--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/g1/heapRegion.hpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,738 @@
+/*
+ * Copyright (c) 2001, 2017, 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_G1_HEAPREGION_HPP
+#define SHARE_VM_GC_G1_HEAPREGION_HPP
+
+#include "gc/g1/g1AllocationContext.hpp"
+#include "gc/g1/g1BlockOffsetTable.hpp"
+#include "gc/g1/g1HeapRegionTraceType.hpp"
+#include "gc/g1/heapRegionTracer.hpp"
+#include "gc/g1/heapRegionType.hpp"
+#include "gc/g1/survRateGroup.hpp"
+#include "gc/shared/ageTable.hpp"
+#include "gc/shared/spaceDecorator.hpp"
+#include "utilities/macros.hpp"
+
+// A HeapRegion is the smallest piece of a G1CollectedHeap that
+// can be collected independently.
+
+// NOTE: Although a HeapRegion is a Space, its
+// Space::initDirtyCardClosure method must not be called.
+// The problem is that the existence of this method breaks
+// the independence of barrier sets from remembered sets.
+// The solution is to remove this method from the definition
+// of a Space.
+
+// Each heap region is self contained. top() and end() can never
+// be set beyond the end of the region. For humongous objects,
+// the first region is a StartsHumongous region. If the humongous
+// object is larger than a heap region, the following regions will
+// be of type ContinuesHumongous. In this case the top() of the
+// StartHumongous region and all ContinuesHumongous regions except
+// the last will point to their own end. The last ContinuesHumongous
+// region may have top() equal the end of object if there isn't
+// room for filler objects to pad out to the end of the region.
+
+class G1CollectedHeap;
+class G1CMBitMap;
+class HeapRegionRemSet;
+class HeapRegionRemSetIterator;
+class HeapRegion;
+class HeapRegionSetBase;
+class nmethod;
+
+#define HR_FORMAT "%u:(%s)[" PTR_FORMAT "," PTR_FORMAT "," PTR_FORMAT "]"
+#define HR_FORMAT_PARAMS(_hr_) \
+ (_hr_)->hrm_index(), \
+ (_hr_)->get_short_type_str(), \
+ p2i((_hr_)->bottom()), p2i((_hr_)->top()), p2i((_hr_)->end())
+
+// sentinel value for hrm_index
+#define G1_NO_HRM_INDEX ((uint) -1)
+
+// The complicating factor is that BlockOffsetTable diverged
+// significantly, and we need functionality that is only in the G1 version.
+// So I copied that code, which led to an alternate G1 version of
+// OffsetTableContigSpace. If the two versions of BlockOffsetTable could
+// be reconciled, then G1OffsetTableContigSpace could go away.
+
+// The idea behind time stamps is the following. We want to keep track of
+// the highest address where it's safe to scan objects for each region.
+// This is only relevant for current GC alloc regions so we keep a time stamp
+// per region to determine if the region has been allocated during the current
+// GC or not. If the time stamp is current we report a scan_top value which
+// was saved at the end of the previous GC for retained alloc regions and which is
+// equal to the bottom for all other regions.
+// There is a race between card scanners and allocating gc workers where we must ensure
+// that card scanners do not read the memory allocated by the gc workers.
+// In order to enforce that, we must not return a value of _top which is more recent than the
+// time stamp. This is due to the fact that a region may become a gc alloc region at
+// some point after we've read the timestamp value as being < the current time stamp.
+// The time stamps are re-initialized to zero at cleanup and at Full GCs.
+// The current scheme that uses sequential unsigned ints will fail only if we have 4b
+// evacuation pauses between two cleanups, which is _highly_ unlikely.
+class G1ContiguousSpace: public CompactibleSpace {
+ friend class VMStructs;
+ HeapWord* volatile _top;
+ protected:
+ G1BlockOffsetTablePart _bot_part;
+ Mutex _par_alloc_lock;
+ volatile uint _gc_time_stamp;
+ // When we need to retire an allocation region, while other threads
+ // are also concurrently trying to allocate into it, we typically
+ // allocate a dummy object at the end of the region to ensure that
+ // no more allocations can take place in it. However, sometimes we
+ // want to know where the end of the last "real" object we allocated
+ // into the region was and this is what this keeps track.
