duke@435: /*
coleenp@6626:  * Copyright (c) 2001, 2014, 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_GC_INTERFACE_COLLECTEDHEAP_HPP
stefank@2314: #define SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP
stefank@2314: 
stefank@2314: #include "gc_interface/gcCause.hpp"
sla@5237: #include "gc_implementation/shared/gcWhen.hpp"
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: #include "memory/barrierSet.hpp"
stefank@2314: #include "runtime/handles.hpp"
stefank@2314: #include "runtime/perfData.hpp"
stefank@2314: #include "runtime/safepoint.hpp"
never@3499: #include "utilities/events.hpp"
stefank@2314: 
duke@435: // A "CollectedHeap" is an implementation of a java heap for HotSpot.  This
duke@435: // is an abstract class: there may be many different kinds of heaps.  This
duke@435: // class defines the functions that a heap must implement, and contains
duke@435: // infrastructure common to all heaps.
duke@435: 
sla@5237: class AdaptiveSizePolicy;
duke@435: class BarrierSet;
sla@5237: class CollectorPolicy;
sla@5237: class GCHeapSummary;
sla@5237: class GCTimer;
sla@5237: class GCTracer;
sla@5237: class MetaspaceSummary;
sla@5237: class Thread;
duke@435: class ThreadClosure;
sla@5237: class VirtualSpaceSummary;
johnc@5548: class nmethod;
duke@435: 
never@3499: class GCMessage : public FormatBuffer<1024> {
never@3499:  public:
never@3499:   bool is_before;
never@3499: 
never@3499:  public:
never@3499:   GCMessage() {}
never@3499: };
never@3499: 
never@3499: class GCHeapLog : public EventLogBase<GCMessage> {
never@3499:  private:
never@3499:   void log_heap(bool before);
never@3499: 
never@3499:  public:
never@3499:   GCHeapLog() : EventLogBase<GCMessage>("GC Heap History") {}
never@3499: 
never@3499:   void log_heap_before() {
never@3499:     log_heap(true);
never@3499:   }
never@3499:   void log_heap_after() {
never@3499:     log_heap(false);
never@3499:   }
never@3499: };
never@3499: 
duke@435: //
duke@435: // CollectedHeap
duke@435: //   SharedHeap
duke@435: //     GenCollectedHeap
duke@435: //     G1CollectedHeap
duke@435: //   ParallelScavengeHeap
duke@435: //
zgu@3900: class CollectedHeap : public CHeapObj<mtInternal> {
duke@435:   friend class VMStructs;
duke@435:   friend class IsGCActiveMark; // Block structured external access to _is_gc_active
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   static int       _fire_out_of_memory_count;
duke@435: #endif
duke@435: 
jcoomes@916:   // Used for filler objects (static, but initialized in ctor).
jcoomes@916:   static size_t _filler_array_max_size;
jcoomes@916: 
never@3499:   GCHeapLog* _gc_heap_log;
never@3499: 
ysr@1601:   // Used in support of ReduceInitialCardMarks; only consulted if COMPILER2 is being used
ysr@1601:   bool _defer_initial_card_mark;
ysr@1601: 
duke@435:  protected:
duke@435:   MemRegion _reserved;
duke@435:   BarrierSet* _barrier_set;
duke@435:   bool _is_gc_active;
jmasa@3357:   uint _n_par_threads;
jmasa@2188: 
duke@435:   unsigned int _total_collections;          // ... started
duke@435:   unsigned int _total_full_collections;     // ... started
duke@435:   NOT_PRODUCT(volatile size_t _promotion_failure_alot_count;)
duke@435:   NOT_PRODUCT(volatile size_t _promotion_failure_alot_gc_number;)
duke@435: 
duke@435:   // Reason for current garbage collection.  Should be set to
duke@435:   // a value reflecting no collection between collections.
duke@435:   GCCause::Cause _gc_cause;
duke@435:   GCCause::Cause _gc_lastcause;
duke@435:   PerfStringVariable* _perf_gc_cause;
duke@435:   PerfStringVariable* _perf_gc_lastcause;
duke@435: 
duke@435:   // Constructor
duke@435:   CollectedHeap();
duke@435: 
ysr@1601:   // Do common initializations that must follow instance construction,
ysr@1601:   // for example, those needing virtual calls.
