--- old/src/share/vm/memory/defNewGeneration.hpp 2015-05-12 11:56:11.793169371 +0200 +++ /dev/null 2015-03-18 17:10:38.111854831 +0100 @@ -1,365 +0,0 @@ -/* - * Copyright (c) 2001, 2015, 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_MEMORY_DEFNEWGENERATION_HPP -#define SHARE_VM_MEMORY_DEFNEWGENERATION_HPP - -#include "gc_implementation/shared/ageTable.hpp" -#include "gc_implementation/shared/cSpaceCounters.hpp" -#include "gc_implementation/shared/generationCounters.hpp" -#include "gc_implementation/shared/copyFailedInfo.hpp" -#include "memory/generation.hpp" -#include "utilities/stack.hpp" - -class ContiguousSpace; -class ScanClosure; -class STWGCTimer; -class CSpaceCounters; -class ScanWeakRefClosure; - -// DefNewGeneration is a young generation containing eden, from- and -// to-space. - -class DefNewGeneration: public Generation { - friend class VMStructs; - -protected: - Generation* _old_gen; - uint _tenuring_threshold; // Tenuring threshold for next collection. - ageTable _age_table; - // Size of object to pretenure in words; command line provides bytes - size_t _pretenure_size_threshold_words; - - ageTable* age_table() { return &_age_table; } - - // Initialize state to optimistically assume no promotion failure will - // happen. - void init_assuming_no_promotion_failure(); - // True iff a promotion has failed in the current collection. - bool _promotion_failed; - bool promotion_failed() { return _promotion_failed; } - PromotionFailedInfo _promotion_failed_info; - - // Handling promotion failure. A young generation collection - // can fail if a live object cannot be copied out of its - // location in eden or from-space during the collection. If - // a collection fails, the young generation is left in a - // consistent state such that it can be collected by a - // full collection. - // Before the collection - // Objects are in eden or from-space - // All roots into the young generation point into eden or from-space. - // - // After a failed collection - // Objects may be in eden, from-space, or to-space - // An object A in eden or from-space may have a copy B - // in to-space. If B exists, all roots that once pointed - // to A must now point to B. - // All objects in the young generation are unmarked. - // Eden, from-space, and to-space will all be collected by - // the full collection. - void handle_promotion_failure(oop); - - // In the absence of promotion failure, we wouldn't look at "from-space" - // objects after a young-gen collection. When promotion fails, however, - // the subsequent full collection will look at from-space objects: - // therefore we must remove their forwarding pointers. - void remove_forwarding_pointers(); - - // Preserve the mark of "obj", if necessary, in preparation for its mark - // word being overwritten with a self-forwarding-pointer. - void preserve_mark_if_necessary(oop obj, markOop m); - void preserve_mark(oop obj, markOop m); // work routine used by the above - - // Together, these keep pairs. - // They should always contain the same number of elements. - Stack _objs_with_preserved_marks; - Stack _preserved_marks_of_objs; - - // Promotion failure handling - ExtendedOopClosure *_promo_failure_scan_stack_closure; - void set_promo_failure_scan_stack_closure(ExtendedOopClosure *scan_stack_closure) { - _promo_failure_scan_stack_closure = scan_stack_closure; - } - - Stack _promo_failure_scan_stack; - void drain_promo_failure_scan_stack(void); - bool _promo_failure_drain_in_progress; - - // Performance Counters - GenerationCounters* _gen_counters; - CSpaceCounters* _eden_counters; - CSpaceCounters* _from_counters; - CSpaceCounters* _to_counters; - - // sizing information - size_t _max_eden_size; - size_t _max_survivor_size; - - // Allocation support - bool _should_allocate_from_space; - bool should_allocate_from_space() const { - return _should_allocate_from_space; - } - void clear_should_allocate_from_space() { - _should_allocate_from_space = false; - } - void set_should_allocate_from_space() { - _should_allocate_from_space = true; - } - - // Tenuring - void adjust_desired_tenuring_threshold(); - - // Spaces - ContiguousSpace* _eden_space; - ContiguousSpace* _from_space; - ContiguousSpace* _to_space; - - STWGCTimer* _gc_timer; - - enum SomeProtectedConstants { - // Generations are GenGrain-aligned and have size that are multiples of - // GenGrain. - MinFreeScratchWords = 100 - }; - - // Return