+ HeapWord* _pre_dummy_top;
+
+ public:
+ G1ContiguousSpace(G1BlockOffsetTable* bot);
+
+ void set_top(HeapWord* value) { _top = value; }
+ HeapWord* top() const { return _top; }
+
+ protected:
+ // Reset the G1ContiguousSpace.
+ virtual void initialize(MemRegion mr, bool clear_space, bool mangle_space);
+
+ HeapWord* volatile* top_addr() { return &_top; }
+ // Try to allocate at least min_word_size and up to desired_size from this Space.
+ // Returns NULL if not possible, otherwise sets actual_word_size to the amount of
+ // space allocated.
+ // This version assumes that all allocation requests to this Space are properly
+ // synchronized.
+ inline HeapWord* allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size);
+ // Try to allocate at least min_word_size and up to desired_size from this Space.
+ // Returns NULL if not possible, otherwise sets actual_word_size to the amount of
+ // space allocated.
+ // This version synchronizes with other calls to par_allocate_impl().
+ inline HeapWord* par_allocate_impl(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size);
+
+ public:
+ void reset_after_compaction() { set_top(compaction_top()); }
+
+ size_t used() const { return byte_size(bottom(), top()); }
+ size_t free() const { return byte_size(top(), end()); }
+ bool is_free_block(const HeapWord* p) const { return p >= top(); }
+
+ MemRegion used_region() const { return MemRegion(bottom(), top()); }
+
+ void object_iterate(ObjectClosure* blk);
+ void safe_object_iterate(ObjectClosure* blk);
+
+ void mangle_unused_area() PRODUCT_RETURN;
+ void mangle_unused_area_complete() PRODUCT_RETURN;
+
+ void record_timestamp();
+ void reset_gc_time_stamp() { _gc_time_stamp = 0; }
+ uint get_gc_time_stamp() { return _gc_time_stamp; }
+
+ // See the comment above in the declaration of _pre_dummy_top for an
+ // explanation of what it is.
+ void set_pre_dummy_top(HeapWord* pre_dummy_top) {
+ assert(is_in(pre_dummy_top) && pre_dummy_top <= top(), "pre-condition");
+ _pre_dummy_top = pre_dummy_top;
+ }
+ HeapWord* pre_dummy_top() {
+ return (_pre_dummy_top == NULL) ? top() : _pre_dummy_top;
+ }
+ void reset_pre_dummy_top() { _pre_dummy_top = NULL; }
+
+ virtual void clear(bool mangle_space);
+
+ HeapWord* block_start(const void* p);
+ HeapWord* block_start_const(const void* p) const;
+
+ // Allocation (return NULL if full). Assumes the caller has established
+ // mutually exclusive access to the space.
+ HeapWord* allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size);
+ // Allocation (return NULL if full). Enforces mutual exclusion internally.
+ HeapWord* par_allocate(size_t min_word_size, size_t desired_word_size, size_t* actual_word_size);
+
+ virtual HeapWord* allocate(size_t word_size);
+ virtual HeapWord* par_allocate(size_t word_size);
+
+ HeapWord* saved_mark_word() const { ShouldNotReachHere(); return NULL; }
+
+ // MarkSweep support phase3
+ virtual HeapWord* initialize_threshold();
+ virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end);
+
+ virtual void print() const;
+
+ void reset_bot() {
+ _bot_part.reset_bot();
+ }
+
+ void print_bot_on(outputStream* out) {
+ _bot_part.print_on(out);
+ }
+};
+
+class HeapRegion: public G1ContiguousSpace {
+ friend class VMStructs;
+ // Allow scan_and_forward to call (private) overrides for auxiliary functions on this class
+ template <typename SpaceType>
+ friend void CompactibleSpace::scan_and_forward(SpaceType* space, CompactPoint* cp);
+ private:
+
+ // The remembered set for this region.
+ // (Might want to make this "inline" later, to avoid some alloc failure
+ // issues.)
+ HeapRegionRemSet* _rem_set;
+
+ // Auxiliary functions for scan_and_forward support.
