--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shenandoah/shenandoahHeap.hpp Mon Dec 10 15:47:44 2018 +0100
@@ -0,0 +1,757 @@
+/*
+ * Copyright (c) 2013, 2018, Red Hat, Inc. All rights reserved.
+ *
+ * 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_SHENANDOAH_SHENANDOAHHEAP_HPP
+#define SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP
+
+#include "gc/shared/markBitMap.hpp"
+#include "gc/shared/softRefPolicy.hpp"
+#include "gc/shared/collectedHeap.hpp"
+#include "gc/shenandoah/shenandoahAsserts.hpp"
+#include "gc/shenandoah/shenandoahAllocRequest.hpp"
+#include "gc/shenandoah/shenandoahHeapLock.hpp"
+#include "gc/shenandoah/shenandoahEvacOOMHandler.hpp"
+#include "gc/shenandoah/shenandoahSharedVariables.hpp"
+#include "services/memoryManager.hpp"
+
+class ConcurrentGCTimer;
+class ReferenceProcessor;
+class ShenandoahAllocTracker;
+class ShenandoahCollectorPolicy;
+class ShenandoahControlThread;
+class ShenandoahGCSession;
+class ShenandoahHeuristics;
+class ShenandoahMarkingContext;
+class ShenandoahPhaseTimings;
+class ShenandoahHeap;
+class ShenandoahHeapRegion;
+class ShenandoahHeapRegionClosure;
+class ShenandoahCollectionSet;
+class ShenandoahFreeSet;
+class ShenandoahConcurrentMark;
+class ShenandoahMarkCompact;
+class ShenandoahMonitoringSupport;
+class ShenandoahPacer;
+class ShenandoahTraversalGC;
+class ShenandoahVerifier;
+class ShenandoahWorkGang;
+class VMStructs;
+
+class ShenandoahRegionIterator : public StackObj {
+private:
+ ShenandoahHeap* _heap;
+
+ DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
+ volatile size_t _index;
+ DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
+
+ // No implicit copying: iterators should be passed by reference to capture the state
+ ShenandoahRegionIterator(const ShenandoahRegionIterator& that);
+ ShenandoahRegionIterator& operator=(const ShenandoahRegionIterator& o);
+
+public:
+ ShenandoahRegionIterator();
+ ShenandoahRegionIterator(ShenandoahHeap* heap);
+
+ // Reset iterator to default state
+ void reset();
+
+ // Returns next region, or NULL if there are no more regions.
+ // This is multi-thread-safe.
+ inline ShenandoahHeapRegion* next();
+
+ // This is *not* MT safe. However, in the absence of multithreaded access, it
+ // can be used to determine if there is more work to do.
+ bool has_next() const;
+};
+
+class ShenandoahHeapRegionClosure : public StackObj {
+public:
+ virtual void heap_region_do(ShenandoahHeapRegion* r) = 0;
+ virtual bool is_thread_safe() { return false; }
+};
+
+class ShenandoahUpdateRefsClosure: public OopClosure {
+private:
+ ShenandoahHeap* _heap;
+
+ template <class T>
+ inline void do_oop_work(T* p);
+
+public:
+ ShenandoahUpdateRefsClosure();
+ inline void do_oop(oop* p);
+ inline void do_oop(narrowOop* p);
+};
+
+#ifdef ASSERT
+class ShenandoahAssertToSpaceClosure : public OopClosure {
+private:
+ template <class T>
+ void do_oop_work(T* p);
+public:
+ void do_oop(narrowOop* p);
+ void do_oop(oop* p);
+};
+#endif
+
+class ShenandoahAlwaysTrueClosure : public BoolObjectClosure {
+public:
+ bool do_object_b(oop p) { return true; }
+};
+
+class ShenandoahForwardedIsAliveClosure: public BoolObjectClosure {
+private:
+ ShenandoahMarkingContext* const _mark_context;
+public:
+ ShenandoahForwardedIsAliveClosure();
+ bool do_object_b(oop obj);
+};
+
+class ShenandoahIsAliveClosure: public BoolObjectClosure {
+private:
+ ShenandoahMarkingContext* const _mark_context;
+public:
+ ShenandoahIsAliveClosure();
+ bool do_object_b(oop obj);
+};
+
+class ShenandoahIsAliveSelector : public StackObj {
+private:
+ ShenandoahIsAliveClosure _alive_cl;
+ ShenandoahForwardedIsAliveClosure _fwd_alive_cl;
+public:
+ BoolObjectClosure* is_alive_closure();
+};
+
+// Shenandoah GC is low-pause concurrent GC that uses Brooks forwarding pointers
+// to encode forwarding data. See BrooksPointer for details on forwarding data encoding.
