Destroy-ing window on Win32

Question

Destroy-ing window on Win32

drjackool 956

Hi

Platform: Win32/VC++/ATL

I create a tooltip for the status bar on my app, my question is should I destroy the tooltip window when the main frame destroyed or system will do it?

Also I set icons for the status bar, should destroy icons or system will do it?

thanks

/*...*/
::SendMessage(m_hwndStatusBar, SB_SETICON, 1, (LPARAM)LoadImage(Module::GetResourceInstance(), MAKEINTRESOURCE(IDI_SOMEICON), IMAGE_ICON, 16, 16, LR_DEFAULTCOLOR));
/*...*/
HWND hwndTip = CreateWindowEx(0, TOOLTIPS_CLASS, NULL, WS_POPUP | TTS_ALWAYSTIP, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, m_hWnd, NULL, Module::GetModuleInstance(), NULL);

David Lowndes 2,595 Reputation points MVP

2023-07-21T09:01:32.31+00:00

Generally you should destroy it prior to whatever might invoke it is destroyed, but if its lifetime is for the process, it probably won't matter.
RLWA32 47,956 Reputation points

2023-07-21T14:39:51.2466667+00:00

IMHO, following is an interesting take on performing resource cleanup at process termination -- When DLL_PROCESS_DETACH tells you that the process is exiting, your best bet is just to return without doing anything
Castorix31 88,216 Reputation points

2023-07-22T11:59:02.83+00:00

With Direct2D, the Direct2D Debug Layer displays warnings if you don't destroy all objects and don't release all interfaces when the propram exits

But everything is freed by the OS; I had posted an extract of M. Russinovich book in this recent thread : https://learn.microsoft.com/en-us/answers/questions/1332745/win32-will-postquitmessage(0)-release-all-the-memo
Xiaopo Yang - MSFT 12,731 Reputation points Microsoft External Staff

2023-08-24T06:28:28.82+00:00
NO, you shouldn't.

Terminating a process has the following results:

Any remaining threads in the process are marked for termination.

Any resources allocated by the process are freed.

All kernel objects are closed.

The process code is removed from memory.

The process exit code is set.

The process object is signaled.

But Note

While open handles to kernel objects are closed automatically when a process terminates, the objects themselves exist until all open handles to them are closed. Therefore, an object will remain valid after a process that is using it terminates if another process has an open handle to it.

@drjackool, any update?

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David Lowndes 2,595 Reputation points MVP

2023-07-21T09:01:32.31+00:00

Generally you should destroy it prior to whatever might invoke it is destroyed, but if its lifetime is for the process, it probably won't matter.
RLWA32 47,956 Reputation points

2023-07-21T14:39:51.2466667+00:00

IMHO, following is an interesting take on performing resource cleanup at process termination -- When DLL_PROCESS_DETACH tells you that the process is exiting, your best bet is just to return without doing anything
Castorix31 88,216 Reputation points

2023-07-22T11:59:02.83+00:00

With Direct2D, the Direct2D Debug Layer displays warnings if you don't destroy all objects and don't release all interfaces when the propram exits

But everything is freed by the OS; I had posted an extract of M. Russinovich book in this recent thread : https://learn.microsoft.com/en-us/answers/questions/1332745/win32-will-postquitmessage(0)-release-all-the-memo
Xiaopo Yang - MSFT 12,731 Reputation points Microsoft External Staff

2023-08-24T06:28:28.82+00:00

NO, you shouldn't.

Terminating a process has the following results:

Any remaining threads in the process are marked for termination.

Any resources allocated by the process are freed.

All kernel objects are closed.

The process code is removed from memory.

The process exit code is set.

The process object is signaled.

But Note

While open handles to kernel objects are closed automatically when a process terminates, the objects themselves exist until all open handles to them are closed. Therefore, an object will remain valid after a process that is using it terminates if another process has an open handle to it.

@drjackool, any update?

Answer 1

Xiaopo Yang - MSFT 12,731 Microsoft External Staff

As comments said, when the process is about to exit,

All this memory management is pointless. The process is exiting. All that memory will be freed when the address space is destroyed. Stop wasting time and just exit already.

This is also mentioned in Terminating a Thread:

Any resources owned by the thread, such as windows and hooks, are freed.

By the way, if you just change the icon, you need to free the previous one.

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Destroy-ing window on Win32

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