bin: config: Provide windows.maxstdio option for increasing I/O limit on Windows

[cosmo0920]

With default limit of I/O on Windows is somewhat small for large amount of log volume environment.
I provide an option to set up this limit up to 2048.

---

Enter [N/A] in the box, if an item is not applicable to your change.

Testing
Before we can approve your change; please submit the following in a comment:

• Example configuration file for the change
• Debug log output from testing the change

• Attached Valgrind output that shows no leaks or memory corruption was found

If this is a change to packaging of containers or native binaries then please confirm it works for all targets.

• Run local packaging test showing all targets (including any new ones) build.
• Set ok-package-test label to test for all targets (requires maintainer to do).

Documentation

• Documentation required for this feature

fluent/fluent-bit-docs#1528

Backporting

• Backport to latest stable release.

---

Fluent Bit is licensed under Apache 2.0, by submitting this pull request I understand that this code will be released under the terms of that license.

[edsiper]

@cosmo0920 we don't do ulimit stuff in Fluent Bit, why should we do it for Windows ? (maybe we just need to update the docs for windows users ?)

[nuclearpidgeon]

Is this limit something that can actually be changed at a system configuration level on Windows?

This is the MS doco about the setter function: https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/setmaxstdio?view=msvc-170 . It seems to be specifically something that's part of the Microsoft C runtime library (CRT).

There's some info here saying that the limit can be further stretched if you use specific Win32 calls directly rather than this C runtime library: https://stackoverflow.com/questions/870173/is-there-a-limit-on-number-of-open-files-in-windows/4276338#4276338

[cosmo0920]

@cosmo0920 we don't do ulimit stuff in Fluent Bit, why should we do it for Windows ? (maybe we just need to update the docs for windows users ?)

In Windows, we need to set up the ulimit like limit via _setmaxstdio. There is no API/mechanism without this API from C runtime.

[edsiper]

thanks folks for the context. @cosmo0920 I suggest to rename this option to windows.maxstdio

[cosmo0920]

Sure, I'll rename it from the previous one.

[cosmo0920]

I rebased off the current master and added windows. prefix on the newly introduced parameter.