+// See ShenandoahControlThread for GC cycle structure.
+//
+class ShenandoahHeap : public CollectedHeap {
+ friend class ShenandoahAsserts;
+ friend class VMStructs;
+ friend class ShenandoahGCSession;
+
+// ---------- Locks that guard important data structures in Heap
+//
+private:
+ ShenandoahHeapLock _lock;
+
+public:
+ ShenandoahHeapLock* lock() {
+ return &_lock;
+ }
+
+ void assert_heaplock_owned_by_current_thread() PRODUCT_RETURN;
+ void assert_heaplock_not_owned_by_current_thread() PRODUCT_RETURN;
+ void assert_heaplock_or_safepoint() PRODUCT_RETURN;
+
+// ---------- Initialization, termination, identification, printing routines
+//
+public:
+ static ShenandoahHeap* heap();
+ static ShenandoahHeap* heap_no_check();
+
+ const char* name() const { return "Shenandoah"; }
+ ShenandoahHeap::Name kind() const { return CollectedHeap::Shenandoah; }
+
+ ShenandoahHeap(ShenandoahCollectorPolicy* policy);
+ jint initialize();
+ void post_initialize();
+ void initialize_heuristics();
+
+ void initialize_serviceability();
+
+ void print_on(outputStream* st) const;
+ void print_extended_on(outputStream *st) const;
+ void print_tracing_info() const;
+ void print_gc_threads_on(outputStream* st) const;
+ void print_heap_regions_on(outputStream* st) const;
+
+ void stop();
+
+ void prepare_for_verify();
+ void verify(VerifyOption vo);
+
+// ---------- Heap counters and metrics
+//
+private:
+ size_t _initial_size;
+ DEFINE_PAD_MINUS_SIZE(0, DEFAULT_CACHE_LINE_SIZE, sizeof(volatile size_t));
+ volatile size_t _used;
+ volatile size_t _committed;
+ volatile size_t _bytes_allocated_since_gc_start;
+ DEFINE_PAD_MINUS_SIZE(1, DEFAULT_CACHE_LINE_SIZE, 0);
+
+public:
+ void increase_used(size_t bytes);
+ void decrease_used(size_t bytes);
+ void set_used(size_t bytes);
+
+ void increase_committed(size_t bytes);
+ void decrease_committed(size_t bytes);
+ void increase_allocated(size_t bytes);
+
+ size_t bytes_allocated_since_gc_start();
+ void reset_bytes_allocated_since_gc_start();
+
+ size_t max_capacity() const;
+ size_t initial_capacity() const;
+ size_t capacity() const;
+ size_t used() const;
+ size_t committed() const;
+
+// ---------- Workers handling
+//
+private:
+ uint _max_workers;
+ ShenandoahWorkGang* _workers;
+ ShenandoahWorkGang* _safepoint_workers;
+
+public:
+ uint max_workers();
+ void assert_gc_workers(uint nworker) PRODUCT_RETURN;
+
+ WorkGang* workers() const;
+ WorkGang* get_safepoint_workers();
+
+ void gc_threads_do(ThreadClosure* tcl) const;
+
+// ---------- Heap regions handling machinery
+//
+private:
+ MemRegion _heap_region;
+ size_t _num_regions;
+ ShenandoahHeapRegion** _regions;
+ ShenandoahRegionIterator _update_refs_iterator;
+
+public:
+ inline size_t num_regions() const { return _num_regions; }
+
+ inline ShenandoahHeapRegion* const heap_region_containing(const void* addr) const;
+ inline size_t heap_region_index_containing(const void* addr) const;
+
+ inline ShenandoahHeapRegion* const get_region(size_t region_idx) const;
+
+ void heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
+ void parallel_heap_region_iterate(ShenandoahHeapRegionClosure* blk) const;
+
+// ---------- GC state machinery
+//
+// GC state describes the important parts of collector state, that may be
+// used to make barrier selection decisions in the native and generated code.
