psOldGen.hpp revision 9056:dc9930a04ab0 
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24
25#ifndef SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP
26#define SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP
27
28#include "gc/parallel/mutableSpace.hpp"
29#include "gc/parallel/objectStartArray.hpp"
30#include "gc/parallel/psGenerationCounters.hpp"
31#include "gc/parallel/psVirtualspace.hpp"
32#include "gc/parallel/spaceCounters.hpp"
33#include "runtime/safepoint.hpp"
34
35class PSMarkSweepDecorator;
36
37class PSOldGen : public CHeapObj<mtGC> {
38  friend class VMStructs;
39  friend class PSPromotionManager; // Uses the cas_allocate methods
40  friend class ParallelScavengeHeap;
41  friend class AdjoiningGenerations;
42
43 protected:
44  MemRegion                _reserved;          // Used for simple containment tests
45  PSVirtualSpace*          _virtual_space;     // Controls mapping and unmapping of virtual mem
46  ObjectStartArray         _start_array;       // Keeps track of where objects start in a 512b block
47  MutableSpace*            _object_space;      // Where all the objects live
48  PSMarkSweepDecorator*    _object_mark_sweep; // The mark sweep view of _object_space
49  const char* const        _name;              // Name of this generation.
50
51  // Performance Counters
52  PSGenerationCounters*    _gen_counters;
53  SpaceCounters*           _space_counters;
54
55  // Sizing information, in bytes, set in constructor
56  const size_t _init_gen_size;
57  const size_t _min_gen_size;
58  const size_t _max_gen_size;
59
60  // Used when initializing the _name field.
61  static inline const char* select_name();
62
63#ifdef ASSERT
64  void assert_block_in_covered_region(MemRegion new_memregion) {
65    // Explictly capture current covered_region in a local
66    MemRegion covered_region = this->start_array()->covered_region();
67    assert(covered_region.contains(new_memregion),
68           "new region is not in covered_region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
69           "new region [ " PTR_FORMAT ", " PTR_FORMAT " ], "
70           "object space [ " PTR_FORMAT ", " PTR_FORMAT " ]",
71           p2i(covered_region.start()),
72           p2i(covered_region.end()),
73           p2i(new_memregion.start()),
74           p2i(new_memregion.end()),
75           p2i(this->object_space()->used_region().start()),
76           p2i(this->object_space()->used_region().end()));
77  }
78#endif
79
80  HeapWord* allocate_noexpand(size_t word_size) {
81    // We assume the heap lock is held here.
82    assert_locked_or_safepoint(Heap_lock);
83    HeapWord* res = object_space()->allocate(word_size);
84    if (res != NULL) {
85      DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
86      _start_array.allocate_block(res);
87    }
88    return res;
89  }
90
91  // Support for MT garbage collection. CAS allocation is lower overhead than grabbing
92  // and releasing the heap lock, which is held during gc's anyway. This method is not
93  // safe for use at the same time as allocate_noexpand()!
94  HeapWord* cas_allocate_noexpand(size_t word_size) {
95    assert(SafepointSynchronize::is_at_safepoint(), "Must only be called at safepoint");
96    HeapWord* res = object_space()->cas_allocate(word_size);
97    if (res != NULL) {
98      DEBUG_ONLY(assert_block_in_covered_region(MemRegion(res, word_size)));
99      _start_array.allocate_block(res);
100    }
101    return res;
102  }
103
104  // Support for MT garbage collection. See above comment.
105  HeapWord* cas_allocate(size_t word_size) {
106    HeapWord* res = cas_allocate_noexpand(word_size);
107    return (res == NULL) ? expand_and_cas_allocate(word_size) : res;
108  }
109
110  HeapWord* expand_and_allocate(size_t word_size);
111  HeapWord* expand_and_cas_allocate(size_t word_size);
112  void expand(size_t bytes);
113  bool expand_by(size_t bytes);
114  bool expand_to_reserved();
115
116  void shrink(size_t bytes);
117
118  void post_resize();
119
120 public:
121  // Initialize the generation.
