Wed, 26 Jun 2013 16:58:37 +0200
8013590: NPG: Add a memory pool MXBean for Metaspace
Reviewed-by: jmasa, mgerdin
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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13 * accompanied this code).
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25 #ifndef SHARE_VM_MEMORY_COLLECTORPOLICY_HPP
26 #define SHARE_VM_MEMORY_COLLECTORPOLICY_HPP
28 #include "memory/allocation.hpp"
29 #include "memory/barrierSet.hpp"
30 #include "memory/generationSpec.hpp"
31 #include "memory/genRemSet.hpp"
32 #include "utilities/macros.hpp"
34 // This class (or more correctly, subtypes of this class)
35 // are used to define global garbage collector attributes.
36 // This includes initialization of generations and any other
37 // shared resources they may need.
38 //
39 // In general, all flag adjustment and validation should be
40 // done in initialize_flags(), which is called prior to
41 // initialize_size_info().
42 //
43 // This class is not fully developed yet. As more collector(s)
44 // are added, it is expected that we will come across further
45 // behavior that requires global attention. The correct place
46 // to deal with those issues is this class.
48 // Forward declarations.
49 class GenCollectorPolicy;
50 class TwoGenerationCollectorPolicy;
51 class AdaptiveSizePolicy;
52 #if INCLUDE_ALL_GCS
53 class ConcurrentMarkSweepPolicy;
54 class G1CollectorPolicy;
55 #endif // INCLUDE_ALL_GCS
57 class GCPolicyCounters;
58 class MarkSweepPolicy;
60 class CollectorPolicy : public CHeapObj<mtGC> {
61 protected:
62 GCPolicyCounters* _gc_policy_counters;
64 // Requires that the concrete subclass sets the alignment constraints
65 // before calling.
66 virtual void initialize_flags();
67 virtual void initialize_size_info();
69 size_t _initial_heap_byte_size;
70 size_t _max_heap_byte_size;
71 size_t _min_heap_byte_size;
73 size_t _min_alignment;
74 size_t _max_alignment;
76 // The sizing of the heap are controlled by a sizing policy.
77 AdaptiveSizePolicy* _size_policy;
79 // Set to true when policy wants soft refs cleared.
80 // Reset to false by gc after it clears all soft refs.
81 bool _should_clear_all_soft_refs;
82 // Set to true by the GC if the just-completed gc cleared all
83 // softrefs. This is set to true whenever a gc clears all softrefs, and
84 // set to false each time gc returns to the mutator. For example, in the
85 // ParallelScavengeHeap case the latter would be done toward the end of
86 // mem_allocate() where it returns op.result()
87 bool _all_soft_refs_clear;
89 CollectorPolicy() :
90 _min_alignment(1),
91 _max_alignment(1),
92 _initial_heap_byte_size(0),
93 _max_heap_byte_size(0),
94 _min_heap_byte_size(0),
95 _size_policy(NULL),
96 _should_clear_all_soft_refs(false),
97 _all_soft_refs_clear(false)
98 {}
100 public:
101 void set_min_alignment(size_t align) { _min_alignment = align; }
102 size_t min_alignment() { return _min_alignment; }
103 void set_max_alignment(size_t align) { _max_alignment = align; }
104 size_t max_alignment() { return _max_alignment; }
106 size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
107 void set_initial_heap_byte_size(size_t v) { _initial_heap_byte_size = v; }
108 size_t max_heap_byte_size() { return _max_heap_byte_size; }
109 void set_max_heap_byte_size(size_t v) { _max_heap_byte_size = v; }
110 size_t min_heap_byte_size() { return _min_heap_byte_size; }
111 void set_min_heap_byte_size(size_t v) { _min_heap_byte_size = v; }
113 enum Name {
114 CollectorPolicyKind,
115 TwoGenerationCollectorPolicyKind,
116 ConcurrentMarkSweepPolicyKind,
117 ASConcurrentMarkSweepPolicyKind,
118 G1CollectorPolicyKind
119 };
121 AdaptiveSizePolicy* size_policy() { return _size_policy; }
122 bool should_clear_all_soft_refs() { return _should_clear_all_soft_refs; }
123 void set_should_clear_all_soft_refs(bool v) { _should_clear_all_soft_refs = v; }
124 // Returns the current value of _should_clear_all_soft_refs.
