Implement setStackSize on Windows

[poweredbypie]

Motivation

See #10540.

Context

This implements setStackSize for Nix using MinGW, with the strategy described in #10540 (SetThreadStackGuarantee). I've tested this on a Windows 10 LTSC VM through NixOS without any issues.

However, I'm not sure if this change is really required. It seems from a bit of skimming that Windows allocates 1 MB of stack space for each thread by default (specified here), and it doesn't seem like that number is modifiable after compilation. As a result, the setStackSize call in main doesn't work with the 64 MB of stack space requested, as on Unix systems.

I've opted to request 1 MB of stack space as a result, but I'm unsure if this is even a useful request, considering the default thread's stack size.

Priorities and Process

Add 👍 to pull requests you find important.

The Nix maintainer team uses a GitHub project board to schedule and track reviews.

[Ericson2314]

@poweredbypie Thanks for trying this, especially the VM testing! Seeing https://stackoverflow.com/questions/156510/increase-stack-size-on-windows-gcc, it looks like we can use that in conjunction with this function, and then do the same size size as on Unix?

[Ericson2314]

per my comment above

[poweredbypie]

I've implemented the linker flag and removed the conditional compilation so both Unix and Windows guarantee 64 MB. However, I've set the linker flag to commit 128 MB of stack rather than 64, since it seems to fail when only set to 64. I've tried with the following tests:

This gives the following on my VM:

The last 3 fail, so I'm assuming the reservation is aligned somewhat and is ignoring individual byte variation. I can do a more conservative reservation of maybe 64.5 or 65 MB if requested, but I don't think this is an issue in the long run since it only reserves the memory and doesn't commit it until actually needed. (see here again.)

[Ericson2314]

Can we do this per executable? So change src/nix/local.mk? The one with the unit tests can be adjusted too.

Also maybe do the trick in https://stackoverflow.com/questions/1926063/how-do-i-perform-arithmetic-in-a-makefile to make things easier to read?

[poweredbypie]

Can we do this per executable? So change src/nix/local.mk? The one with the unit tests can be adjusted too.

Done, I added the flag to nix and all the libnix*-tests binaries. However, I'm not sure if that's what you're referring to. Do you mean all the tests or just the libnixutil-tests binary?

Also maybe do the trick in https://stackoverflow.com/questions/1926063/how-do-i-perform-arithmetic-in-a-makefile to make things easier to read?

Done!

[Ericson2314]

@poweredbypie Thanks for all your testing work! Yes it does seem that the "user portion" of the stack is a bit smaller. If you can make a 65 or 66 MiB work, I do agree that would be best!

[poweredbypie]

@poweredbypie Thanks for all your testing work! Yes it does seem that the "user portion" of the stack is a bit smaller. If you can make a 65 or 66 MiB work, I do agree that would be best!

Sure. 65 MB seems to work fine:

I'm using CFF Explorer to check the PE header (it shows 0x4100000, which is 65 MB in hex)

[Ericson2314]

https://learn.microsoft.com/en-us/cpp/build/reference/stack-stack-allocations?view=msvc-170

says

Use this option only when you build an .exe file. The /STACK option is ignored when applied to .dll files.

That definitely matches my intuition. Can we remove this from the libraries, or did you find it does in fact make a difference when testing?

[poweredbypie]

https://learn.microsoft.com/en-us/cpp/build/reference/stack-stack-allocations?view=msvc-170

says

Use this option only when you build an .exe file. The /STACK option is ignored when applied to .dll files.

That definitely matches my intuition. Can we remove this from the libraries, or did you find it does in fact make a difference when testing?

Sorry, I'm not sure what you mean. I added the flags to the test binaries, which are still exe files:


(SizeOfStackReserve is 0x4100000 for libnixexpr-tests.exe)
The support libraries do not get the flag:

(SizeOfStackReserve is 0x200000 for libnixexpr-tests-support.dll, the default)
I can still remove them, since I'm not sure if they need the extra stack space, but the flag is taking effect.

[Ericson2314]

Sorry! I misread