Re: [wxlua-users] Strange (occasional) crash in wxLuaState::LuaPCall
Hi John, lua_yield is a coroutine function, are you running coroutines? If so, then Lua will be swapping lua_States in and out and pausing them whenever it wants to, making the stack seem very strange. I do (in general), but it's in a completely different part (for debugging) and is not involved there; so, it's indeed puzzling. You're not trying to install event handlers in a coroutine are you? As we discussed, that's always a bad idea. No; this affects the applications that I debug, but not ZBS itself. I'm careful not to even open new windows while in coroutines and all events like this are delayed in the application until it's safe to do (and is only done in the main thread). Did you ever create a wxProgressDialog? The Lua garbage collector may simply be running and finally getting around to deleting it. No; and that's another puzzling part. I don't use wxProgressDialog at all. Not sure why it would be deleted... Can you rebuild in debug mode? The stack should have line numbers which will clear things up. That's a good suggestion; I prepared a debug build, but haven't heard back from the user yet. BTW, the dll is 186M in debug more ;). Everything is normal up to LuaPCall, but then I presume you're running a coroutine that's calling the lua_yield, and wxLua does use lua_getinfo for a few things so that may be normal, but the lua_close is very wrong unless you're closing a coroutine, perhaps the coroutine had a wxProgressDialog and that's why it's getting deleted at this point? I can't imagine who's calling AddPendingEvent though, are you? I agree; everything looks normal up to that LuaPCall, but very strange after that. I do have one AddPendingEvent call (and it's in one of the branches for AddChar event, so it *can* be related), but definitely not from wxProgressDialog destructor. Thank you for confirming my suspicions. I'll see if I can get any additional information from the debug build... Paul. -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ wxlua-users mailing list wxlua-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wxlua-users
Re: [wxlua-users] Strange (occasional) crash in wxLuaState::LuaPCall
On Thu, Jun 13, 2013 at 1:17 AM, Paul K paulclin...@yahoo.com wrote: Hi John, I got several reports (from the same machine) of crashes in my application when a user types something in wxSTC control. It's difficult to reproduce and seems to happen infrequently, but the captured stack trace points to wxLuaState::LuaPCall call. This is running wxlua 2.8.12.2 and wxwidgets 2.9.5 (compiled at the end of April). The wxLua C++ event handler callback uses LuaPCall() to run your Lua event handler function for the wxStyledTextEvent. From the stack it looks like the event is a char added event. I'm including the top part of the stack trace below (the full stack is in this ticket: https://github.com/pkulchenko/ZeroBraneStudio/issues/164), but there are several odd things I noticed. 1. The trace shows lua51!lua_yield call after wxLuaState::LuaPCall call, but I don't see any lua_yield calls in that function. lua_yield is a coroutine function, are you running coroutines? If so, then Lua will be swapping lua_States in and out and pausing them whenever it wants to, making the stack seem very strange. You're not trying to install event handlers in a coroutine are you? As we discussed, that's always a bad idea. 2. The trace shows wxProgressDialog_delete_function call in the stack, but I don't use that component anywhere in the application; the stack looks wrong at that point as I wouldn't expect any wxProgressDialog call from lua_getinfo. Did you ever create a wxProgressDialog? The Lua garbage collector may simply be running and finally getting around to deleting it. 3. The crash seems to be in this fragment in wxlua/wxlcallb.cpp: // Don't track the wxEvent since we don't own it and tracking it // causes clashes in the object registry table since many can be // created and deleted and the mem address is resused by C++. wxlState.wxluaT_PushUserDataType(event, event_wxl_type, false); wxlState.LuaPCall(1, 0); // one input no returns What events are being referred to here as we don't own it? Is it possible to check for these events explicitly? Any idea why it may be crashing here and how to avoid this? Thank you! We meaning, wxLua/Lua, does not own the allocated memory for the wxEvent class so even though wxLua pushes it onto the Lua stack wxLua/Lua will not try to delete it when the function ends. Think of wxMouseEvents, if you have a very simple event handler function it may happen that each successive wxMouseEvent will use the same memory. Therefore, wxLua cannot track the event since the Lua garbage collector can be slow to clean up and we get seemingly duplicate tracked items, but the first one is long gone, this is merely book keeping. The event is a wxStyledTextEvent based on the stack. Can you rebuild in debug mode? The stack should have line numbers which will clear things up. Everything is normal up to LuaPCall, but then I presume you're running a coroutine that's calling the lua_yield, and wxLua does use lua_getinfo for a few things so that