[foreign-memaccess] RFR: JDK-8243284: Remove Foreign class

[Maurizio Cimadamore]

On Tue, 21 Apr 2020 18:21:47 GMT, Henry Jen <henryjen at openjdk.org> wrote:

>> The Foreign class is currently used for 3 methods:
>> 
>> * withSize, which takes an unchecked address and gives it a size
>> * asUnconfined, which takes an existing segment and turns it into an unconfined segment
>> * asMallocSegment, which takes an unchecked address and converts that into a segment which can be closed, and where
>>   closed is mapped into "free"
>> 
>> This patch replaces all these with this method:
>> 
>> static MemorySegment ofNativeUnsafe(MemoryAddress addr, long bytesSize, Thread owner, AutoCloseable cleanup, Object
>> attachment)
>> Which is then moved directly into MemorySegment - so that we can garbage-collect the Foreign class.
>> 
>> I've also made some changes on the JDK property - new name is simply "jdk.foreign" and I now made sure that it cannot
>> be bypassed with a simple static initializer.
>
> src/jdk.incubator.foreign/share/classes/jdk/internal/foreign/Utils.java line 89:
> 
>> 88:                     s
>> 89:                             .forEach(f -> sb.append(System.lineSeparator()).append("\tat ").append(f));
>> 90:                     return null;
> 
> Is this format intentional? Also it seems to me this can be replaced with
> 
> StackWalker().getInstance().forEach()?

I didn't change this code, I just moved it around; I'll make another pass.

-------------

PR: https://git.openjdk.java.net/panama-foreign/pull/122