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

[David Holmes]

Hi Yumin,

This looks pretty good.

On 12/04/2013 4:12 PM, Yumin Qi wrote:
>    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/>

src/share/vm/classfile/altHashing.cpp

Can these be directly stack-allocated arrays instead of C-Heap ?

---

allocation.cpp

672 // %% note this is causing a problem on solaris debug build. the global
673 // new is being called from jdk source and causing data corruption.
674 // 
src/share/native/sun/awt/font/fontmanager/textcache/hsMemory.cpp::hsSoftNew

Is this still an issue?

As a general comment do we need all the operator new[] additions?

---

allocation.inline.hpp

Can we reduce code duplication by changing, eg:

#ifdef ASSERT
     void* p = (void*)AllocateHeap(size, F, (caller_pc != 0 ? caller_pc 
: CALLER_PC));
     if (PrintMallocFree) trace_heap_malloc(size, "CHeapObj-new", p);
     return p;
#else
     return (void *) AllocateHeap(size, F, (caller_pc != 0 ? caller_pc : 
CALLER_PC));
#endif

to

     void* p = (void*)AllocateHeap(size, F, (caller_pc != 0 ? caller_pc 
: CALLER_PC));
#ifdef ASSERT
     if (PrintMallocFree) trace_heap_malloc(size, "CHeapObj-new", p);
#endif
     return p;

---

src/share/vm/memory/cardTableModRefBS.cpp

86   for (i = 0; i < max_covered_regions; i++) {
87     _covered[i].set_start(NULL)  ; _covered[i].set_word_size(0)  ;
88     _committed[i].set_start(NULL); _committed[i].set_word_size(0);
89   }

this appears to be a semantic change, which leads me to ask:

Given "new MemRegion[1]" vs NEW_C_HEAP_ARRAY(...,1,...) what are the 
array contents initialized to in each case?

---

src/share/vm/memory/cardTableRS.cpp

   68 CardTableRS::~CardTableRS() {
   69   if (_last_cur_val_in_gen) {
   70     // FREE_C_HEAP_ARRAY(jbyte, _last_cur_val_in_gen, mtInternal);
   71   }
   72 }

Was this an existing memory leak? I'm noticing that most uses of "new 
X[n]" don't have a corresponding delete!

But why is this commented out?

---

src/share/vm/runtime/handles.hpp

initialize_thread shouldn't need to be public. What is calling it?

---

src/share/vm/runtime/thread.cpp

These changes don't look right - why doesn't HandleMark extend one of 
the allocation base classes ?


Thanks,
David
-----

>    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
>
>