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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#ifndef SHARE_VM_MEMORY_TENUREDGENERATION_HPP
#define SHARE_VM_MEMORY_TENUREDGENERATION_HPP
#include "gc_implementation/shared/cSpaceCounters.hpp"
#include "gc_implementation/shared/gcStats.hpp"
#include "gc_implementation/shared/generationCounters.hpp"
#include "memory/generation.hpp"
// TenuredGeneration models the heap containing old (promoted/tenured) objects.
class ParGCAllocBufferWithBOT;
class TenuredGeneration: public OneContigSpaceCardGeneration {
friend class VMStructs;
protected:
// current shrinking effect: this damps shrinking when the heap gets empty.
size_t _shrink_factor;
// Some statistics from before gc started.
// These are gathered in the gc_prologue (and should_collect)
// to control growing/shrinking policy in spite of promotions.
size_t _capacity_at_prologue;
size_t _used_at_prologue;
#ifndef SERIALGC
// To support parallel promotion: an array of parallel allocation
// buffers, one per thread, initially NULL.
ParGCAllocBufferWithBOT** _alloc_buffers;
#endif // SERIALGC
// Retire all alloc buffers before a full GC, so that they will be
// re-allocated at the start of the next young GC.
void retire_alloc_buffers_before_full_gc();
GenerationCounters* _gen_counters;
CSpaceCounters* _space_counters;
public:
TenuredGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
GenRemSet* remset);
Generation::Name kind() { return Generation::MarkSweepCompact; }
// Printing
const char* name() const;
const char* short_name() const { return "Tenured"; }
bool must_be_youngest() const { return false; }
bool must_be_oldest() const { return true; }
// Does a "full" (forced) collection invoked on this generation collect
// all younger generations as well? Note that this is a
// hack to allow the collection of the younger gen first if the flag is
// set. This is better than using th policy's should_collect_gen0_first()
// since that causes us to do an extra unnecessary pair of restart-&-stop-world.
virtual bool full_collects_younger_generations() const {
return !CollectGen0First;
}
// Mark sweep support
void compute_new_size();
virtual void gc_prologue(bool full);
virtual void gc_epilogue(bool full);
bool should_collect(bool full,
size_t word_size,
bool is_tlab);
virtual void collect(bool full,
bool clear_all_soft_refs,
size_t size,
bool is_tlab);
#ifndef SERIALGC
// Overrides.
virtual oop par_promote(int thread_num,
oop obj, markOop m, size_t word_sz);
virtual void par_promote_alloc_undo(int thread_num,
HeapWord* obj, size_t word_sz);
virtual void par_promote_alloc_done(int thread_num);
#endif // SERIALGC
// Performance Counter support
void update_counters();
// Statistics
virtual void update_gc_stats(int level, bool full);
virtual bool promotion_attempt_is_safe(size_t max_promoted_in_bytes) const;
void verify_alloc_buffers_clean();
};
#endif // SHARE_VM_MEMORY_TENUREDGENERATION_HPP