1 /*
2 * Copyright 2001-2010 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 */
24
25 class AdjoiningGenerations;
26 class GCTaskManager;
27 class PSAdaptiveSizePolicy;
28 class GenerationSizer;
29 class CollectorPolicy;
30
31 class ParallelScavengeHeap : public CollectedHeap {
32 friend class VMStructs;
33 private:
34 static PSYoungGen* _young_gen;
35 static PSOldGen* _old_gen;
36 static PSPermGen* _perm_gen;
37
38 // Sizing policy for entire heap
39 static PSAdaptiveSizePolicy* _size_policy;
40 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
41
42 static ParallelScavengeHeap* _psh;
43
44 size_t _perm_gen_alignment;
45 size_t _young_gen_alignment;
46 size_t _old_gen_alignment;
47
48 GenerationSizer* _collector_policy;
49
50 inline size_t set_alignment(size_t& var, size_t val);
51
52 // Collection of generations that are adjacent in the
53 // space reserved for the heap.
54 AdjoiningGenerations* _gens;
55
56 static GCTaskManager* _gc_task_manager; // The task manager.
57
58 protected:
59 static inline size_t total_invocations();
60 HeapWord* allocate_new_tlab(size_t size);
61
62 public:
63 ParallelScavengeHeap() : CollectedHeap() {
64 set_alignment(_perm_gen_alignment, intra_heap_alignment());
65 set_alignment(_young_gen_alignment, intra_heap_alignment());
66 set_alignment(_old_gen_alignment, intra_heap_alignment());
67 }
68
69 // For use by VM operations
70 enum CollectionType {
71 Scavenge,
72 MarkSweep
73 };
74
75 ParallelScavengeHeap::Name kind() const {
76 return CollectedHeap::ParallelScavengeHeap;
77 }
78
79 CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
80 // GenerationSizer* collector_policy() const { return _collector_policy; }
81
82 static PSYoungGen* young_gen() { return _young_gen; }
83 static PSOldGen* old_gen() { return _old_gen; }
84 static PSPermGen* perm_gen() { return _perm_gen; }
85
86 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
87
88 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
89
90 static ParallelScavengeHeap* heap();
91
92 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
93
94 AdjoiningGenerations* gens() { return _gens; }
95
96 // Returns JNI_OK on success
97 virtual jint initialize();
98
99 void post_initialize();
100 void update_counters();
101 // The alignment used for the various generations.
102 size_t perm_gen_alignment() const { return _perm_gen_alignment; }
103 size_t young_gen_alignment() const { return _young_gen_alignment; }
104 size_t old_gen_alignment() const { return _old_gen_alignment; }
105
106 // The alignment used for eden and survivors within the young gen
107 // and for boundary between young gen and old gen.
108 size_t intra_heap_alignment() const { return 64 * K; }
109
110 size_t capacity() const;
111 size_t used() const;
112
113 // Return "true" if all generations (but perm) have reached the
114 // maximal committed limit that they can reach, without a garbage
115 // collection.
116 virtual bool is_maximal_no_gc() const;
117
118 // Does this heap support heap inspection? (+PrintClassHistogram)
119 bool supports_heap_inspection() const { return true; }
120
121 size_t permanent_capacity() const;
122 size_t permanent_used() const;
123
124 size_t max_capacity() const;
125
126 // Whether p is in the allocated part of the heap
127 bool is_in(const void* p) const;
128
129 bool is_in_reserved(const void* p) const;
130 bool is_in_permanent(const void *p) const { // reserved part
131 return perm_gen()->reserved().contains(p);
132 }
133
134 bool is_permanent(const void *p) const { // committed part
135 return perm_gen()->is_in(p);
136 }
137
138 inline bool is_in_young(oop p); // reserved part
139 inline bool is_in_old_or_perm(oop p); // reserved part
140
141 // Memory allocation. "gc_time_limit_was_exceeded" will
142 // be set to true if the adaptive size policy determine that
143 // an excessive amount of time is being spent doing collections
144 // and caused a NULL to be returned. If a NULL is not returned,
145 // "gc_time_limit_was_exceeded" has an undefined meaning.