ysr@1601:   // This code could perhaps be moved into initialize() but would
ysr@1601:   // be slightly more awkward because we want the latter to be a
ysr@1601:   // pure virtual.
ysr@1601:   void pre_initialize();
ysr@1601: 
tonyp@2971:   // Create a new tlab. All TLAB allocations must go through this.
duke@435:   virtual HeapWord* allocate_new_tlab(size_t size);
duke@435: 
duke@435:   // Accumulate statistics on all tlabs.
duke@435:   virtual void accumulate_statistics_all_tlabs();
duke@435: 
duke@435:   // Reinitialize tlabs before resuming mutators.
duke@435:   virtual void resize_all_tlabs();
duke@435: 
duke@435:   // Allocate from the current thread's TLAB, with broken-out slow path.
sla@5237:   inline static HeapWord* allocate_from_tlab(KlassHandle klass, Thread* thread, size_t size);
sla@5237:   static HeapWord* allocate_from_tlab_slow(KlassHandle klass, Thread* thread, size_t size);
duke@435: 
duke@435:   // Allocate an uninitialized block of the given size, or returns NULL if
duke@435:   // this is impossible.
sla@5237:   inline static HeapWord* common_mem_allocate_noinit(KlassHandle klass, size_t size, TRAPS);
duke@435: 
duke@435:   // Like allocate_init, but the block returned by a successful allocation
duke@435:   // is guaranteed initialized to zeros.
sla@5237:   inline static HeapWord* common_mem_allocate_init(KlassHandle klass, size_t size, TRAPS);
duke@435: 
duke@435:   // Helper functions for (VM) allocation.
brutisso@3675:   inline static void post_allocation_setup_common(KlassHandle klass, HeapWord* obj);
duke@435:   inline static void post_allocation_setup_no_klass_install(KlassHandle klass,
brutisso@3675:                                                             HeapWord* objPtr);
duke@435: 
coleenp@6627:   inline static void post_allocation_setup_obj(KlassHandle klass, HeapWord* obj, int size);
duke@435: 
duke@435:   inline static void post_allocation_setup_array(KlassHandle klass,
brutisso@3675:                                                  HeapWord* obj, int length);
duke@435: 
duke@435:   // Clears an allocated object.
duke@435:   inline static void init_obj(HeapWord* obj, size_t size);
duke@435: 
jcoomes@916:   // Filler object utilities.
jcoomes@916:   static inline size_t filler_array_hdr_size();
jcoomes@916:   static inline size_t filler_array_min_size();
jcoomes@916: 
jcoomes@916:   DEBUG_ONLY(static void fill_args_check(HeapWord* start, size_t words);)
johnc@1600:   DEBUG_ONLY(static void zap_filler_array(HeapWord* start, size_t words, bool zap = true);)
jcoomes@916: 
jcoomes@916:   // Fill with a single array; caller must ensure filler_array_min_size() <=
jcoomes@916:   // words <= filler_array_max_size().
johnc@1600:   static inline void fill_with_array(HeapWord* start, size_t words, bool zap = true);
jcoomes@916: 
jcoomes@916:   // Fill with a single object (either an int array or a java.lang.Object).
johnc@1600:   static inline void fill_with_object_impl(HeapWord* start, size_t words, bool zap = true);
jcoomes@916: 
sla@5237:   virtual void trace_heap(GCWhen::Type when, GCTracer* tracer);
sla@5237: 
duke@435:   // Verification functions
duke@435:   virtual void check_for_bad_heap_word_value(HeapWord* addr, size_t size)
duke@435:     PRODUCT_RETURN;
duke@435:   virtual void check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
duke@435:     PRODUCT_RETURN;
jmasa@977:   debug_only(static void check_for_valid_allocation_state();)
duke@435: 
duke@435:  public:
duke@435:   enum Name {
duke@435:     Abstract,
duke@435:     SharedHeap,
duke@435:     GenCollectedHeap,
duke@435:     ParallelScavengeHeap,
duke@435:     G1CollectedHeap
duke@435:   };
duke@435: 
brutisso@3668:   static inline size_t filler_array_max_size() {
brutisso@3668:     return _filler_array_max_size;
brutisso@3668:   }
brutisso@3668: 
duke@435:   virtual CollectedHeap::Name kind() const { return CollectedHeap::Abstract; }
duke@435: 
duke@435:   /**
duke@435:    * Returns JNI error code JNI_ENOMEM if memory could not be allocated,
duke@435:    * and JNI_OK on success.
