duke@435: /*
tschatzl@5701:  * Copyright (c) 2000, 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_GENCOLLECTEDHEAP_HPP
stefank@2314: #define SHARE_VM_MEMORY_GENCOLLECTEDHEAP_HPP
stefank@2314: 
stefank@2314: #include "gc_implementation/shared/adaptiveSizePolicy.hpp"
stefank@2314: #include "memory/collectorPolicy.hpp"
stefank@2314: #include "memory/generation.hpp"
stefank@2314: #include "memory/sharedHeap.hpp"
stefank@2314: 
duke@435: class SubTasksDone;
duke@435: 
duke@435: // A "GenCollectedHeap" is a SharedHeap that uses generational
duke@435: // collection.  It is represented with a sequence of Generation's.
duke@435: class GenCollectedHeap : public SharedHeap {
duke@435:   friend class GenCollectorPolicy;
duke@435:   friend class Generation;
duke@435:   friend class DefNewGeneration;
duke@435:   friend class TenuredGeneration;
duke@435:   friend class ConcurrentMarkSweepGeneration;
duke@435:   friend class CMSCollector;
duke@435:   friend class GenMarkSweep;
duke@435:   friend class VM_GenCollectForAllocation;
duke@435:   friend class VM_GenCollectFull;
duke@435:   friend class VM_GenCollectFullConcurrent;
duke@435:   friend class VM_GC_HeapInspection;
duke@435:   friend class VM_HeapDumper;
duke@435:   friend class HeapInspection;
duke@435:   friend class GCCauseSetter;
duke@435:   friend class VMStructs;
duke@435: public:
duke@435:   enum SomeConstants {
duke@435:     max_gens = 10
duke@435:   };
duke@435: 
duke@435:   friend class VM_PopulateDumpSharedSpace;
duke@435: 
duke@435:  protected:
duke@435:   // Fields:
duke@435:   static GenCollectedHeap* _gch;
duke@435: 
duke@435:  private:
duke@435:   int _n_gens;
duke@435:   Generation* _gens[max_gens];
duke@435:   GenerationSpec** _gen_specs;
duke@435: 
duke@435:   // The generational collector policy.
duke@435:   GenCollectorPolicy* _gen_policy;
duke@435: 
ysr@2243:   // Indicates that the most recent previous incremental collection failed.
ysr@2243:   // The flag is cleared when an action is taken that might clear the
ysr@2243:   // condition that caused that incremental collection to fail.
ysr@2243:   bool _incremental_collection_failed;
duke@435: 
duke@435:   // In support of ExplicitGCInvokesConcurrent functionality
duke@435:   unsigned int _full_collections_completed;
duke@435: 
duke@435:   // Data structure for claiming the (potentially) parallel tasks in
stefank@6992:   // (gen-specific) roots processing.
stefank@6992:   SubTasksDone* _gen_process_roots_tasks;
stefank@6992:   SubTasksDone* gen_process_roots_tasks() { return _gen_process_roots_tasks; }
duke@435: 
duke@435:   // In block contents verification, the number of header words to skip
duke@435:   NOT_PRODUCT(static size_t _skip_header_HeapWords;)
duke@435: 
duke@435: protected:
duke@435:   // Helper functions for allocation
duke@435:   HeapWord* attempt_allocation(size_t size,
duke@435:                                bool   is_tlab,
duke@435:                                bool   first_only);
duke@435: 
duke@435:   // Helper function for two callbacks below.
duke@435:   // Considers collection of the first max_level+1 generations.
duke@435:   void do_collection(bool   full,
duke@435:                      bool   clear_all_soft_refs,
duke@435:                      size_t size,
duke@435:                      bool   is_tlab,
duke@435:                      int    max_level);
duke@435: 
duke@435:   // Callback from VM_GenCollectForAllocation operation.
duke@435:   // This function does everything necessary/possible to satisfy an
duke@435:   // allocation request that failed in the youngest generation that should
duke@435:   // have handled it (including collection, expansion, etc.)
duke@435:   HeapWord* satisfy_failed_allocation(size_t size, bool is_tlab);
duke@435: 
duke@435:   // Callback from VM_GenCollectFull operation.
duke@435:   // Perform a full collection of the first max_level+1 generations.
