Thu, 12 Jun 2008 13:50:55 -0700
Merge
1 /*
2 * Copyright 2001-2006 Sun Microsystems, Inc. All Rights Reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 // This class (or more correctly, subtypes of this class)
26 // are used to define global garbage collector attributes.
27 // This includes initialization of generations and any other
28 // shared resources they may need.
29 //
30 // In general, all flag adjustment and validation should be
31 // done in initialize_flags(), which is called prior to
32 // initialize_size_info().
33 //
34 // This class is not fully developed yet. As more collector(s)
35 // are added, it is expected that we will come across further
36 // behavior that requires global attention. The correct place
37 // to deal with those issues is this class.
39 // Forward declarations.
40 class GenCollectorPolicy;
41 class TwoGenerationCollectorPolicy;
42 class AdaptiveSizePolicy;
43 #ifndef SERIALGC
44 class ConcurrentMarkSweepPolicy;
45 class G1CollectorPolicy;
46 #endif // SERIALGC
48 class GCPolicyCounters;
49 class PermanentGenerationSpec;
50 class MarkSweepPolicy;
52 class CollectorPolicy : public CHeapObj {
53 protected:
54 PermanentGenerationSpec *_permanent_generation;
55 GCPolicyCounters* _gc_policy_counters;
57 // Requires that the concrete subclass sets the alignment constraints
58 // before calling.
59 virtual void initialize_flags();
60 virtual void initialize_size_info();
61 // Initialize "_permanent_generation" to a spec for the given kind of
62 // Perm Gen.
63 void initialize_perm_generation(PermGen::Name pgnm);
65 size_t _initial_heap_byte_size;
66 size_t _max_heap_byte_size;
67 size_t _min_heap_byte_size;
69 size_t _min_alignment;
70 size_t _max_alignment;
72 CollectorPolicy() :
73 _min_alignment(1),
74 _max_alignment(1),
75 _initial_heap_byte_size(0),
76 _max_heap_byte_size(0),
77 _min_heap_byte_size(0)
78 {}
80 public:
81 void set_min_alignment(size_t align) { _min_alignment = align; }
82 size_t min_alignment() { return _min_alignment; }
83 void set_max_alignment(size_t align) { _max_alignment = align; }
84 size_t max_alignment() { return _max_alignment; }
86 size_t initial_heap_byte_size() { return _initial_heap_byte_size; }
87 void set_initial_heap_byte_size(size_t v) { _initial_heap_byte_size = v; }
88 size_t max_heap_byte_size() { return _max_heap_byte_size; }
89 void set_max_heap_byte_size(size_t v) { _max_heap_byte_size = v; }
90 size_t min_heap_byte_size() { return _min_heap_byte_size; }
91 void set_min_heap_byte_size(size_t v) { _min_heap_byte_size = v; }
93 enum Name {
94 CollectorPolicyKind,
95 TwoGenerationCollectorPolicyKind,
96 ConcurrentMarkSweepPolicyKind,
97 ASConcurrentMarkSweepPolicyKind,
98 G1CollectorPolicyKind
99 };
101 // Identification methods.
102 virtual GenCollectorPolicy* as_generation_policy() { return NULL; }
103 virtual TwoGenerationCollectorPolicy* as_two_generation_policy() { return NULL; }
104 virtual MarkSweepPolicy* as_mark_sweep_policy() { return NULL; }
105 #ifndef SERIALGC
106 virtual ConcurrentMarkSweepPolicy* as_concurrent_mark_sweep_policy() { return NULL; }
107 virtual G1CollectorPolicy* as_g1_policy() { return NULL; }
108 #endif // SERIALGC
109 // Note that these are not virtual.
110 bool is_generation_policy() { return as_generation_policy() != NULL; }
111 bool is_two_generation_policy() { return as_two_generation_policy() != NULL; }
112 bool is_mark_sweep_policy() { return as_mark_sweep_policy() != NULL; }
113 #ifndef SERIALGC
114 bool is_concurrent_mark_sweep_policy() { return as_concurrent_mark_sweep_policy() != NULL; }
115 bool is_g1_policy() { return as_g1_policy() != NULL; }
116 #else // SERIALGC
117 bool is_concurrent_mark_sweep_policy() { return false; }
118 bool is_g1_policy() { return false; }
119 #endif // SERIALGC
122 virtual PermanentGenerationSpec *permanent_generation() {
123 assert(_permanent_generation != NULL, "Sanity check");
124 return _permanent_generation;
125 }
127 virtual BarrierSet::Name barrier_set_name() = 0;
128 virtual GenRemSet::Name rem_set_name() = 0;
130 // Create the remembered set (to cover the given reserved region,
131 // allowing breaking up into at most "max_covered_regions").
132 virtual GenRemSet* create_rem_set(MemRegion reserved,
133 int max_covered_regions);
135 // This method controls how a collector satisfies a request
136 // for a block of memory. "gc_time_limit_was_exceeded" will
137 // be set to true if the adaptive size policy determine that
138 // an excessive amount of time is being spent doing collections
139 // and caused a NULL to be returned. If a NULL is not returned,
140 // "gc_time_limit_was_exceeded" has an undefined meaning.
141 virtual HeapWord* mem_allocate_work(size_t size,
142 bool is_tlab,
143 bool* gc_overhead_limit_was_exceeded) = 0;
145 // This method controls how a collector handles one or more
146 // of its generations being fully allocated.