+// Multiple bits can be set at once.
+//
+// Important invariant: when GC state is zero, the heap is stable, and no barriers
+// are required.
+//
+public:
+ enum GCStateBitPos {
+ // Heap has forwarded objects: need RB, ACMP, CAS barriers.
+ HAS_FORWARDED_BITPOS = 0,
+
+ // Heap is under marking: needs SATB barriers.
+ MARKING_BITPOS = 1,
+
+ // Heap is under evacuation: needs WB barriers. (Set together with UNSTABLE)
+ EVACUATION_BITPOS = 2,
+
+ // Heap is under updating: needs SVRB/SVWB barriers.
+ UPDATEREFS_BITPOS = 3,
+
+ // Heap is under traversal collection
+ TRAVERSAL_BITPOS = 4,
+ };
+
+ enum GCState {
+ STABLE = 0,
+ HAS_FORWARDED = 1 << HAS_FORWARDED_BITPOS,
+ MARKING = 1 << MARKING_BITPOS,
+ EVACUATION = 1 << EVACUATION_BITPOS,
+ UPDATEREFS = 1 << UPDATEREFS_BITPOS,
+ TRAVERSAL = 1 << TRAVERSAL_BITPOS,
+ };
+
+private:
+ ShenandoahSharedBitmap _gc_state;
+ ShenandoahSharedFlag _degenerated_gc_in_progress;
+ ShenandoahSharedFlag _full_gc_in_progress;
+ ShenandoahSharedFlag _full_gc_move_in_progress;
+ ShenandoahSharedFlag _progress_last_gc;
+
+ void set_gc_state_all_threads(char state);
+ void set_gc_state_mask(uint mask, bool value);
+
+public:
+ char gc_state() const;
+ static address gc_state_addr();
+
+ void set_concurrent_mark_in_progress(bool in_progress);
+ void set_evacuation_in_progress(bool in_progress);
+ void set_update_refs_in_progress(bool in_progress);
+ void set_degenerated_gc_in_progress(bool in_progress);
+ void set_full_gc_in_progress(bool in_progress);
+ void set_full_gc_move_in_progress(bool in_progress);
+ void set_concurrent_traversal_in_progress(bool in_progress);
+ void set_has_forwarded_objects(bool cond);
+
+ inline bool is_stable() const;
+ inline bool is_idle() const;
+ inline bool is_concurrent_mark_in_progress() const;
+ inline bool is_update_refs_in_progress() const;
+ inline bool is_evacuation_in_progress() const;
+ inline bool is_degenerated_gc_in_progress() const;
+ inline bool is_full_gc_in_progress() const;
+ inline bool is_full_gc_move_in_progress() const;
+ inline bool is_concurrent_traversal_in_progress() const;
+ inline bool has_forwarded_objects() const;
+ inline bool is_gc_in_progress_mask(uint mask) const;
+
+// ---------- GC cancellation and degeneration machinery
+//
+// Cancelled GC flag is used to notify concurrent phases that they should terminate.