duke@435:    */
duke@435:   virtual jint initialize() = 0;
duke@435: 
duke@435:   // In many heaps, there will be a need to perform some initialization activities
duke@435:   // after the Universe is fully formed, but before general heap allocation is allowed.
duke@435:   // This is the correct place to place such initialization methods.
duke@435:   virtual void post_initialize() = 0;
duke@435: 
pliden@6690:   // Stop any onging concurrent work and prepare for exit.
pliden@6690:   virtual void stop() {}
pliden@6690: 
duke@435:   MemRegion reserved_region() const { return _reserved; }
coleenp@548:   address base() const { return (address)reserved_region().start(); }
duke@435: 
duke@435:   virtual size_t capacity() const = 0;
duke@435:   virtual size_t used() const = 0;
duke@435: 
duke@435:   // Return "true" if the part of the heap that allocates Java
duke@435:   // objects has reached the maximal committed limit that it can
duke@435:   // reach, without a garbage collection.
duke@435:   virtual bool is_maximal_no_gc() const = 0;
duke@435: 
duke@435:   // Support for java.lang.Runtime.maxMemory():  return the maximum amount of
duke@435:   // memory that the vm could make available for storing 'normal' java objects.
duke@435:   // This is based on the reserved address space, but should not include space
coleenp@4037:   // that the vm uses internally for bookkeeping or temporary storage
coleenp@4037:   // (e.g., in the case of the young gen, one of the survivor
duke@435:   // spaces).
duke@435:   virtual size_t max_capacity() const = 0;
duke@435: 
duke@435:   // Returns "TRUE" if "p" points into the reserved area of the heap.
duke@435:   bool is_in_reserved(const void* p) const {
duke@435:     return _reserved.contains(p);
duke@435:   }
duke@435: 
duke@435:   bool is_in_reserved_or_null(const void* p) const {
duke@435:     return p == NULL || is_in_reserved(p);
duke@435:   }
duke@435: 
stefank@3335:   // Returns "TRUE" iff "p" points into the committed areas of the heap.
stefank@3335:   // Since this method can be expensive in general, we restrict its
duke@435:   // use to assertion checking only.
duke@435:   virtual bool is_in(const void* p) const = 0;
duke@435: 
duke@435:   bool is_in_or_null(const void* p) const {
duke@435:     return p == NULL || is_in(p);
duke@435:   }
duke@435: 
coleenp@4037:   bool is_in_place(Metadata** p) {
coleenp@4037:     return !Universe::heap()->is_in(p);
coleenp@4037:   }
coleenp@4037:   bool is_in_place(oop* p) { return Universe::heap()->is_in(p); }
coleenp@4037:   bool is_in_place(narrowOop* p) {
coleenp@4037:     oop o = oopDesc::load_decode_heap_oop_not_null(p);
coleenp@4037:     return Universe::heap()->is_in((const void*)o);
coleenp@4037:   }
coleenp@4037: 
duke@435:   // Let's define some terms: a "closed" subset of a heap is one that
duke@435:   //
duke@435:   // 1) contains all currently-allocated objects, and
duke@435:   //
duke@435:   // 2) is closed under reference: no object in the closed subset
duke@435:   //    references one outside the closed subset.
duke@435:   //
duke@435:   // Membership in a heap's closed subset is useful for assertions.
duke@435:   // Clearly, the entire heap is a closed subset, so the default
duke@435:   // implementation is to use "is_in_reserved".  But this may not be too
duke@435:   // liberal to perform useful checking.  Also, the "is_in" predicate
duke@435:   // defines a closed subset, but may be too expensive, since "is_in"
duke@435:   // verifies that its argument points to an object head.  The
duke@435:   // "closed_subset" method allows a heap to define an intermediate
duke@435:   // predicate, allowing more precise checking than "is_in_reserved" at
duke@435:   // lower cost than "is_in."