coleenp@4037:   virtual void do_full_collection(bool clear_all_soft_refs);
duke@435:   void do_full_collection(bool clear_all_soft_refs, int max_level);
duke@435: 
duke@435:   // Does the "cause" of GC indicate that
duke@435:   // we absolutely __must__ clear soft refs?
duke@435:   bool must_clear_all_soft_refs();
duke@435: 
duke@435: public:
duke@435:   GenCollectedHeap(GenCollectorPolicy *policy);
duke@435: 
duke@435:   GCStats* gc_stats(int level) const;
duke@435: 
duke@435:   // Returns JNI_OK on success
duke@435:   virtual jint initialize();
coleenp@4037:   char* allocate(size_t alignment,
duke@435:                  size_t* _total_reserved, int* _n_covered_regions,
duke@435:                  ReservedSpace* heap_rs);
duke@435: 
duke@435:   // Does operations required after initialization has been done.
duke@435:   void post_initialize();
duke@435: 
duke@435:   // Initialize ("weak") refs processing support
duke@435:   virtual void ref_processing_init();
duke@435: 
duke@435:   virtual CollectedHeap::Name kind() const {
duke@435:     return CollectedHeap::GenCollectedHeap;
duke@435:   }
duke@435: 
duke@435:   // The generational collector policy.
duke@435:   GenCollectorPolicy* gen_policy() const { return _gen_policy; }
coleenp@4037:   virtual CollectorPolicy* collector_policy() const { return (CollectorPolicy*) gen_policy(); }
duke@435: 
duke@435:   // Adaptive size policy
duke@435:   virtual AdaptiveSizePolicy* size_policy() {
duke@435:     return gen_policy()->size_policy();
duke@435:   }
duke@435: 
tschatzl@5701:   // Return the (conservative) maximum heap alignment
tschatzl@5701:   static size_t conservative_max_heap_alignment() {
tschatzl@5701:     return Generation::GenGrain;
tschatzl@5701:   }
tschatzl@5701: 
duke@435:   size_t capacity() const;
duke@435:   size_t used() const;
duke@435: 
coleenp@4037:   // Save the "used_region" for generations level and lower.
coleenp@4037:   void save_used_regions(int level);
duke@435: 
duke@435:   size_t max_capacity() const;
duke@435: 
duke@435:   HeapWord* mem_allocate(size_t size,
duke@435:                          bool*  gc_overhead_limit_was_exceeded);
duke@435: 
duke@435:   // We may support a shared contiguous allocation area, if the youngest
duke@435:   // generation does.
duke@435:   bool supports_inline_contig_alloc() const;
duke@435:   HeapWord** top_addr() const;
duke@435:   HeapWord** end_addr() const;
duke@435: 
duke@435:   // Return an estimate of the maximum allocation that could be performed
duke@435:   // without triggering any collection activity.  In a generational
duke@435:   // collector, for example, this is probably the largest allocation that
duke@435:   // could be supported in the youngest generation.  It is "unsafe" because
duke@435:   // no locks are taken; the result should be treated as an approximation,
duke@435:   // not a guarantee.
duke@435:   size_t unsafe_max_alloc();
duke@435: 
duke@435:   // Does this heap support heap inspection? (+PrintClassHistogram)
duke@435:   virtual bool supports_heap_inspection() const { return true; }
duke@435: 
duke@435:   // Perform a full collection of the heap; intended for use in implementing
duke@435:   // "System.gc". This implies as full a collection as the CollectedHeap
duke@435:   // supports. Caller does not hold the Heap_lock on entry.
duke@435:   void collect(GCCause::Cause cause);
duke@435: 
duke@435:   // The same as above but assume that the caller holds the Heap_lock.
duke@435:   void collect_locked(GCCause::Cause cause);
duke@435: 
duke@435:   // Perform a full collection of the first max_level+1 generations.
duke@435:   // Mostly used for testing purposes. Caller does not hold the Heap_lock on entry.
duke@435:   void collect(GCCause::Cause cause, int max_level);
duke@435: 
stefank@3335:   // Returns "TRUE" iff "p" points into the committed areas of the heap.
duke@435:   // The methods is_in(), is_in_closed_subset() and is_in_youngest() may
duke@435:   // be expensive to compute in general, so, to prevent
duke@435:   // their inadvertent use in product jvm's, we restrict their use to
duke@435:   // assertion checking or verification only.