+//
+public:
+ enum ShenandoahDegenPoint {
+ _degenerated_unset,
+ _degenerated_traversal,
+ _degenerated_outside_cycle,
+ _degenerated_mark,
+ _degenerated_evac,
+ _degenerated_updaterefs,
+ _DEGENERATED_LIMIT,
+ };
+
+ static const char* degen_point_to_string(ShenandoahDegenPoint point) {
+ switch (point) {
+ case _degenerated_unset:
+ return "<UNSET>";
+ case _degenerated_traversal:
+ return "Traversal";
+ case _degenerated_outside_cycle:
+ return "Outside of Cycle";
+ case _degenerated_mark:
+ return "Mark";
+ case _degenerated_evac:
+ return "Evacuation";
+ case _degenerated_updaterefs:
+ return "Update Refs";
+ default:
+ ShouldNotReachHere();
+ return "ERROR";
+ }
+ };
+
+private:
+ enum CancelState {
+ // Normal state. GC has not been cancelled and is open for cancellation.
+ // Worker threads can suspend for safepoint.
+ CANCELLABLE,
+
+ // GC has been cancelled. Worker threads can not suspend for
+ // safepoint but must finish their work as soon as possible.
+ CANCELLED,
+
+ // GC has not been cancelled and must not be cancelled. At least
+ // one worker thread checks for pending safepoint and may suspend
+ // if a safepoint is pending.
+ NOT_CANCELLED
+ };
+
+ ShenandoahSharedEnumFlag<CancelState> _cancelled_gc;
+ inline bool try_cancel_gc();
+
+public:
+ static address cancelled_gc_addr();
+
+ inline bool cancelled_gc() const;
+ inline bool check_cancelled_gc_and_yield(bool sts_active = true);
+
+ inline void clear_cancelled_gc();
+
+ void cancel_gc(GCCause::Cause cause);
+
+// ---------- GC operations entry points
+//
+public:
+ // Entry points to STW GC operations, these cause a related safepoint, that then
+ // call the entry method below
+ void vmop_entry_init_mark();
+ void vmop_entry_final_mark();
+ void vmop_entry_final_evac();
+ void vmop_entry_init_updaterefs();
+ void vmop_entry_final_updaterefs();
+ void vmop_entry_init_traversal();
+ void vmop_entry_final_traversal();
+ void vmop_entry_full(GCCause::Cause cause);
+ void vmop_degenerated(ShenandoahDegenPoint point);
+
+ // Entry methods to normally STW GC operations. These set up logging, monitoring
+ // and workers for net VM operation
+ void entry_init_mark();
+ void entry_final_mark();
+ void entry_final_evac();
+ void entry_init_updaterefs();
+ void entry_final_updaterefs();
+ void entry_init_traversal();
+ void entry_final_traversal();
+ void entry_full(GCCause::Cause cause);
+ void entry_degenerated(int point);
+
+ // Entry methods to normally concurrent GC operations. These set up logging, monitoring
+ // for concurrent operation.
+ void entry_reset();
+ void entry_mark();
+ void entry_preclean();
+ void entry_cleanup();
+ void entry_evac();
+ void entry_updaterefs();
+ void entry_traversal();
+ void entry_uncommit(double shrink_before);
+
+private:
+ // Actual work for the phases
+ void op_init_mark();
+ void op_final_mark();
+ void op_final_evac();
+ void op_init_updaterefs();
+ void op_final_updaterefs();
+ void op_init_traversal();
+ void op_final_traversal();
+ void op_full(GCCause::Cause cause);
+ void op_degenerated(ShenandoahDegenPoint point);
+ void op_degenerated_fail();
+ void op_degenerated_futile();
+
+ void op_reset();
+ void op_mark();
+ void op_preclean();
+ void op_cleanup();
+ void op_conc_evac();
+ void op_stw_evac();
+ void op_updaterefs();
+ void op_traversal();
+ void op_uncommit(double shrink_before);
+
+ // Messages for GC trace events, they have to be immortal for
+ // passing around the logging/tracing systems
+ const char* init_mark_event_message() const;
+ const char* final_mark_event_message() const;
+ const char* conc_mark_event_message() const;
+ const char* degen_event_message(ShenandoahDegenPoint point) const;
+
+// ---------- GC subsystems
+//
+private:
+ ShenandoahControlThread* _control_thread;
+ ShenandoahCollectorPolicy* _shenandoah_policy;
+ ShenandoahHeuristics* _heuristics;
+ ShenandoahFreeSet* _free_set;
+ ShenandoahConcurrentMark* _scm;
+ ShenandoahTraversalGC* _traversal_gc;
+ ShenandoahMarkCompact* _full_gc;
+ ShenandoahPacer* _pacer;
+ ShenandoahVerifier* _verifier;
+
+ ShenandoahAllocTracker* _alloc_tracker;
+ ShenandoahPhaseTimings* _phase_timings;
+
+ ShenandoahControlThread* control_thread() { return _control_thread; }
+ ShenandoahMarkCompact* full_gc() { return _full_gc; }
+
+public:
+ ShenandoahCollectorPolicy* shenandoah_policy() const { return _shenandoah_policy; }
+ ShenandoahHeuristics* heuristics() const { return _heuristics; }
+ ShenandoahFreeSet* free_set() const { return _free_set; }
+ ShenandoahConcurrentMark* concurrent_mark() { return _scm; }
+ ShenandoahTraversalGC* traversal_gc() { return _traversal_gc; }
+ ShenandoahPacer* pacer() const { return _pacer; }
+
+ ShenandoahPhaseTimings* phase_timings() const { return _phase_timings; }
+ ShenandoahAllocTracker* alloc_tracker() const { return _alloc_tracker; }
+
+ ShenandoahVerifier* verifier();
+
+// ---------- VM subsystem bindings
+//
+private:
+ ShenandoahMonitoringSupport* _monitoring_support;
+ MemoryPool* _memory_pool;
+ GCMemoryManager _stw_memory_manager;
+ GCMemoryManager _cycle_memory_manager;
+ ConcurrentGCTimer* _gc_timer;
+ SoftRefPolicy _soft_ref_policy;
+
+public:
+ ShenandoahMonitoringSupport* monitoring_support() { return _monitoring_support; }
+ GCMemoryManager* cycle_memory_manager() { return &_cycle_memory_manager; }
+ GCMemoryManager* stw_memory_manager() { return &_stw_memory_manager; }
+ SoftRefPolicy* soft_ref_policy() { return &_soft_ref_policy; }
+
+ GrowableArray<GCMemoryManager*> memory_managers();
+ GrowableArray<MemoryPool*> memory_pools();
+ GCTracer* tracer();
+ GCTimer* gc_timer() const;
+ CollectorPolicy* collector_policy() const;
+
+// ---------- Reference processing
+//
+private:
+ AlwaysTrueClosure _subject_to_discovery;
+ ReferenceProcessor* _ref_processor;
+ ShenandoahSharedFlag _process_references;
+
+ void ref_processing_init();
+
+public:
+ ReferenceProcessor* ref_processor() { return _ref_processor; }
+ void set_process_references(bool pr);
+ bool process_references() const;
+
+// ---------- Class Unloading
+//
+private:
+ ShenandoahSharedFlag _unload_classes;
+
+public:
+ void set_unload_classes(bool uc);
+ bool unload_classes() const;
+
+ // Delete entries for dead interned string and clean up unreferenced symbols
+ // in symbol table, possibly in parallel.
+ void unload_classes_and_cleanup_tables(bool full_gc);
+
+// ---------- Generic interface hooks
+// Minor things that super-interface expects us to implement to play nice with
+// the rest of runtime. Some of the things here are not required to be implemented,
+// and can be stubbed out.