the size of a survivor space if this generation were of size - // gen_size. - size_t compute_survivor_size(size_t gen_size, size_t alignment) const { - size_t n = gen_size / (SurvivorRatio + 2); - return n > alignment ? align_size_down(n, alignment) : alignment; - } - - public: // was "protected" but caused compile error on win32 - class IsAliveClosure: public BoolObjectClosure { - Generation* _g; - public: - IsAliveClosure(Generation* g); - bool do_object_b(oop p); - }; - - class KeepAliveClosure: public OopClosure { - protected: - ScanWeakRefClosure* _cl; - CardTableRS* _rs; - template void do_oop_work(T* p); - public: - KeepAliveClosure(ScanWeakRefClosure* cl); - virtual void do_oop(oop* p); - virtual void do_oop(narrowOop* p); - }; - - class FastKeepAliveClosure: public KeepAliveClosure { - protected: - HeapWord* _boundary; - template void do_oop_work(T* p); - public: - FastKeepAliveClosure(DefNewGeneration* g, ScanWeakRefClosure* cl); - virtual void do_oop(oop* p); - virtual void do_oop(narrowOop* p); - }; - - class EvacuateFollowersClosure: public VoidClosure { - GenCollectedHeap* _gch; - int _level; - ScanClosure* _scan_cur_or_nonheap; - ScanClosure* _scan_older; - public: - EvacuateFollowersClosure(GenCollectedHeap* gch, int level, - ScanClosure* cur, ScanClosure* older); - void do_void(); - }; - - class FastEvacuateFollowersClosure: public VoidClosure { - GenCollectedHeap* _gch; - int _level; - DefNewGeneration* _gen; - FastScanClosure* _scan_cur_or_nonheap; - FastScanClosure* _scan_older; - public: - FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level, - DefNewGeneration* gen, - FastScanClosure* cur, - FastScanClosure* older); - void do_void(); - }; - - public: - DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level, - const char* policy="Copy"); - - virtual void ref_processor_init(); - - virtual Generation::Name kind() { return Generation::DefNew; } - - // Accessing spaces - ContiguousSpace* eden() const { return _eden_space; } - ContiguousSpace* from() const { return _from_space; } - ContiguousSpace* to() const { return _to_space; } - - virtual CompactibleSpace* first_compaction_space() const; - - // Space enquiries - size_t capacity() const; - size_t used() const; - size_t free() const; - size_t max_capacity() const; - size_t capacity_before_gc() const; - size_t unsafe_max_alloc_nogc() const; - size_t contiguous_available() const; - - size_t max_eden_size() const { return _max_eden_size; } - size_t max_survivor_size() const { return _max_survivor_size; } - - bool supports_inline_contig_alloc() const { return true; } - HeapWord** top_addr() const; - HeapWord** end_addr() const; - - // Thread-local allocation buffers - bool supports_tlab_allocation() const { return true; } - size_t tlab_capacity() const; - size_t tlab_used() const; - size_t unsafe_max_tlab_alloc() const; - - // Grow the generation by the specified number of bytes. - // The size of bytes is assumed to be properly aligned. - // Return true if the expansion was successful. - bool expand(size_t bytes); - - // DefNewGeneration cannot currently expand except at - // a GC. - virtual bool is_maximal_no_gc() const { return true; } - - // Iteration - void object_iterate(ObjectClosure* blk); - - void younger_refs_iterate(OopsInGenClosure* cl); - - void space_iterate(SpaceClosure* blk, bool usedOnly = false); - - // Allocation support - virtual bool should_allocate(size_t word_size, bool is_tlab) { - assert(UseTLAB || !is_tlab, "Should not allocate tlab"); - - size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize); - - const bool non_zero = word_size > 0; - const bool overflows = word_size >= overflow_limit; - const bool check_too_big = _pretenure_size_threshold_words > 0; - const bool not_too_big = word_size < _pretenure_size_threshold_words; - const bool size_ok = is_tlab || !check_too_big || not_too_big; - - bool result = !overflows && - non_zero && - size_ok; - - return result; - } - - HeapWord* allocate(size_t word_size, bool is_tlab); - HeapWord* allocate_from_space(size_t word_size); - - HeapWord* par_allocate(size_t word_size, bool is_tlab); - - virtual void gc_epilogue(bool full); - - // Save the tops for eden, from, and to - virtual void record_spaces_top(); - - // Doesn't require additional work during GC prologue and epilogue - virtual bool performs_in_place_marking() const { return false; } - - // Accessing marks - void