+ // See comments for CompactibleSpace for more information.
+ inline HeapWord* scan_limit() const {
+ return top();
+ }
+
+ inline bool scanned_block_is_obj(const HeapWord* addr) const {
+ return true; // Always true, since scan_limit is top
+ }
+
+ inline size_t scanned_block_size(const HeapWord* addr) const {
+ return HeapRegion::block_size(addr); // Avoid virtual call
+ }
+
+ void report_region_type_change(G1HeapRegionTraceType::Type to);
+
+ // Returns whether the given object address refers to a dead object, and either the
+ // size of the object (if live) or the size of the block (if dead) in size.
+ // May
+ // - only called with obj < top()
+ // - not called on humongous objects or archive regions
+ inline bool is_obj_dead_with_size(const oop obj, const G1CMBitMap* const prev_bitmap, size_t* size) const;
+
+ protected:
+ // The index of this region in the heap region sequence.
+ uint _hrm_index;
+
+ AllocationContext_t _allocation_context;
+
+ HeapRegionType _type;
+
+ // For a humongous region, region in which it starts.
+ HeapRegion* _humongous_start_region;
+
+ // True iff an attempt to evacuate an object in the region failed.
+ bool _evacuation_failed;
+
+ // Fields used by the HeapRegionSetBase class and subclasses.
+ HeapRegion* _next;
+ HeapRegion* _prev;
+#ifdef ASSERT
+ HeapRegionSetBase* _containing_set;
+#endif // ASSERT
+
+ // We use concurrent marking to determine the amount of live data
+ // in each heap region.
+ size_t _prev_marked_bytes; // Bytes known to be live via last completed marking.
+ size_t _next_marked_bytes; // Bytes known to be live via in-progress marking.
+
+ // The calculated GC efficiency of the region.
+ double _gc_efficiency;
+
+ int _young_index_in_cset;
+ SurvRateGroup* _surv_rate_group;
+ int _age_index;
+
+ // The start of the unmarked area. The unmarked area extends from this
+ // word until the top and/or end of the region, and is the part
+ // of the region for which no marking was done, i.e. objects may
+ // have been allocated in this part since the last mark phase.
+ // "prev" is the top at the start of the last completed marking.
+ // "next" is the top at the start of the in-progress marking (if any.)
+ HeapWord* _prev_top_at_mark_start;
+ HeapWord* _next_top_at_mark_start;
+ // If a collection pause is in progress, this is the top at the start
+ // of that pause.
+
+ void init_top_at_mark_start() {
+ assert(_prev_marked_bytes == 0 &&
+ _next_marked_bytes == 0,
+ "Must be called after zero_marked_bytes.");
+ HeapWord* bot = bottom();
+ _prev_top_at_mark_start = bot;
+ _next_top_at_mark_start = bot;
+ }
+
+ // Cached attributes used in the collection set policy information
+
+ // The RSet length that was added to the total value
+ // for the collection set.
+ size_t _recorded_rs_length;
+
+ // The predicted elapsed time that was added to total value
+ // for the collection set.
+ double _predicted_elapsed_time_ms;
+
+ // Iterate over the references in a humongous objects and apply the given closure
+ // to them.
+ // Humongous objects are allocated directly in the old-gen. So we need special
+ // handling for concurrent processing encountering an in-progress allocation.
+ template <class Closure, bool is_gc_active>
+ inline bool do_oops_on_card_in_humongous(MemRegion mr,
+ Closure* cl,
+ G1CollectedHeap* g1h);
+
+ // Returns the block size of the given (dead, potentially having its class unloaded) object
+ // starting at p extending to at most the prev TAMS using the given mark bitmap.
+ inline size_t block_size_using_bitmap(const HeapWord* p, const G1CMBitMap* const prev_bitmap) const;
+ public:
+ HeapRegion(uint hrm_index,
+ G1BlockOffsetTable* bot,
+ MemRegion mr);
+
+ // Initializing the HeapRegion not only resets the data structure, but also
+ // resets the BOT for that heap region.
+ // The default values for clear_space means that we will do the clearing if
+ // there's clearing to be done ourselves. We also always mangle the space.
