8227866: Shenandoah: Split weak root processing and class unloading in parallel cleaning task
Reviewed-by: rkennke
/*
* Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* 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).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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#ifndef SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
#define SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP
#include "memory/allocation.hpp"
#include "gc/shenandoah/shenandoahHeap.hpp"
#include "gc/shenandoah/shenandoahHeapRegion.hpp"
class ShenandoahCollectionSet : public CHeapObj<mtGC> {
friend class ShenandoahHeap;
private:
size_t const _map_size;
size_t const _region_size_bytes_shift;
ReservedSpace _map_space;
char* const _cset_map;
// Bias cset map's base address for fast test if an oop is in cset
char* const _biased_cset_map;
ShenandoahHeap* const _heap;
size_t _garbage;
size_t _live_data;
size_t _used;
size_t _region_count;
DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
volatile jint _current_index;
DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
public:
ShenandoahCollectionSet(ShenandoahHeap* heap, char* heap_base, size_t size);
// Add region to collection set
void add_region(ShenandoahHeapRegion* r);
bool add_region_check_for_duplicates(ShenandoahHeapRegion* r);
// Bring per-region statuses to consistency with this collection.
// TODO: This is a transitional interface that bridges the gap between
// region statuses and this collection. Should go away after we merge them.
void update_region_status();
// Remove region from collection set
void remove_region(ShenandoahHeapRegion* r);
// MT version
ShenandoahHeapRegion* claim_next();
// Single-thread version
ShenandoahHeapRegion* next();
size_t count() const { return _region_count; }
bool is_empty() const { return _region_count == 0; }
void clear_current_index() {
_current_index = 0;
}
inline bool is_in(ShenandoahHeapRegion* r) const;
inline bool is_in(size_t region_number) const;
inline bool is_in(HeapWord* p) const;
void print_on(outputStream* out) const;
size_t used() const { return _used; }
size_t live_data() const { return _live_data; }
size_t garbage() const { return _garbage; }
void clear();
private:
char* map_address() const {
return _cset_map;
}
char* biased_map_address() const {
return _biased_cset_map;
}
};
#endif // SHARE_GC_SHENANDOAH_SHENANDOAHCOLLECTIONSET_HPP