RFR: 8010992: Remove calls to global ::operator new[] and new

[Yumin Qi]

For HandleMark,


On 4/14/2013 11:07 PM, David Holmes wrote:
> Hi Yumin,
>
> On 13/04/2013 7:07 AM, Yumin Qi wrote:
>> After take feedback and modify, new webrev
>>
>> http://cr.openjdk.java.net/~minqi/8010992/webrev1
>> <http://cr.openjdk.java.net/%7Eminqi/8010992/webrev1>
>
> I still find the HandleMark changes unsatisfactory. The CHeap 
> allocated HandleMark in the Thread() constructor is a bit of a hack. 
> HandleMarks should be stack-allocated. Plus we seem to leak that CHeap 
> allocated HandleMark as we don't keep any pointer to it! I think this 
> needs to be re-visited, but as a separate CR.
>

The default constructor for HandleMark:
inline HandleMark::HandleMark() {
   initialize(Thread::current());
}

In thread.cpp, Thread::Thread(), the last HandleMark is created in heap,
-  new HandleMark(this);
-
+  HandleMark *hm = NEW_C_HEAP_OBJ(HandleMark, mtThread);
+  hm->initialize(this);
The original code, is calling the constructor with 'this'.  Unless we 
code a macro to pass 'this' as argument, which looks specific not 
generic, to call the constructor.  When call default constructor here, 
will assert current thread is NULL --- the real native thread has not 
created yet , the thread id is not cached so we get back a NULL for 
Thread::current(). That is, we could not call the default constructor at 
this time, this change seems strange but works --- first created the 
object without calling constructor in heap, then initialize with 'this'.

The problem is ~HandleMark is not called this way. Need to have a 
version to call dtor which seems ugly.

The handle mark here for what? I could  not spot any handle allocated 
from this point in Thread creation.

Thanks
Yumin


> ---
>
> allocation.hpp:
>
> If  NEW_C_HEAP_OBJECT_ARRAY invokes the ctor for each array element 
> don't we need a new FREE_C_HEAP_OBJECT_ARRAY to invoke the dtor's 
> before deallocating ?
>
> ---
>
> src/share/vm/utilities/quickSort.cpp
>
> Why does only Solaris need the allocation headers included ?? I would 
> expect all platforms to need to the same headers here.
>
> Thanks,
> David
>
>>
>>
>> Thanks
>> Yumin
>>
>> On 4/12/2013 10:45 AM, Zhengyu Gu wrote:
>>> .
>>>>> cardTableModRefBS.cpp
>>>>>   #87 and #88, why set_start(NULL) are needed?
>>>>>
>>>> This is default constructor does, here just copy that code. Since we
>>>> did not call constructor by using this MACRO. It is a _ValueObj,
>>>> should not call new, but I think we can use NEW_C_HEAP_OBJ3, which
>>>> will call ctors.
>>> NEW_C_HEAP_OBJECT_ARRAY macro does invoke ctor ... that is what
>>> allocation.hpp #618 does.
>>>
>>> Thanks,
>>>
>>> -Zhengyu
>>>
>>>
>>>>> carTableRS.cpp
>>>>>   #70, why it is commented out? If so, you don't need the dstor
>>>>>
>>>>>
>>>> See reply to David H.
>>>>
>>>>
>>>> Thanks
>>>> Yumin
>>>>> -Zhengyu
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 4/12/2013 2:12 AM, Yumin Qi wrote:
>>>>>> Hi,
>>>>>>
>>>>>>   Can I have your inputs for the fix?
>>>>>>   webrev:
>>>>>>
>>>>>>  http://cr.openjdk.java.net/~minqi/8010992/webrev/
>>>>>> <http://cr.openjdk.java.net/%7Eminqi/8010992/webrev/>
>>>>>>
>>>>>>   Bug:  8010992: Remove calls to global ::operator new[] and new
>>>>>> https://jbs.oracle.com/bugs/browse/JDK-8010992
>>>>>>
>>>>>> Problem description:  Remove the usage of global operator ::new[]
>>>>>> and ::new. In hotspot debug build, disable the usage of global
>>>>>> new[] and new.  Hotspot does not throw c++ exceptions, but it
>>>>>> cannot prevent third party code to catch such exceptions.  By
>>>>>> disabling use of global operator new[] and new, we constrain the
>>>>>> exception disposal within hotspot. C++ classes (as same for
>>>>>> structs) in hotspot have to either extends from CHeapObj or
>>>>>> ResourceObj unless they are stack objects or values which have to
>>>>>> be from StackObj or _ValueObj respectively.  Or they have to
>>>>>> implement their own operator new[] or new.
>>>>>>
>>>>>> Thanks
>>>>>> Yumin
>>>>>>
>>>>>>
>>>>>
>>>>
>>>
>>