Summary

Deprecate the JDI/JDWP capabilities canUnrestrictedlyRedefineClasses and canAddMethod.

Problem

The JDWP/JDI canUnrestrictedlyRedefineClasses and canAddMethod capabilities are not compatible with the JVM TI spec as the JVM TI does not allow unrestricted class redefinition. It is why these capabilities are always false in the reference implementation of the JDI.

Solution

Deprecate these capabilities and make it clear that it returns always false in the reference implementation.

Specification

1. Update the JDWP VirtualMachine::capabilitiesNew command spec:

   Update the description of capabilities canUnrestrictedlyRedefineClasses and canAddMethod in the ReplyData section of the capabilitiesNew command:

   • add the deprecation annotation before method declaration:

@Deprecated(since="15") A JVM TI based JDWP back-end will never set this capability to true.

2. Update the java-doc for JDI

   Updated the com.sun.jdi.VirtualMachine spec for methods canUnrestrictedlyRedefineClasses and canAddMethod:

   • add the deprecation annotation before method declaration:

@Deprecated(since="15")

• add a deprecation comment:

@deprecated A JVM TI based JDWP back-end will never set this capability to true.

Webrev:

http://cr.openjdk.java.net/~sspitsyn/webrevs/2020/jdwp-depr.1/src/

Updated JDWP VirtualMachine::capabilitiesNew spec:

http://cr.openjdk.java.net/~sspitsyn/webrevs/2020/jdwp-depr.1/docs/specs/jdwp/jdwp-protocol.html#JDWP_VirtualMachine_CapabilitiesNew

Updated JDI com.sun.jdi.VirtualMachine spec:

http://cr.openjdk.java.net/~sspitsyn/webrevs/2020/jdwp-depr.1/docs/api/jdk.jdi/com/sun/jdi/VirtualMachine.html#canAddMethod()

http://cr.openjdk.java.net/~sspitsyn/webrevs/2020/jdwp-depr.1/docs/api/jdk.jdi/com/sun/jdi/VirtualMachine.html#canUnrestrictedlyRedefineClasses()