125 // _should_clear_all_soft_refs is set to false as a side effect.
126 bool use_should_clear_all_soft_refs(bool v);
127 bool all_soft_refs_clear() { return _all_soft_refs_clear; }
128 void set_all_soft_refs_clear(bool v) { _all_soft_refs_clear = v; }
130 // Called by the GC after Soft Refs have been cleared to indicate
131 // that the request in _should_clear_all_soft_refs has been fulfilled.
132 void cleared_all_soft_refs();
134 // Identification methods.
135 virtual GenCollectorPolicy* as_generation_policy() { return NULL; }
136 virtual TwoGenerationCollectorPolicy* as_two_generation_policy() { return NULL; }
137 virtual MarkSweepPolicy* as_mark_sweep_policy() { return NULL; }
138 #if INCLUDE_ALL_GCS
139 virtual ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return NULL; }
140 virtual G1CollectorPolicy* as_g1_policy() { return NULL; }
141 #endif // INCLUDE_ALL_GCS
142 // Note that these are not virtual.
143 bool is_generation_policy() { return as_generation_policy() != NULL; }
144 bool is_two_generation_policy() { return as_two_generation_policy() != NULL; }
145 bool is_mark_sweep_policy() { return as_mark_sweep_policy() != NULL; }
146 #if INCLUDE_ALL_GCS
147 bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; }
148 bool is_g1_policy() { return as_g1_policy() != NULL; }
149 #else // INCLUDE_ALL_GCS
150 bool is_concurrent_mark_sweep_policy() { return false; }
151 bool is_g1_policy() { return false; }
152 #endif // INCLUDE_ALL_GCS
155 virtual BarrierSet::Name barrier_set_name() = 0;
156 virtual GenRemSet::Name rem_set_name() = 0;
158 // Create the remembered set (to cover the given reserved region,
159 // allowing breaking up into at most "max_covered_regions").
160 virtual GenRemSet* create_rem_set(MemRegion reserved,
161 int max_covered_regions);
163 // This method controls how a collector satisfies a request
164 // for a block of memory. "gc_time_limit_was_exceeded" will
165 // be set to true if the adaptive size policy determine that
166 // an excessive amount of time is being spent doing collections
167 // and caused a NULL to be returned. If a NULL is not returned,
168 // "gc_time_limit_was_exceeded" has an undefined meaning.
169 virtual HeapWord* mem_allocate_work(size_t size,
170 bool is_tlab,
171 bool* gc_overhead_limit_was_exceeded) = 0;
173 // This method controls how a collector handles one or more
174 // of its generations being fully allocated.
175 virtual HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab) = 0;
176 // This method controls how a collector handles a metadata allocation
177 // failure.
178 virtual MetaWord* satisfy_failed_metadata_allocation(ClassLoaderData* loader_data,
179 size_t size,
180 Metaspace::MetadataType mdtype);
182 // Performace Counter support
183 GCPolicyCounters* counters() { return _gc_policy_counters; }
185 // Create the jstat counters for the GC policy. By default, policy's
186 // don't have associated counters, and we complain if this is invoked.
187 virtual void initialize_gc_policy_counters() {
188 ShouldNotReachHere();
189 }
191 virtual CollectorPolicy::Name kind() {
192 return CollectorPolicy::CollectorPolicyKind;
193 }
195 // Returns true if a collector has eden space with soft end.
196 virtual bool has_soft_ended_eden() {
197 return false;
198 }
200 };
202 class ClearedAllSoftRefs : public StackObj {
203 bool _clear_all_soft_refs;
204 CollectorPolicy* _collector_policy;
205 public:
206 ClearedAllSoftRefs(bool clear_all_soft_refs,
207 CollectorPolicy* collector_policy) :
208 _clear_all_soft_refs(clear_all_soft_refs),
209 _collector_policy(collector_policy) {}
211 ~ClearedAllSoftRefs() {
212 if (_clear_all_soft_refs) {
213 _collector_policy->cleared_all_soft_refs();
214 }
215 }
216 };
218 class GenCollectorPolicy : public CollectorPolicy {
219 protected:
220 size_t _min_gen0_size;
221 size_t _initial_gen0_size;
222 size_t _max_gen0_size;
224 GenerationSpec **_generations;
226 // Return true if an allocation should be attempted in the older
227 // generation if it fails in the younger generation. Return
228 // false, otherwise.
