RFR: 8367719: Refactor JNI code that uses class_to_verify_considering_redefinition()

[David Holmes]

On Tue, 16 Sep 2025 02:44:26 GMT, Ioi Lam <iklam at openjdk.org> wrote:

> Simplify the boilerplate code in jvm.cpp that calls `JvmtiThreadState::class_to_verify_considering_redefinition()`, and reduce the number of `InstanceKlass::cast()` calls.
> 
> I also changed a few fields/arguments from `Klass*` to `InstanceKlass*` as these are used exclusively with `InstanceKlass*`.

Looks good. Just some minor nits.

Thanks

src/hotspot/share/prims/jvm.cpp line 2263:

> 2261: // Please, refer to the description in the jvmtiThreadState.hpp.
> 2262: 
> 2263: inline Klass* get_klass_considering_redefinition(jclass cls, JavaThread *thread) {

Suggestion:

inline Klass* get_klass_considering_redefinition(jclass cls, JavaThread* thread) {

src/hotspot/share/prims/jvm.cpp line 2269:

> 2267: }
> 2268: 
> 2269: inline InstanceKlass* get_instance_klass_considering_redefinition(jclass cls, JavaThread *thread) {

Suggestion:

inline InstanceKlass* get_instance_klass_considering_redefinition(jclass cls, JavaThread* thread) {

src/hotspot/share/prims/jvmtiThreadState.hpp line 31:

> 29: #include "memory/allocation.hpp"
> 30: #include "oops/oopHandle.hpp"
> 31: #include "oops/instanceKlass.hpp"

Suggestion:

#include "oops/instanceKlass.hpp"
#include "oops/oopHandle.hpp"

Include order is wrong.

src/hotspot/share/prims/jvmtiThreadState.hpp line 438:

> 436:   static inline
> 437:   Klass* class_to_verify_considering_redefinition(Klass* klass,
> 438:                                                   JavaThread *thread) {

Suggestion:

                                                  JavaThread* thread) {

src/hotspot/share/prims/jvmtiThreadState.hpp line 445:

> 443:     } else {
> 444:       return class_to_verify_considering_redefinition(InstanceKlass::cast(klass),
> 445:                                                       thread);

Suggestion:

      return class_to_verify_considering_redefinition(InstanceKlass::cast(klass), thread);

src/hotspot/share/prims/jvmtiThreadState.hpp line 451:

> 449:   static inline
> 450:   InstanceKlass* class_to_verify_considering_redefinition(InstanceKlass* klass,
> 451:                                                           JavaThread *thread) {

Suggestion:

                                                          JavaThread* thread) {

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

Changes requested by dholmes (Reviewer).

PR Review: https://git.openjdk.org/jdk/pull/27303#pullrequestreview-3227749202
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351033232
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351035033
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351044566
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351048289
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351050636
PR Review Comment: https://git.openjdk.org/jdk/pull/27303#discussion_r2351051532