New process suspend implementation based on async signaling

3 files changed, 104 insertions, 31 deletions

diff --git a/erts/preloaded/src/erlang.erl b/erts/preloaded/src/erlang.erl
index 5fcad25c6d..cf746c3d51 100644
--- a/erts/preloaded/src/erlang.erl
+++ b/erts/preloaded/src/erlang.erl
@@ -1521,8 +1521,21 @@ pre_loaded() ->
 -spec erlang:process_display(Pid, Type) -> true when
       Pid :: pid(),
       Type :: backtrace.
-process_display(_Pid, _Type) ->
-    erlang:nif_error(undefined).
+process_display(Pid, Type) ->
+    case case erts_internal:process_display(Pid, Type) of
+             Ref when erlang:is_reference(Ref) ->
+                 receive
+                     {Ref, Res} ->
+                         Res
+                 end;
+             Res ->
+                 Res
+         end of
+        badarg ->
+            erlang:error(badarg, [Pid, Type]);
+        Result ->
+            Result
+    end.
 
 %% process_flag/3
 -spec process_flag(Pid, Flag, Value) -> OldValue when
@@ -1530,8 +1543,15 @@ process_display(_Pid, _Type) ->
       Flag :: save_calls,
       Value :: non_neg_integer(),
       OldValue :: non_neg_integer().
-process_flag(_Pid, _Flag, _Value) ->
-    erlang:nif_error(undefined).
+process_flag(Pid, Flag, Value) ->
+    case case erts_internal:process_flag(Pid, Flag, Value) of
+             Ref when erlang:is_reference(Ref) ->
+                 receive {Ref, Res} -> Res end;
+             Res -> Res
+         end of
+        badarg -> erlang:error(badarg, [Pid, Flag, Value]);
+        Result -> Result
+    end.
 
 %% process_info/1
 -spec process_info(Pid) -> Info when
@@ -1749,9 +1769,32 @@ start_timer(_Time, _Dest, _Msg, _Options) ->
 -spec erlang:suspend_process(Suspendee, OptList) -> boolean() when
       Suspendee :: pid(),
       OptList :: [Opt],
-      Opt :: unless_suspending | asynchronous.
-suspend_process(_Suspendee, _OptList) ->
-    erlang:nif_error(undefined).
+      Opt :: unless_suspending | asynchronous | {asynchronous, term()}.
+suspend_process(Suspendee, OptList) ->
+    case case erts_internal:suspend_process(Suspendee, OptList) of
+	     Ref when erlang:is_reference(Ref) ->
+                 receive {Ref, Res} -> Res end;
+             Res ->
+                 Res
+         end of
+	true -> true;
+	false -> false;
+	Error -> erlang:error(Error, [Suspendee, OptList])
+    end.
+
+-spec erlang:suspend_process(Suspendee) -> 'true' when
+      Suspendee :: pid().
+suspend_process(Suspendee) ->
+    case case erts_internal:suspend_process(Suspendee, []) of
+	     Ref when erlang:is_reference(Ref) ->
+                 receive {Ref, Res} -> Res end;
+             Res ->
+                 Res
+	 end of
+	true -> true;
+        false -> erlang:error(internal_error, [Suspendee]);
+	Error -> erlang:error(Error, [Suspendee])
+    end.
 
 %% system_monitor/0
 -spec erlang:system_monitor() -> MonSettings when
@@ -3045,15 +3088,6 @@ send_nosuspend(Pid, Msg, Opts) ->
 localtime_to_universaltime(Localtime) ->
     erlang:localtime_to_universaltime(Localtime, undefined).
 
