1 files changed, 119 insertions, 0 deletions
diff --git a/erts/preloaded/src/atomics.erl b/erts/preloaded/src/atomics.erl
new file mode 100644
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+++ b/erts/preloaded/src/atomics.erl
@@ -0,0 +1,119 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2018. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%
+%% %CopyrightEnd%
+%%
+
+%% Purpose : Main atomics API module.
+
+-module(atomics).
+
+-export([new/2,
+         put/3, get/2,
+         add/3, add_get/3,
+         sub/3, sub_get/3,
+         exchange/3, compare_exchange/4,
+         info/1]).
+
+-export_type([atomics_ref/0]).
+
+-opaque atomics_ref() :: reference().
+
+-define(OPT_SIGNED, (1 bsl 0)).
+-define(OPT_DEFAULT, ?OPT_SIGNED).
+
+-spec new(Arity, Opts) -> atomics_ref() when
+      Arity :: pos_integer(),
+      Opts :: [Opt],
+      Opt :: {signed, boolean()}.
+new(Arity, Opts) ->
+    erts_internal:atomics_new(Arity, encode_opts(Opts, ?OPT_DEFAULT)).
+
+encode_opts([{signed, true}|T], Acc) ->
+    encode_opts(T, Acc bor ?OPT_SIGNED);
+encode_opts([{signed, false}|T], Acc) ->
+    encode_opts(T, Acc band (bnot ?OPT_SIGNED));
+encode_opts([], Acc) ->
+    Acc;
+encode_opts(_, _) ->
+    erlang:error(badarg).
+
+-spec put(Ref, Ix, Value) -> ok when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Value :: integer().
+put(_Ref, _Ix, _Value) ->
+    erlang:nif_error(undef).
+
+-spec get(Ref, Ix) -> integer() when
+      Ref  :: atomics_ref(),
+      Ix :: integer().
+get(_Ref, _Ix) ->
+    erlang:nif_error(undef).
+
+-spec add(Ref, Ix, Incr) -> ok when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Incr :: integer().
+add(_Ref, _Ix, _Incr) ->
+    erlang:nif_error(undef).
+
+-spec add_get(Ref, Ix, Incr) -> integer() when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Incr :: integer().
+add_get(_Ref, _Ix, _Incr) ->
+    erlang:nif_error(undef).
+
+-spec sub(Ref, Ix, Decr) -> ok when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Decr :: integer().
+sub(Ref, Ix, Decr) ->
+    ?MODULE:add(Ref, Ix, -Decr).
+
+-spec sub_get(Ref, Ix, Decr) -> integer() when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Decr :: integer().
+sub_get(Ref, Ix, Decr) ->
+    ?MODULE:add_get(Ref, Ix, -Decr).
+
+-spec exchange(Ref, Ix, Desired) -> integer() when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Desired :: integer().
+exchange(_Ref, _Ix, _Desired) ->
+    erlang:nif_error(undef).
+
+-spec compare_exchange(Ref, Ix, Expected, Desired) -> ok | integer() when
+      Ref  :: atomics_ref(),
+      Ix :: integer(),
+      Expected :: integer(),
+      Desired :: integer().
+compare_exchange(_Ref, _Ix, _Expected, _Desired) ->
+    erlang:nif_error(undef).
+
+-spec info(Ref) -> Info when
+      Ref  :: atomics_ref(),
+      Info :: #{'size':=Size,'max':=Max,'min':=Min,'memory':=Memory},
+      Size :: non_neg_integer(),
+      Max :: integer(),
+      Min :: integer(),
+      Memory :: non_neg_integer().
+info(_Ref) ->
+    erlang:nif_error(undef).