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8189871: Refactor GC barriers to use declarative semantics

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Reviewed-by: pliden, rkennke, coleenp, dholmes, kbarrett, stefank
This commit is contained in:
Erik Österlund 2017-11-20 13:07:44 +01:00
parent 63122ba705
commit 3e5e2f03b1
45 changed files with 3458 additions and 806 deletions
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39
src/hotspot/share/oops/objArrayKlass.cpp
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@ -44,7 +44,6 @@
#include "oops/symbol.hpp"
#include "runtime/handles.inline.hpp"
#include "runtime/mutexLocker.hpp"
#include "utilities/copy.hpp"
#include "utilities/macros.hpp"
ObjArrayKlass* ObjArrayKlass::allocate(ClassLoaderData* loader_data, int n, Klass* k, Symbol* name, TRAPS) {
@ -221,55 +220,25 @@ oop ObjArrayKlass::multi_allocate(int rank, jint* sizes, TRAPS) {
// Either oop or narrowOop depending on UseCompressedOops.
template <class T> void ObjArrayKlass::do_copy(arrayOop s, T* src,
arrayOop d, T* dst, int length, TRAPS) {
BarrierSet* bs = Universe::heap()->barrier_set();
// For performance reasons, we assume we are that the write barrier we
// are using has optimized modes for arrays of references. At least one
// of the asserts below will fail if this is not the case.
if (s == d) {
// since source and destination are equal we do not need conversion checks.
assert(length > 0, "sanity check");
bs->write_ref_array_pre(dst, length);
Copy::conjoint_oops_atomic(src, dst, length);
HeapAccess<>::oop_arraycopy(s, d, src, dst, length);
} else {
// We have to make sure all elements conform to the destination array
Klass* bound = ObjArrayKlass::cast(d->klass())->element_klass();
Klass* stype = ObjArrayKlass::cast(s->klass())->element_klass();
if (stype == bound || stype->is_subtype_of(bound)) {
// elements are guaranteed to be subtypes, so no check necessary
bs->write_ref_array_pre(dst, length);
Copy::conjoint_oops_atomic(src, dst, length);
HeapAccess<ARRAYCOPY_DISJOINT>::oop_arraycopy(s, d, src, dst, length);
} else {
// slow case: need individual subtype checks
// note: don't use obj_at_put below because it includes a redundant store check
T* from = src;
T* end = from + length;
for (T* p = dst; from < end; from++, p++) {
// XXX this is going to be slow.
T element = *from;
// even slower now
bool element_is_null = oopDesc::is_null(element);
oop new_val = element_is_null ? oop(NULL)
: oopDesc::decode_heap_oop_not_null(element);
if (element_is_null ||
(new_val->klass())->is_subtype_of(bound)) {
bs->write_ref_field_pre(p, new_val);
*p = element;
} else {
// We must do a barrier to cover the partial copy.
const size_t pd = pointer_delta(p, dst, (size_t)heapOopSize);
// pointer delta is scaled to number of elements (length field in
// objArrayOop) which we assume is 32 bit.
assert(pd == (size_t)(int)pd, "length field overflow");
bs->write_ref_array((HeapWord*)dst, pd);
THROW(vmSymbols::java_lang_ArrayStoreException());
return;
}
if (!HeapAccess<ARRAYCOPY_DISJOINT | ARRAYCOPY_CHECKCAST>::oop_arraycopy(s, d, src, dst, length)) {
THROW(vmSymbols::java_lang_ArrayStoreException());
}
}
}
bs->write_ref_array((HeapWord*)dst, length);
}
void ObjArrayKlass::copy_array(arrayOop s, int src_pos, arrayOop d,