+ virtual void initialize(MemRegion mr, bool clear_space = false, bool mangle_space = SpaceDecorator::Mangle);
+
+ static int LogOfHRGrainBytes;
+ static int LogOfHRGrainWords;
+
+ static size_t GrainBytes;
+ static size_t GrainWords;
+ static size_t CardsPerRegion;
+
+ static size_t align_up_to_region_byte_size(size_t sz) {
+ return (sz + (size_t) GrainBytes - 1) &
+ ~((1 << (size_t) LogOfHRGrainBytes) - 1);
+ }
+
+
+ // Returns whether a field is in the same region as the obj it points to.
+ template <typename T>
+ static bool is_in_same_region(T* p, oop obj) {
+ assert(p != NULL, "p can't be NULL");
+ assert(obj != NULL, "obj can't be NULL");
+ return (((uintptr_t) p ^ cast_from_oop<uintptr_t>(obj)) >> LogOfHRGrainBytes) == 0;
+ }
+
+ static size_t max_region_size();
+ static size_t min_region_size_in_words();
+
+ // It sets up the heap region size (GrainBytes / GrainWords), as
+ // well as other related fields that are based on the heap region
+ // size (LogOfHRGrainBytes / LogOfHRGrainWords /
+ // CardsPerRegion). All those fields are considered constant
+ // throughout the JVM's execution, therefore they should only be set
+ // up once during initialization time.
+ static void setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size);
+
+ // All allocated blocks are occupied by objects in a HeapRegion
+ bool block_is_obj(const HeapWord* p) const;
+
+ // Returns whether the given object is dead based on TAMS and bitmap.
+ bool is_obj_dead(const oop obj, const G1CMBitMap* const prev_bitmap) const;
+
+ // Returns the object size for all valid block starts
+ // and the amount of unallocated words if called on top()
+ size_t block_size(const HeapWord* p) const;
+
+ // Override for scan_and_forward support.
+ void prepare_for_compaction(CompactPoint* cp);
+
+ inline HeapWord* par_allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* word_size);
+ inline HeapWord* allocate_no_bot_updates(size_t word_size);
+ inline HeapWord* allocate_no_bot_updates(size_t min_word_size, size_t desired_word_size, size_t* actual_size);
+
+ // If this region is a member of a HeapRegionManager, the index in that
+ // sequence, otherwise -1.
+ uint hrm_index() const { return _hrm_index; }
+
+ // The number of bytes marked live in the region in the last marking phase.
+ size_t marked_bytes() { return _prev_marked_bytes; }
+ size_t live_bytes() {
+ return (top() - prev_top_at_mark_start()) * HeapWordSize + marked_bytes();
+ }
+
+ // The number of bytes counted in the next marking.
+ size_t next_marked_bytes() { return _next_marked_bytes; }
+ // The number of bytes live wrt the next marking.
+ size_t next_live_bytes() {
+ return
+ (top() - next_top_at_mark_start()) * HeapWordSize + next_marked_bytes();
+ }
+
+ // A lower bound on the amount of garbage bytes in the region.
+ size_t garbage_bytes() {
+ size_t used_at_mark_start_bytes =
+ (prev_top_at_mark_start() - bottom()) * HeapWordSize;
+ return used_at_mark_start_bytes - marked_bytes();
+ }
+
+ // Return the amount of bytes we'll reclaim if we collect this
+ // region. This includes not only the known garbage bytes in the
+ // region but also any unallocated space in it, i.e., [top, end),
+ // since it will also be reclaimed if we collect the region.
+ size_t reclaimable_bytes() {
+ size_t known_live_bytes = live_bytes();
+ assert(known_live_bytes <= capacity(), "sanity");
+ return capacity() - known_live_bytes;
+ }
+
+ // An upper bound on the number of live bytes in the region.
