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Developer forums (C::B DEVELOPMENT STRICTLY!) => Development => Topic started by: oBFusCATed on April 29, 2012, 05:50:46 pm

Title: Crash when unloading compiler plugin
Post by: oBFusCATed on April 29, 2012, 05:50:46 pm

I'm playing a bit with the plugins and I found a rather strange crash.

To reproduce:
1. Open codeblocks
2. Open Plugins -> Manager ...
3. Unload the compiler plugin
4. Load the compiler plugin
5. Unload the compiler plugin -> codeblocks crashes

Tested on gentoo linux amd64 wxgtk 2.8.12.x latest trunk version of c::b, compiled in c::b

Here is the backtrace:

Code

#0 0x7ffff497c835	wxWindowBase::TryParent(wxEvent&) () (/usr/lib64/libwx_gtk2u_core-2.8.so.0:??)
#1 0x7ffff420b2b0	wxEvtHandler::ProcessEvent(wxEvent&) () (/usr/lib64/libwx_baseu-2.8.so.0:??)
#2 0x7ffff5737943	wxAuiNotebook::SetSelection(unsigned long) () (/usr/lib64/libwx_gtk2u_aui-2.8.so.0:??)
#3 0x7ffff5739542	wxAuiNotebook::RemovePage(unsigned long) () (/usr/lib64/libwx_gtk2u_aui-2.8.so.0:??)
#4 0x7ffff57396cd	wxAuiNotebook::DeletePage(unsigned long) () (/usr/lib64/libwx_gtk2u_aui-2.8.so.0:??)
#5 0x7ffff3c1ff6f	cbAuiNotebook::DeletePage(this=0xe7ec00, page=3) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/sdk/cbauibook.cpp:590)
#6 0x4b2b85	InfoPane::DeleteLogger(this=0xe7ec00, l=0x1da7fa0) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/src/infopane.cpp:452)
#7 0x46a1dc	MainFrame::OnRemoveLogWindow(this=0xb46220, event=...) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/src/main.cpp:4613)
#8 0x47a0a7	cbEventFunctor<MainFrame, CodeBlocksLogEvent>::Call(this=0x1452810, event=...) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/include/cbfunctor.h:35)
#9 0x7ffff3c21f58	Manager::ProcessEvent(this=0x8775c0, event=...) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/sdk/manager.cpp:211)
#10 0x7fffe212e43d	CompilerGCC::OnRelease(this=0x1317100, appShutDown=false) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/plugins/compilergcc/compilergcc.cpp:492)
#11 0x7ffff3c2dfb4	cbPlugin::Release(this=0x1317100, appShutDown=false) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/sdk/cbplugin.cpp:85)
#12 0x7ffff3c62b86	PluginManager::DetachPlugin(this=0x116aa50, plugin=0x1317100) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/sdk/pluginmanager.cpp:207)
#13 0x7ffff3b2622b	PluginsConfigurationDlg::OnToggle(this=0x7fffffffc420, event=...) (/home/obfuscated/projects/codeblocks/dev/trunk2/src/sdk/pluginsconfigurationdlg.cpp:200)
#14 0x7ffff420ae56	wxEvtHandler::ProcessEventIfMatches(wxEventTableEntryBase const&, wxEvtHandler*, wxEvent&) () (/usr/lib64/libwx_baseu-2.8.so.0:??)
#15 0x7ffff420afdb	wxEventHashTable::HandleEvent(wxEvent&, wxEvtHandler*) () (/usr/lib64/libwx_baseu-2.8.so.0:??)
#16 0x7ffff420b314	wxEvtHandler::ProcessEvent(wxEvent&) () (/usr/lib64/libwx_baseu-2.8.so.0:??)
#17 0x7ffff497c838	wxWindowBase::TryParent(wxEvent&) () (/usr/lib64/libwx_gtk2u_core-2.8.so.0:??)
#18 0x7ffff48d92e9	??() (/usr/lib64/libwx_gtk2u_core-2.8.so.0:??)
#19 0x7ffff5c9358e	??() (/usr/lib64/libgobject-2.0.so.0:??)
#20 0x7ffff5cabedd	g_signal_emit_valist() (/usr/lib64/libgobject-2.0.so.0:??)
#21 0x7ffff5caca15	g_signal_emit() (/usr/lib64/libgobject-2.0.so.0:??)
#22 0x7ffff7833245	??() (/usr/lib64/libgtk-x11-2.0.so.0:??)
#23 0x7ffff5c9358e	??() (/usr/lib64/libgobject-2.0.so.0:??)
#24 0x7ffff5cabedd	g_signal_emit_valist() (/usr/lib64/libgobject-2.0.so.0:??)
#25 0x7ffff5caca15	g_signal_emit() (/usr/lib64/libgobject-2.0.so.0:??)
#26 0x7ffff7831ffd	??() (/usr/lib64/libgtk-x11-2.0.so.0:??)
#27 0x7ffff78dcba8	??() (/usr/lib64/libgtk-x11-2.0.so.0:??)
#28 0x7ffff5c932db	g_closure_invoke() (/usr/lib64/libgobject-2.0.so.0:??)
#29 0x7ffff5ca4b9d	??() (/usr/lib64/libgobject-2.0.so.0:??)

