[socket] Add cancel and the first recvfrom(nowait) cancel test case

Add the (public) cancel function and the first of
the cancel test cases (recvfrom(nowait)).

3 files changed, 266 insertions, 2 deletions

diff --git a/erts/emulator/test/socket_SUITE.erl b/erts/emulator/test/socket_SUITE.erl
index b63a6fc526..aecd65096e 100644
--- a/erts/emulator/test/socket_SUITE.erl
+++ b/erts/emulator/test/socket_SUITE.erl
@@ -86,6 +86,11 @@
          api_a_sendmsg_and_recvmsg_udp4/1,
          api_a_send_and_recv_tcp4/1,
          api_a_sendmsg_and_recvmsg_tcp4/1,
+         api_a_recvfrom_cancel_udp4/1,
+         %% api_a_recvmsg_cancel_udp4/1,
+         %% api_a_accept_cancel_tcp4/1,
+         %% api_a_recv_cancel_tcp4/1,
+         %% api_a_recvmsg_cancel_tcp4/1,
 
          %% *** API Options ***
          api_opt_simple_otp_options/1,
@@ -672,7 +677,12 @@ api_async_cases() ->
      api_a_sendto_and_recvfrom_udp4,
      api_a_sendmsg_and_recvmsg_udp4,
      api_a_send_and_recv_tcp4,
-     api_a_sendmsg_and_recvmsg_tcp4
+     api_a_sendmsg_and_recvmsg_tcp4,
+     api_a_recvfrom_cancel_udp4%% ,
+     %% api_a_recvmsg_cancel_udp4,
+     %% api_a_accept_cancel_tcp4,
+     %% api_a_recv_cancel_tcp4,
+     %% api_a_recvmsg_cancel_tcp4
     ].
 
 api_options_cases() ->
@@ -3683,6 +3693,239 @@ api_a_send_and_recv_tcp(InitState) ->
 