+ size_t max_live_bytes() { return used() - garbage_bytes(); }
+
+ void add_to_marked_bytes(size_t incr_bytes) {
+ _next_marked_bytes = _next_marked_bytes + incr_bytes;
+ }
+
+ void zero_marked_bytes() {
+ _prev_marked_bytes = _next_marked_bytes = 0;
+ }
+
+ const char* get_type_str() const { return _type.get_str(); }
+ const char* get_short_type_str() const { return _type.get_short_str(); }
+ G1HeapRegionTraceType::Type get_trace_type() { return _type.get_trace_type(); }
+
+ bool is_free() const { return _type.is_free(); }
+
+ bool is_young() const { return _type.is_young(); }
+ bool is_eden() const { return _type.is_eden(); }
+ bool is_survivor() const { return _type.is_survivor(); }
+
+ bool is_humongous() const { return _type.is_humongous(); }
+ bool is_starts_humongous() const { return _type.is_starts_humongous(); }
+ bool is_continues_humongous() const { return _type.is_continues_humongous(); }
+
+ bool is_old() const { return _type.is_old(); }
+
+ bool is_old_or_humongous() const { return _type.is_old_or_humongous(); }
+
+ // A pinned region contains objects which are not moved by garbage collections.
+ // Humongous regions and archive regions are pinned.
+ bool is_pinned() const { return _type.is_pinned(); }
+
+ // An archive region is a pinned region, also tagged as old, which
+ // should not be marked during mark/sweep. This allows the address
+ // space to be shared by JVM instances.
+ bool is_archive() const { return _type.is_archive(); }
+ bool is_open_archive() const { return _type.is_open_archive(); }
+ bool is_closed_archive() const { return _type.is_closed_archive(); }
+
+ // For a humongous region, region in which it starts.
+ HeapRegion* humongous_start_region() const {
+ return _humongous_start_region;
+ }
+
+ // Makes the current region be a "starts humongous" region, i.e.,
+ // the first region in a series of one or more contiguous regions
+ // that will contain a single "humongous" object.
+ //
+ // obj_top : points to the top of the humongous object.
+ // fill_size : size of the filler object at the end of the region series.
+ void set_starts_humongous(HeapWord* obj_top, size_t fill_size);
+
+ // Makes the current region be a "continues humongous'
+ // region. first_hr is the "start humongous" region of the series
+ // which this region will be part of.
+ void set_continues_humongous(HeapRegion* first_hr);
+
+ // Unsets the humongous-related fields on the region.
+ void clear_humongous();
+
+ // If the region has a remembered set, return a pointer to it.
+ HeapRegionRemSet* rem_set() const {
+ return _rem_set;
+ }
+
+ inline bool in_collection_set() const;
+
+ void set_allocation_context(AllocationContext_t context) {
+ _allocation_context = context;
+ }
+
+ AllocationContext_t allocation_context() const {
+ return _allocation_context;
+ }
+
+ // Methods used by the HeapRegionSetBase class and subclasses.
+
+ // Getter and setter for the next and prev fields used to link regions into
+ // linked lists.
+ HeapRegion* next() { return _next; }
+ HeapRegion* prev() { return _prev; }
+
+ void set_next(HeapRegion* next) { _next = next; }
+ void set_prev(HeapRegion* prev) { _prev = prev; }
+
+ // Every region added to a set is tagged with a reference to that
+ // set. This is used for doing consistency checking to make sure that
+ // the contents of a set are as they should be and it's only
+ // available in non-product builds.
+#ifdef ASSERT
+ void set_containing_set(HeapRegionSetBase* containing_set) {
+ assert((containing_set == NULL && _containing_set != NULL) ||
+ (containing_set != NULL && _containing_set == NULL),
+ "containing_set: " PTR_FORMAT " "
+ "_containing_set: " PTR_FORMAT,
+ p2i(containing_set), p2i(_containing_set));
+
+ _containing_set = containing_set;
+ }
+
+ HeapRegionSetBase* containing_set() { return _containing_set; }
+#else // ASSERT
+ void set_containing_set(HeapRegionSetBase* containing_set) { }
+
+ // containing_set() is only used in asserts so there's no reason
+ // to provide a dummy version of it.
+#endif // ASSERT
+
+
+ // Reset the HeapRegion to default values.
+ // If skip_remset is true, do not clear the remembered set.
+ void hr_clear(bool skip_remset, bool clear_space, bool locked = false);
+ // Clear the parts skipped by skip_remset in hr_clear() in the HeapRegion during
+ // a concurrent phase.