+//
+public:
+ AdaptiveSizePolicy* size_policy() shenandoah_not_implemented_return(NULL);
+ bool is_maximal_no_gc() const shenandoah_not_implemented_return(false);
+
+ bool is_in(const void* p) const;
+
+ size_t obj_size(oop obj) const;
+ virtual ptrdiff_t cell_header_size() const;
+
+ // All objects can potentially move
+ bool is_scavengable(oop obj) { return true; };
+
+ void collect(GCCause::Cause cause);
+ void do_full_collection(bool clear_all_soft_refs);
+
+ // Used for parsing heap during error printing
+ HeapWord* block_start(const void* addr) const;
+ size_t block_size(const HeapWord* addr) const;
+ bool block_is_obj(const HeapWord* addr) const;
+
+ // Used for native heap walkers: heap dumpers, mostly
+ void object_iterate(ObjectClosure* cl);
+ void safe_object_iterate(ObjectClosure* cl);
+
+ // Used by RMI
+ jlong millis_since_last_gc();
+
+// ---------- Safepoint interface hooks
+//
+public:
+ void safepoint_synchronize_begin();
+ void safepoint_synchronize_end();
+
+// ---------- Code roots handling hooks
+//
+public:
+ void register_nmethod(nmethod* nm);
+ void unregister_nmethod(nmethod* nm);
+
+// ---------- Pinning hooks
+//
+public:
+ // Shenandoah supports per-object (per-region) pinning
+ bool supports_object_pinning() const { return true; }
+
+ oop pin_object(JavaThread* thread, oop obj);
+ void unpin_object(JavaThread* thread, oop obj);
+
+// ---------- Allocation support
+//
+private:
+ HeapWord* allocate_memory_under_lock(ShenandoahAllocRequest& request, bool& in_new_region);
+ inline HeapWord* allocate_from_gclab(Thread* thread, size_t size);
+ HeapWord* allocate_from_gclab_slow(Thread* thread, size_t size);
+ HeapWord* allocate_new_gclab(size_t min_size, size_t word_size, size_t* actual_size);
+ void retire_and_reset_gclabs();
+
+public:
+ HeapWord* allocate_memory(ShenandoahAllocRequest& request);
+ HeapWord* mem_allocate(size_t size, bool* what);
+ MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
+ size_t size,
+ Metaspace::MetadataType mdtype);
+
+ oop obj_allocate(Klass* klass, int size, TRAPS);
+ oop array_allocate(Klass* klass, int size, int length, bool do_zero, TRAPS);
+ oop class_allocate(Klass* klass, int size, TRAPS);
+
+ void notify_mutator_alloc_words(size_t words, bool waste);
+
+ // Shenandoah supports TLAB allocation
+ bool supports_tlab_allocation() const { return true; }
+
+ HeapWord* allocate_new_tlab(size_t min_size, size_t requested_size, size_t* actual_size);
+ size_t tlab_capacity(Thread *thr) const;
+ size_t unsafe_max_tlab_alloc(Thread *thread) const;
+ size_t max_tlab_size() const;
+ size_t tlab_used(Thread* ignored) const;
+
+ HeapWord* tlab_post_allocation_setup(HeapWord* obj);
+ void fill_with_dummy_object(HeapWord* start, HeapWord* end, bool zap);
+ size_t min_dummy_object_size() const;
+
+ void resize_tlabs();
+
+ void ensure_parsability(bool retire_tlabs);
+ void make_parsable(bool retire_tlabs);
+
+// ---------- Marking support
+//
+private:
+ ShenandoahMarkingContext* _marking_context;
+ MemRegion _bitmap_region;
+ MemRegion _aux_bitmap_region;
+ MarkBitMap _verification_bit_map;
+ MarkBitMap _aux_bit_map;
+
+ size_t _bitmap_size;
+ size_t _bitmap_regions_per_slice;
+ size_t _bitmap_bytes_per_slice;
+
+ // Used for buffering per-region liveness data.
