub_binaries/1]).
+         create_binaries/0,create_sub_binaries/1,
+         dump_persistent_terms/0,
+         create_persistent_terms/0]).
 -compile(r18).
 -include_lib("common_test/include/ct.hrl").
 
@@ -142,4 +144,47 @@ create_maps() ->
     Map3 = lists:foldl(fun(I, A) ->
                                A#{I=>I*I}
                        end, Map2, lists:seq(-10, 0)),
-    #{a=>Map0,b=>Map1,c=>Map2,d=>Map3,e=>#{}}.
+    #{a=>Map0,b=>Map1,c=>Map2,d=>Map3,e=>#{},literal=>literal_map()}.
+
+literal_map() ->
+    %% A literal map such as the one below will produce a heap dump
+    %% like this:
+    %%
+    %%   Address1:t4:H<Address3>,H<Address4>,H<Address5>,H<Address6>
+    %%   Address2:Mf4:H<Adress1>:I1,I2,I3,I4
+    %%   Address3: ...  % "one"
+    %%   Address4: ...  % "two"
+    %%   Address5: ...  % "three"
+    %%   Address6: ...  % "four"
+    %%
+    %% The map cannot be reconstructed in a single sequential pass.
+    %%
+    %% To reconstruct the map, first the string keys "one"
+    %% through "four" must be reconstructed, then the tuple at
+    %% Adress1, then the map at Address2.
+
+    #{"one"=>1,"two"=>2,"three"=>3,"four"=>4}.
+
+%%%
+%%% Test dumping of persistent terms (from OTP 21.2).
+%%%
+
+dump_persistent_terms() ->
+    Parent = self(),
+    F = fun() ->
+                register(aaaaaaaa_persistent_terms, self()),
+                put(pts, create_persistent_terms()),
+                Parent ! {self(),done},
+                receive _ -> ok end
+        end,
+    Pid = spawn_link(F),
+    receive
+        {Pid,done} ->
+            {ok,Pid}
+    end.
+
+create_persistent_terms() ->
+    persistent_term:put({?MODULE,first}, {pid,42.0}),
+    persistent_term:put({?MODULE,second}, [1,2,3]),
+    persistent_term:get().
+