146
147 HeapWord* mem_allocate(size_t size,
148 bool is_noref,
149 bool is_tlab,
150 bool* gc_overhead_limit_was_exceeded);
151 HeapWord* failed_mem_allocate(size_t size, bool is_tlab);
152
153 HeapWord* permanent_mem_allocate(size_t size);
154 HeapWord* failed_permanent_mem_allocate(size_t size);
155
156 // Support for System.gc()
157 void collect(GCCause::Cause cause);
158
159 // This interface assumes that it's being called by the
160 // vm thread. It collects the heap assuming that the
161 // heap lock is already held and that we are executing in
162 // the context of the vm thread.
163 void collect_as_vm_thread(GCCause::Cause cause);
164
165 // These also should be called by the vm thread at a safepoint (e.g., from a
166 // VM operation).
167 //
168 // The first collects the young generation only, unless the scavenge fails; it
169 // will then attempt a full gc. The second collects the entire heap; if
170 // maximum_compaction is true, it will compact everything and clear all soft
171 // references.
172 inline void invoke_scavenge();
173 inline void invoke_full_gc(bool maximum_compaction);
174
175 size_t large_typearray_limit() { return FastAllocateSizeLimit; }
176
177 bool supports_inline_contig_alloc() const { return !UseNUMA; }
178
179 HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
180 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
181
182 void ensure_parsability(bool retire_tlabs);
183 void accumulate_statistics_all_tlabs();
184 void resize_all_tlabs();
185
186 size_t unsafe_max_alloc();
187
188 bool supports_tlab_allocation() const { return true; }
189
190 size_t tlab_capacity(Thread* thr) const;
191 size_t unsafe_max_tlab_alloc(Thread* thr) const;
192
193 // Can a compiler initialize a new object without store barriers?
194 // This permission only extends from the creation of a new object
195 // via a TLAB up to the first subsequent safepoint.
196 virtual bool can_elide_tlab_store_barriers() const {
197 return true;
198 }
199
200 virtual bool card_mark_must_follow_store() const {
201 return false;
202 }
203
204 // Return true if we don't we need a store barrier for
205 // initializing stores to an object at this address.
206 virtual bool can_elide_initializing_store_barrier(oop new_obj);
207
208 // Can a compiler elide a store barrier when it writes
209 // a permanent oop into the heap? Applies when the compiler
210 // is storing x to the heap, where x->is_perm() is true.
211 virtual bool can_elide_permanent_oop_store_barriers() const {
212 return true;
213 }
214
215 void oop_iterate(OopClosure* cl);
216 void object_iterate(ObjectClosure* cl);
217 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
218 void permanent_oop_iterate(OopClosure* cl);
219 void permanent_object_iterate(ObjectClosure* cl);
220
221 HeapWord* block_start(const void* addr) const;
222 size_t block_size(const HeapWord* addr) const;
223 bool block_is_obj(const HeapWord* addr) const;
224
225 jlong millis_since_last_gc();
226
227 void prepare_for_verify();
228 void print() const;
229 void print_on(outputStream* st) const;
230 virtual void print_gc_threads_on(outputStream* st) const;
231 virtual void gc_threads_do(ThreadClosure* tc) const;
232 virtual void print_tracing_info() const;
233
234 void verify(bool allow_dirty, bool silent, bool /* option */);
235
236 void print_heap_change(size_t prev_used);
237
238 // Resize the young generation. The reserved space for the
239 // generation may be expanded in preparation for the resize.
240 void resize_young_gen(size_t eden_size, size_t survivor_size);
241
242 // Resize the old generation. The reserved space for the
243 // generation may be expanded in preparation for the resize.
244 void resize_old_gen(size_t desired_free_space);
245
246 // Save the tops of the spaces in all generations
247 void record_gen_tops_before_GC() PRODUCT_RETURN;
248
249 // Mangle the unused parts of all spaces in the heap
250 void gen_mangle_unused_area() PRODUCT_RETURN;
251
252 // Call these in sequential code around the processing of strong roots.
253 class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
254 public:
255 ParStrongRootsScope();
256 ~ParStrongRootsScope();
257 };
258 };
259
260 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)
261 {
262 assert(is_power_of_2((intptr_t)val), "must be a power of 2");
263 var = round_to(val, intra_heap_alignment());
264 return var;
265 }