duke@435: 
duke@435:   // One important case is a heap composed of disjoint contiguous spaces,
duke@435:   // such as the Garbage-First collector.  Such heaps have a convenient
duke@435:   // closed subset consisting of the allocated portions of those
duke@435:   // contiguous spaces.
duke@435: 
duke@435:   // Return "TRUE" iff the given pointer points into the heap's defined
duke@435:   // closed subset (which defaults to the entire heap).
duke@435:   virtual bool is_in_closed_subset(const void* p) const {
duke@435:     return is_in_reserved(p);
duke@435:   }
duke@435: 
duke@435:   bool is_in_closed_subset_or_null(const void* p) const {
duke@435:     return p == NULL || is_in_closed_subset(p);
duke@435:   }
duke@435: 
jmasa@2909: #ifdef ASSERT
jmasa@2909:   // Returns true if "p" is in the part of the
jmasa@2909:   // heap being collected.
jmasa@2909:   virtual bool is_in_partial_collection(const void *p) = 0;
jmasa@2909: #endif
jmasa@2909: 
jrose@1424:   // An object is scavengable if its location may move during a scavenge.
jrose@1424:   // (A scavenge is a GC which is not a full GC.)
jmasa@2909:   virtual bool is_scavengable(const void *p) = 0;
jrose@1424: 
duke@435:   void set_gc_cause(GCCause::Cause v) {
duke@435:      if (UsePerfData) {
duke@435:        _gc_lastcause = _gc_cause;
duke@435:        _perf_gc_lastcause->set_value(GCCause::to_string(_gc_lastcause));
duke@435:        _perf_gc_cause->set_value(GCCause::to_string(v));
duke@435:      }
duke@435:     _gc_cause = v;
duke@435:   }
duke@435:   GCCause::Cause gc_cause() { return _gc_cause; }
duke@435: 
jmasa@2188:   // Number of threads currently working on GC tasks.
jmasa@3357:   uint n_par_threads() { return _n_par_threads; }
jmasa@2188: 
jmasa@2188:   // May be overridden to set additional parallelism.
jmasa@3357:   virtual void set_par_threads(uint t) { _n_par_threads = t; };
jmasa@2188: 
duke@435:   // General obj/array allocation facilities.
duke@435:   inline static oop obj_allocate(KlassHandle klass, int size, TRAPS);
duke@435:   inline static oop array_allocate(KlassHandle klass, int size, int length, TRAPS);
kvn@3157:   inline static oop array_allocate_nozero(KlassHandle klass, int size, int length, TRAPS);
duke@435: 
coleenp@4037:   inline static void post_allocation_install_obj_klass(KlassHandle klass,
coleenp@4037:                                                        oop obj);
duke@435: 
duke@435:   // Raw memory allocation facilities
duke@435:   // The obj and array allocate methods are covers for these methods.
coleenp@4037:   // mem_allocate() should never be
tonyp@2971:   // called to allocate TLABs, only individual objects.
duke@435:   virtual HeapWord* mem_allocate(size_t size,
duke@435:                                  bool* gc_overhead_limit_was_exceeded) = 0;
duke@435: 
jcoomes@916:   // Utilities for turning raw memory into filler objects.
jcoomes@916:   //
jcoomes@916:   // min_fill_size() is the smallest region that can be filled.
jcoomes@916:   // fill_with_objects() can fill arbitrary-sized regions of the heap using
jcoomes@916:   // multiple objects.  fill_with_object() is for regions known to be smaller
jcoomes@916:   // than the largest array of integers; it uses a single object to fill the
jcoomes@916:   // region and has slightly less overhead.
jcoomes@916:   static size_t min_fill_size() {
jcoomes@916:     return size_t(align_object_size(oopDesc::header_size()));
jcoomes@916:   }
jcoomes@916: 
johnc@1600:   static void fill_with_objects(HeapWord* start, size_t words, bool zap = true);
jcoomes@916: 
johnc@1600:   static void fill_with_object(HeapWord* start, size_t words, bool zap = true);
johnc@1600:   static void fill_with_object(MemRegion region, bool zap = true) {
johnc@1600:     fill_with_object(region.start(), region.word_size(), zap);
jcoomes@916:   }
johnc@1600:   static void fill_with_object(HeapWord* start, HeapWord* end, bool zap = true) {
johnc@1600:     fill_with_object(start, pointer_delta(end, start), zap);
jcoomes@916:   }
jcoomes@916: 
jmasa@7031:   // Return the address "addr" aligned by "alignment_in_bytes" if such
jmasa@7031:   // an address is below "end".  Return NULL otherwise.