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+%% Basically we make an async (Timeout = nowait) call to recvfrom,
+%% wait some time and then cancel.
+%%
+api_a_recvfrom_cancel_udp4(suite) ->
+    [];
+api_a_recvfrom_cancel_udp4(doc) ->
+    [];
+api_a_recvfrom_cancel_udp4(_Config) when is_list(_Config) ->
+    ?TT(?SECS(5)),
+    tc_try(api_a_recvfrom_cancel_udp4,
+           fun() ->
+                   Recv = fun(Sock) ->
+                                  case socket:recvfrom(Sock, 0, nowait) of
+                                      {ok, _} = OK ->
+                                          OK;
+                                      {error, _} = ERROR ->
+                                          ERROR
+                                  end
+                          end,
+                   InitState = #{domain => inet,
+                                 recv   => Recv},
+                   ok = api_a_recv_cancel_udp(InitState)
+           end).
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+api_a_recv_cancel_udp(InitState) ->
+    ServerSeq = 
+        [
+         %% *** Wait for start order part ***
+         #{desc => "await start",
+           cmd  => fun(State) ->
+                           Tester = ?SEV_AWAIT_START(),
+                           {ok, State#{tester => Tester}}
+                   end},
+         #{desc => "monitor tester",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           _MRef = erlang:monitor(process, Tester),
+                           ok
+                   end},
+
+         %% *** Init part ***
+         #{desc => "which local address",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           LAddr = which_local_addr(Domain),
+                           LSA   = #{family => Domain, addr => LAddr},
+                           {ok, State#{local_sa => LSA}}
+                   end},
+         #{desc => "create socket",
+           cmd  => fun(#{domain := Domain} = State) ->
+                           case socket:open(Domain, dgram, udp) of
+                               {ok, Sock} ->
+                                   {ok, State#{sock => Sock}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "bind socket (to local address)",
+           cmd  => fun(#{sock := Sock, local_sa := LSA} = State) ->
+                           case socket:bind(Sock, LSA) of
+                               {ok, Port} ->
+                                   {ok, State#{port => Port}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (init)",
+           cmd  => fun(#{tester := Tester, local_sa := LSA, port := Port}) ->
+                           ServerSA = LSA#{port => Port},
+                           ?SEV_ANNOUNCE_READY(Tester, init, ServerSA),
+                           ok
+                   end},
+
+         %% The actual test
+         #{desc => "await continue (recv)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, recv)
+                   end},
+         #{desc => "try recv request (with nowait, expect select)",
+           cmd  => fun(#{sock := Sock, recv := Recv} = State) ->
+                           case Recv(Sock) of
+                               {ok, {select, _, RecvRef} = SelectInfo} ->
+                                   {ok, State#{recv_select_info => SelectInfo}};
+                               {ok, X} ->
+                                   {error, {unexpected_select_info, X}};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "announce ready (recv_select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, recv_select),
+                           ok
+                   end},
+         #{desc => "await select message (without success)",
+           cmd  => fun(#{sock := Sock}) ->
+                           receive
+                               {'$socket', Sock, select, Ref} ->
+                                   {error, {unexpected_select, Ref}}
+                           after 5000 ->
+                                   ok
+                           end
+                   end},
+         #{desc => "announce ready (no select)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, no_select),
+                           ok
+                   end},
+         #{desc => "await continue (cancel)",
+           cmd  => fun(#{tester := Tester} = _State) ->
+                           ?SEV_AWAIT_CONTINUE(Tester, tester, cancel)
+                   end},
+         #{desc => "cancel",
+           cmd  => fun(#{sock := Sock, recv_select_info := SelectInfo}) ->
+                           ok = socket:cancel(Sock, SelectInfo)
+                   end},
+         #{desc => "announce ready (cancel)",
+           cmd  => fun(#{tester := Tester}) ->
+                           ?SEV_ANNOUNCE_READY(Tester, cancel),
+                           ok
+                   end},
+
+         %% Termination
+         #{desc => "await terminate (from tester)",
+           cmd  => fun(#{tester := Tester} = State) ->
+                           case ?SEV_AWAIT_TERMINATE(Tester, tester) of
+                               ok ->
+                                   State2 = maps:remove(tester,    State),
+                                   State3 = maps:remove(recv_stag, State2),
+                                   State4 = maps:remove(recv_sref, State3),
+                                   State5 = maps:remove(req_src,   State4),
+                                   {ok, State5};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+         #{desc => "close socket",
+           cmd  => fun(#{sock := Sock} = State) ->
+                           ok = socket:close(Sock),
+                           {ok, maps:remove(sock, State)}
+                   end},
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+
+    TesterSeq = 
+        [
+         %% *** Init part ***
+         #{desc => "monitor server",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           _MRef = erlang:monitor(process, Pid),
+                           ok
+                   end},
+
+         %% Start the server
+         #{desc => "order server start",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_START(Pid),
+                           ok
+                   end},
+         #{desc => "await server ready (init)",
+           cmd  => fun(#{server := Pid} = State) ->
+                           {ok, ServerSA} = ?SEV_AWAIT_READY(Pid, server, init),
+                           {ok, State#{server_sa => ServerSA}}
+                   end},
+
+         %% The actual test
+         #{desc => "order server continue (recv)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, recv),
+                           ok
+                   end},
+         #{desc => "await server ready (recv select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, recv_select)
+                   end},
+         #{desc => "await server ready (no select)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, no_select)
+                   end},
+         #{desc => "order server continue (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_CONTINUE(Pid, cancel),
+                           ok
+                   end},
+         #{desc => "await server ready (cancel)",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ok = ?SEV_AWAIT_READY(Pid, server, cancel)
+                   end},
+
+         %% Terminations
+         #{desc => "order server to terminate",
+           cmd  => fun(#{server := Pid} = _State) ->
+                           ?SEV_ANNOUNCE_TERMINATE(Pid),
+                           ok
+                   end},
+         #{desc => "await server termination",
+           cmd  => fun(#{server := Pid} = State) ->
+                           case ?SEV_AWAIT_TERMINATION(Pid) of
+                               ok ->
+                                   State1 = maps:remove(server, State),
+                                   {ok, State1};
+                               {error, _} = ERROR ->
+                                   ERROR
+                           end
+                   end},
+
+
+         %% *** We are done ***
+         ?SEV_FINISH_NORMAL
+        ],
+
+    i("start server evaluator"),
+    ServerInitState = InitState,
+    Server = ?SEV_START("server", ServerSeq, ServerInitState),
+
+    i("start 'tester' evaluator"),
+    TesterInitState = #{server => Server#ev.pid},
+    Tester = ?SEV_START("tester", TesterSeq, TesterInitState),
+
+    i("await evaluator"),
+    ok = ?SEV_AWAIT_FINISH([Server, Tester]).
+
+
+
+
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %%                                                                     %%
 %%                           API OPTIONS                               %%
diff --git a/erts/preloaded/ebin/socket.beam b/erts/preloaded/ebin/socket.beam
index 98adde8ae5..b8983eb8e8 100644
--- a/erts/preloaded/ebin/socket.beam
+++ b/erts/preloaded/ebin/socket.beam
diff --git a/erts/preloaded/src/socket.erl b/erts/preloaded/src/socket.erl
index c805c5586d..f4d8f175f8 100644
--- a/erts/preloaded/src/socket.erl
+++ b/erts/preloaded/src/socket.erl
@@ -53,7 +53,9 @@
          getopt/3,
 
          sockname/1,
-         peername/1
+         peername/1,
+
+         cancel/2
         ]).
 
 -export_type([
@@ -2586,6 +2588,25 @@ peername(#socket{ref = SockRef}) ->
     nif_peername(SockRef).
 
 
+%% ===========================================================================
+%%
+%% cancel - cancel an operation resulting in a select
+%%
+%% A call to accept, recv/recvfrom/recvmsg and send/sendto/sendmsg
+%% can result in a select if they are called with the Timeout argument
+%% set to nowait. This is indicated by the return of the select-info.
+%% Such a operation can be cancelled by calling this function.
+%%
+
+-spec cancel(Socket, SelectInfo) -> ok | {error, Reason} when
+      Socket     :: socket(),
+      SelectInfo :: select_info(),
+      Reason     :: term().
+
+cancel(#socket{ref = SockRef}, {select, Tag, Ref}) ->
+    cancel(SockRef, Tag, Ref).
+
+
 
 %% ===========================================================================
 %%