1 /*
2 * Copyright 2001-2009 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
29 class ParallelScavengeHeap : public CollectedHeap {
30 friend class VMStructs;
31 private:
32 static PSYoungGen* _young_gen;
33 static PSOldGen* _old_gen;
34 static PSPermGen* _perm_gen;
35
36 // Sizing policy for entire heap
37 static PSAdaptiveSizePolicy* _size_policy;
38 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
39
40 static ParallelScavengeHeap* _psh;
41
42 size_t _perm_gen_alignment;
43 size_t _young_gen_alignment;
44 size_t _old_gen_alignment;
45
46 inline size_t set_alignment(size_t& var, size_t val);
47
48 // Collection of generations that are adjacent in the
49 // space reserved for the heap.
50 AdjoiningGenerations* _gens;
51
52 static GCTaskManager* _gc_task_manager; // The task manager.
53
54 protected:
55 static inline size_t total_invocations();
56 HeapWord* allocate_new_tlab(size_t size);
57
58 public:
59 ParallelScavengeHeap() : CollectedHeap() {
60 set_alignment(_perm_gen_alignment, intra_heap_alignment());
61 set_alignment(_young_gen_alignment, intra_heap_alignment());
62 set_alignment(_old_gen_alignment, intra_heap_alignment());
63 }
64
65 // For use by VM operations
66 enum CollectionType {
67 Scavenge,
68 MarkSweep
69 };
70
71 ParallelScavengeHeap::Name kind() const {
72 return CollectedHeap::ParallelScavengeHeap;
73 }
74
75 static PSYoungGen* young_gen() { return _young_gen; }
76 static PSOldGen* old_gen() { return _old_gen; }
77 static PSPermGen* perm_gen() { return _perm_gen; }
78
79 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
80
81 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
82
83 static ParallelScavengeHeap* heap();
84
85 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
86
87 AdjoiningGenerations* gens() { return _gens; }
88
89 // Returns JNI_OK on success
90 virtual jint initialize();
91
92 void post_initialize();
93 void update_counters();
94 // The alignment used for the various generations.
95 size_t perm_gen_alignment() const { return _perm_gen_alignment; }
96 size_t young_gen_alignment() const { return _young_gen_alignment; }
97 size_t old_gen_alignment() const { return _old_gen_alignment; }
98
99 // The alignment used for eden and survivors within the young gen
100 // and for boundary between young gen and old gen.
101 size_t intra_heap_alignment() const { return 64 * K; }
102
103 size_t capacity() const;
104 size_t used() const;
105
106 // Return "true" if all generations (but perm) have reached the
107 // maximal committed limit that they can reach, without a garbage
108 // collection.
109 virtual bool is_maximal_no_gc() const;
110
111 // Does this heap support heap inspection? (+PrintClassHistogram)
112 bool supports_heap_inspection() const { return true; }
113
114 size_t permanent_capacity() const;
115 size_t permanent_used() const;
116
117 size_t max_capacity() const;
118
119 // Whether p is in the allocated part of the heap
120 bool is_in(const void* p) const;
121
122 bool is_in_reserved(const void* p) const;
123 bool is_in_permanent(const void *p) const { // reserved part
124 return perm_gen()->reserved().contains(p);
125 }
126
127 bool is_permanent(const void *p) const { // committed part
128 return perm_gen()->is_in(p);
129 }
130
131 inline bool is_in_young(oop p); // reserved part
132 inline bool is_in_old_or_perm(oop p); // reserved part
133
134 // Memory allocation. "gc_time_limit_was_exceeded" will
135 // be set to true if the adaptive size policy determine that
136 // an excessive amount of time is being spent doing collections
137 // and caused a NULL to be returned. If a NULL is not returned,
138 // "gc_time_limit_was_exceeded" has an undefined meaning.
139
140 HeapWord* mem_allocate(size_t size,
141 bool is_noref,
142 bool is_tlab,
143 bool* gc_overhead_limit_was_exceeded);
144 HeapWord* failed_mem_allocate(size_t size, bool is_tlab);
145
146 HeapWord* permanent_mem_allocate(size_t size);
147 HeapWord* failed_permanent_mem_allocate(size_t size);
148
149 // Support for System.gc()
150 void collect(GCCause::Cause cause);
151
152 // This interface assumes that it's being called by the
153 // vm thread. It collects the heap assuming that the
154 // heap lock is already held and that we are executing in
155 // the context of the vm thread.