jmasa@7031:   inline static HeapWord* align_allocation_or_fail(HeapWord* addr,
jmasa@7031:                                                    HeapWord* end,
jmasa@7031:                                                    unsigned short alignment_in_bytes);
jmasa@7031: 
duke@435:   // Some heaps may offer a contiguous region for shared non-blocking
duke@435:   // allocation, via inlined code (by exporting the address of the top and
duke@435:   // end fields defining the extent of the contiguous allocation region.)
duke@435: 
duke@435:   // This function returns "true" iff the heap supports this kind of
duke@435:   // allocation.  (Default is "no".)
duke@435:   virtual bool supports_inline_contig_alloc() const {
duke@435:     return false;
duke@435:   }
duke@435:   // These functions return the addresses of the fields that define the
duke@435:   // boundaries of the contiguous allocation area.  (These fields should be
duke@435:   // physically near to one another.)
duke@435:   virtual HeapWord** top_addr() const {
duke@435:     guarantee(false, "inline contiguous allocation not supported");
duke@435:     return NULL;
duke@435:   }
duke@435:   virtual HeapWord** end_addr() const {
duke@435:     guarantee(false, "inline contiguous allocation not supported");
duke@435:     return NULL;
duke@435:   }
duke@435: 
duke@435:   // Some heaps may be in an unparseable state at certain times between
duke@435:   // collections. This may be necessary for efficient implementation of
duke@435:   // certain allocation-related activities. Calling this function before
duke@435:   // attempting to parse a heap ensures that the heap is in a parsable
duke@435:   // state (provided other concurrent activity does not introduce
duke@435:   // unparsability). It is normally expected, therefore, that this
duke@435:   // method is invoked with the world stopped.
duke@435:   // NOTE: if you override this method, make sure you call
duke@435:   // super::ensure_parsability so that the non-generational
duke@435:   // part of the work gets done. See implementation of
duke@435:   // CollectedHeap::ensure_parsability and, for instance,
duke@435:   // that of GenCollectedHeap::ensure_parsability().
duke@435:   // The argument "retire_tlabs" controls whether existing TLABs
duke@435:   // are merely filled or also retired, thus preventing further
duke@435:   // allocation from them and necessitating allocation of new TLABs.
duke@435:   virtual void ensure_parsability(bool retire_tlabs);
duke@435: 
duke@435:   // Section on thread-local allocation buffers (TLABs)
duke@435:   // If the heap supports thread-local allocation buffers, it should override
duke@435:   // the following methods:
duke@435:   // Returns "true" iff the heap supports thread-local allocation buffers.
duke@435:   // The default is "no".
brutisso@6376:   virtual bool supports_tlab_allocation() const = 0;
brutisso@6376: 
duke@435:   // The amount of space available for thread-local allocation buffers.
brutisso@6376:   virtual size_t tlab_capacity(Thread *thr) const = 0;
brutisso@6376: 
brutisso@6376:   // The amount of used space for thread-local allocation buffers for the given thread.
brutisso@6376:   virtual size_t tlab_used(Thread *thr) const = 0;
brutisso@6376: 
brutisso@6376:   virtual size_t max_tlab_size() const;
brutisso@6376: 
duke@435:   // An estimate of the maximum allocation that could be performed
duke@435:   // for thread-local allocation buffers without triggering any
duke@435:   // collection or expansion activity.
duke@435:   virtual size_t unsafe_max_tlab_alloc(Thread *thr) const {
duke@435:     guarantee(false, "thread-local allocation buffers not supported");
duke@435:     return 0;
duke@435:   }
ysr@1462: 
duke@435:   // Can a compiler initialize a new object without store barriers?