--spec erlang:suspend_process(Suspendee) -> 'true' when
-      Suspendee :: pid().
-suspend_process(P) ->
-    case catch erlang:suspend_process(P, []) of
-	{'EXIT', {Reason, _}} -> erlang:error(Reason, [P]);
-	{'EXIT', Reason} -> erlang:error(Reason, [P]);
-	Res -> Res
-    end.
-
 %%
 %% Port BIFs
 %%
diff --git a/erts/preloaded/src/erts_dirty_process_signal_handler.erl b/erts/preloaded/src/erts_dirty_process_signal_handler.erl
index ab71790b9d..381f81ef14 100644
--- a/erts/preloaded/src/erts_dirty_process_signal_handler.erl
+++ b/erts/preloaded/src/erts_dirty_process_signal_handler.erl
@@ -50,10 +50,12 @@ handle_request(Pid) when is_pid(Pid) ->
     handle_incoming_signals(Pid, 0);
 handle_request({Requester, Target, Prio,
                 {SysTaskOp, ReqId, Arg} = Op} = Request) ->
-    case handle_sys_task(Requester, Target, SysTaskOp, ReqId, Arg) of
-        true ->
+    case handle_sys_task(Requester, Target, SysTaskOp, ReqId, Arg, 0) of
+        done ->
             ok;
-        false ->
+        busy ->
+            self() ! Request;
+        normal ->
             %% Target has stopped executing dirty since the
             %% initial request was made. Dispatch the
             %% request to target and let it handle it itself...
@@ -83,15 +85,19 @@ handle_incoming_signals(Pid, N) ->
         _Res -> ok
     end.
 
-handle_sys_task(Requester, Target, check_process_code, ReqId, Module) ->
-    case erts_internal:is_process_executing_dirty(Target) of
-        false ->
-            false;
-        true ->
-            _ = check_process(Requester, Target, ReqId, Module),
-            true
+handle_sys_task(Requester, Target, check_process_code, ReqId, Module, N) ->
+    case erts_internal:check_dirty_process_code(Target, Module) of
+        Bool when Bool == true; Bool == false ->
+            Requester ! {check_process_code, ReqId, Bool},
+            done;
+        busy ->
+            case N > 5 of
+                true ->
+                    busy;
+                false ->
+                    handle_sys_task(Requester, Target, check_process_code,
+                                    ReqId, Module, N+1)
+            end;
+        Res ->
+            Res
     end.
-
-check_process(Requester, Target, ReqId, Module) ->
-    Result = erts_internal:check_dirty_process_code(Target, Module),
-    Requester ! {check_process_code, ReqId, Result}.
diff --git a/erts/preloaded/src/erts_internal.erl b/erts/preloaded/src/erts_internal.erl
index 79169b7d23..f0f83b7e9d 100644
--- a/erts/preloaded/src/erts_internal.erl
+++ b/erts/preloaded/src/erts_internal.erl
@@ -82,6 +82,12 @@
 
 -export([gather_alloc_histograms/1, gather_carrier_info/1]).
 
+-export([suspend_process/2]).
+
+-export([process_display/2]).
+
+-export([process_flag/3]).
+
 %%
 %% Await result of send to port
 %%
@@ -303,7 +309,8 @@ get_cpc_opts([{allow_gc, AllowGC} | Options], Async) when AllowGC == true;
 get_cpc_opts([], Async) ->
     Async.
 
--spec check_dirty_process_code(Pid,Module) -> 'true' | 'false' when
+-spec check_dirty_process_code(Pid, Module) -> Result when
+      Result :: boolean() | 'normal' | 'busy',
       Pid :: pid(),
       Module :: module().
 check_dirty_process_code(_Pid,_Module) ->
@@ -644,3 +651,29 @@ gather_alloc_histograms(_) ->
 
 gather_carrier_info(_) ->
     erlang:nif_error(undef).
+
+-spec suspend_process(Suspendee, OptList) -> Result when
+      Result :: boolean() | 'badarg' | reference(),
+      Suspendee :: pid(),
+      OptList :: [Opt],
+      Opt :: unless_suspending | asynchronous | {asynchronous, term()}.
+
+suspend_process(_Suspendee, _OptList) ->
+    erlang:nif_error(undefined).
+
+%% process_display/2
+-spec process_display(Pid, Type) -> 'true' | 'badarg' | reference() when
+      Pid :: pid(),
+      Type :: backtrace.
+process_display(_Pid, _Type) ->
+    erlang:nif_error(undefined).
+
+%% process_flag/3
+-spec process_flag(Pid, Flag, Value) -> OldValue | 'badarg' | reference() when
+      Pid :: pid(),
+      Flag :: save_calls,
+      Value :: non_neg_integer(),
+      OldValue :: non_neg_integer().
+process_flag(_Pid, _Flag, _Value) ->
+    erlang:nif_error(undefined).
+