src/hotspot/share/gc/g1/g1ParScanThreadState.hpp - platform/libcore - Git at Google

 /*
  * Copyright (c) 2014, 2018, 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_G1_G1PARSCANTHREADSTATE_HPP
 #define SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP

 #include "gc/g1/dirtyCardQueue.hpp"
 #include "gc/g1/g1CardTable.hpp"
 #include "gc/g1/g1CollectedHeap.hpp"
 #include "gc/g1/g1OopClosures.hpp"
 #include "gc/g1/g1Policy.hpp"
 #include "gc/g1/g1RemSet.hpp"
 #include "gc/g1/heapRegionRemSet.hpp"
 #include "gc/shared/ageTable.hpp"
 #include "memory/allocation.hpp"
 #include "oops/oop.hpp"
 #include "utilities/ticks.hpp"

 class G1PLABAllocator;
 class G1EvacuationRootClosures;
 class HeapRegion;
 class outputStream;

 class G1ParScanThreadState : public CHeapObj<mtGC> {
   G1CollectedHeap* _g1h;
   RefToScanQueue*  _refs;
   DirtyCardQueue   _dcq;
   G1CardTable*     _ct;
   G1EvacuationRootClosures* _closures;

   G1PLABAllocator*  _plab_allocator;

   AgeTable          _age_table;
   InCSetState       _dest[InCSetState::Num];
   // Local tenuring threshold.
   uint              _tenuring_threshold;
   G1ScanEvacuatedObjClosure  _scanner;

   int  _hash_seed;
   uint _worker_id;

   // Upper and lower threshold to start and end work queue draining.
   uint const _stack_trim_upper_threshold;
   uint const _stack_trim_lower_threshold;

   Tickspan _trim_ticks;
   // Map from young-age-index (0 == not young, 1 is youngest) to
   // surviving words. base is what we get back from the malloc call
   size_t* _surviving_young_words_base;
   // this points into the array, as we use the first few entries for padding
   size_t* _surviving_young_words;

   // Indicates whether in the last generation (old) there is no more space
   // available for allocation.
   bool _old_gen_is_full;

 #define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))

   DirtyCardQueue& dirty_card_queue()             { return _dcq;  }
   G1CardTable* ct()                              { return _ct; }

   InCSetState dest(InCSetState original) const {
     assert(original.is_valid(),
            "Original state invalid: " CSETSTATE_FORMAT, original.value());
     assert(_dest[original.value()].is_valid_gen(),
            "Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
     return _dest[original.value()];
   }

 public:
   G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
   virtual ~G1ParScanThreadState();

   void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }

 #ifdef ASSERT
   bool queue_is_empty() const { return _refs->is_empty(); }

   bool verify_ref(narrowOop* ref) const;
   bool verify_ref(oop* ref) const;
   bool verify_task(StarTask ref) const;
 #endif // ASSERT

   template <class T> void do_oop_ext(T* ref);
   template <class T> void push_on_queue(T* ref);

   template <class T> void update_rs(HeapRegion* from, T* p, oop o) {
     assert(!HeapRegion::is_in_same_region(p, o), "Caller should have filtered out cross-region references already.");
     // If the field originates from the to-space, we don't need to include it
     // in the remembered set updates. Also, if we are not tracking the remembered
     // set in the destination region, do not bother either.
     if (!from->is_young() && _g1h->heap_region_containing((HeapWord*)o)->rem_set()->is_tracked()) {
       size_t card_index = ct()->index_for(p);
       // If the card hasn't been added to the buffer, do it.
       if (ct()->mark_card_deferred(card_index)) {
         dirty_card_queue().enqueue((jbyte*)ct()->byte_for_index(card_index));
       }
     }
   }

   G1EvacuationRootClosures* closures() { return _closures; }
   uint worker_id() { return _worker_id; }

   // Returns the current amount of waste due to alignment or not being able to fit
   // objects within LABs and the undo waste.
   virtual void waste(size_t& wasted, size_t& undo_wasted);

   size_t* surviving_young_words() {
     // We add one to hide entry 0 which accumulates surviving words for
     // age -1 regions (i.e. non-young ones)
     return _surviving_young_words + 1;
   }

   void flush(size_t* surviving_young_words);

 private:
   #define G1_PARTIAL_ARRAY_MASK 0x2

   inline bool has_partial_array_mask(oop* ref) const {
     return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
   }

   // We never encode partial array oops as narrowOop*, so return false immediately.
   // This allows the compiler to create optimized code when popping references from
   // the work queue.
   inline bool has_partial_array_mask(narrowOop* ref) const {
     assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
     return false;
   }

   // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
   // We always encode partial arrays as regular oop, to allow the
   // specialization for has_partial_array_mask() for narrowOops above.
   // This means that unintentional use of this method with narrowOops are caught
   // by the compiler.
   inline oop* set_partial_array_mask(oop obj) const {
     assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
     return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
   }

   inline oop clear_partial_array_mask(oop* ref) const {
     return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
   }

   inline void do_oop_partial_array(oop* p);