save_marks(); - void reset_saved_marks(); - bool no_allocs_since_save_marks(); - - // Need to declare the full complement of closures, whether we'll - // override them or not, or get message from the compiler: - // oop_since_save_marks_iterate_nv hides virtual function... -#define DefNew_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ - void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); - - ALL_SINCE_SAVE_MARKS_CLOSURES(DefNew_SINCE_SAVE_MARKS_DECL) - -#undef DefNew_SINCE_SAVE_MARKS_DECL - - // For non-youngest collection, the DefNewGeneration can contribute - // "to-space". - virtual void contribute_scratch(ScratchBlock*& list, Generation* requestor, - size_t max_alloc_words); - - // Reset for contribution of "to-space". - virtual void reset_scratch(); - - // GC support - virtual void compute_new_size(); - - // Returns true if the collection is likely to be safely - // completed. Even if this method returns true, a collection - // may not be guaranteed to succeed, and the system should be - // able to safely unwind and recover from that failure, albeit - // at some additional cost. Override superclass's implementation. - virtual bool collection_attempt_is_safe(); - - virtual void collect(bool full, - bool clear_all_soft_refs, - size_t size, - bool is_tlab); - HeapWord* expand_and_allocate(size_t size, - bool is_tlab, - bool parallel = false); - - oop copy_to_survivor_space(oop old); - uint tenuring_threshold() { return _tenuring_threshold; } - - // Performance Counter support - void update_counters(); - - // Printing - virtual const char* name() const; - virtual const char* short_name() const { return "DefNew"; } - - // PrintHeapAtGC support. - void print_on(outputStream* st) const; - - void verify(); - - bool promo_failure_scan_is_complete() const { - return _promo_failure_scan_stack.is_empty(); - } - - protected: - // If clear_space is true, clear the survivor spaces. Eden is - // cleared if the minimum size of eden is 0. If mangle_space - // is true, also mangle the space in debug mode. - void compute_space_boundaries(uintx minimum_eden_size, - bool clear_space, - bool mangle_space); - // Scavenge support - void swap_spaces(); -}; - -#endif // SHARE_VM_MEMORY_DEFNEWGENERATION_HPP --- /dev/null 2015-03-18 17:10:38.111854831 +0100 +++ new/src/share/vm/gc/serial/defNewGeneration.hpp 2015-05-12 11:56:11.593160943 +0200 @@ -0,0 +1,365 @@ +/* + * Copyright (c) 2001, 2015, 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_SERIAL_DEFNEWGENERATION_HPP +#define SHARE_VM_GC_SERIAL_DEFNEWGENERATION_HPP + +#include "gc/shared/ageTable.hpp" +#include "gc/shared/cSpaceCounters.hpp" +#include "gc/shared/copyFailedInfo.hpp" +#include "gc/shared/generation.hpp" +#include "gc/shared/generationCounters.hpp" +#include "utilities/stack.hpp" + +class ContiguousSpace; +class ScanClosure; +class STWGCTimer; +class CSpaceCounters; +class ScanWeakRefClosure; + +// DefNewGeneration is a young generation containing eden, from- and +// to-space. + +class DefNewGeneration: public Generation { + friend class VMStructs; + +protected: + Generation* _old_gen; + uint _tenuring_threshold; // Tenuring threshold for next collection. + ageTable _age_table; + // Size of object to pretenure in words; command line provides bytes + size_t _pretenure_size_threshold_words; + + ageTable* age_table() { return &_age_table; } + + // Initialize state to optimistically assume no promotion failure will + // happen. + void init_assuming_no_promotion_failure(); + // True iff a promotion has failed in the current collection. + bool _promotion_failed; + bool promotion_failed() { return _promotion_failed; } + PromotionFailedInfo _promotion_failed_info; + + // Handling promotion failure. A young generation collection + // can fail if a live object cannot be copied out of its + // location in eden or from-space during the collection. If + // a collection fails, the young generation is left in a + // consistent state such that it can be collected by a + // full collection. + // Before the collection + // Objects are in eden or from-space + // All roots into the young generation point into eden or from-space. + // + // After a failed collection + // Objects may be in eden, from-space, or to-space + // An object A in eden or from-space may have a copy B + // in to-space. If B exists, all roots that once pointed + // to A must now point to B. + // All objects in the young generation