parallelScavengeHeap.hpp revision 9727:f944761a3ce3 
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24
25#ifndef SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
26#define SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
27
28#include "gc/parallel/generationSizer.hpp"
29#include "gc/parallel/objectStartArray.hpp"
30#include "gc/parallel/psGCAdaptivePolicyCounters.hpp"
31#include "gc/parallel/psOldGen.hpp"
32#include "gc/parallel/psYoungGen.hpp"
33#include "gc/shared/collectedHeap.hpp"
34#include "gc/shared/collectorPolicy.hpp"
35#include "gc/shared/gcPolicyCounters.hpp"
36#include "gc/shared/gcWhen.hpp"
37#include "gc/shared/strongRootsScope.hpp"
38#include "memory/metaspace.hpp"
39#include "utilities/ostream.hpp"
40
41class AdjoiningGenerations;
42class GCHeapSummary;
43class GCTaskManager;
44class PSAdaptiveSizePolicy;
45class PSHeapSummary;
46
47class ParallelScavengeHeap : public CollectedHeap {
48  friend class VMStructs;
49 private:
50  static PSYoungGen* _young_gen;
51  static PSOldGen*   _old_gen;
52
53  // Sizing policy for entire heap
54  static PSAdaptiveSizePolicy*       _size_policy;
55  static PSGCAdaptivePolicyCounters* _gc_policy_counters;
56
57  GenerationSizer* _collector_policy;
58
59  // Collection of generations that are adjacent in the
60  // space reserved for the heap.
61  AdjoiningGenerations* _gens;
62  unsigned int _death_march_count;
63
64  // The task manager
65  static GCTaskManager* _gc_task_manager;
66
67  void trace_heap(GCWhen::Type when, const GCTracer* tracer);
68
69 protected:
70  static inline size_t total_invocations();
71  HeapWord* allocate_new_tlab(size_t size);
72
73  inline bool should_alloc_in_eden(size_t size) const;
74  inline void death_march_check(HeapWord* const result, size_t size);
75  HeapWord* mem_allocate_old_gen(size_t size);
76
77 public:
78  ParallelScavengeHeap(GenerationSizer* policy) :
79    CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
80
81  // For use by VM operations
82  enum CollectionType {
83    Scavenge,
84    MarkSweep
85  };
86
87  virtual Name kind() const {
88    return CollectedHeap::ParallelScavengeHeap;
89  }
90
91  virtual const char* name() const {
92    return "Parallel";
93  }
94
95  virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
96
97  static PSYoungGen* young_gen() { return _young_gen; }
98  static PSOldGen* old_gen()     { return _old_gen; }
99
100  virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
101
102  static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
103
104  static ParallelScavengeHeap* heap();
105
106  static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
107
108  AdjoiningGenerations* gens() { return _gens; }
109
110  // Returns JNI_OK on success
111  virtual jint initialize();
112
113  void post_initialize();
114  void update_counters();
115
116  // The alignment used for the various areas
117  size_t space_alignment()      { return _collector_policy->space_alignment(); }
118  size_t generation_alignment() { return _collector_policy->gen_alignment(); }
119
120  // Return the (conservative) maximum heap alignment
121  static size_t conservative_max_heap_alignment() {
122    return CollectorPolicy::compute_heap_alignment();
123  }
124
125  size_t capacity() const;
126  size_t used() const;
127
128  // Return "true" if all generations have reached the
129  // maximal committed limit that they can reach, without a garbage
130  // collection.
131  virtual bool is_maximal_no_gc() const;
132
133  // Return true if the reference points to an object that
134  // can be moved in a partial collection.  For currently implemented
135  // generational collectors that means during a collection of
136  // the young gen.
137  virtual bool is_scavengable(const void* addr);
138
139  size_t max_capacity() const;
140
141  // Whether p is in the allocated part of the heap
142  bool is_in(const void* p) const;
143
144  bool is_in_reserved(const void* p) const;
145
146  bool is_in_young(oop p);  // reserved part
147  bool is_in_old(oop p);    // reserved part
148
149  // Memory allocation.   "gc_time_limit_was_exceeded" will
150  // be set to true if the adaptive size policy determine that
151  // an excessive amount of time is being spent doing collections
152  // and caused a NULL to be returned.  If a NULL is not returned,
153  // "gc_time_limit_was_exceeded" has an undefined meaning.
