File not closed properly after usage on Windows

[abx78]

Even on basic scenarios, a file on windows does not get released correctly by the process

data = open(file_name) do f
    read(f, String)
end

After this, the Computer Management on Windows will show the file in the Open Files for a while.

This can help temporarily fixing the issue

function open(f, file)
    io = open(file)
    handle = Libc._get_osfhandle(RawFD(fd(io)))
    try
        return f(io)
    finally
        close(io)
        ccall(:CloseHandle, stdcall, Cint, (Ptr{Cvoid},), handle)
    end
end

julia> versioninfo()
Julia Version 1.6.4
Commit 35f0c91 (2021-11-19 03:54 UTC)
Platform Info:
OS: Windows (x86_64-w64-mingw32)
CPU: Intel(R) Xeon(R) Gold 6242 CPU @ 2.80GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-11.0.1 (ORCJIT, skylake-avx512)

[ararslan]

@abx78 and I were discussing this a bit in Slack. Interestingly, the call to CloseHandle is necessary for Windows to release the file handle but the return code from the call is 0, which supposedly denotes an error. I wonder whether https://github.com/JuliaLang/julia/blob/master/base/stream.jl#L370 isn't doing the right thing on Windows? I can't figure out where that _close actually comes from. (it's a Windows API function)

[ararslan]

cc @vtjnash who may have some insight

[IanButterworth]

Related issue? #39457

[vtjnash]

I don't see this. When I run the code above, it appears in Computer Management. Then when I close the file and click the refresh button in Computer Management it disappears, as expected.

[yummy527]

OS: windows 10
Julia Version: 1.9.2

When trying to rm a file after open and check the file, I often get the error "resource busy or locked". I suspect that something is wrong with the open or read function, which leading me here.

By the way, the same code does not trigger an error on my Linux computer.

Please fix it on Windows.

[vtjnash]

Yes, posix-compliant kernels don't have this problem; it is unique to the NT kernel implementation. This is often a problem with running virus checkers, so do you happen to have one running?

[abx78]

In my case, I did.