Mercurial > hg > graal-compiler
view src/share/vm/memory/defNewGeneration.hpp @ 12033:bd902affe102
8023021: Unnecessary clearing of the card table introduced by the fix for JDK-8023013
Reviewed-by: stefank, ehelin
author | brutisso |
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date | Thu, 15 Aug 2013 10:05:50 +0200 |
parents | 71180a6e5080 |
children | 1e1c8d358b52 |
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/* * Copyright (c) 2001, 2013, 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.inline.hpp" #include "utilities/stack.hpp" class EdenSpace; class ContiguousSpace; class ScanClosure; class STWGCTimer; // DefNewGeneration is a young generation containing eden, from- and // to-space. class DefNewGeneration: public Generation { friend class VMStructs; protected: Generation* _next_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 <object with a preserved mark, mark value> pairs. // They should always contain the same number of elements. Stack<oop, mtGC> _objs_with_preserved_marks; Stack<markOop, mtGC> _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<oop, mtGC> _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 EdenSpace* _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 <class T> 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 <class T> 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 EdenSpace* 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 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); // Prologue & Epilogue virtual void gc_prologue(bool full); 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"; } bool must_be_youngest() const { return true; } bool must_be_oldest() const { return false; } // 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