tree 75d9efa2fe555115b411796e9226dd4bb52ccd54
parent 23b0dabe630b463b28ffc2871505befb3c5d3b4b
author qmuntal <quimmuntal@gmail.com> 1728297252 +0200
committer Quim Muntal <quimmuntal@gmail.com> 1728328622 +0000

windows: manually initialize NewNTUnicodeString

The `RtlInitUnicodeString` syscall can be avoided by manually
initializing the `NTUnicodeString`.

The process is described in [WdmlibRtlInitUnicodeStringEx](https://learn.microsoft.com/en-us/windows-hardware/drivers/ddi/wdmsec/nf-wdmsec-wdmlibrtlinitunicodestringex).

The less syscalls, the better. It also makes the function faster:

```
goos: windows
goarch: amd64
pkg: golang.org/x/sys/windows
cpu: Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz
                      │    old.txt    │               new.txt                │
                      │    sec/op     │    sec/op     vs base                │
NewNTUnicodeString-12   181.05n ± 15%   96.32n ± 11%  -46.80% (p=0.000 n=10)
```

Change-Id: Iaf079acdcc2024cdca6b6b649a711f6be99c5b87
Reviewed-on: https://go-review.googlesource.com/c/sys/+/618175
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>