duke@435:   // This permission only extends from the creation of a new object
ysr@1462:   // via a TLAB up to the first subsequent safepoint. If such permission
ysr@1462:   // is granted for this heap type, the compiler promises to call
ysr@1462:   // defer_store_barrier() below on any slow path allocation of
ysr@1462:   // a new object for which such initializing store barriers will
ysr@1462:   // have been elided.
ysr@777:   virtual bool can_elide_tlab_store_barriers() const = 0;
ysr@777: 
duke@435:   // If a compiler is eliding store barriers for TLAB-allocated objects,
duke@435:   // there is probably a corresponding slow path which can produce
duke@435:   // an object allocated anywhere.  The compiler's runtime support
duke@435:   // promises to call this function on such a slow-path-allocated
duke@435:   // object before performing initializations that have elided
ysr@1462:   // store barriers. Returns new_obj, or maybe a safer copy thereof.
ysr@1601:   virtual oop new_store_pre_barrier(JavaThread* thread, oop new_obj);
ysr@1462: 
ysr@1462:   // Answers whether an initializing store to a new object currently
ysr@1601:   // allocated at the given address doesn't need a store
ysr@1462:   // barrier. Returns "true" if it doesn't need an initializing
ysr@1462:   // store barrier; answers "false" if it does.
ysr@1462:   virtual bool can_elide_initializing_store_barrier(oop new_obj) = 0;
ysr@1462: 
ysr@1601:   // If a compiler is eliding store barriers for TLAB-allocated objects,
ysr@1601:   // we will be informed of a slow-path allocation by a call
ysr@1601:   // to new_store_pre_barrier() above. Such a call precedes the
ysr@1601:   // initialization of the object itself, and no post-store-barriers will
ysr@1601:   // be issued. Some heap types require that the barrier strictly follows
ysr@1601:   // the initializing stores. (This is currently implemented by deferring the
ysr@1601:   // barrier until the next slow-path allocation or gc-related safepoint.)
ysr@1601:   // This interface answers whether a particular heap type needs the card
ysr@1601:   // mark to be thus strictly sequenced after the stores.
ysr@1601:   virtual bool card_mark_must_follow_store() const = 0;
ysr@1601: 
ysr@1462:   // If the CollectedHeap was asked to defer a store barrier above,
ysr@1462:   // this informs it to flush such a deferred store barrier to the
ysr@1462:   // remembered set.
ysr@1462:   virtual void flush_deferred_store_barrier(JavaThread* thread);
duke@435: 
duke@435:   // Does this heap support heap inspection (+PrintClassHistogram?)
ysr@777:   virtual bool supports_heap_inspection() const = 0;
duke@435: 
duke@435:   // Perform a collection of the heap; intended for use in implementing
duke@435:   // "System.gc".  This probably implies as full a collection as the
duke@435:   // "CollectedHeap" supports.
duke@435:   virtual void collect(GCCause::Cause cause) = 0;
duke@435: 
coleenp@4037:   // Perform a full collection
coleenp@4037:   virtual void do_full_collection(bool clear_all_soft_refs) = 0;
coleenp@4037: 
duke@435:   // This interface assumes that it's being called by the
duke@435:   // vm thread. It collects the heap assuming that the
duke@435:   // heap lock is already held and that we are executing in
duke@435:   // the context of the vm thread.
coleenp@4037:   virtual void collect_as_vm_thread(GCCause::Cause cause);
coleenp@4037: 
duke@435:   // Returns the barrier set for this heap
duke@435:   BarrierSet* barrier_set() { return _barrier_set; }
duke@435: 
duke@435:   // Returns "true" iff there is a stop-world GC in progress.  (I assume
duke@435:   // that it should answer "false" for the concurrent part of a concurrent
duke@435:   // collector -- dld).
duke@435:   bool is_gc_active() const { return _is_gc_active; }
duke@435: 
duke@435:   // Total number of GC collections (started)
duke@435:   unsigned int total_collections() const { return _total_collections; }
duke@435:   unsigned int total_full_collections() const { return _total_full_collections;}
duke@435: 
duke@435:   // Increment total number of GC collections (started)
duke@435:   // Should be protected but used by PSMarkSweep - cleanup for 1.4.2
duke@435:   void increment_total_collections(bool full = false) {
duke@435:     _total_collections++;
duke@435:     if (full) {
duke@435:       increment_total_full_collections();
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   void increment_total_full_collections() { _total_full_collections++; }
duke@435: 
duke@435:   // Return the AdaptiveSizePolicy for the heap.
