Perform check_process_code while process is executing dirty

3 files changed, 111 insertions, 3 deletions

diff --git a/erts/preloaded/src/Makefile b/erts/preloaded/src/Makefile
index df4645070b..2ab9edaf5e 100644
--- a/erts/preloaded/src/Makefile
+++ b/erts/preloaded/src/Makefile
@@ -45,7 +45,8 @@ PRE_LOADED_ERL_MODULES = \
 	erlang \
 	erts_internal \
 	erl_tracer \
-	erts_literal_area_collector
+	erts_literal_area_collector \
+	erts_dirty_process_code_checker
 
 PRE_LOADED_BEAM_MODULES = \
 	prim_eval
diff --git a/erts/preloaded/src/erts_dirty_process_code_checker.erl b/erts/preloaded/src/erts_dirty_process_code_checker.erl
new file mode 100644
index 0000000000..911642082c
--- /dev/null
+++ b/erts/preloaded/src/erts_dirty_process_code_checker.erl
@@ -0,0 +1,82 @@
+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2016. 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%
+%%
+
+-module(erts_dirty_process_code_checker).
+
+-export([start/0]).
+
+%%
+%% The erts_dirty_process_code_checker is started at
+%% VM boot by the VM. It is a spawned as a system
+%% process, i.e, the whole VM will terminate if
+%% this process terminates.
+%%
+start() ->
+    process_flag(trap_exit, true),
+    msg_loop().
+
+msg_loop() ->
+    _ = receive
+	    Request ->
+		handle_request(Request)
+	end,
+    msg_loop().
+
+check_process(Requester, Target, ReqId, Module) ->
+    Result = erts_internal:check_dirty_process_code(Target, Module),
+    Requester ! {check_process_code, ReqId, Result}.
+					  
+handle_request({Requester,
+		Target,
+		Prio,
+		{check_process_code,
+		 ReqId,
+		 Module,
+		 _Flags} = Op}) ->
+    %%
+    %% Target may have stopped executing dirty since the
+    %% initial request was made. Check its current state
+    %% and try to send the request if possible; otherwise,
+    %% check the dirty executing process and send the result...
+    %%
+    try
+	case erts_internal:is_process_executing_dirty(Target) of
+	    true ->
+		check_process(Requester, Target, ReqId, Module);
+	    false ->
+		case erts_internal:request_system_task(Requester,
+						       Target,
+						       Prio,
+						       Op) of
+		    ok ->
+			ok;
+		    dirty_execution ->
+			check_process(Requester, Target, ReqId, Module)
+		end
+	end
+    catch
+	_ : _ ->
+	    ok %% Ignore all failures; someone passed us garbage...
+    end;
+handle_request(_Garbage) ->
+    ignore.
+
+		    
+	    
diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl
index 2a6d626279..6229754c8c 100644
--- a/erts/preloaded/src/erts_internal.erl
+++ b/erts/preloaded/src/erts_internal.erl
@@ -38,9 +38,11 @@
 -export([system_check/1,
          gather_system_check_result/1]).
 
--export([request_system_task/3]).
+-export([request_system_task/3, request_system_task/4]).
 
 -export([check_process_code/3]).
+-export([check_dirty_process_code/2]).
+-export([is_process_executing_dirty/1]).
 -export([release_literal_area_switch/0]).
 -export([purge_module/2]).
 
@@ -204,12 +206,24 @@ port_info(_Result, _Item) ->
 -spec request_system_task(Pid, Prio, Request) -> 'ok' when
       Prio :: 'max' | 'high' | 'normal' | 'low',
       Request :: {'garbage_collect', term()}
-	       | {'check_process_code', term(), module(), non_neg_integer()},
+	       | {'check_process_code', term(), module(), non_neg_integer()}
+	       | {'copy_literals', term(), boolean()},
       Pid :: pid().
 
 request_system_task(_Pid, _Prio, _Request) ->
     erlang:nif_error(undefined).
 
+-spec request_system_task(RequesterPid, TargetPid, Prio, Request) -> 'ok' | 'dirty_execution' when
+      Prio :: 'max' | 'high' | 'normal' | 'low',
+      Request :: {'garbage_collect', term()}
+	       | {'check_process_code', term(), module(), non_neg_integer()}
+	       | {'copy_literals', term(), boolean()},
+      RequesterPid :: pid(),
+      TargetPid :: pid().
+
+request_system_task(_RequesterPid, _TargetPid, _Prio, _Request) ->
+    erlang:nif_error(undefined).
+
 -define(ERTS_CPC_ALLOW_GC, (1 bsl 0)).
 
 -spec check_process_code(Module, Flags) -> boolean() when
@@ -272,6 +286,17 @@ cpc_flags(OldFlags, Bit, true) ->
 cpc_flags(OldFlags, Bit, false) ->
     OldFlags band (bnot Bit).
 
+-spec check_dirty_process_code(Pid,Module) -> 'true' | 'false' when
+      Pid :: pid(),
+      Module :: module().
+check_dirty_process_code(_Pid,_Module) ->
+    erlang:nif_error(undefined).
+
+-spec is_process_executing_dirty(Pid) -> 'true' | 'false' when
+      Pid :: pid().
+is_process_executing_dirty(_Pid) ->
+    erlang:nif_error(undefined).
+
 -spec release_literal_area_switch() -> 'true' | 'false'.
 
 release_literal_area_switch() ->