RFR: 8264774: Implementation of Foreign Function and Memory API (Incubator)

[Alan Bateman]

On Mon, 26 Apr 2021 17:10:13 GMT, Maurizio Cimadamore <mcimadamore at openjdk.org> wrote:

> This PR contains the API and implementation changes for JEP-412 [1]. A more detailed description of such changes, to avoid repetitions during the review process, is included as a separate comment.
> 
> [1] - https://openjdk.java.net/jeps/412

src/java.base/share/classes/java/lang/Module.java line 253:

> 251:     }
> 252: 
> 253:     boolean isEnableNativeAccess() {

Would it be possible change isEnableNativeAccess and addNEnableNativeAccess to keep them consistent with the existing methods in this file.

src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java line 384:

> 382:     Module addEnableNativeAccess(Module m);
> 383: 
> 384:     boolean isEnableNativeAccess(Module m);

Probably better to co-locate these with the other module methods, and add a comment so that it's consistent with the existing methods.

src/java.base/share/classes/jdk/internal/module/ModuleBootstrap.java line 272:

> 270:         BootLoader.loadModule(base);
> 271:         SharedSecrets.getJavaLangAccess()
> 272:                 .addEnableNativeAccess(Modules.defineModule(null, base.descriptor(), baseUri));

This would be cleaner if you replace it with:

Module baseModule = Modules.defineModule(null, base.descriptor(), baseUri);
JLA.addEnableNativeAccess(baseModule);

You can use JLA in addEnableNativeAccess too, no need for "jla".

src/java.base/share/classes/jdk/internal/module/ModuleBootstrap.java line 876:

> 874:     }
> 875: 
> 876:     private static void addEnableNativeAccess(ModuleLayer layer) {

It would be useful to add a method description in the same style as the existing methods, just to keep these methods consistent.

src/java.base/share/classes/sun/nio/ch/IOUtil.java line 57:

> 55: 
> 56:     static int write(FileDescriptor fd, ByteBuffer src, long position,
> 57:                      boolean async, NativeDispatcher nd)

UnixAsynchronousSocketChannel is an outlier user of IOUtil and I think we need to see if we can avoid extending this class to async if possible.

src/java.base/share/classes/sun/nio/ch/IOUtil.java line 466:

> 464:     }
> 465: 
> 466:     private static final JavaNioAccess NIO_ACCESS = SharedSecrets.getJavaNioAccess();

It might be cleaner to move to acquire/release methods to their own supporting class as it's not really IOUtil.

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PR: https://git.openjdk.java.net/jdk/pull/3699