duke@435:   virtual AdaptiveSizePolicy* size_policy() = 0;
duke@435: 
jmasa@1822:   // Return the CollectorPolicy for the heap
jmasa@1822:   virtual CollectorPolicy* collector_policy() const = 0;
jmasa@1822: 
coleenp@4037:   void oop_iterate_no_header(OopClosure* cl);
coleenp@4037: 
duke@435:   // Iterate over all the ref-containing fields of all objects, calling
coleenp@4037:   // "cl.do_oop" on each.
coleenp@4037:   virtual void oop_iterate(ExtendedOopClosure* cl) = 0;
duke@435: 
duke@435:   // Iterate over all objects, calling "cl.do_object" on each.
duke@435:   virtual void object_iterate(ObjectClosure* cl) = 0;
duke@435: 
jmasa@952:   // Similar to object_iterate() except iterates only
jmasa@952:   // over live objects.
jmasa@952:   virtual void safe_object_iterate(ObjectClosure* cl) = 0;
jmasa@952: 
duke@435:   // NOTE! There is no requirement that a collector implement these
duke@435:   // functions.
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 = 0;
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.
duke@435:   virtual size_t block_size(const HeapWord* addr) const = 0;
duke@435: 
duke@435:   // Requires "addr" to be the start of a block, and returns "TRUE" iff
duke@435:   // the block is an object.
duke@435:   virtual bool block_is_obj(const HeapWord* addr) const = 0;
duke@435: 
duke@435:   // Returns the longest time (in ms) that has elapsed since the last
duke@435:   // time that any part of the heap was examined by a garbage collection.
duke@435:   virtual jlong millis_since_last_gc() = 0;
duke@435: 
duke@435:   // Perform any cleanup actions necessary before allowing a verification.
duke@435:   virtual void prepare_for_verify() = 0;
duke@435: 
ysr@1050:   // Generate any dumps preceding or following a full gc
sla@5237:   void pre_full_gc_dump(GCTimer* timer);
sla@5237:   void post_full_gc_dump(GCTimer* timer);
sla@5237: 
sla@5237:   VirtualSpaceSummary create_heap_space_summary();
sla@5237:   GCHeapSummary create_heap_summary();
sla@5237: 
sla@5237:   MetaspaceSummary create_metaspace_summary();
ysr@1050: 
tonyp@3269:   // Print heap information on the given outputStream.
duke@435:   virtual void print_on(outputStream* st) const = 0;
tonyp@3269:   // The default behavior is to call print_on() on tty.
tonyp@3269:   virtual void print() const {
tonyp@3269:     print_on(tty);
tonyp@3269:   }
tonyp@3269:   // Print more detailed heap information on the given
sla@5237:   // outputStream. The default behavior is to call print_on(). It is
tonyp@3269:   // up to each subclass to override it and add any additional output
tonyp@3269:   // it needs.
tonyp@3269:   virtual void print_extended_on(outputStream* st) const {
tonyp@3269:     print_on(st);
tonyp@3269:   }
duke@435: 
stefank@4904:   virtual void print_on_error(outputStream* st) const {
stefank@4904:     st->print_cr("Heap:");
stefank@4904:     print_extended_on(st);
stefank@4904:     st->cr();
stefank@4904: 
stefank@4904:     _barrier_set->print_on(st);
stefank@4904:   }
stefank@4904: 
duke@435:   // Print all GC threads (other than the VM thread)
duke@435:   // used by this heap.
duke@435:   virtual void print_gc_threads_on(outputStream* st) const = 0;
tonyp@3269:   // The default behavior is to call print_gc_threads_on() on tty.
tonyp@3269:   void print_gc_threads() {
tonyp@3269:     print_gc_threads_on(tty);
tonyp@3269:   }
duke@435:   // Iterator for all GC threads (other than VM thread)
duke@435:   virtual void gc_threads_do(ThreadClosure* tc) const = 0;
duke@435: 
duke@435:   // Print any relevant tracing info that flags imply.
duke@435:   // Default implementation does nothing.