may be normal, but the lua_close is very wrong unless you're closing a coroutine, perhaps the coroutine had a wxProgressDialog and that's why it's getting deleted at this point? I can't imagine who's calling AddPendingEvent though, are you? In any case, if you do create a wxProgressDialog I suggest that you explicitly call dlg:Destroy() on it to ensure that it's cleaned up immediately instead of waiting for the garbage collector. Regards, John 0028eb1c 5dac0207 unknown!unknown+0x0 0028eb20 02270b3f wx!ZN12wxEvtHandler15AddPendingEventERK7wxEvent+0x1b 0028eb40 01ed3fe7 wx!Z38wxLua_wxProgressDialog_delete_functionPPv+0x88a 0028eb60 66d85a49 lua51!lua_getinfo+0x1015 0028eb70 66d8ddd1 lua51!lua_close+0x1eb9 0028ebb0 66d8ea14 lua51!lua_close+0x2afc 0028ec50 66d85e34 lua51!lua_getinfo+0x1400 0028ed00 66d85f89 lua51!lua_yield+0x81 0028ed10 66d86431 lua51!lua_yield+0x529 0028ed80 01f65c4e wx!ZN10wxLuaState8LuaPCallEii+0x7c 0028edc0 01f5b2da wx!ZN18wxLuaEventCallback7OnEventEP7wxEvent+0x1f4 0028ee20 01f5b09b wx!ZN18wxLuaEventCallback11OnAllEventsER7wxEvent+0x59 0028ee70 02197e3a wx!ZNK16wxAppConsoleBase16CallEventHandlerEP12wxEvtHandlerR14wxEventFunctorR7wxEvent+0x42 0028eec0 02199839 wx!ZN12wxEvtHandler23ProcessEventIfMatchesIdERK21wxEventTableEntryBasePS_R7wxEvent+0x65 0028eef0 02199aa3 wx!ZN12wxEvtHandler23SearchDynamicEventTableER7wxEvent+0x4f 0028ef20 02199ae2 wx!ZN12wxEvtHandler11TryHereOnlyER7wxEvent+0x28 0028ef40 02199b48 wx!ZN12wxEvtHandler19ProcessEventLocallyER7wxEvent+0x1a 0028ef60 02199bc9 wx!ZN12wxEvtHandler12ProcessEventER7wxEvent+0x63 0028ef90 01f72fb0 wx!ZN16wxStyledTextCtrl12NotifyParentEP14SCNotification+0x252 0028f070 01f75022 wx!ZN11ScintillaWX12NotifyParentE14SCNotification+0x1e 0028f090 01f82de0 wx!ZN6Editor10NotifyCharEi+0x3a 0028f160 01f92f85 wx!ZN6Editor10AddCharUTFEPcjb+0x3e1 0028f1c0 01f7c151
[wxlua-users] Strange (occasional) crash in wxLuaState::LuaPCall
Hi John, I got several reports (from the same machine) of crashes in my application when a user types something in wxSTC control. It's difficult to reproduce and seems to happen infrequently, but the captured stack trace points to wxLuaState::LuaPCall call. This is running wxlua 2.8.12.2 and wxwidgets 2.9.5 (compiled at the end of April). I'm including the top part of the stack trace below (the full stack is in this ticket: https://github.com/pkulchenko/ZeroBraneStudio/issues/164), but there are several odd things I noticed. 1. The trace shows lua51!lua_yield call after wxLuaState::LuaPCall call, but I don't see any lua_yield calls in that function. 2. The trace shows wxProgressDialog_delete_function call in the stack, but I don't use that component anywhere in the application; the stack looks wrong at that point as I wouldn't expect any wxProgressDialog call from lua_getinfo. 3. The crash seems to be in this fragment in wxlua/wxlcallb.cpp: // Don't track the wxEvent since we don't own it and tracking it // causes clashes in the object registry table since many can be // created and deleted and the mem address is resused by C++. wxlState.wxluaT_PushUserDataType(event, event_wxl_type, false); wxlState.LuaPCall(1, 0); // one input no returns What events are being referred to here as we don't own it? Is it possible to check for these events explicitly? Any idea why it may be crashing here and how to avoid this? Thank you! I also asked in wx-user maillist, but it may be more wxlua related than wxwidgets related. I'll post an update if I get any additional information. Paul. 0028eb1c 5dac0207 unknown!unknown+0x0 0028eb20 02270b3f wx!ZN12wxEvtHandler15AddPendingEventERK7wxEvent+0x1b 0028eb40 01ed3fe7 wx!Z38wxLua_wxProgressDialog_delete_functionPPv+0x88a 0028eb60 66d85a49 lua51!lua_getinfo+0x1015 0028eb70 66d8ddd1 lua51!lua_close+0x1eb9 0028ebb0 66d8ea14 lua51!lua_close+0x2afc 0028ec50 66d85e34 lua51!lua_getinfo+0x1400 0028ed00 66d85f89 lua51!lua_yield+0x81 0028ed10 66d86431 lua51!lua_yield+0x529 0028ed80 01f65c4e wx!ZN10wxLuaState8LuaPCallEii+0x7c 0028edc0 01f5b2da wx!ZN18wxLuaEventCallback7OnEventEP7wxEvent+0x1f4 0028ee20 01f5b09b wx!ZN18wxLuaEventCallback11OnAllEventsER7wxEvent+0x59 0028ee70 02197e3a wx!ZNK16wxAppConsoleBase16CallEventHandlerEP12wxEvtHandlerR14wxEventFunctorR7wxEvent+0x42 0028eec0 02199839 wx!ZN12wxEvtHandler23ProcessEventIfMatchesIdERK21wxEventTableEntryBasePS_R7wxEvent+0x65 0028eef0 02199aa3 wx!ZN12wxEvtHandler23SearchDynamicEventTableER7wxEvent+0x4f 0028ef20 02199ae2 wx!ZN12wxEvtHandler11TryHereOnlyER7wxEvent+0x28 0028ef40 02199b48 wx!ZN12wxEvtHandler19ProcessEventLocallyER7wxEvent+0x1a 0028ef60 02199bc9 wx!ZN12wxEvtHandler12ProcessEventER7wxEvent+0x63 0028ef90 01f72fb0 wx!ZN16wxStyledTextCtrl12NotifyParentEP14SCNotification+0x252 0028f070 01f75022 wx!ZN11ScintillaWX12NotifyParentE14SCNotification+0x1e 0028f090 01f82de0 wx!ZN6Editor10NotifyCharEi+0x3a 0028f160 01f92f85 wx!ZN6Editor10AddCharUTFEPcjb+0x3e1 0028f1c0 01f7c151 wx!ZN13ScintillaBase10AddCharUTFEPcjb+0x9f 0028f200 01f766a9 wx!ZN11ScintillaWX9DoAddCharEi+0x6f ... -- This SF.net email is sponsored by Windows: Build for Windows Store. http://p.sf.net/sfu/windows-dev2dev ___ wxlua-users mailing list wxlua-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wxlua-users
