duke@435: /* sla@5237: * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved. duke@435: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. duke@435: * duke@435: * This code is free software; you can redistribute it and/or modify it duke@435: * under the terms of the GNU General Public License version 2 only, as duke@435: * published by the Free Software Foundation. duke@435: * duke@435: * This code is distributed in the hope that it will be useful, but WITHOUT duke@435: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or duke@435: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License duke@435: * version 2 for more details (a copy is included in the LICENSE file that duke@435: * accompanied this code). duke@435: * duke@435: * You should have received a copy of the GNU General Public License version duke@435: * 2 along with this work; if not, write to the Free Software Foundation, duke@435: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. duke@435: * trims@1907: * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA trims@1907: * or visit www.oracle.com if you need additional information or have any trims@1907: * questions. duke@435: * duke@435: */ duke@435: stefank@2314: #ifndef SHARE_VM_MEMORY_DEFNEWGENERATION_HPP stefank@2314: #define SHARE_VM_MEMORY_DEFNEWGENERATION_HPP stefank@2314: stefank@2314: #include "gc_implementation/shared/ageTable.hpp" stefank@2314: #include "gc_implementation/shared/cSpaceCounters.hpp" stefank@2314: #include "gc_implementation/shared/generationCounters.hpp" sla@5237: #include "gc_implementation/shared/copyFailedInfo.hpp" stefank@2314: #include "memory/generation.inline.hpp" stefank@2314: #include "utilities/stack.hpp" stefank@2314: duke@435: class EdenSpace; duke@435: class ContiguousSpace; coleenp@548: class ScanClosure; sla@5237: class STWGCTimer; duke@435: duke@435: // DefNewGeneration is a young generation containing eden, from- and duke@435: // to-space. duke@435: duke@435: class DefNewGeneration: public Generation { duke@435: friend class VMStructs; duke@435: duke@435: protected: duke@435: Generation* _next_gen; jwilhelm@4129: uint _tenuring_threshold; // Tenuring threshold for next collection. duke@435: ageTable _age_table; duke@435: // Size of object to pretenure in words; command line provides bytes sla@5237: size_t _pretenure_size_threshold_words; duke@435: duke@435: ageTable* age_table() { return &_age_table; } sla@5237: duke@435: // Initialize state to optimistically assume no promotion failure will duke@435: // happen. duke@435: void init_assuming_no_promotion_failure(); duke@435: // True iff a promotion has failed in the current collection. duke@435: bool _promotion_failed; duke@435: bool promotion_failed() { return _promotion_failed; } sla@5237: PromotionFailedInfo _promotion_failed_info; duke@435: duke@435: // Handling promotion failure. A young generation collection duke@435: // can fail if a live object cannot be copied out of its duke@435: // location in eden or from-space during the collection. If duke@435: // a collection fails, the young generation is left in a duke@435: // consistent state such that it can be collected by a duke@435: // full collection. duke@435: // Before the collection duke@435: // Objects are in eden or from-space duke@435: // All roots into the young generation point into eden or from-space. duke@435: // duke@435: // After a failed collection duke@435: // Objects may be in eden, from-space, or to-space duke@435: // An object A in eden or from-space may have a copy B duke@435: // in to-space. If B exists, all roots that once pointed duke@435: // to A must now point to B. duke@435: // All objects in the young generation are unmarked. duke@435: // Eden, from-space, and to-space will all be collected by duke@435: // the