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/*
* Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* 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
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
#include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
#include "gc_implementation/parallelScavenge/psVirtualspace.hpp"
#include "gc_implementation/shared/collectorCounters.hpp"
#include "memory/allocation.hpp"
#include "oops/oop.hpp"
#include "utilities/stack.hpp"
class GCTaskManager;
class GCTaskQueue;
class OopStack;
class ReferenceProcessor;
class ParallelScavengeHeap;
class PSIsAliveClosure;
class PSRefProcTaskExecutor;
class PSScavenge: AllStatic {
friend class PSIsAliveClosure;
friend class PSKeepAliveClosure;
friend class PSPromotionManager;
enum ScavengeSkippedCause {
not_skipped = 0,
to_space_not_empty,
promoted_too_large,
full_follows_scavenge
};
// Saved value of to_space->top(), used to prevent objects in to_space from
// being rescanned.
static HeapWord* _to_space_top_before_gc;
// Number of consecutive attempts to scavenge that were skipped
static int _consecutive_skipped_scavenges;
protected:
// Flags/counters
static ReferenceProcessor* _ref_processor; // Reference processor for scavenging.
static PSIsAliveClosure _is_alive_closure; // Closure used for reference processing
static CardTableExtension* _card_table; // We cache the card table for fast access.
static bool _survivor_overflow; // Overflow this collection
static int _tenuring_threshold; // tenuring threshold for next scavenge
static elapsedTimer _accumulated_time; // total time spent on scavenge
static HeapWord* _young_generation_boundary; // The lowest address possible for the young_gen.
// This is used to decide if an oop should be scavenged,
// cards should be marked, etc.
static Stack<markOop> _preserved_mark_stack; // List of marks to be restored after failed promotion
static Stack<oop> _preserved_oop_stack; // List of oops that need their mark restored.
static CollectorCounters* _counters; // collector performance counters
static bool _promotion_failed;
static void clean_up_failed_promotion();
static bool should_attempt_scavenge();
static HeapWord* to_space_top_before_gc() { return _to_space_top_before_gc; }
static inline void save_to_space_top_before_gc();
// Private accessors
static CardTableExtension* const card_table() { assert(_card_table != NULL, "Sanity"); return _card_table; }
public:
// Accessors
static int tenuring_threshold() { return _tenuring_threshold; }
static elapsedTimer* accumulated_time() { return &_accumulated_time; }
static bool promotion_failed() { return _promotion_failed; }
static int consecutive_skipped_scavenges()
{ return _consecutive_skipped_scavenges; }
// Performance Counters
static CollectorCounters* counters() { return _counters; }
// Used by scavenge_contents && psMarkSweep
static ReferenceProcessor* const reference_processor() {
assert(_ref_processor != NULL, "Sanity");
return _ref_processor;
}
// Used to add tasks
static GCTaskManager* const gc_task_manager();
// The promotion managers tell us if they encountered overflow
static void set_survivor_overflow(bool state) {
_survivor_overflow = state;
}
// Adaptive size policy support. When the young generation/old generation
// boundary moves, _young_generation_boundary must be reset
static void set_young_generation_boundary(HeapWord* v) {
_young_generation_boundary = v;
}
// Called by parallelScavengeHeap to init the tenuring threshold
static void initialize();
// Scavenge entry point
static void invoke();
// Return true is a collection was done. Return
// false if the collection was skipped.
static bool invoke_no_policy();
// If an attempt to promote fails, this method is invoked
static void oop_promotion_failed(oop obj, markOop obj_mark);
template <class T> static inline bool should_scavenge(T* p);
// These call should_scavenge() above and, if it returns true, also check that
// the object was not newly copied into to_space. The version with the bool
// argument is a convenience wrapper that fetches the to_space pointer from
// the heap and calls the other version (if the arg is true).
template <class T> static inline bool should_scavenge(T* p, MutableSpace* to_space);
template <class T> static inline bool should_scavenge(T* p, bool check_to_space);
template <class T> inline static void copy_and_push_safe_barrier(PSPromotionManager* pm, T* p);
// Is an object in the young generation
// This assumes that the HeapWord argument is in the heap,
// so it only checks one side of the complete predicate.
inline static bool is_obj_in_young(HeapWord* o) {
const bool result = (o >= _young_generation_boundary);
return result;
}
};
#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_HPP
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