duke@435:   bool is_in(const void* p) const;
duke@435: 
duke@435:   // override
duke@435:   bool is_in_closed_subset(const void* p) const {
duke@435:     if (UseConcMarkSweepGC) {
duke@435:       return is_in_reserved(p);
duke@435:     } else {
duke@435:       return is_in(p);
duke@435:     }
duke@435:   }
duke@435: 
jmasa@2909:   // Returns true if the reference is to an object in the reserved space
jmasa@2909:   // for the young generation.
jmasa@2909:   // Assumes the the young gen address range is less than that of the old gen.
jmasa@2909:   bool is_in_young(oop p);
jmasa@2909: 
jmasa@2909: #ifdef ASSERT
jmasa@2909:   virtual bool is_in_partial_collection(const void* p);
jmasa@2909: #endif
jmasa@2909: 
jmasa@2909:   virtual bool is_scavengable(const void* addr) {
jmasa@2909:     return is_in_young((oop)addr);
jmasa@2909:   }
duke@435: 
duke@435:   // Iteration functions.
coleenp@4037:   void oop_iterate(ExtendedOopClosure* cl);
duke@435:   void object_iterate(ObjectClosure* cl);
jmasa@952:   void safe_object_iterate(ObjectClosure* cl);
duke@435:   Space* space_containing(const void* addr) const;
duke@435: 
duke@435:   // A CollectedHeap is divided into a dense sequence of "blocks"; that is,
duke@435:   // each address in the (reserved) heap is a member of exactly
duke@435:   // one block.  The defining characteristic of a block is that it is
duke@435:   // possible to find its size, and thus to progress forward to the next
duke@435:   // block.  (Blocks may be of different sizes.)  Thus, blocks may
duke@435:   // represent Java objects, or they might be free blocks in a
duke@435:   // free-list-based heap (or subheap), as long as the two kinds are
duke@435:   // distinguishable and the size of each is determinable.
duke@435: 
duke@435:   // Returns the address of the start of the "block" that contains the
duke@435:   // address "addr".  We say "blocks" instead of "object" since some heaps
duke@435:   // may not pack objects densely; a chunk may either be an object or a
duke@435:   // non-object.
duke@435:   virtual HeapWord* block_start(const void* addr) const;
duke@435: 
duke@435:   // Requires "addr" to be the start of a chunk, and returns its size.
duke@435:   // "addr + size" is required to be the start of a new chunk, or the end
duke@435:   // of the active area of the heap. Assumes (and verifies in non-product
duke@435:   // builds) that addr is in the allocated part of the heap and is
duke@435:   // the start of a chunk.
duke@435:   virtual size_t block_size(const HeapWord* addr) const;
duke@435: 
duke@435:   // Requires "addr" to be the start of a block, and returns "TRUE" iff
duke@435:   // the block is an object. Assumes (and verifies in non-product
duke@435:   // builds) that addr is in the allocated part of the heap and is
duke@435:   // the start of a chunk.
duke@435:   virtual bool block_is_obj(const HeapWord* addr) const;
duke@435: 
duke@435:   // Section on TLAB's.
duke@435:   virtual bool supports_tlab_allocation() const;
duke@435:   virtual size_t tlab_capacity(Thread* thr) const;
brutisso@6376:   virtual size_t tlab_used(Thread* thr) const;
duke@435:   virtual size_t unsafe_max_tlab_alloc(Thread* thr) const;
duke@435:   virtual HeapWord* allocate_new_tlab(size_t size);
duke@435: 
ysr@777:   // Can a compiler initialize a new object without store barriers?
ysr@777:   // This permission only extends from the creation of a new object
ysr@777:   // via a TLAB up to the first subsequent safepoint.
ysr@777:   virtual bool can_elide_tlab_store_barriers() const {
ysr@777:     return true;
ysr@777:   }
ysr@777: 
ysr@1601:   virtual bool card_mark_must_follow_store() const {
ysr@1601:     return UseConcMarkSweepGC;
ysr@1601:   }
ysr@1601: 
ysr@1462:   // We don't need barriers for stores to objects in the
ysr@1462:   // young gen and, a fortiori, for initializing stores to
ysr@1462:   // objects therein. This applies to {DefNew,ParNew}+{Tenured,CMS}
ysr@1462:   // only and may need to be re-examined in case other
ysr@1462:   // kinds of collectors are implemented in the future.
