RFR: 8247470: Fix CHeap GrowableArray NMT accounting

[Stefan Karlsson]

Hi all,

Please review this patch to fix the NMT accounting of CHeap 
GrowableArray allocations.

https://cr.openjdk.java.net/~stefank/8247470/webrev.01/
https://bugs.openjdk.java.net/browse/JDK-8247470

The initial reason why I started fixing this was that I found code like 
this:

src/hotspot/share/classfile/javaClasses.cpp:
     new (ResourceObj::C_HEAP, mtModule) GrowableArray<Klass*>(500, true);

Before this patch, the GrowableArray constructor looked like this:

GrowableArray(int initial_size, bool C_heap = false, MEMFLAGS F = 
mtInternal)
: GenericGrowableArray(initial_size, 0, C_heap, F) {
_data = (E*)raw_allocate(sizeof(E));

and:

GenericGrowableArray(int initial_size, int initial_len, bool c_heap, 
MEMFLAGS flags = mtNone) { _len = initial_len; _max = initial_size; 
_memflags = flags;

and:
void* GenericGrowableArray::raw_allocate(int elementSize) {
...
return (void*)AllocateHeap(byte_size, _memflags);

This means that the GrowableArray instance was accounted to mtModule, 
but the backing memory for the array was accounted to mtInternal.

My proposal for fixing this is to fuse the (c_heap, flags) duality into 
one parameter (flags). The call sites are then changed like this:

For resource allocations:
GrowableArray(...) -> GrowableArray(...)
GrowableArray(... /* c_heap */ false) -> GrowableArray(...)
GrowableArray(... /* c_heap */ false, /* flags */ mtXX) -> 
GrowableArray(...)

For CHeap allocations:
GrowableArray(... /* c_heap */ true, /* flags */ mtXX) -> 
GrowableArray(..., mtXX)
GrowableArray(... /* c_heap */ true) -> GrowableArray(..., mtInternal)

That is, if you specify a "valid" mtXX tag it invokes the CHeap 
allocation path. If you don't specify a mtXX tag, then 'flags' get the 
mtNone default value. This is a marker for the code that no CHeap 
allocation should be done.

While properly tagging all GrowableArray allocations, I went ahead and 
changed most GrowableArray mtInternal tags to the appropriate values. I 
also introduced a new mtServiceability tag, since a lot of the 
mtInternal tags were in areas dealing with serviceability code. I could 
split this out into a separate patch, if necessary.

This hasn't been fully tested yet, because I'd like to get some early 
feedback.

Thanks,
StefanK