RFR: 8035938: Memory leak in JvmtiEnv::GetConstantPool

[Kevin Walls]

Thanks Serguei, thanks Dan!


On 16/01/2015 17:51, Daniel D. Daugherty wrote:
> > src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>
>     These lines allocate:
>
>     line 59:      _symmap = new SymbolHashMap();
>     line 60:      _classmap = new SymbolHashMap();
>
>     and these lines free incorrectly:
>
>     line 71:        os::free(_symmap);
>     line 75:        os::free(_classmap);
>
>     so the proposed fix looks good!
>
>
> Dan
>
>
> On 1/16/15 3:17 AM, Mattis Castegren wrote:
>> Hi
>>
>> This bug is targeted for 7u80, with rdp2 next Tuesday. It would be 
>> great to get a review for this fix as soon as possible, so that we 
>> can get this fix out in the last public JDK 7 release.
>>
>> Kind Regards
>> /Mattis
>>
>> -----Original Message-----
>> From: Kevin Walls
>> Sent: den 15 januari 2015 15:18
>> To: serviceability-dev at openjdk.java.net
>> Subject: RFR: 8035938: Memory leak in JvmtiEnv::GetConstantPool
>>
>> Hi,
>>
>> This is a review request for a change in JVMTI, where we os::free() some
>> objects where we should delete them.  The problem was logged against 7,
>> though it exists up to the present day, below is a diff in current
>> latest http://hg.openjdk.java.net/jdk9/hs-rt/hotspot
>>
>>
>> Testing:
>> I've used a native JVMTI agent to call GetConstantPool() during an
>> object allocation callback.  Memory usage does appear less after the
>> change, it can be 5-6MB in a trivial testcase with a small number of
>> allocations monitored, each inoking GetConstantlPool().
>>
>> (In my test agent the  GetConstantPool() call returns a JVMTI error 101
>> after a fairly short time and a relatively small number of allocations
>> are monitored.)
>>
>> If this is OK to submit without testcase that's great.  I don't see
>> other examples of native agents in the standard hotspot tests.
>>
>> bug
>> https://bugs.openjdk.java.net/browse/JDK-8035938
>>
>> diff:
>> $ hg diff src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>> diff --git a/src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>> b/src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>> --- a/src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>> +++ b/src/share/vm/prims/jvmtiClassFileReconstituter.hpp
>> @@ -68,11 +68,11 @@
>>
>>      ~JvmtiConstantPoolReconstituter() {
>>        if (_symmap != NULL) {
>> -      os::free(_symmap);
>> +      delete _symmap;
>>          _symmap = NULL;
>>        }
>>        if (_classmap != NULL) {
>> -      os::free(_classmap);
>> +      delete _classmap;
>>          _classmap = NULL;
>>        }
>>      }
>>
>>
>>
>> Thanks
>> Kevin
>>
>>
>>
>