ysr@1462:   virtual bool can_elide_initializing_store_barrier(oop new_obj) {
ysr@1463:     // We wanted to assert that:-
ysr@1463:     // assert(UseParNewGC || UseSerialGC || UseConcMarkSweepGC,
ysr@1463:     //       "Check can_elide_initializing_store_barrier() for this collector");
ysr@1463:     // but unfortunately the flag UseSerialGC need not necessarily always
ysr@1463:     // be set when DefNew+Tenured are being used.
jmasa@2909:     return is_in_young(new_obj);
ysr@1462:   }
ysr@1462: 
duke@435:   // The "requestor" generation is performing some garbage collection
duke@435:   // action for which it would be useful to have scratch space.  The
duke@435:   // requestor promises to allocate no more than "max_alloc_words" in any
duke@435:   // older generation (via promotion say.)   Any blocks of space that can
duke@435:   // be provided are returned as a list of ScratchBlocks, sorted by
duke@435:   // decreasing size.
duke@435:   ScratchBlock* gather_scratch(Generation* requestor, size_t max_alloc_words);
jmasa@698:   // Allow each generation to reset any scratch space that it has
jmasa@698:   // contributed as it needs.
jmasa@698:   void release_scratch();
duke@435: 
duke@435:   // Ensure parsability: override
duke@435:   virtual void ensure_parsability(bool retire_tlabs);
duke@435: 
duke@435:   // Time in ms since the longest time a collector ran in
duke@435:   // in any generation.
duke@435:   virtual jlong millis_since_last_gc();
duke@435: 
duke@435:   // Total number of full collections completed.
duke@435:   unsigned int total_full_collections_completed() {
duke@435:     assert(_full_collections_completed <= _total_full_collections,
duke@435:            "Can't complete more collections than were started");
duke@435:     return _full_collections_completed;
duke@435:   }
duke@435: 
duke@435:   // Update above counter, as appropriate, at the end of a stop-world GC cycle
duke@435:   unsigned int update_full_collections_completed();
duke@435:   // Update above counter, as appropriate, at the end of a concurrent GC cycle
duke@435:   unsigned int update_full_collections_completed(unsigned int count);
duke@435: 
duke@435:   // Update "time of last gc" for all constituent generations
duke@435:   // to "now".
duke@435:   void update_time_of_last_gc(jlong now) {
duke@435:     for (int i = 0; i < _n_gens; i++) {
duke@435:       _gens[i]->update_time_of_last_gc(now);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Update the gc statistics for each generation.
duke@435:   // "level" is the level of the lastest collection
duke@435:   void update_gc_stats(int current_level, bool full) {
duke@435:     for (int i = 0; i < _n_gens; i++) {
duke@435:       _gens[i]->update_gc_stats(current_level, full);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   // Override.
duke@435:   bool no_gc_in_progress() { return !is_gc_active(); }
duke@435: 
duke@435:   // Override.
duke@435:   void prepare_for_verify();
duke@435: 
duke@435:   // Override.
brutisso@3711:   void verify(bool silent, VerifyOption option);
duke@435: 
duke@435:   // Override.
tonyp@3269:   virtual void print_on(outputStream* st) const;
duke@435:   virtual void print_gc_threads_on(outputStream* st) const;
duke@435:   virtual void gc_threads_do(ThreadClosure* tc) const;
duke@435:   virtual void print_tracing_info() const;
stefank@4904:   virtual void print_on_error(outputStream* st) const;
duke@435: 
duke@435:   // PrintGC, PrintGCDetails support
duke@435:   void print_heap_change(size_t prev_used) const;
duke@435: 
duke@435:   // The functions below are helper functions that a subclass of
duke@435:   // "CollectedHeap" can use in the implementation of its virtual
duke@435:   // functions.
duke@435: 
duke@435:   class GenClosure : public StackObj {
duke@435:    public:
duke@435:     virtual void do_generation(Generation* gen) = 0;
duke@435:   };
duke@435: 
coleenp@4037:   // Apply "cl.do_generation" to all generations in the heap
coleenp@4037:   // If "old_to_young" determines the order.
duke@435:   void generation_iterate(GenClosure* cl, bool old_to_young);
duke@435: 
duke@435:   void space_iterate(SpaceClosure* cl);
duke@435: 
coleenp@4037:   // Return "true" if all generations have reached the
duke@435:   // maximal committed limit that they can reach, without a garbage
duke@435:   // collection.
duke@435:   virtual bool is_maximal_no_gc() const;
duke@435: 
brutisso@5516:   // Return the generation before "gen".
