6962589: remove breadth first scanning code from parallel gc
Summary: Remove the breadth-first copying order from ParallelScavenge and use depth-first by default.
Reviewed-by: jcoomes, ysr, johnc
/*
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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// A SpaceCounter is a holder class for performance counters
// that track a space;
class SpaceCounters: public CHeapObj {
friend class VMStructs;
private:
PerfVariable* _capacity;
PerfVariable* _used;
// Constant PerfData types don't need to retain a reference.
// However, it's a good idea to document them here.
// PerfConstant* _size;
MutableSpace* _object_space;
char* _name_space;
public:
SpaceCounters(const char* name, int ordinal, size_t max_size,
MutableSpace* m, GenerationCounters* gc);
~SpaceCounters() {
if (_name_space != NULL) FREE_C_HEAP_ARRAY(char, _name_space);
}
inline void update_capacity() {
_capacity->set_value(_object_space->capacity_in_bytes());
}
inline void update_used() {
_used->set_value(_object_space->used_in_bytes());
}
inline void update_all() {
update_used();
update_capacity();
}
const char* name_space() const { return _name_space; }
};
class MutableSpaceUsedHelper: public PerfLongSampleHelper {
private:
MutableSpace* _m;
public:
MutableSpaceUsedHelper(MutableSpace* m) : _m(m) { }
inline jlong take_sample() {
return _m->used_in_bytes();
}
};