229 virtual bool should_try_older_generation_allocation(size_t word_size) const;
231 void initialize_flags();
232 void initialize_size_info();
234 // Try to allocate space by expanding the heap.
235 virtual HeapWord* expand_heap_and_allocate(size_t size, bool is_tlab);
237 // compute max heap alignment
238 size_t compute_max_alignment();
240 // Scale the base_size by NewRation according to
241 // result = base_size / (NewRatio + 1)
242 // and align by min_alignment()
243 size_t scale_by_NewRatio_aligned(size_t base_size);
245 // Bound the value by the given maximum minus the
246 // min_alignment.
247 size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);
249 public:
250 // Accessors
251 size_t min_gen0_size() { return _min_gen0_size; }
252 void set_min_gen0_size(size_t v) { _min_gen0_size = v; }
253 size_t initial_gen0_size() { return _initial_gen0_size; }
254 void set_initial_gen0_size(size_t v) { _initial_gen0_size = v; }
255 size_t max_gen0_size() { return _max_gen0_size; }
256 void set_max_gen0_size(size_t v) { _max_gen0_size = v; }
258 virtual int number_of_generations() = 0;
260 virtual GenerationSpec **generations() {
261 assert(_generations != NULL, "Sanity check");
262 return _generations;
263 }
265 virtual GenCollectorPolicy* as_generation_policy() { return this; }
267 virtual void initialize_generations() = 0;
269 virtual void initialize_all() {
270 initialize_flags();
271 initialize_size_info();
272 initialize_generations();
273 }
275 HeapWord* mem_allocate_work(size_t size,
276 bool is_tlab,
277 bool* gc_overhead_limit_was_exceeded);
279 HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab);
281 // Adaptive size policy
282 virtual void initialize_size_policy(size_t init_eden_size,
283 size_t init_promo_size,
284 size_t init_survivor_size);
285 };
287 // All of hotspot's current collectors are subtypes of this
288 // class. Currently, these collectors all use the same gen[0],
289 // but have different gen[1] types. If we add another subtype
290 // of CollectorPolicy, this class should be broken out into
291 // its own file.
293 class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
294 protected:
295 size_t _min_gen1_size;
296 size_t _initial_gen1_size;
297 size_t _max_gen1_size;
299 void initialize_flags();
300 void initialize_size_info();
301 void initialize_generations() { ShouldNotReachHere(); }
303 public:
304 // Accessors
305 size_t min_gen1_size() { return _min_gen1_size; }
306 void set_min_gen1_size(size_t v) { _min_gen1_size = v; }
307 size_t initial_gen1_size() { return _initial_gen1_size; }
308 void set_initial_gen1_size(size_t v) { _initial_gen1_size = v; }
309 size_t max_gen1_size() { return _max_gen1_size; }
310 void set_max_gen1_size(size_t v) { _max_gen1_size = v; }
312 // Inherited methods
313 TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }
315 int number_of_generations() { return 2; }
316 BarrierSet::Name barrier_set_name() { return BarrierSet::CardTableModRef; }
317 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
319 virtual CollectorPolicy::Name kind() {
320 return CollectorPolicy::TwoGenerationCollectorPolicyKind;
321 }
323 // Returns true is gen0 sizes were adjusted
324 bool adjust_gen0_sizes(size_t* gen0_size_ptr, size_t* gen1_size_ptr,
325 const size_t heap_size, const size_t min_gen1_size);
326 };
328 class MarkSweepPolicy : public TwoGenerationCollectorPolicy {
329 protected:
330 void initialize_generations();
332 public:
333 MarkSweepPolicy();
335 MarkSweepPolicy* as_mark_sweep_policy() { return this; }
337 void initialize_gc_policy_counters();
338 };
340 #endif // SHARE_VM_MEMORY_COLLECTORPOLICY_HPP