duke@435:   Generation* prev_gen(Generation* gen) const {
duke@435:     int l = gen->level();
brutisso@5516:     guarantee(l > 0, "Out of bounds");
brutisso@5516:     return _gens[l-1];
duke@435:   }
duke@435: 
brutisso@5516:   // Return the generation after "gen".
duke@435:   Generation* next_gen(Generation* gen) const {
duke@435:     int l = gen->level() + 1;
brutisso@5516:     guarantee(l < _n_gens, "Out of bounds");
brutisso@5516:     return _gens[l];
duke@435:   }
duke@435: 
duke@435:   Generation* get_gen(int i) const {
brutisso@5516:     guarantee(i >= 0 && i < _n_gens, "Out of bounds");
brutisso@5516:     return _gens[i];
duke@435:   }
duke@435: 
duke@435:   int n_gens() const {
duke@435:     assert(_n_gens == gen_policy()->number_of_generations(), "Sanity");
duke@435:     return _n_gens;
duke@435:   }
duke@435: 
duke@435:   // Convenience function to be used in situations where the heap type can be
duke@435:   // asserted to be this type.
duke@435:   static GenCollectedHeap* heap();
duke@435: 
jmasa@3357:   void set_par_threads(uint t);
duke@435: 
duke@435:   // Invoke the "do_oop" method of one of the closures "not_older_gens"
duke@435:   // or "older_gens" on root locations for the generation at
duke@435:   // "level".  (The "older_gens" closure is used for scanning references
duke@435:   // from older generations; "not_older_gens" is used everywhere else.)
duke@435:   // If "younger_gens_as_roots" is false, younger generations are
duke@435:   // not scanned as roots; in this case, the caller must be arranging to
duke@435:   // scan the younger generations itself.  (For example, a generation might
duke@435:   // explicitly mark reachable objects in younger generations, to avoid
coleenp@4037:   // excess storage retention.)
coleenp@4037:   // The "so" argument determines which of the roots
duke@435:   // the closure is applied to:
duke@435:   // "SO_None" does none;
stefank@6992:  private:
stefank@6992:   void gen_process_roots(int level,
stefank@6992:                          bool younger_gens_as_roots,
stefank@6992:                          bool activate_scope,
stefank@6992:                          SharedHeap::ScanningOption so,
stefank@6992:                          OopsInGenClosure* not_older_gens,
stefank@6992:                          OopsInGenClosure* weak_roots,
stefank@6992:                          OopsInGenClosure* older_gens,
stefank@6992:                          CLDClosure* cld_closure,
stefank@6992:                          CLDClosure* weak_cld_closure,
stefank@6992:                          CodeBlobClosure* code_closure);
stefank@6992: 
stefank@6992:  public:
stefank@6992:   static const bool StrongAndWeakRoots = false;
stefank@6992:   static const bool StrongRootsOnly    = true;
stefank@6992: 
stefank@6992:   void gen_process_roots(int level,
stefank@6992:                          bool younger_gens_as_roots,
stefank@6992:                          bool activate_scope,
stefank@6992:                          SharedHeap::ScanningOption so,
stefank@6992:                          bool only_strong_roots,
stefank@6992:                          OopsInGenClosure* not_older_gens,
stefank@6992:                          OopsInGenClosure* older_gens,
stefank@6992:                          CLDClosure* cld_closure);
duke@435: 
stefank@6971:   // Apply "root_closure" to all the weak roots of the system.
stefank@6971:   // These include JNI weak roots, string table,
stefank@6971:   // and referents of reachable weak refs.
stefank@6971:   void gen_process_weak_roots(OopClosure* root_closure);
duke@435: 
duke@435:   // Set the saved marks of generations, if that makes sense.
duke@435:   // In particular, if any generation might iterate over the oops
duke@435:   // in other generations, it should call this method.
duke@435:   void save_marks();
duke@435: 
duke@435:   // Apply "cur->do_oop" or "older->do_oop" to all the oops in objects
duke@435:   // allocated since the last call to save_marks in generations at or above
coleenp@4037:   // "level".  The "cur" closure is
duke@435:   // applied to references in the generation at "level", and the "older"
coleenp@4037:   // closure to older generations.