duke@435:   virtual void print_tracing_info() const = 0;
duke@435: 
sla@5237:   void print_heap_before_gc();
sla@5237:   void print_heap_after_gc();
sla@5237: 
johnc@5548:   // Registering and unregistering an nmethod (compiled code) with the heap.
johnc@5548:   // Override with specific mechanism for each specialized heap type.
johnc@5548:   virtual void register_nmethod(nmethod* nm);
johnc@5548:   virtual void unregister_nmethod(nmethod* nm);
johnc@5548: 
sla@5237:   void trace_heap_before_gc(GCTracer* gc_tracer);
sla@5237:   void trace_heap_after_gc(GCTracer* gc_tracer);
never@3499: 
duke@435:   // Heap verification
brutisso@3711:   virtual void verify(bool silent, VerifyOption option) = 0;
duke@435: 
duke@435:   // Non product verification and debugging.
duke@435: #ifndef PRODUCT
duke@435:   // Support for PromotionFailureALot.  Return true if it's time to cause a
duke@435:   // promotion failure.  The no-argument version uses
duke@435:   // this->_promotion_failure_alot_count as the counter.
duke@435:   inline bool promotion_should_fail(volatile size_t* count);
duke@435:   inline bool promotion_should_fail();
duke@435: 
duke@435:   // Reset the PromotionFailureALot counters.  Should be called at the end of a
sla@5237:   // GC in which promotion failure occurred.
duke@435:   inline void reset_promotion_should_fail(volatile size_t* count);
duke@435:   inline void reset_promotion_should_fail();
duke@435: #endif  // #ifndef PRODUCT
duke@435: 
duke@435: #ifdef ASSERT
duke@435:   static int fired_fake_oom() {
duke@435:     return (CIFireOOMAt > 1 && _fire_out_of_memory_count >= CIFireOOMAt);
duke@435:   }
duke@435: #endif
jmasa@2188: 
jmasa@2188:  public:
jmasa@2188:   // This is a convenience method that is used in cases where
jmasa@2188:   // the actual number of GC worker threads is not pertinent but
jmasa@2188:   // only whether there more than 0.  Use of this method helps
jmasa@2188:   // reduce the occurrence of ParallelGCThreads to uses where the
jmasa@2188:   // actual number may be germane.
jmasa@2188:   static bool use_parallel_gc_threads() { return ParallelGCThreads > 0; }
stefank@3335: 
jcoomes@7160:   // Copy the current allocation context statistics for the specified contexts.
jcoomes@7160:   // For each context in contexts, set the corresponding entries in the totals
jcoomes@7160:   // and accuracy arrays to the current values held by the statistics.  Each
jcoomes@7160:   // array should be of length len.
sjohanss@7298:   // Returns true if there are more stats available.
sjohanss@7298:   virtual bool copy_allocation_context_stats(const jint* contexts,
jcoomes@7160:                                              jlong* totals,
jcoomes@7160:                                              jbyte* accuracy,
sjohanss@7298:                                              jint len) {
sjohanss@7298:     return false;
sjohanss@7298:   }
jcoomes@7160: 
stefank@3335:   /////////////// Unit tests ///////////////
stefank@3335: 
stefank@3335:   NOT_PRODUCT(static void test_is_in();)
duke@435: };
duke@435: 
duke@435: // Class to set and reset the GC cause for a CollectedHeap.
duke@435: 
duke@435: class GCCauseSetter : StackObj {
duke@435:   CollectedHeap* _heap;
duke@435:   GCCause::Cause _previous_cause;
duke@435:  public:
duke@435:   GCCauseSetter(CollectedHeap* heap, GCCause::Cause cause) {
duke@435:     assert(SafepointSynchronize::is_at_safepoint(),
duke@435:            "This method manipulates heap state without locking");
duke@435:     _heap = heap;
duke@435:     _previous_cause = _heap->gc_cause();
duke@435:     _heap->set_gc_cause(cause);
duke@435:   }
duke@435: 
duke@435:   ~GCCauseSetter() {
duke@435:     assert(SafepointSynchronize::is_at_safepoint(),
duke@435:           "This method manipulates heap state without locking");
duke@435:     _heap->set_gc_cause(_previous_cause);
duke@435:   }
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP