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Removing subclass in UnloadDll causes crash #259960 14/02/17 03:15 PM
A Artalus
Artalus A	Hello everyone! Developing a small autocompletion tool for mIRC I've encountered a problem. At dll loading (/dll plugin.dll Start) I subclass the current channel window with my own WndProc. When I later remove this subclass in UnloadDll, direct call "/dll -u plugin.dll" causes immediate termination of mIRC. However if I remove the subclass in some other function before unloading dll (/dll plugin.dll Stop; /dll -u plugin.dll), everything is fine. It happens only if I subclass the chat window; subclassing main mIRC window works fine. Also, once I subclass anything else, WinApi's GetLastError() starts flooding with 6 "invalid handle" and 126 "module not found" errors. For some reason there are also two possible stack traces: First one in debug mode: Code: > 0fa45551() Unknown [Frames below may be incorrect and/or missing] comctl32.dll!_CallNextSubclassProc@20() Unknown comctl32.dll!_MasterSubclassProc@16() Unknown user32.dll!76466238() Unknown user32.dll!764668ea() Unknown user32.dll!764678b0() Unknown user32.dll!76467d31() Unknown user32.dll!76467dfa() Unknown mIRC.exe!014a7f9f() Unknown mIRC.exe!014ae0e9() Unknown mIRC.exe!0158ec7c() Unknown kernel32.dll!@BaseThreadInitThunk@12() Unknown ntdll.dll!___RtlUserThreadStart@8() Unknown ntdll.dll!__RtlUserThreadStart@8() Unknown And the other in release mode: Code: 0f187cd5() Unknown [Frames below may be incorrect and/or missing] user32.dll!76466238() Unknown msctf.dll!ATL::CComPtr<struct IBackingStoreHolder>::CComPtr<struct IBackingStoreHolder>(struct IBackingStoreHolder *) Unknown msctf.dll!CicBridge::OnSysKeyboardProc(unsigned int,long) Unknown

Re: Removing subclass in UnloadDll causes crash #259961 14/02/17 03:18 PM
Joined: Jul 2006 Posts: 4,020 France W Wims Hoopy frood
Wims Hoopy frood W Joined: Jul 2006 Posts: 4,020 France	Please provide the source code of the dll #mircscripting @ irc.swiftirc.net == the best mIRC help channel

Re: Removing subclass in UnloadDll causes crash #259967 15/02/17 09:31 AM
A Artalus
Artalus A	Dll source example The crash is caused even at unloading this simplest dll.

Re: Removing subclass in UnloadDll causes crash #259969 15/02/17 02:28 PM
Joined: Dec 2002 Posts: 3,842 London, UK Khaled Hoopy frood
Khaled Hoopy frood Joined: Dec 2002 Posts: 3,842 London, UK	Quote: At dll loading (/dll plugin.dll Start) I subclass the current channel window with my own WndProc. When I later remove this subclass in UnloadDll, direct call "/dll -u plugin.dll" causes immediate termination of mIRC. However if I remove the subclass in some other function before unloading dll (/dll plugin.dll Stop; /dll -u plugin.dll), everything is fine. This means that Windows is sending messages related the subclass when you unload it. You will need to follow the steps you have described: remove the subclass first, return control to mIRC to allow it to process any Windows messages, and then unload the DLL.

Re: Removing subclass in UnloadDll causes crash Khaled #259978 16/02/17 12:24 PM
A Artalus
Artalus A	So you mean that this is more of a feature than a bug? Is there a way then to somehow unload dll from the dll itself after a small timeout? Like, on "/dll plugin.dll Stop" the Stop() function would fill the char* data with "/wait 500; /dll -u plugin.dll".

Re: Removing subclass in UnloadDll causes crash #259979 16/02/17 02:08 PM
Joined: Dec 2002 Posts: 3,842 London, UK Khaled Hoopy frood
Khaled Hoopy frood Joined: Dec 2002 Posts: 3,842 London, UK	This is neither a feature nor a bug. As the developer of the DLL, you will need to ensure that your DLL is designed to work with the application you are hooking into. It would not be possible for mIRC to cater for all of the situations that another developer creates in an external application. In this case, your DLL needs to make sure that once the subclass is removed, it returns control to mIRC to allow it to process any pending Windows messages, after which it would be safe to make mIRC unload the DLL. I am not sure what the best way to do this would be - someone else on the forum with more experience creating DLLs for mIRC might be able to help though.

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