duke@435: #define GCH_SINCE_SAVE_MARKS_ITERATE_DECL(OopClosureType, nv_suffix)    \
duke@435:   void oop_since_save_marks_iterate(int level,                          \
duke@435:                                     OopClosureType* cur,                \
duke@435:                                     OopClosureType* older);
duke@435: 
duke@435:   ALL_SINCE_SAVE_MARKS_CLOSURES(GCH_SINCE_SAVE_MARKS_ITERATE_DECL)
duke@435: 
duke@435: #undef GCH_SINCE_SAVE_MARKS_ITERATE_DECL
duke@435: 
duke@435:   // Returns "true" iff no allocations have occurred in any generation at
coleenp@4037:   // "level" or above since the last
duke@435:   // call to "save_marks".
duke@435:   bool no_allocs_since_save_marks(int level);
duke@435: 
ysr@2243:   // Returns true if an incremental collection is likely to fail.
ysr@2336:   // We optionally consult the young gen, if asked to do so;
ysr@2336:   // otherwise we base our answer on whether the previous incremental
ysr@2336:   // collection attempt failed with no corrective action as of yet.
ysr@2336:   bool incremental_collection_will_fail(bool consult_young) {
ysr@2243:     // Assumes a 2-generation system; the first disjunct remembers if an
ysr@2243:     // incremental collection failed, even when we thought (second disjunct)
ysr@2243:     // that it would not.
ysr@2243:     assert(heap()->collector_policy()->is_two_generation_policy(),
ysr@2243:            "the following definition may not be suitable for an n(>2)-generation system");
ysr@2336:     return incremental_collection_failed() ||
ysr@2336:            (consult_young && !get_gen(0)->collection_attempt_is_safe());
ysr@2243:   }
ysr@2243: 
duke@435:   // If a generation bails out of an incremental collection,
duke@435:   // it sets this flag.
ysr@2243:   bool incremental_collection_failed() const {
ysr@2243:     return _incremental_collection_failed;
duke@435:   }
ysr@2243:   void set_incremental_collection_failed() {
ysr@2243:     _incremental_collection_failed = true;
duke@435:   }
ysr@2243:   void clear_incremental_collection_failed() {
ysr@2243:     _incremental_collection_failed = false;
duke@435:   }
duke@435: 
coleenp@4037:   // Promotion of obj into gen failed.  Try to promote obj to higher
duke@435:   // gens in ascending order; return the new location of obj if successful.
brutisso@5516:   // Otherwise, try expand-and-allocate for obj in both the young and old
brutisso@5516:   // generation; return the new location of obj if successful.  Otherwise, return NULL.
brutisso@5516:   oop handle_failed_promotion(Generation* old_gen,
duke@435:                               oop obj,
coleenp@548:                               size_t obj_size);
duke@435: 
duke@435: private:
duke@435:   // Accessor for memory state verification support
duke@435:   NOT_PRODUCT(
duke@435:     static size_t skip_header_HeapWords() { return _skip_header_HeapWords; }
duke@435:   )
duke@435: 
duke@435:   // Override
duke@435:   void check_for_non_bad_heap_word_value(HeapWord* addr,
duke@435:     size_t size) PRODUCT_RETURN;
duke@435: 
duke@435:   // For use by mark-sweep.  As implemented, mark-sweep-compact is global
duke@435:   // in an essential way: compaction is performed across generations, by
duke@435:   // iterating over spaces.
duke@435:   void prepare_for_compaction();
duke@435: 
duke@435:   // Perform a full collection of the first max_level+1 generations.
duke@435:   // This is the low level interface used by the public versions of
duke@435:   // collect() and collect_locked(). Caller holds the Heap_lock on entry.
duke@435:   void collect_locked(GCCause::Cause cause, int max_level);
duke@435: 
duke@435:   // Returns success or failure.
duke@435:   bool create_cms_collector();
duke@435: 
duke@435:   // In support of ExplicitGCInvokesConcurrent functionality
duke@435:   bool should_do_concurrent_full_gc(GCCause::Cause cause);
duke@435:   void collect_mostly_concurrent(GCCause::Cause cause);
duke@435: 
jmasa@698:   // Save the tops of the spaces in all generations
jmasa@698:   void record_gen_tops_before_GC() PRODUCT_RETURN;
jmasa@698: 
duke@435: protected:
duke@435:   virtual void gc_prologue(bool full);
duke@435:   virtual void gc_epilogue(bool full);
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_MEMORY_GENCOLLECTEDHEAP_HPP