Add compatibility to allow for OTP version advancement

Add compatibility libraries
Add compatibility to random operations
Add compatibility to OTP20 for ssl operations
Update PR to remove rand_compat calls

rebar.config

@@ -1,5 +1,6 @@
 {deps, [
-    {time_compat, "0.0.1"}
+    {time_compat, "0.0.1"},
+    {stacktrace_compat, "1.1.1"}
 ]}.
 
 {erl_opts, [
@@ -11,5 +12,7 @@
   warn_shadow_vars,
   warn_unused_function,
   warn_obsolete_guard,
-  warn_unused_import
+  warn_unused_import,
+  {parse_transform, stacktrace_transform},
+  {platform_define, "^[2-9]", post19}
 ]}.

rebar.lock

@@ -1,6 +1,8 @@
 {"1.1.0",
-[{<<"time_compat">>,{pkg,<<"time_compat">>,<<"0.0.1">>},0}]}.
+[{<<"stacktrace_compat">>,{pkg,<<"stacktrace_compat">>,<<"1.1.1">>},0},
+ {<<"time_compat">>,{pkg,<<"time_compat">>,<<"0.0.1">>},0}]}.
 [
 {pkg_hash,[
+ {<<"stacktrace_compat">>, <<"1C064BC1725F5BD6470853487AC7FBDA5D5E8745CE4B57D0AE71765C85B4414A">>},
  {<<"time_compat">>, <<"23FE0AD1FDF3B5B88821B2D04B4B5E865BF587AE66056D671FE0F53514ED8139">>}]}
 ].

src/gen_server2.erl

@@ -767,7 +767,7 @@ adjust_timeout_state(SleptAt, AwokeAt, {backoff, CurrentTO, MinimumTO,
             true -> lists:max([MinimumTO, CurrentTO div 2]);
             false -> CurrentTO
         end,
-    {Extra, RandomState1} = random:uniform_s(Base, RandomState),
+    {Extra, RandomState1} = rand:uniform_s(Base, RandomState),
     CurrentTO1 = Base + Extra,
     {backoff, CurrentTO1, MinimumTO, DesiredHibPeriod, RandomState1}.
 

src/rabbit_misc.erl

@@ -1166,12 +1166,13 @@ moving_average(Time,  HalfLife,  Next, Current) ->
 random(N) ->
     case get(random_seed) of
         undefined ->
-            random:seed(erlang:phash2([node()]),
-                        time_compat:monotonic_time(),
-                        time_compat:unique_integer());
+            rand:seed(exsplus, 
+                        {erlang:phash2([node()]),
+                         time_compat:monotonic_time(),
+                         time_compat:unique_integer()});
         _ -> ok
     end,
-    random:uniform(N).
+    rand:uniform(N).
 
 %% Moved from rabbit/src/rabbit_cli.erl
 %% If the server we are talking to has non-standard net_ticktime, and

src/ssl_compat.erl

@@ -38,13 +38,13 @@
 
 connection_information(SslSocket) ->
     code_version:update(?MODULE),
-    ssl_compat:connection_information(SslSocket).
+    compat_connection_information(SslSocket).
 
 connection_information_post_18(SslSocket) ->
-    ssl:connection_information(SslSocket).
+    compat_connection_information(SslSocket).
 
 connection_information_pre_18(SslSocket) ->
-    case ssl:connection_info(SslSocket) of
+    case compat_connection_information(SslSocket) of
         {ok, {ProtocolVersion, CipherSuite}} ->
             {ok, [{protocol, ProtocolVersion},
                   {cipher_suite, CipherSuite}]};
@@ -64,7 +64,7 @@ connection_information_pre_18(SslSocket, Items) ->
     WantCipherSuite = lists:member(cipher_suite, Items),
     if
         WantProtocolVersion orelse WantCipherSuite ->
-            case ssl:connection_info(SslSocket) of
+            case compat_connection_information(SslSocket) of
                 {ok, {ProtocolVersion, CipherSuite}} ->
                     filter_information_items(ProtocolVersion,
                                              CipherSuite,
@@ -90,3 +90,12 @@ filter_information_items(ProtocolVersion, CipherSuite, [_ | Rest],
     filter_information_items(ProtocolVersion, CipherSuite, Rest, Result);
 filter_information_items(_ProtocolVersion, _CipherSuite, [], Result) ->
     {ok, lists:reverse(Result)}.
+
+
+-ifdef(post19).
+compat_connection_information(SslSocket) ->
+    ssl:connection_information(SslSocket).
+-else.
+compat_connection_information(SslSocket) ->
+    ssl:connection_info(SslSocket).
+-endif.