+ void par_clear();
+
+ // Get the start of the unmarked area in this region.
+ HeapWord* prev_top_at_mark_start() const { return _prev_top_at_mark_start; }
+ HeapWord* next_top_at_mark_start() const { return _next_top_at_mark_start; }
+
+ // Note the start or end of marking. This tells the heap region
+ // that the collector is about to start or has finished (concurrently)
+ // marking the heap.
+
+ // Notify the region that concurrent marking is starting. Initialize
+ // all fields related to the next marking info.
+ inline void note_start_of_marking();
+
+ // Notify the region that concurrent marking has finished. Copy the
+ // (now finalized) next marking info fields into the prev marking
+ // info fields.
+ inline void note_end_of_marking();
+
+ // Notify the region that it will be used as to-space during a GC
+ // and we are about to start copying objects into it.
+ inline void note_start_of_copying(bool during_initial_mark);
+
+ // Notify the region that it ceases being to-space during a GC and
+ // we will not copy objects into it any more.
+ inline void note_end_of_copying(bool during_initial_mark);
+
+ // Notify the region that we are about to start processing
+ // self-forwarded objects during evac failure handling.
+ void note_self_forwarding_removal_start(bool during_initial_mark,
+ bool during_conc_mark);
+
+ // Notify the region that we have finished processing self-forwarded
+ // objects during evac failure handling.
+ void note_self_forwarding_removal_end(size_t marked_bytes);
+
+ // Returns "false" iff no object in the region was allocated when the
+ // last mark phase ended.
+ bool is_marked() { return _prev_top_at_mark_start != bottom(); }
+
+ void reset_during_compaction() {
+ assert(is_humongous(),
+ "should only be called for humongous regions");
+
+ zero_marked_bytes();
+ init_top_at_mark_start();
+ }
+
+ void calc_gc_efficiency(void);
+ double gc_efficiency() { return _gc_efficiency;}
+
+ int young_index_in_cset() const { return _young_index_in_cset; }
+ void set_young_index_in_cset(int index) {
+ assert( (index == -1) || is_young(), "pre-condition" );
+ _young_index_in_cset = index;
+ }
+
+ int age_in_surv_rate_group() {
+ assert( _surv_rate_group != NULL, "pre-condition" );
+ assert( _age_index > -1, "pre-condition" );
+ return _surv_rate_group->age_in_group(_age_index);
+ }
+
+ void record_surv_words_in_group(size_t words_survived) {
+ assert( _surv_rate_group != NULL, "pre-condition" );
+ assert( _age_index > -1, "pre-condition" );
+ int age_in_group = age_in_surv_rate_group();
+ _surv_rate_group->record_surviving_words(age_in_group, words_survived);
+ }
+
+ int age_in_surv_rate_group_cond() {
+ if (_surv_rate_group != NULL)
+ return age_in_surv_rate_group();
+ else
+ return -1;
+ }
+
+ SurvRateGroup* surv_rate_group() {
+ return _surv_rate_group;
+ }
+
+ void install_surv_rate_group(SurvRateGroup* surv_rate_group) {
+ assert( surv_rate_group != NULL, "pre-condition" );
+ assert( _surv_rate_group == NULL, "pre-condition" );
+ assert( is_young(), "pre-condition" );
+
+ _surv_rate_group = surv_rate_group;
+ _age_index = surv_rate_group->next_age_index();
+ }
+
+ void uninstall_surv_rate_group() {
+ if (_surv_rate_group != NULL) {
+ assert( _age_index > -1, "pre-condition" );
+ assert( is_young(), "pre-condition" );
+
+ _surv_rate_group = NULL;
+ _age_index = -1;
+ } else {
+ assert( _age_index == -1, "pre-condition" );
+ }
+ }
+
+ void set_free();
+
+ void set_eden();
+ void set_eden_pre_gc();
+ void set_survivor();
+
+ void move_to_old();
+ void set_old();
+
+ void set_open_archive();
+ void set_closed_archive();
+
+ // Determine if an object has been allocated since the last
+ // mark performed by the collector. This returns true iff the object
+ // is within the unmarked area of the region.