full collection. duke@435: void handle_promotion_failure(oop); duke@435: duke@435: // In the absence of promotion failure, we wouldn't look at "from-space" duke@435: // objects after a young-gen collection. When promotion fails, however, duke@435: // the subsequent full collection will look at from-space objects: duke@435: // therefore we must remove their forwarding pointers. duke@435: void remove_forwarding_pointers(); duke@435: duke@435: // Preserve the mark of "obj", if necessary, in preparation for its mark duke@435: // word being overwritten with a self-forwarding-pointer. duke@435: void preserve_mark_if_necessary(oop obj, markOop m); ysr@2380: void preserve_mark(oop obj, markOop m); // work routine used by the above duke@435: jcoomes@2191: // Together, these keep pairs. jcoomes@2191: // They should always contain the same number of elements. zgu@3900: Stack _objs_with_preserved_marks; zgu@3900: Stack _preserved_marks_of_objs; duke@435: duke@435: // Promotion failure handling coleenp@4037: ExtendedOopClosure *_promo_failure_scan_stack_closure; coleenp@4037: void set_promo_failure_scan_stack_closure(ExtendedOopClosure *scan_stack_closure) { duke@435: _promo_failure_scan_stack_closure = scan_stack_closure; duke@435: } duke@435: zgu@3900: Stack _promo_failure_scan_stack; duke@435: void drain_promo_failure_scan_stack(void); duke@435: bool _promo_failure_drain_in_progress; duke@435: duke@435: // Performance Counters duke@435: GenerationCounters* _gen_counters; duke@435: CSpaceCounters* _eden_counters; duke@435: CSpaceCounters* _from_counters; duke@435: CSpaceCounters* _to_counters; duke@435: duke@435: // sizing information duke@435: size_t _max_eden_size; duke@435: size_t _max_survivor_size; duke@435: duke@435: // Allocation support duke@435: bool _should_allocate_from_space; duke@435: bool should_allocate_from_space() const { duke@435: return _should_allocate_from_space; duke@435: } duke@435: void clear_should_allocate_from_space() { duke@435: _should_allocate_from_space = false; duke@435: } duke@435: void set_should_allocate_from_space() { duke@435: _should_allocate_from_space = true; duke@435: } duke@435: brutisso@4452: // Tenuring brutisso@4452: void adjust_desired_tenuring_threshold(); brutisso@4452: duke@435: // Spaces duke@435: EdenSpace* _eden_space; duke@435: ContiguousSpace* _from_space; duke@435: ContiguousSpace* _to_space; duke@435: sla@5237: STWGCTimer* _gc_timer; sla@5237: duke@435: enum SomeProtectedConstants { duke@435: // Generations are GenGrain-aligned and have size that are multiples of duke@435: // GenGrain. duke@435: MinFreeScratchWords = 100 duke@435: }; duke@435: duke@435: // Return the size of a survivor space if this generation were of size duke@435: // gen_size. duke@435: size_t compute_survivor_size(size_t gen_size, size_t alignment) const { duke@435: size_t n = gen_size / (SurvivorRatio + 2); duke@435: return n > alignment ? align_size_down(n, alignment) : alignment; duke@435: } duke@435: duke@435: public: // was "protected" but caused compile error on win32 duke@435: class IsAliveClosure: public BoolObjectClosure { duke@435: Generation* _g; duke@435: public: duke@435: IsAliveClosure(Generation* g); duke@435: bool do_object_b(oop p); duke@435: }; duke@435: duke@435: class KeepAliveClosure: public OopClosure { duke@435: protected: duke@435: ScanWeakRefClosure* _cl; duke@435: CardTableRS* _rs; coleenp@548: template void do_oop_work(T* p); duke@435: public: duke@435: KeepAliveClosure(ScanWeakRefClosure* cl); coleenp@548: virtual void do_oop(oop* p); coleenp@548: virtual void do_oop(narrowOop* p); duke@435: }; duke@435: duke@435: class FastKeepAliveClosure: public KeepAliveClosure { duke@435: protected: duke@435: HeapWord* _boundary; coleenp@548: template void do_oop_work(T* p); duke@435: public: duke@435: FastKeepAliveClosure(DefNewGeneration* g, ScanWeakRefClosure* cl); coleenp@548: virtual void do_oop(oop* p); coleenp@548: virtual void do_oop(narrowOop* p); duke@435: }; duke@435: duke@435: class EvacuateFollowersClosure: public VoidClosure { duke@435: GenCollectedHeap* _gch; duke@435: int _level; duke@435: ScanClosure* _scan_cur_or_nonheap; duke@435: ScanClosure* _scan_older; duke@435: public: duke@435: EvacuateFollowersClosure(GenCollectedHeap* gch, int level, duke@435: ScanClosure* cur, ScanClosure* older); duke@435: void do_void(); duke@435: }; duke@435: duke@435: class FastEvacuateFollowersClosure: public VoidClosure { duke@435: GenCollectedHeap* _gch; duke@435: int _level; duke@435: DefNewGeneration* _gen; duke@435: FastScanClosure* _scan_cur_or_nonheap; duke@435: FastScanClosure* _scan_older; duke@435: public: duke@435: FastEvacuateFollowersClosure(GenCollectedHeap* gch, int level, duke@435: DefNewGeneration* gen, duke@435: FastScanClosure* cur, duke@435: FastScanClosure* older); duke@435: void do_void(); duke@435: }; duke@435: duke@435: public: duke@435: DefNewGeneration(ReservedSpace rs, size_t initial_byte_size, int level, duke@435: const char* policy="Copy"); duke@435: sla@5237: virtual void ref_processor_init(); sla@5237: duke@435: virtual Generation::Name kind() { return Generation::DefNew; } duke@435: duke@435: // Accessing spaces duke@435: EdenSpace* eden() const { return _eden_space; } duke@435: ContiguousSpace* from() const { return _from_space; } duke@435: ContiguousSpace* to() const { return _to_space; } duke@435: coleenp@548: virtual CompactibleSpace* first_compaction_space() const; duke@435: duke@435: // Space enquiries duke@435: size_t capacity() const; duke@435: size_t used() const; duke@435: size_t free() const; duke@435: size_t max_capacity() const; duke@435: size_t capacity_before_gc() const; duke@435: size_t unsafe_max_alloc_nogc() const; duke@435: size_t contiguous_available() const; duke@435: duke@435: size_t max_eden_size() const { return _max_eden_size; } duke@435: size_t max_survivor_size() const { return _max_survivor_size; } duke@435: duke@435: bool supports_inline_contig_alloc() const { return true; } duke@435: HeapWord** top_addr() const; duke@435: HeapWord** end_addr() const; duke@435: duke@435: // Thread-local allocation buffers duke@435: bool supports_tlab_allocation() const { return true; } coleenp@548: size_t tlab_capacity() const; brutisso@6376: size_t tlab_used() const; coleenp@548: size_t unsafe_max_tlab_alloc() const; duke@435: duke@435: // Grow the generation by the specified number of bytes. duke@435: // The size of bytes is assumed to be properly aligned. duke@435: // Return true if the expansion was successful. duke@435: bool expand(size_t bytes); duke@435: duke@435: // DefNewGeneration cannot currently expand except at duke@435: // a GC. duke@435: virtual bool is_maximal_no_gc() const { return true; } duke@435: duke@435: // Iteration duke@435: void object_iterate(ObjectClosure* blk); duke@435: duke@435: void younger_refs_iterate(OopsInGenClosure* cl); duke@435: duke@435: void space_iterate(SpaceClosure* blk, bool usedOnly = false); duke@435: duke@435: // Allocation support duke@435: virtual bool should_allocate(size_t word_size, bool is_tlab) { duke@435: assert(UseTLAB || !is_tlab, "Should not allocate tlab"); duke@435: duke@435: size_t overflow_limit = (size_t)1 << (BitsPerSize_t - LogHeapWordSize); duke@435: duke@435: const bool non_zero = word_size > 0; duke@435: const bool overflows = word_size >= overflow_limit; duke@435: const bool check_too_big = _pretenure_size_threshold_words > 0; duke@435: const bool not_too_big = word_size < _pretenure_size_threshold_words; duke@435: const bool size_ok = is_tlab || !check_too_big || not_too_big; duke@435: duke@435: bool result = !overflows && duke@435: non_zero && duke@435: size_ok; duke@435: duke@435: return result; duke@435: } duke@435: coleenp@548: HeapWord* allocate(size_t word_size, bool is_tlab); duke@435: HeapWord* allocate_from_space(size_t word_size); duke@435: coleenp@548: HeapWord* par_allocate(size_t word_size, bool is_tlab); duke@435: duke@435: // Prologue & Epilogue coleenp@548: virtual void gc_prologue(bool full); duke@435: virtual void gc_epilogue(bool full); duke@435: jmasa@698: // Save the tops for eden, from, and to jmasa@698: virtual void record_spaces_top(); jmasa@698: duke@435: // Doesn't require additional work during GC prologue and epilogue duke@435: virtual bool performs_in_place_marking() const { return false; } duke@435: duke@435: // Accessing marks duke@435: void save_marks(); duke@435: void reset_saved_marks(); duke@435: bool no_allocs_since_save_marks(); duke@435: duke@435: // Need to declare the full complement of closures, whether we'll duke@435: // override them or not, or get message from the compiler: duke@435: // oop_since_save_marks_iterate_nv hides virtual function... duke@435: #define DefNew_SINCE_SAVE_MARKS_DECL(OopClosureType, nv_suffix) \ duke@435: void oop_since_save_marks_iterate##nv_suffix(OopClosureType* cl); duke@435: duke@435: ALL_SINCE_SAVE_MARKS_CLOSURES(DefNew_SINCE_SAVE_MARKS_DECL) duke@435: duke@435: #undef DefNew_SINCE_SAVE_MARKS_DECL duke@435: duke@435: // For non-youngest collection, the DefNewGeneration can contribute duke@435: // "to-space". jmasa@698: virtual void contribute_scratch(ScratchBlock*& list, Generation* requestor, duke@435: size_t max_alloc_words); duke@435: jmasa@698: // Reset for contribution of "to-space". jmasa@698: virtual void reset_scratch(); jmasa@698: duke@435: // GC support duke@435: virtual void compute_new_size(); ysr@2243: ysr@2243: // Returns true if the collection is likely to be safely ysr@2243: // completed. Even if this method returns true, a collection ysr@2243: // may not be guaranteed to succeed, and the system should be ysr@2243: // able to safely unwind and recover from that failure, albeit ysr@2243: // at some additional cost. Override superclass's implementation. ysr@2243: virtual bool collection_attempt_is_safe(); ysr@2243: duke@435: virtual void collect(bool full, duke@435: bool clear_all_soft_refs, duke@435: size_t size, duke@435: bool is_tlab); duke@435: HeapWord* expand_and_allocate(size_t size, duke@435: bool is_tlab, duke@435: bool parallel = false); duke@435: coleenp@548: oop copy_to_survivor_space(oop old); jwilhelm@4129: uint tenuring_threshold() { return _tenuring_threshold; } duke@435: duke@435: // Performance Counter support duke@435: void update_counters(); duke@435: duke@435: // Printing duke@435: virtual const char* name() const; duke@435: virtual const char* short_name() const { return "DefNew"; } duke@435: duke@435: bool must_be_youngest() const { return true; } duke@435: bool must_be_oldest() const { return false; } duke@435: duke@435: // PrintHeapAtGC support. duke@435: void print_on(outputStream* st) const; duke@435: brutisso@3711: void verify(); duke@435: jcoomes@2191: bool promo_failure_scan_is_complete() const { jcoomes@2191: return _promo_failure_scan_stack.is_empty(); jcoomes@2191: } jcoomes@2191: duke@435: protected: jmasa@698: // If clear_space is true, clear the survivor spaces. Eden is jmasa@698: // cleared if the minimum size of eden is 0. If mangle_space jmasa@698: // is true, also mangle the space in debug mode. jmasa@698: void compute_space_boundaries(uintx minimum_eden_size, jmasa@698: bool clear_space, jmasa@698: bool mangle_space); duke@435: // Scavenge support duke@435: void swap_spaces(); duke@435: }; stefank@2314: stefank@2314: #endif // SHARE_VM_MEMORY_DEFNEWGENERATION_HPP