Title: Re: Crash when unloading compiler plugin
Post by: frithjofh on April 29, 2012, 08:53:08 pm

same confirmed here. SuSE 12.1 on AMD x84_64, wxgtk 2.8.12. code::blocks svn7948 self compiled

[attachment deleted by admin]

Title: Re: Crash when unloading compiler plugin
Post by: Jenna on April 29, 2012, 10:05:53 pm

I see why it happens, not sure whether it is am issue in C::B or wxWidgets.
I hope I find a fix soon.

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on April 29, 2012, 11:31:57 pm

I'll be happy if you explain what is the reason for this :)

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on April 30, 2012, 08:38:22 am

Quote from: oBFusCATed on April 29, 2012, 11:31:57 pm

I'll be happy if you explain what is the reason for this :)

Just from the log I'd guess its a deleted pointer that did not get NULLed and is re-used...

Title: Re: Crash when unloading compiler plugin
Post by: Jenna on April 30, 2012, 10:28:21 am

For some obscure reasons parts of OnRelease will be run twice, if it is called the second time.
The crash happens in wxAuiNotebook::SetSelectionToWindow if m_pLog is deleted first, and in some sizer-releated code, if m_pListLog is deleted first. Butthe crash is just a symptom, there must be a real problem, probably in our code, or with the compiler.

The crash happens with wx2.8 and wx2.9, C::B is compiled with wx4.6 and pch's.
I try it with pch's disabled now.

Title: Re: Crash when unloading compiler plugin
Post by: Jenna on April 30, 2012, 10:58:47 am

Quote from: jens on April 30, 2012, 10:28:21 am

I try it with pch's disabled now.

Exactly the same behaviour.

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on April 30, 2012, 08:23:41 pm

Using this patch fixes the problem: http://cmpt.benbmp.org/codeblocks/patches/compiler_load_unload.patch

It seems that removing the event handler from the chain in the main window fixes it.
Also by reading the docs of wxEvtHandler, I've found this:

Quote

When using multiple inheritance it is imperative that the wxEvtHandler(-derived) class be the first class inherited such that the "this" pointer for the overall object will be identical to the "this" pointer for the wxEvtHandler portion.

I'm not sure why this is the case, but I've modified the class to obey this rule. There are other cases which violate it, so they need to be fixed, too.
I guess probably they are casting a void pointer or something like that to wxEvtHandler in some of the macros and they rely on this hack.

Title: Re: Crash when unloading compiler plugin
Post by: Jenna on April 30, 2012, 09:27:06 pm

Good catch !
Your patch works fine here, tested with wx2.9 on debian 64bit.

From my point of view, you should commit it, if it is does not break anything on windows.

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 01, 2012, 10:29:43 am

Quote from: jens on April 30, 2012, 09:27:06 pm

From my point of view, you should commit it, if it is does not break anything on windows.

I'll try both patches (the other one of the ToDo list plugin) today on Windows. BTW: This is especially "critical" in wx29 as the event handler chain has caused a lot trouble there...I'll report back.

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 01, 2012, 01:17:54 pm

Unfortunately, now I get the following warning with wx2.9.x:
---------------------------
wxWidgets Debug Alert
---------------------------
../../src/common/wincmn.cpp(1448): assert "Assert failure" failed in RemoveEventHandler(): where has the event handler gone?
Do you want to stop the program?
You can also choose [Cancel] to suppress further warnings.

Not nice. :-/

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 01, 2012, 01:25:45 pm

Same on 64 bit build. I don't thinks that's a good thing to do. Either it is simply wrong, or we screw the event queue somewhere else. Disabling the todo (and compiler) plugin makes the debug messages go away again, so the other core plugins seem to make wx happy.

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on May 01, 2012, 01:45:13 pm

Morten: Do you see the crash without the patch in cb-wx28? Does it fix it there if there is a crash?

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 01, 2012, 02:10:02 pm

Quote from: oBFusCATed on May 01, 2012, 01:45:13 pm

Morten: Do you see the crash without the patch in cb-wx28? Does it fix it there if there is a crash?

wx28: Crash w/o patch, no crash w/ patch. (Win7/64 bit)

EDIT: Maybe you should surround this with if (!Manager::Get()->IsAppShuttingdown()) to fix the assertion failures I see? (I don't recall the method's name exactly, but you get the idea...).

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on May 02, 2012, 07:57:13 pm

Hm, Can you try it yourself and then tell me if it works? Can you try to debug it? Is this debug notification debuggable with wx29 in wx28 they are pretty pointless in release builds at least.

I have no wx29-windows working config and I'm not eager to try it or to try to setup one.

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on May 04, 2012, 02:04:48 pm

Morten: Any progress with trying the "if (!Manager::Get()->IsAppShuttingdown()) " idea?

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 04, 2012, 02:35:42 pm

Quote from: oBFusCATed on May 04, 2012, 02:04:48 pm

Morten: Any progress with trying the "if (!Manager::Get()->IsAppShuttingdown()) " idea?

Nope, I am too busy atm... sorry.

Title: Re: Crash when unloading compiler plugin
Post by: oBFusCATed on May 19, 2012, 12:42:47 am

In svn... including the isappshuttingdown check...

Title: Re: Crash when unloading compiler plugin
Post by: MortenMacFly on May 19, 2012, 03:10:06 pm

Quote from: oBFusCATed on May 19, 2012, 12:42:47 am

In svn... including the isappshuttingdown check...

NICE! ...but you missed one. I've added it in r7981. ;-)

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Developer forums (C::B DEVELOPMENT STRICTLY!) => Development => Topic started by: oBFusCATed on April 29, 2012, 05:50:46 pm