are unmarked. + // Eden, from-space, and to-space will all be collected by + // the full collection. + void handle_promotion_failure(oop); + + // In the absence of promotion failure, we wouldn't look at "from-space" + // objects after a young-gen collection. When promotion fails, however, + // the subsequent full collection will look at from-space objects: + // therefore we must remove their forwarding pointers. + void remove_forwarding_pointers(); + + // Preserve the mark of "obj", if necessary, in preparation for its mark + // word being overwritten with a self-forwarding-pointer. + void preserve_mark_if_necessary(oop obj, markOop m); + void preserve_mark(oop obj, markOop m); // work routine used by the above + + // Together, these keep pairs. + // They should always contain the same number of elements. + Stack _objs_with_preserved_marks; + Stack _preserved_marks_of_objs; + + // Promotion failure handling + ExtendedOopClosure *_promo_failure_scan_stack_closure; + void set_promo_failure_scan_stack_closure(ExtendedOopClosure *scan_stack_closure) { + _promo_failure_scan_stack_closure = scan_stack_closure; + } + + Stack _promo_failure_scan_stack; + void drain_promo_failure_scan_stack(void); + bool _promo_failure_drain_in_progress; + + // Performance Counters + GenerationCounters* _gen_counters; + CSpaceCounters* _eden_counters; + CSpaceCounters* _from_counters; + CSpaceCounters* _to_counters; + + // sizing information + size_t _max_eden_size; + size_t _max_survivor_size; + + // Allocation support + bool _should_allocate_from_space; + bool should_allocate_from_space() const { + return _should_allocate_from_space; + } + void clear_should_allocate_from_space() { + _should_allocate_from_space = false; + } + void set_should_allocate_from_space() { + _should_allocate_from_space = true; + } + + // Tenuring + void adjust_desired_tenuring_threshold(); + + // Spaces + ContiguousSpace* _eden_space; + ContiguousSpace* _from_space; + ContiguousSpace* _to_space; + + STWGCTimer* _gc_timer; + + enum SomeProtectedConstants { + // Generations are GenGrain-aligned and have size that are multiples of + // GenGrain. + MinFreeScratchWords = 100 + }; + + // Return the size of a survivor space if this generation were of size + // gen_size. + size_t compute_survivor_size(size_t gen_size, size_t alignment) const { + size_t n = gen_size / (SurvivorRatio + 2); + return n > alignment ? align_size_down(n, alignment) : alignment; + } + + public: // was "protected" but caused compile error on win32 + class IsAliveClosure: public BoolObjectClosure { + Generation* _g; + public: + IsAliveClosure(Generation* g); + bool do_object_b(oop p); + }; + + class KeepAliveClosure: public OopClosure { + protected: + ScanWeakRefClosure* _cl; + CardTableRS* _rs; + template void do_oop_work(T* p); + public: + KeepAliveClosure(ScanWeakRefClosure* cl); + virtual void do_oop(oop* p); + virtual void do_oop(narrowOop* p); + }; + + class FastKeepAliveClosure: public KeepAliveClosure { + protected: + HeapWord* _boundary; + template void do_oop_work(T* p); + public: + FastKeepAliveClosure(DefNewGeneration* g, ScanWeakRefClosure* cl); + virtual void do_oop(oop* p); + virtual void do_oop(narrowOop* p); + }; + + class EvacuateFollowersClosure: public VoidClosure { + GenCollectedHeap* _gch; + int _level; + ScanClosure* _scan_cur_or_nonheap; + ScanClosure* _scan_older; + public: + EvacuateFollowersClosure(GenCollectedHeap* gch, int level, + ScanClosure* cur, ScanClosure* older); + void do_void(); + }; + + class FastEvacuateFollowersClosure: public VoidClosure { + GenCollectedHeap* _gch; + int _level; + DefNewGeneration* _gen; + FastScanClosure* _scan_cur_or_nonheap; + FastScanClosure* _scan_older; + public: + FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level, + DefNewGeneration* gen, + FastScanClosure* cur, + FastScanClosure* older); + void do_void(); + }; + + public: + DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level, + const char* policy="Copy"); + + virtual void ref_processor_init(); + + virtual Generation::Name kind() { return Generation::DefNew; } + + // Accessing spaces + ContiguousSpace* eden() const { return _eden_space; } + ContiguousSpace* from() const { return _from_space; } + ContiguousSpace* to() const { return _to_space; } + + virtual CompactibleSpace* first_compaction_space() const; + + // Space enquiries + size_t capacity() const; + size_t used() const; + size_t