156 void collect_as_vm_thread(GCCause::Cause cause);
157
158 // These also should be called by the vm thread at a safepoint (e.g., from a
159 // VM operation).
160 //
161 // The first collects the young generation only, unless the scavenge fails; it
162 // will then attempt a full gc. The second collects the entire heap; if
163 // maximum_compaction is true, it will compact everything and clear all soft
164 // references.
165 inline void invoke_scavenge();
166 inline void invoke_full_gc(bool maximum_compaction);
167
168 size_t large_typearray_limit() { return FastAllocateSizeLimit; }
169
170 bool supports_inline_contig_alloc() const { return !UseNUMA; }
171
172 HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
173 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
174
175 void ensure_parsability(bool retire_tlabs);
176 void accumulate_statistics_all_tlabs();
177 void resize_all_tlabs();
178
179 size_t unsafe_max_alloc();
180
181 bool supports_tlab_allocation() const { return true; }
182
183 size_t tlab_capacity(Thread* thr) const;
184 size_t unsafe_max_tlab_alloc(Thread* thr) const;
185
186 // Can a compiler initialize a new object without store barriers?
187 // This permission only extends from the creation of a new object
188 // via a TLAB up to the first subsequent safepoint.
189 virtual bool can_elide_tlab_store_barriers() const {
190 return true;
191 }
192
193 virtual bool card_mark_must_follow_store() const {
194 return false;
195 }
196
197 // Return true if we don't we need a store barrier for
198 // initializing stores to an object at this address.
199 virtual bool can_elide_initializing_store_barrier(oop new_obj);
200
201 // Can a compiler elide a store barrier when it writes
202 // a permanent oop into the heap? Applies when the compiler
203 // is storing x to the heap, where x->is_perm() is true.
204 virtual bool can_elide_permanent_oop_store_barriers() const {
205 return true;
206 }
207
208 void oop_iterate(OopClosure* cl);
209 void object_iterate(ObjectClosure* cl);
210 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
211 void permanent_oop_iterate(OopClosure* cl);
212 void permanent_object_iterate(ObjectClosure* cl);
213
214 HeapWord* block_start(const void* addr) const;
215 size_t block_size(const HeapWord* addr) const;
216 bool block_is_obj(const HeapWord* addr) const;
217
218 jlong millis_since_last_gc();
219
220 void prepare_for_verify();
221 void print() const;
222 void print_on(outputStream* st) const;
223 virtual void print_gc_threads_on(outputStream* st) const;
224 virtual void gc_threads_do(ThreadClosure* tc) const;
225 virtual void print_tracing_info() const;
226
227 void verify(bool allow_dirty, bool silent, bool /* option */);
228
229 void print_heap_change(size_t prev_used);
230
231 // Resize the young generation. The reserved space for the
232 // generation may be expanded in preparation for the resize.
233 void resize_young_gen(size_t eden_size, size_t survivor_size);
234
235 // Resize the old generation. The reserved space for the
236 // generation may be expanded in preparation for the resize.
237 void resize_old_gen(size_t desired_free_space);
238
239 // Save the tops of the spaces in all generations
240 void record_gen_tops_before_GC() PRODUCT_RETURN;
241
242 // Mangle the unused parts of all spaces in the heap
243 void gen_mangle_unused_area() PRODUCT_RETURN;
244
245 // Try to shrink the heap based on the free ratio
246 bool try_to_shrink_by_free_ratio(bool isFullGC);
247
248 // Call these in sequential code around the processing of strong roots.
249 class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
250 public:
251 ParStrongRootsScope();
252 ~ParStrongRootsScope();
253 };
254 };
255
256 inline size_t ParallelScavengeHeap::set_alignment(size_t& var, size_t val)
257 {
258 assert(is_power_of_2((intptr_t)val), "must be a power of 2");
259 var = round_to(val, intra_heap_alignment());
260 return var;
261 }