RFR: JDK-8298277: Replace "session" with "scope" for FFM access

[Maurizio Cimadamore]

On Thu, 8 Dec 2022 14:11:29 GMT, Per Minborg <pminborg at openjdk.org> wrote:

> This PR proposes changing variable names and text from "session" to "scope". The proposed changes are only for the FFM API and not other parts like the Vector API and test classes.

src/java.base/share/classes/jdk/internal/foreign/AbstractMemorySegmentImpl.java line 157:

> 155:      * Mismatch over long lengths.
> 156:      */
> 157:     public static long vectorizedMismatchLargeForBytes(MemorySessionImpl aScope, MemorySessionImpl bScope,

this seems unnecessary - note that the type is `MemorySessionImpl`

src/java.base/share/classes/jdk/internal/foreign/ConfinedSession.java line 35:

> 33: 
> 34: /**
> 35:  * A confined scope, which features an owner thread. The liveness check features an additional

This should be left as session (since we have not changed the name of the class)

src/java.base/share/classes/jdk/internal/foreign/ConfinedSession.java line 36:

> 34: /**
> 35:  * A confined scope, which features an owner thread. The liveness check features an additional
> 36:  * confinement check - that is, calling any operation on this scope from a thread other than the

Same here

src/java.base/share/classes/jdk/internal/foreign/GlobalSession.java line 31:

> 29: 
> 30: /**
> 31:  * The global, non-closeable, shared scope. Similar to a shared scope, but its {@link #close()} method throws unconditionally.

And here.

src/java.base/share/classes/jdk/internal/foreign/ImplicitSession.java line 34:

> 32: 
> 33: /**
> 34:  * This is an implicit, GC-backed memory scope. Implicit scopes cannot be closed explicitly.

These should not be changed.

src/java.base/share/classes/jdk/internal/foreign/MemorySessionImpl.java line 42:

> 40: /**
> 41:  * This class manages the temporal bounds associated with a memory segment as well
> 42:  * as thread confinement. A scope has a liveness bit, which is updated when the scope is closed

Probably all the usages of `session` here should be left as is

src/java.base/share/classes/jdk/internal/foreign/MemorySessionImpl.java line 178:

> 176:     }
> 177: 
> 178:     public static boolean sameOwnerThread(SegmentScope scope1, SegmentScope scope2) {

This renaming is the only one that should survive

src/java.base/share/classes/jdk/internal/foreign/MemorySessionImpl.java line 320:

> 318: 
> 319:     static UnsupportedOperationException nonCloseable() {
> 320:         return new UnsupportedOperationException("Attempted to close a non-closeable scope");

I wonder how much we still need this - e.g. through the API is no longer possible to get there?

src/java.base/share/classes/jdk/internal/foreign/SharedSession.java line 35:

> 33: 
> 34: /**
> 35:  * A shared scope, which can be shared across multiple threads. Closing a shared scope has to ensure that

These should not be changed

src/java.base/share/classes/jdk/internal/foreign/abi/Binding.java line 255:

> 253:          * the context's allocator is accessed.
> 254:          */
> 255:         public static Context ofScope() {

I think `ofArena` seems more apt here?

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PR: https://git.openjdk.org/jdk/pull/11593