+ bool obj_allocated_since_prev_marking(oop obj) const {
+ return (HeapWord *) obj >= prev_top_at_mark_start();
+ }
+ bool obj_allocated_since_next_marking(oop obj) const {
+ return (HeapWord *) obj >= next_top_at_mark_start();
+ }
+
+ // Returns the "evacuation_failed" property of the region.
+ bool evacuation_failed() { return _evacuation_failed; }
+
+ // Sets the "evacuation_failed" property of the region.
+ void set_evacuation_failed(bool b) {
+ _evacuation_failed = b;
+
+ if (b) {
+ _next_marked_bytes = 0;
+ }
+ }
+
+ // Iterate over the objects overlapping part of a card, applying cl
+ // to all references in the region. This is a helper for
+ // G1RemSet::refine_card*, and is tightly coupled with them.
+ // mr is the memory region covered by the card, trimmed to the
+ // allocated space for this region. Must not be empty.
+ // This region must be old or humongous.
+ // Returns true if the designated objects were successfully
+ // processed, false if an unparsable part of the heap was
+ // encountered; that only happens when invoked concurrently with the
+ // mutator.
+ template <bool is_gc_active, class Closure>
+ inline bool oops_on_card_seq_iterate_careful(MemRegion mr, Closure* cl);
+
+ size_t recorded_rs_length() const { return _recorded_rs_length; }
+ double predicted_elapsed_time_ms() const { return _predicted_elapsed_time_ms; }
+
+ void set_recorded_rs_length(size_t rs_length) {
+ _recorded_rs_length = rs_length;
+ }
+
+ void set_predicted_elapsed_time_ms(double ms) {
+ _predicted_elapsed_time_ms = ms;
+ }
+
+ virtual CompactibleSpace* next_compaction_space() const;
+
+ virtual void reset_after_compaction();
+
+ // Routines for managing a list of code roots (attached to the
+ // this region's RSet) that point into this heap region.
+ void add_strong_code_root(nmethod* nm);
+ void add_strong_code_root_locked(nmethod* nm);
+ void remove_strong_code_root(nmethod* nm);
+
+ // Applies blk->do_code_blob() to each of the entries in
+ // the strong code roots list for this region
+ void strong_code_roots_do(CodeBlobClosure* blk) const;
+
+ // Verify that the entries on the strong code root list for this
+ // region are live and include at least one pointer into this region.
+ void verify_strong_code_roots(VerifyOption vo, bool* failures) const;
+
+ void print() const;
+ void print_on(outputStream* st) const;
+
+ // vo == UsePrevMarking -> use "prev" marking information,
+ // vo == UseNextMarking -> use "next" marking information
+ // vo == UseMarkWord -> use the mark word in the object header
+ //
+ // NOTE: Only the "prev" marking information is guaranteed to be
+ // consistent most of the time, so most calls to this should use
+ // vo == UsePrevMarking.
+ // Currently, there is only one case where this is called with
+ // vo == UseNextMarking, which is to verify the "next" marking
+ // information at the end of remark.
+ // Currently there is only one place where this is called with
+ // vo == UseMarkWord, which is to verify the marking during a
+ // full GC.
+ void verify(VerifyOption vo, bool *failures) const;
+
+ // Override; it uses the "prev" marking information
+ virtual void verify() const;
+
+ void verify_rem_set(VerifyOption vo, bool *failures) const;
+ void verify_rem_set() const;
+};
+
+// HeapRegionClosure is used for iterating over regions.
+// Terminates the iteration when the "doHeapRegion" method returns "true".
+class HeapRegionClosure : public StackObj {
+ friend class HeapRegionManager;
+ friend class G1CollectionSet;
+
+ bool _complete;
+ void incomplete() { _complete = false; }
+
+ public:
+ HeapRegionClosure(): _complete(true) {}
+
+ // Typically called on each region until it returns true.
+ virtual bool doHeapRegion(HeapRegion* r) = 0;
+
+ // True after iteration if the closure was applied to all heap regions
+ // and returned "false" in all cases.
+ bool complete() { return _complete; }
+};
+
+#endif // SHARE_VM_GC_G1_HEAPREGION_HPP