From 997168383605d68ad15f7af3d249ffc888c3e498 Mon Sep 17 00:00:00 2001
From: Dan Gudmundsson <dgud@erlang.org>
Date: Tue, 1 Mar 2016 12:50:27 +0100
Subject: wx: Wait before throwing away early callbacks to wx_objects

If synced callbacks arrive early before the return value from
init had been synced to proc_lib. The callbacks where ignored.

Added a short timeout to avoid the scheduling raise but we don't want
block the wxe_server in case of deadlock in init, so sleep for a short
while and check again, and drop the callback when init takes to long.
---
 lib/wx/src/wxe_server.erl | 22 +++++++++++++++-------
 1 file changed, 15 insertions(+), 7 deletions(-)

(limited to 'lib/wx/src')

diff --git a/lib/wx/src/wxe_server.erl b/lib/wx/src/wxe_server.erl
index ae9440f890..693a008e3d 100644
--- a/lib/wx/src/wxe_server.erl
+++ b/lib/wx/src/wxe_server.erl
@@ -272,7 +272,7 @@ invoke_callback(Pid, Ev, Ref) ->
 		 wx:set_env(Env),
 		 wxe_util:cast(?WXE_CB_START, <<>>),
 		 try
-		     case get_wx_object_state(Pid) of
+		     case get_wx_object_state(Pid, 5) of
 			 ignore ->
 			     %% Ignore early events
 			     wxEvent:skip(Ref);
@@ -307,16 +307,24 @@ invoke_callback_fun(Fun) ->
     wxe_util:cast(?WXE_CB_RETURN, Res).
 
 
-get_wx_object_state(Pid) ->
+get_wx_object_state(Pid, N) when N > 0 ->
     case process_info(Pid, dictionary) of
 	{dictionary, Dict} ->
 	    case lists:keysearch('_wx_object_',1,Dict) of
-		{value, {'_wx_object_', {_Mod, '_wx_init_'}}} -> ignore;
-		{value, {'_wx_object_', Value}} -> Value;
-		_ -> ignore
+		{value, {'_wx_object_', {_Mod, '_wx_init_'}}} ->
+		    timer:sleep(50),
+		    get_wx_object_state(Pid, N-1);
+		{value, {'_wx_object_', Value}} ->
+		    Value;
+		_ ->
+		    ignore
 	    end;
-	_ -> ignore
-    end.
+	_ ->
+	    ignore
+    end;
+get_wx_object_state(_, _) ->
+    ignore.
+
 
 attach_fun(Fun, S = #state{cb=CB,cb_cnt=Next}) ->
     case gb_trees:lookup(Fun,CB) of
-- 
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