147 virtual HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab) = 0;
148 // Performace Counter support
149 GCPolicyCounters* counters() { return _gc_policy_counters; }
151 // Create the jstat counters for the GC policy. By default, policy's
152 // don't have associated counters, and we complain if this is invoked.
153 virtual void initialize_gc_policy_counters() {
154 ShouldNotReachHere();
155 }
157 virtual CollectorPolicy::Name kind() {
158 return CollectorPolicy::CollectorPolicyKind;
159 }
161 // Returns true if a collector has eden space with soft end.
162 virtual bool has_soft_ended_eden() {
163 return false;
164 }
166 };
168 class GenCollectorPolicy : public CollectorPolicy {
169 protected:
170 size_t _min_gen0_size;
171 size_t _initial_gen0_size;
172 size_t _max_gen0_size;
174 GenerationSpec **_generations;
176 // The sizing of the different generations in the heap are controlled
177 // by a sizing policy.
178 AdaptiveSizePolicy* _size_policy;
180 // Return true if an allocation should be attempted in the older
181 // generation if it fails in the younger generation. Return
182 // false, otherwise.
183 virtual bool should_try_older_generation_allocation(size_t word_size) const;
185 void initialize_flags();
186 void initialize_size_info();
188 // Try to allocate space by expanding the heap.
189 virtual HeapWord* expand_heap_and_allocate(size_t size, bool is_tlab);
191 // compute max heap alignment
192 size_t compute_max_alignment();
194 // Scale the base_size by NewRation according to
195 // result = base_size / (NewRatio + 1)
196 // and align by min_alignment()
197 size_t scale_by_NewRatio_aligned(size_t base_size);
199 // Bound the value by the given maximum minus the
200 // min_alignment.
201 size_t bound_minus_alignment(size_t desired_size, size_t maximum_size);
203 public:
204 // Accessors
205 size_t min_gen0_size() { return _min_gen0_size; }
206 void set_min_gen0_size(size_t v) { _min_gen0_size = v; }
207 size_t initial_gen0_size() { return _initial_gen0_size; }
208 void set_initial_gen0_size(size_t v) { _initial_gen0_size = v; }
209 size_t max_gen0_size() { return _max_gen0_size; }
210 void set_max_gen0_size(size_t v) { _max_gen0_size = v; }
212 virtual int number_of_generations() = 0;
214 virtual GenerationSpec **generations() {
215 assert(_generations != NULL, "Sanity check");
216 return _generations;
217 }
219 virtual GenCollectorPolicy* as_generation_policy() { return this; }
221 virtual void initialize_generations() = 0;
223 virtual void initialize_all() {
224 initialize_flags();
225 initialize_size_info();
226 initialize_generations();
227 }
229 HeapWord* mem_allocate_work(size_t size,
230 bool is_tlab,
231 bool* gc_overhead_limit_was_exceeded);
233 HeapWord *satisfy_failed_allocation(size_t size, bool is_tlab);
235 // The size that defines a "large array".
236 virtual size_t large_typearray_limit();
238 // Adaptive size policy
239 AdaptiveSizePolicy* size_policy() { return _size_policy; }
240 virtual void initialize_size_policy(size_t init_eden_size,
241 size_t init_promo_size,
242 size_t init_survivor_size);
244 };
247 // All of hotspot's current collectors are subtypes of this
248 // class. Currently, these collectors all use the same gen[0],
249 // but have different gen[1] types. If we add another subtype
250 // of CollectorPolicy, this class should be broken out into
251 // its own file.
253 class TwoGenerationCollectorPolicy : public GenCollectorPolicy {
254 protected:
255 size_t _min_gen1_size;
256 size_t _initial_gen1_size;
257 size_t _max_gen1_size;
259 void initialize_flags();
260 void initialize_size_info();
261 void initialize_generations() { ShouldNotReachHere(); }
263 public:
264 // Accessors
265 size_t min_gen1_size() { return _min_gen1_size; }
266 void set_min_gen1_size(size_t v) { _min_gen1_size = v; }
267 size_t initial_gen1_size() { return _initial_gen1_size; }
268 void set_initial_gen1_size(size_t v) { _initial_gen1_size = v; }
269 size_t max_gen1_size() { return _max_gen1_size; }
270 void set_max_gen1_size(size_t v) { _max_gen1_size = v; }
272 // Inherited methods
273 TwoGenerationCollectorPolicy* as_two_generation_policy() { return this; }
275 int number_of_generations() { return 2; }
276 BarrierSet::Name barrier_set_name() { return BarrierSet::CardTableModRef; }
277 GenRemSet::Name rem_set_name() { return GenRemSet::CardTable; }
279 virtual CollectorPolicy::Name kind() {
280 return CollectorPolicy::TwoGenerationCollectorPolicyKind;
281 }
283 // Returns true is gen0 sizes were adjusted
284 bool adjust_gen0_sizes(size_t* gen0_size_ptr, size_t* gen1_size_ptr,
285 size_t heap_size, size_t min_gen1_size);
286 };
288 class MarkSweepPolicy : public TwoGenerationCollectorPolicy {
289 protected:
290 void initialize_generations();
292 public:
293 MarkSweepPolicy();
295 MarkSweepPolicy* as_mark_sweep_policy() { return this; }
297 void initialize_gc_policy_counters();
298 };