   // This method is applied to the fields of the objects that have just been copied.
   template <class T> inline void do_oop_evac(T* p);

   inline void deal_with_reference(oop* ref_to_scan);
   inline void deal_with_reference(narrowOop* ref_to_scan);

   inline void dispatch_reference(StarTask ref);

   // Tries to allocate word_sz in the PLAB of the next "generation" after trying to
   // allocate into dest. State is the original (source) cset state for the object
   // that is allocated for. Previous_plab_refill_failed indicates whether previously
   // a PLAB refill into "state" failed.
   // Returns a non-NULL pointer if successful, and updates dest if required.
   // Also determines whether we should continue to try to allocate into the various
   // generations or just end trying to allocate.
   HeapWord* allocate_in_next_plab(InCSetState const state,
                                   InCSetState* dest,
                                   size_t word_sz,
                                   bool previous_plab_refill_failed);

   inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);

   void report_promotion_event(InCSetState const dest_state,
                               oop const old, size_t word_sz, uint age,
                               HeapWord * const obj_ptr) const;

   inline bool needs_partial_trimming() const;
   inline bool is_partially_trimmed() const;

   inline void trim_queue_to_threshold(uint threshold);
 public:
   oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);

   void trim_queue();
   void trim_queue_partially();

   Tickspan trim_ticks() const;
   void reset_trim_ticks();

   inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);

   // An attempt to evacuate "obj" has failed; take necessary steps.
   oop handle_evacuation_failure_par(oop obj, markOop m);
 };

 class G1ParScanThreadStateSet : public StackObj {
   G1CollectedHeap* _g1h;
   G1ParScanThreadState** _states;
   size_t* _surviving_young_words_total;
   size_t _young_cset_length;
   uint _n_workers;
   bool _flushed;

  public:
   G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length);
   ~G1ParScanThreadStateSet();

   void flush();

   G1ParScanThreadState* state_for_worker(uint worker_id);

   const size_t* surviving_young_words() const;

  private:
   G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
 };

 #endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP
	/*
	* Copyright (c) 2014, 2018, 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_G1_G1PARSCANTHREADSTATE_HPP
	#define SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP

	#include "gc/g1/dirtyCardQueue.hpp"
	#include "gc/g1/g1CardTable.hpp"
	#include "gc/g1/g1CollectedHeap.hpp"
	#include "gc/g1/g1OopClosures.hpp"
	#include "gc/g1/g1Policy.hpp"
	#include "gc/g1/g1RemSet.hpp"
	#include "gc/g1/heapRegionRemSet.hpp"
	#include "gc/shared/ageTable.hpp"
	#include "memory/allocation.hpp"
	#include "oops/oop.hpp"
	#include "utilities/ticks.hpp"

	class G1PLABAllocator;
	class G1EvacuationRootClosures;
	class HeapRegion;
	class outputStream;

	class G1ParScanThreadState : public CHeapObj<mtGC> {
	G1CollectedHeap* _g1h;
	RefToScanQueue* _refs;
	DirtyCardQueue _dcq;
	G1CardTable* _ct;
	G1EvacuationRootClosures* _closures;

	G1PLABAllocator* _plab_allocator;

	AgeTable _age_table;
	InCSetState _dest[InCSetState::Num];
	// Local tenuring threshold.
	uint _tenuring_threshold;
	G1ScanEvacuatedObjClosure _scanner;

	int _hash_seed;
	uint _worker_id;

	// Upper and lower threshold to start and end work queue draining.
	uint const _stack_trim_upper_threshold;
	uint const _stack_trim_lower_threshold;

	Tickspan _trim_ticks;
	// Map from young-age-index (0 == not young, 1 is youngest) to
	// surviving words. base is what we get back from the malloc call
	size_t* _surviving_young_words_base;
	// this points into the array, as we use the first few entries for padding
	size_t* _surviving_young_words;

	// Indicates whether in the last generation (old) there is no more space
	// available for allocation.
	bool _old_gen_is_full;

	#define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))

	DirtyCardQueue& dirty_card_queue() { return _dcq; }
	G1CardTable* ct() { return _ct; }

	InCSetState dest(InCSetState original) const {
	assert(original.is_valid(),
	"Original state invalid: " CSETSTATE_FORMAT, original.value());
	assert(_dest[original.value()].is_valid_gen(),
	"Dest state is invalid: " CSETSTATE_FORMAT, _dest[original.value()].value());
	return _dest[original.value()];
	}

	public:
	G1ParScanThreadState(G1CollectedHeap* g1h, uint worker_id, size_t young_cset_length);
	virtual ~G1ParScanThreadState();

	void set_ref_discoverer(ReferenceDiscoverer* rd) { _scanner.set_ref_discoverer(rd); }

