RFR: 8286637: (fc) Memory mapped regions bigger than 2GB do not work correctly on Windows

[Maurizio Cimadamore]

On Thu, 12 May 2022 19:15:23 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

> Cast the last parameter `dwNumberOfBytesToMap` of `MapViewOfFile()` to a `SIZE_T`, not a `DWORD`, to avoid truncation.

test/jdk/java/nio/channels/FileChannel/LargeMapTest.java line 64:

> 62:         MemorySegment mappedMemorySegment = MemorySegment.mapFile(p, 0,
> 63:             p.toFile().length(), FileChannel.MapMode.READ_WRITE,
> 64:             ResourceScope.newSharedScope());

Note that I've integrated JEP 424. As a result, you will need to update this test in the following ways:

* replace `jdk.incubator.foreign` with `java.lang.foreign`
* add @enablePreview to the test
* replace `ResourceScope` with `MemorySession`
* the `map` method for segments has moved into `FileChannel`, for constistency

In addition, I think it would be better to use `MemorySession.openImplicit()` as session/scope parameter, since we don't want to call close explicitly.

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PR: https://git.openjdk.java.net/jdk/pull/8686