free() const; + size_t max_capacity() const; + size_t capacity_before_gc() const; + size_t unsafe_max_alloc_nogc() const; + size_t contiguous_available() const; + + size_t max_eden_size() const { return _max_eden_size; } + size_t max_survivor_size() const { return _max_survivor_size; } + + bool supports_inline_contig_alloc() const { return true; } + HeapWord** top_addr() const; + HeapWord** end_addr() const; + + // Thread-local allocation buffers + bool supports_tlab_allocation() const { return true; } + size_t tlab_capacity() const; + size_t tlab_used() const; + size_t unsafe_max_tlab_alloc() const; + + // Grow the generation by the specified number of bytes. + // The size of bytes is assumed to be properly aligned. + // Return true if the expansion was successful. + bool expand(size_t bytes); + + // DefNewGeneration cannot currently expand except at + // a GC. + virtual bool is_maximal_no_gc() const { return true; } + + // Iteration + void object_iterate(ObjectClosure* blk); + + void younger_refs_iterate(OopsInGenClosure* cl); + + void space_iterate(SpaceClosure* blk, bool usedOnly = false); + + // Allocation support + virtual bool should_allocate(size_t word_size, bool is_tlab) { + assert(UseTLAB || !is_tlab, "Should not allocate tlab"); + + size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize); + + const bool non_zero = word_size > 0; + const bool overflows = word_size >= overflow_limit; + const bool check_too_big = _pretenure_size_threshold_words > 0; + const bool not_too_big = word_size < _pretenure_size_threshold_words; + const bool size_ok = is_tlab || !check_too_big || not_too_big; + + bool result = !overflows && + non_zero && + size_ok; + + return result; + } + + HeapWord* allocate(size_t word_size, bool is_tlab); + HeapWord* allocate_from_space(size_t word_size); + + HeapWord* par_allocate(size_t word_size, bool is_tlab); + + virtual void gc_epilogue(bool full); + + // Save the tops for eden, from, and to + virtual void record_spaces_top(); + + // Doesn't require additional work during GC prologue and epilogue + virtual bool performs_in_place_marking() const { return false; } + + // Accessing marks + void save_marks(); + void reset_saved_marks(); + bool no_allocs_since_save_marks(); + + // Need to declare the full complement of closures, whether we'll + // override them or not, or get message from the compiler: + // oop_since_save_marks_iterate_nv hides virtual function... +#define DefNew_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ + void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); + + ALL_SINCE_SAVE_MARKS_CLOSURES(DefNew_SINCE_SAVE_MARKS_DECL) + +#undef DefNew_SINCE_SAVE_MARKS_DECL + + // For non-youngest collection, the DefNewGeneration can contribute + // "to-space". + virtual void contribute_scratch(ScratchBlock*& list, Generation* requestor, + size_t max_alloc_words); + + // Reset for contribution of "to-space". + virtual void reset_scratch(); + + // GC support + virtual void compute_new_size(); + + // Returns true if the collection is likely to be safely + // completed. Even if this method returns true, a collection + // may not be guaranteed to succeed, and the system should be + // able to safely unwind and recover from that failure, albeit + // at some additional cost. Override superclass's implementation. + virtual bool collection_attempt_is_safe(); + + virtual void collect(bool full, + bool clear_all_soft_refs, + size_t size, + bool is_tlab); + HeapWord* expand_and_allocate(size_t size, + bool is_tlab, + bool parallel = false); + + oop copy_to_survivor_space(oop old); + uint tenuring_threshold() { return _tenuring_threshold; } + + // Performance Counter support + void update_counters(); + + // Printing + virtual const char* name() const; + virtual const char* short_name() const { return "DefNew"; } + + // PrintHeapAtGC support. + void print_on(outputStream* st) const; + + void verify(); + + bool promo_failure_scan_is_complete() const { + return _promo_failure_scan_stack.is_empty(); + } + + protected: + // If clear_space is true, clear the survivor spaces. Eden is + // cleared if the minimum size of eden is 0. If mangle_space + // is true, also mangle the space in debug mode. + void compute_space_boundaries(uintx minimum_eden_size, + bool clear_space, + bool mangle_space); + // Scavenge support + void swap_spaces(); +}; + +#endif // SHARE_VM_GC_SERIAL_DEFNEWGENERATION_HPP