Re: RFR (XS): 8150725 JDWP specification: referenceTypeID size needs clarification

[Daniel D. Daugherty]

Ties moduleID to objectID and there's existing verbiage about
objectID being possibly variant in size depending on the
implementation.

Thumbs up.

Dan


On 4/28/16 1:00 AM, serguei.spit...@oracle.com wrote:

Please, review the JDWP spec change in the pubs repository.

This is the jdwp-spec.html patch:

diff -r 419446ca4a1b docs/technotes/guides/jpda/jdwp-spec.html

--- a/docs/technotes/guides/jpda/jdwp-spec.html Thu Apr 21 13:37:56 2016 -0700 +++ b/docs/technotes/guides/jpda/jdwp-spec.html Wed Apr 27 20:02:12 2016 -0700

@@ -277,6 +277,12 @@
 is a value.</td>
 </tr>
 <tr>
+<td><code>moduleID</code></td>
+<td>same as objectID</td>
+<td>Uniquely identifies an object in the target VM that is known to
+be a module object</td>
+</tr>
+<tr>
 <td><code>classLoaderID</code></td>
 <td>same as objectID</td>
 <td>Uniquely identifies an object in the target VM that is known to
@@ -296,7 +302,7 @@
 </tr>
 <tr>
 <td><code>referenceTypeID</code></td>
-<td>same as objectID</td>
+<td>Target VM-specific, up to 8 bytes (see below)</td>
 <td>Uniquely identifies a reference type in the target VM. It
 should not be assumed that for a particular class, the
 <code>classObjectID</code> and the <code>referenceTypeID</code> are


Summary:

JDWP specification at https://docs.oracle.com/javase/8/docs/technotes/guides/jpda/jdwp-spec.html says:

  Name               Size
  referenceTypeID  | same as objectID | ...

While the text at the bottom of the page is calling out referenceTypeID as being sized independently (along with objectID, fieidID, etc): "Object ids, reference type ids, field ids, method ids, and frame ids may be sized differently in different target VM implementations"

  IDSizes JDWP command also specifies referenceTypeID size.

The referenceTypeID "Size" column should say: "Target VM-specific, up to 8 bytes (see below)".

Also, the push of the "JDK-8049365: Update JDI and JDWP for modules" missed to update

  the jdwp-spec.html with introduction of the moduleID type:

Name        Size                Description

----------+-------------------+----------------------------------------------- moduleID | same as objectID | Uniquely identifies an object in the target VM that is known to be a module object.

Testing:

   Checked the jdwp-spec.html in the browser window.
   No other testing is needed.


Thanks,
Serguei