RFR (S) 8249137: Remove CollectedHeap::obj_size

[Chris Plummer]

Looks good to me.

Chris

On 7/10/20 8:07 AM, Daniel D. Daugherty wrote:
> On 7/10/20 4:37 AM, Aleksey Shipilev wrote:
>> Okay, thanks.
>>
>> I already have 2 reviewers (rkennke, tschatzl), do I need more 
>> specifically from serviceability-dev@?
>
> Since you're touching the Serviceability team's code, it would be
> polite to wait for a review...
>
> Dan
>
>
>>
>> -Aleksey
>>
>> On 7/9/20 3:34 PM, Daniel D. Daugherty wrote:
>>> Adding serviceability-dev at ... since a couple of JVM/TI files are 
>>> changed
>>> in this RFR. Also, I moved the bug from hotspot/runtime -> hotspot/gc.
>>>
>>> Dan
>>>
>>>
>>> On 7/9/20 2:36 AM, Aleksey Shipilev wrote:
>>>> RFE:
>>>>     https://bugs.openjdk.java.net/browse/JDK-8249137
>>>>
>>>> It was added by JDK-8211270 to support old-style Shenandoah that 
>>>> needed a separate fwdptr slot.
>>>> After JDK-8224584 it does not need this anymore. Additionally, 
>>>> CH::obj_size may disagree with other
>>>> code that pokes at layout helper directly, for example 
>>>> GraphKit::new_instance.
>>>>
>>>> This also avoids a virtual call on some paths, although those paths 
>>>> are not very performance-sensitive.
>>>>
>>>> The patch is a simple series of few-liners:
>>>>
>>>> diff -r 9cc348ebdc82 src/hotspot/share/gc/shared/collectedHeap.cpp
>>>> --- a/src/hotspot/share/gc/shared/collectedHeap.cpp     Thu Jul 09 
>>>> 04:32:30 2020 +0200
>>>> +++ b/src/hotspot/share/gc/shared/collectedHeap.cpp     Thu Jul 09 
>>>> 08:05:46 2020 +0200
>>>> @@ -578,6 +578,2 @@
>>>>
>>>> -size_t CollectedHeap::obj_size(oop obj) const {
>>>> -  return obj->size();
>>>> -}
>>>> -
>>>>    uint32_t CollectedHeap::hash_oop(oop obj) const {
>>>> diff -r 9cc348ebdc82 src/hotspot/share/gc/shared/collectedHeap.hpp
>>>> --- a/src/hotspot/share/gc/shared/collectedHeap.hpp     Thu Jul 09 
>>>> 04:32:30 2020 +0200
>>>> +++ b/src/hotspot/share/gc/shared/collectedHeap.hpp     Thu Jul 09 
>>>> 08:05:46 2020 +0200
>>>> @@ -495,4 +495,2 @@
>>>>
>>>> -  virtual size_t obj_size(oop obj) const;
>>>> -
>>>>      // Non product verification and debugging.
>>>> diff -r 9cc348ebdc82 src/hotspot/share/prims/jvmtiEnv.cpp
>>>> --- a/src/hotspot/share/prims/jvmtiEnv.cpp      Thu Jul 09 04:32:30 
>>>> 2020 +0200
>>>> +++ b/src/hotspot/share/prims/jvmtiEnv.cpp      Thu Jul 09 08:05:46 
>>>> 2020 +0200
>>>> @@ -488,3 +488,3 @@
>>>>      NULL_CHECK(mirror, JVMTI_ERROR_INVALID_OBJECT);
>>>> -  *size_ptr = (jlong)Universe::heap()->obj_size(mirror) * wordSize;
>>>> +  *size_ptr = (jlong)mirror->size() * wordSize;
>>>>      return JVMTI_ERROR_NONE;
>>>> diff -r 9cc348ebdc82 src/hotspot/share/prims/jvmtiExport.cpp
>>>> --- a/src/hotspot/share/prims/jvmtiExport.cpp   Thu Jul 09 04:32:30 
>>>> 2020 +0200
>>>> +++ b/src/hotspot/share/prims/jvmtiExport.cpp   Thu Jul 09 08:05:46 
>>>> 2020 +0200
>>>> @@ -1067,3 +1067,3 @@
>>>>         _jobj = (jobject)to_jobject(obj);
>>>> -     _size = Universe::heap()->obj_size(obj) * wordSize;
>>>> +     _size = obj->size() * wordSize;
>>>>       };
>>>> diff -r 9cc348ebdc82 src/hotspot/share/prims/whitebox.cpp
>>>> --- a/src/hotspot/share/prims/whitebox.cpp      Thu Jul 09 04:32:30 
>>>> 2020 +0200
>>>> +++ b/src/hotspot/share/prims/whitebox.cpp      Thu Jul 09 08:05:46 
>>>> 2020 +0200
>>>> @@ -389,3 +389,3 @@
>>>>      oop p = JNIHandles::resolve(obj);
>>>> -  return Universe::heap()->obj_size(p) * HeapWordSize;
>>>> +  return p->size() * HeapWordSize;
>>>>    WB_END
>>>>
>>>> Testing: tier{1,2}; jdk-submit (running)
>>>>
>>
>