122  PSOldGen(ReservedSpace rs, size_t alignment,
123           size_t initial_size, size_t min_size, size_t max_size,
124           const char* perf_data_name, int level);
125
126  PSOldGen(size_t initial_size, size_t min_size, size_t max_size,
127           const char* perf_data_name, int level);
128
129  virtual void initialize(ReservedSpace rs, size_t alignment,
130                  const char* perf_data_name, int level);
131  void initialize_virtual_space(ReservedSpace rs, size_t alignment);
132  virtual void initialize_work(const char* perf_data_name, int level);
133  virtual void initialize_performance_counters(const char* perf_data_name, int level);
134
135  MemRegion reserved() const                { return _reserved; }
136  virtual size_t max_gen_size()             { return _max_gen_size; }
137  size_t min_gen_size()                     { return _min_gen_size; }
138
139  // Returns limit on the maximum size of the generation.  This
140  // is the same as _max_gen_size for PSOldGen but need not be
141  // for a derived class.
142  virtual size_t gen_size_limit();
143
144  bool is_in(const void* p) const           {
145    return _virtual_space->contains((void *)p);
146  }
147
148  bool is_in_reserved(const void* p) const {
149    return reserved().contains(p);
150  }
151
152  MutableSpace*         object_space() const      { return _object_space; }
153  PSMarkSweepDecorator* object_mark_sweep() const { return _object_mark_sweep; }
154  ObjectStartArray*     start_array()             { return &_start_array; }
155  PSVirtualSpace*       virtual_space() const     { return _virtual_space;}
156
157  // Has the generation been successfully allocated?
158  bool is_allocated();
159
160  // MarkSweep methods
161  virtual void precompact();
162  void adjust_pointers();
163  void compact();
164
165  // Size info
166  size_t capacity_in_bytes() const        { return object_space()->capacity_in_bytes(); }
167  size_t used_in_bytes() const            { return object_space()->used_in_bytes(); }
168  size_t free_in_bytes() const            { return object_space()->free_in_bytes(); }
169
170  size_t capacity_in_words() const        { return object_space()->capacity_in_words(); }
171  size_t used_in_words() const            { return object_space()->used_in_words(); }
172  size_t free_in_words() const            { return object_space()->free_in_words(); }
173
174  // Includes uncommitted memory
175  size_t contiguous_available() const;
176
177  bool is_maximal_no_gc() const {
178    return virtual_space()->uncommitted_size() == 0;
179  }
180
181  // Calculating new sizes
182  void resize(size_t desired_free_space);
183
184  // Allocation. We report all successful allocations to the size policy
185  // Note that the perm gen does not use this method, and should not!
186  HeapWord* allocate(size_t word_size);
187
188  // Iteration.
189  void oop_iterate_no_header(OopClosure* cl) { object_space()->oop_iterate_no_header(cl); }
190  void object_iterate(ObjectClosure* cl) { object_space()->object_iterate(cl); }
191
192  // Debugging - do not use for time critical operations
193  virtual void print() const;
194  virtual void print_on(outputStream* st) const;
195  void print_used_change(size_t prev_used) const;
196
197  void verify();
198  void verify_object_start_array();
199
200  // These should not used
201  virtual void reset_after_change();
202
203  // These should not used
204  virtual size_t available_for_expansion();
205  virtual size_t available_for_contraction();
206
207  void space_invariants() PRODUCT_RETURN;
208
209  // Performance Counter support
210  void update_counters();
211
212  // Printing support
213  virtual const char* name() const { return _name; }
214
215  // Debugging support
216  // Save the tops of all spaces for later use during mangling.
217  void record_spaces_top() PRODUCT_RETURN;
218};
219
220#endif // SHARE_VM_GC_PARALLEL_PSOLDGEN_HPP
221