	#ifdef ASSERT
	bool queue_is_empty() const { return _refs->is_empty(); }

	bool verify_ref(narrowOop* ref) const;
	bool verify_ref(oop* ref) const;
	bool verify_task(StarTask ref) const;
	#endif // ASSERT

	template <class T> void do_oop_ext(T* ref);
	template <class T> void push_on_queue(T* ref);

	template <class T> void update_rs(HeapRegion* from, T* p, oop o) {
	assert(!HeapRegion::is_in_same_region(p, o), "Caller should have filtered out cross-region references already.");
	// If the field originates from the to-space, we don't need to include it
	// in the remembered set updates. Also, if we are not tracking the remembered
	// set in the destination region, do not bother either.
	if (!from->is_young() && _g1h->heap_region_containing((HeapWord*)o)->rem_set()->is_tracked()) {
	size_t card_index = ct()->index_for(p);
	// If the card hasn't been added to the buffer, do it.
	if (ct()->mark_card_deferred(card_index)) {
	dirty_card_queue().enqueue((jbyte*)ct()->byte_for_index(card_index));
	}
	}
	}

	G1EvacuationRootClosures* closures() { return _closures; }
	uint worker_id() { return _worker_id; }

	// Returns the current amount of waste due to alignment or not being able to fit
	// objects within LABs and the undo waste.
	virtual void waste(size_t& wasted, size_t& undo_wasted);

	size_t* surviving_young_words() {
	// We add one to hide entry 0 which accumulates surviving words for
	// age -1 regions (i.e. non-young ones)
	return _surviving_young_words + 1;
	}

	void flush(size_t* surviving_young_words);

	private:
	#define G1_PARTIAL_ARRAY_MASK 0x2

	inline bool has_partial_array_mask(oop* ref) const {
	return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
	}

	// We never encode partial array oops as narrowOop*, so return false immediately.
	// This allows the compiler to create optimized code when popping references from
	// the work queue.
	inline bool has_partial_array_mask(narrowOop* ref) const {
	assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
	return false;
	}

	// Only implement set_partial_array_mask() for regular oops, not for narrowOops.
	// We always encode partial arrays as regular oop, to allow the
	// specialization for has_partial_array_mask() for narrowOops above.
	// This means that unintentional use of this method with narrowOops are caught
	// by the compiler.
	inline oop* set_partial_array_mask(oop obj) const {
	assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
	return (oop) ((uintptr_t)(void )obj \| G1_PARTIAL_ARRAY_MASK);
	}

	inline oop clear_partial_array_mask(oop* ref) const {
	return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
	}

	inline void do_oop_partial_array(oop* p);

	// This method is applied to the fields of the objects that have just been copied.
	template <class T> inline void do_oop_evac(T* p);

	inline void deal_with_reference(oop* ref_to_scan);
	inline void deal_with_reference(narrowOop* ref_to_scan);

	inline void dispatch_reference(StarTask ref);

	// Tries to allocate word_sz in the PLAB of the next "generation" after trying to
	// allocate into dest. State is the original (source) cset state for the object
	// that is allocated for. Previous_plab_refill_failed indicates whether previously
	// a PLAB refill into "state" failed.
	// Returns a non-NULL pointer if successful, and updates dest if required.
	// Also determines whether we should continue to try to allocate into the various
	// generations or just end trying to allocate.
	HeapWord* allocate_in_next_plab(InCSetState const state,
	InCSetState* dest,
	size_t word_sz,
	bool previous_plab_refill_failed);

	inline InCSetState next_state(InCSetState const state, markOop const m, uint& age);

	void report_promotion_event(InCSetState const dest_state,
	oop const old, size_t word_sz, uint age,
	HeapWord * const obj_ptr) const;

	inline bool needs_partial_trimming() const;
	inline bool is_partially_trimmed() const;

	inline void trim_queue_to_threshold(uint threshold);
	public:
	oop copy_to_survivor_space(InCSetState const state, oop const obj, markOop const old_mark);

	void trim_queue();
	void trim_queue_partially();

	Tickspan trim_ticks() const;
	void reset_trim_ticks();

	inline void steal_and_trim_queue(RefToScanQueueSet *task_queues);

	// An attempt to evacuate "obj" has failed; take necessary steps.
	oop handle_evacuation_failure_par(oop obj, markOop m);
	};

	class G1ParScanThreadStateSet : public StackObj {
	G1CollectedHeap* _g1h;
	G1ParScanThreadState** _states;
	size_t* _surviving_young_words_total;
	size_t _young_cset_length;
	uint _n_workers;
	bool _flushed;

	public:
	G1ParScanThreadStateSet(G1CollectedHeap* g1h, uint n_workers, size_t young_cset_length);
	~G1ParScanThreadStateSet();

	void flush();

	G1ParScanThreadState* state_for_worker(uint worker_id);

	const size_t* surviving_young_words() const;

	private:
	G1ParScanThreadState* new_par_scan_state(uint worker_id, size_t young_cset_length);
	};

	#endif // SHARE_VM_GC_G1_G1PARSCANTHREADSTATE_HPP