154  HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
155
156  // Allocation attempt(s) during a safepoint. It should never be called
157  // to allocate a new TLAB as this allocation might be satisfied out
158  // of the old generation.
159  HeapWord* failed_mem_allocate(size_t size);
160
161  // Support for System.gc()
162  void collect(GCCause::Cause cause);
163
164  // These also should be called by the vm thread at a safepoint (e.g., from a
165  // VM operation).
166  //
167  // The first collects the young generation only, unless the scavenge fails; it
168  // will then attempt a full gc.  The second collects the entire heap; if
169  // maximum_compaction is true, it will compact everything and clear all soft
170  // references.
171  inline void invoke_scavenge();
172
173  // Perform a full collection
174  virtual void do_full_collection(bool clear_all_soft_refs);
175
176  bool supports_inline_contig_alloc() const { return !UseNUMA; }
177
178  HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
179  HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
180
181  void ensure_parsability(bool retire_tlabs);
182  void accumulate_statistics_all_tlabs();
183  void resize_all_tlabs();
184
185  bool supports_tlab_allocation() const { return true; }
186
187  size_t tlab_capacity(Thread* thr) const;
188  size_t tlab_used(Thread* thr) const;
189  size_t unsafe_max_tlab_alloc(Thread* thr) const;
190
191  // Can a compiler initialize a new object without store barriers?
192  // This permission only extends from the creation of a new object
193  // via a TLAB up to the first subsequent safepoint.
194  virtual bool can_elide_tlab_store_barriers() const {
195    return true;
196  }
197
198  virtual bool card_mark_must_follow_store() const {
199    return false;
200  }
201
202  // Return true if we don't we need a store barrier for
203  // initializing stores to an object at this address.
204  virtual bool can_elide_initializing_store_barrier(oop new_obj);
205
206  void object_iterate(ObjectClosure* cl);
207  void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
208
209  HeapWord* block_start(const void* addr) const;
210  size_t block_size(const HeapWord* addr) const;
211  bool block_is_obj(const HeapWord* addr) const;
212
213  jlong millis_since_last_gc();
214
215  void prepare_for_verify();
216  PSHeapSummary create_ps_heap_summary();
217  virtual void print_on(outputStream* st) const;
218  virtual void print_on_error(outputStream* st) const;
219  virtual void print_gc_threads_on(outputStream* st) const;
220  virtual void gc_threads_do(ThreadClosure* tc) const;
221  virtual void print_tracing_info() const;
222
223  void verify(VerifyOption option /* ignored */);
224
225  // Resize the young generation.  The reserved space for the
226  // generation may be expanded in preparation for the resize.
227  void resize_young_gen(size_t eden_size, size_t survivor_size);
228
229  // Resize the old generation.  The reserved space for the
230  // generation may be expanded in preparation for the resize.
231  void resize_old_gen(size_t desired_free_space);
232
233  // Save the tops of the spaces in all generations
234  void record_gen_tops_before_GC() PRODUCT_RETURN;
235
236  // Mangle the unused parts of all spaces in the heap
237  void gen_mangle_unused_area() PRODUCT_RETURN;
238
239  // Call these in sequential code around the processing of strong roots.
240  class ParStrongRootsScope : public MarkScope {
241   public:
242    ParStrongRootsScope();
243    ~ParStrongRootsScope();
244  };
245};
246
247// Simple class for storing info about the heap at the start of GC, to be used
248// after GC for comparison/printing.
249class PreGCValues {
250public:
251  PreGCValues(ParallelScavengeHeap* heap) :
252      _heap_used(heap->used()),
253      _young_gen_used(heap->young_gen()->used_in_bytes()),
254      _old_gen_used(heap->old_gen()->used_in_bytes()),
255      _metadata_used(MetaspaceAux::used_bytes()) { };
256
257  size_t heap_used() const      { return _heap_used; }
258  size_t young_gen_used() const { return _young_gen_used; }
259  size_t old_gen_used() const   { return _old_gen_used; }
260  size_t metadata_used() const  { return _metadata_used; }
261
262private:
263  size_t _heap_used;
264  size_t _young_gen_used;
265  size_t _old_gen_used;
266  size_t _metadata_used;
267};
268
269#endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
270