+ // Needed since ShenandoahHeapRegion uses atomics to update liveness.
+ //
+ // The array has max-workers elements, each of which is an array of
+ // jushort * max_regions. The choice of jushort is not accidental:
+ // there is a tradeoff between static/dynamic footprint that translates
+ // into cache pressure (which is already high during marking), and
+ // too many atomic updates. size_t/jint is too large, jbyte is too small.
+ jushort** _liveness_cache;
+
+public:
+ inline ShenandoahMarkingContext* complete_marking_context() const;
+ inline ShenandoahMarkingContext* marking_context() const;
+ inline void mark_complete_marking_context();
+ inline void mark_incomplete_marking_context();
+
+ template<class T>
+ inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl);
+
+ template<class T>
+ inline void marked_object_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
+
+ template<class T>
+ inline void marked_object_oop_iterate(ShenandoahHeapRegion* region, T* cl, HeapWord* limit);
+
+ void reset_mark_bitmap();
+
+ // SATB barriers hooks
+ inline bool requires_marking(const void* entry) const;
+ void force_satb_flush_all_threads();
+
+ // Support for bitmap uncommits
+ bool commit_bitmap_slice(ShenandoahHeapRegion *r);
+ bool uncommit_bitmap_slice(ShenandoahHeapRegion *r);
+ bool is_bitmap_slice_committed(ShenandoahHeapRegion* r, bool skip_self = false);
+
+ // Liveness caching support
+ jushort* get_liveness_cache(uint worker_id);
+ void flush_liveness_cache(uint worker_id);
+
+// ---------- Evacuation support
+//
+private:
+ ShenandoahCollectionSet* _collection_set;
+ ShenandoahEvacOOMHandler _oom_evac_handler;
+
+ void evacuate_and_update_roots();
+
+public:
+ static address in_cset_fast_test_addr();
+
+ ShenandoahCollectionSet* collection_set() const { return _collection_set; }
+
+ template <class T>
+ inline bool in_collection_set(T obj) const;
+
+ // Avoid accidentally calling the method above with ShenandoahHeapRegion*, which would be *wrong*.
+ inline bool in_collection_set(ShenandoahHeapRegion* r) shenandoah_not_implemented_return(false);
+
+ // Evacuates object src. Returns the evacuated object, either evacuated
+ // by this thread, or by some other thread.
+ inline oop evacuate_object(oop src, Thread* thread);
+
+ // Call before/after evacuation.
+ void enter_evacuation();
+ void leave_evacuation();
+
+// ---------- Helper functions
+//
+public:
+ template <class T>
+ inline oop evac_update_with_forwarded(T* p);
+
+ template <class T>
+ inline oop maybe_update_with_forwarded(T* p);
+
+ template <class T>
+ inline oop maybe_update_with_forwarded_not_null(T* p, oop obj);
+
+ template <class T>
+ inline oop update_with_forwarded_not_null(T* p, oop obj);
+
+ inline oop atomic_compare_exchange_oop(oop n, narrowOop* addr, oop c);
+ inline oop atomic_compare_exchange_oop(oop n, oop* addr, oop c);
+
+ void trash_humongous_region_at(ShenandoahHeapRegion *r);
+
+ void deduplicate_string(oop str);
+
+ void stop_concurrent_marking();
+
+ void roots_iterate(OopClosure* cl);
+
+private:
+ void trash_cset_regions();
+ void update_heap_references(bool concurrent);
+
+// ---------- Testing helpers functions
+//
+private:
+ ShenandoahSharedFlag _inject_alloc_failure;
+
+ void try_inject_alloc_failure();
+ bool should_inject_alloc_failure();
+};
+
+#endif // SHARE_VM_GC_SHENANDOAH_SHENANDOAHHEAP_HPP