1 /*
2 * Copyright (c) 2001, 2017, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
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23 */
24
25 #ifndef SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
26 #define SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP
27
28 #include "gc/parallel/generationSizer.hpp"
29 #include "gc/parallel/objectStartArray.hpp"
30 #include "gc/parallel/psGCAdaptivePolicyCounters.hpp"
31 #include "gc/parallel/psOldGen.hpp"
32 #include "gc/parallel/psYoungGen.hpp"
33 #include "gc/shared/collectedHeap.hpp"
34 #include "gc/shared/collectorPolicy.hpp"
35 #include "gc/shared/gcPolicyCounters.hpp"
36 #include "gc/shared/gcWhen.hpp"
37 #include "gc/shared/strongRootsScope.hpp"
38 #include "memory/metaspace.hpp"
39 #include "utilities/growableArray.hpp"
40 #include "utilities/ostream.hpp"
41
42 class AdjoiningGenerations;
43 class GCHeapSummary;
44 class GCTaskManager;
45 class MemoryManager;
46 class MemoryPool;
47 class PSAdaptiveSizePolicy;
48 class PSHeapSummary;
49
50 class ParallelScavengeHeap : public CollectedHeap {
51 friend class VMStructs;
52 private:
53 static PSYoungGen* _young_gen;
54 static PSOldGen* _old_gen;
55
56 // Sizing policy for entire heap
57 static PSAdaptiveSizePolicy* _size_policy;
58 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
59
60 GenerationSizer* _collector_policy;
61
62 // Collection of generations that are adjacent in the
63 // space reserved for the heap.
64 AdjoiningGenerations* _gens;
65 unsigned int _death_march_count;
66
67 // The task manager
68 static GCTaskManager* _gc_task_manager;
69
70 GCMemoryManager* _young_manager;
71 GCMemoryManager* _old_manager;
72
73 MemoryPool* _eden_pool;
74 MemoryPool* _survivor_pool;
75 MemoryPool* _old_pool;
76
77 void trace_heap(GCWhen::Type when, const GCTracer* tracer);
78
79 protected:
80 static inline size_t total_invocations();
81 HeapWord* allocate_new_tlab(size_t size);
82
83 inline bool should_alloc_in_eden(size_t size) const;
84 inline void death_march_check(HeapWord* const result, size_t size);
85 HeapWord* mem_allocate_old_gen(size_t size);
86
87 public:
88 ParallelScavengeHeap(GenerationSizer* policy) :
89 CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
90
91 // For use by VM operations
92 enum CollectionType {
93 Scavenge,
94 MarkSweep
95 };
96
97 virtual Name kind() const {
98 return CollectedHeap::ParallelScavengeHeap;
99 }
100
101 virtual const char* name() const {
102 return "Parallel";
103 }
104
105 virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
106
107 virtual GrowableArray<GCMemoryManager*> memory_managers();
108 virtual GrowableArray<MemoryPool*> memory_pools();
109
110 static PSYoungGen* young_gen() { return _young_gen; }
111 static PSOldGen* old_gen() { return _old_gen; }
112
113 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
114
115 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
116
117 static ParallelScavengeHeap* heap();
118
119 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
120
121 AdjoiningGenerations* gens() { return _gens; }
122
123 // Returns JNI_OK on success
124 virtual jint initialize();
125
126 void post_initialize();
127 void update_counters();
128
129 // The alignment used for the various areas
130 size_t space_alignment() { return _collector_policy->space_alignment(); }
131 size_t generation_alignment() { return _collector_policy->gen_alignment(); }
132
133 // Return the (conservative) maximum heap alignment
134 static size_t conservative_max_heap_alignment() {
135 return CollectorPolicy::compute_heap_alignment();
136 }
137
138 size_t capacity() const;
139 size_t used() const;
140
141 // Return "true" if all generations have reached the
142 // maximal committed limit that they can reach, without a garbage
143 // collection.
144 virtual bool is_maximal_no_gc() const;
145
146 // Return true if the reference points to an object that
147 // can be moved in a partial collection. For currently implemented
148 // generational collectors that means during a collection of
149 // the young gen.
150 virtual bool is_scavengable(oop obj);
151 virtual void register_nmethod(nmethod* nm);
152 virtual void verify_nmethod(nmethod* nmethod);
153
154 size_t max_capacity() const;
155
156 // Whether p is in the allocated part of the heap
157 bool is_in(const void* p) const;
158
159 bool is_in_reserved(const void* p) const;
160
161 bool is_in_young(oop p); // reserved part
162 bool is_in_old(oop p); // reserved part
163
164 // Memory allocation. "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 HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
170
171 // Allocation attempt(s) during a safepoint. It should never be called
172 // to allocate a new TLAB as this allocation might be satisfied out
173 // of the old generation.
174 HeapWord* failed_mem_allocate(size_t size);
175
176 // Support for System.gc()
177 void collect(GCCause::Cause cause);
178
179 // These also should be called by the vm thread at a safepoint (e.g., from a
180 // VM operation).
181 //
182 // The first collects the young generation only, unless the scavenge fails; it
183 // will then attempt a full gc. The second collects the entire heap; if
184 // maximum_compaction is true, it will compact everything and clear all soft
185 // references.
186 inline void invoke_scavenge();
187
188 // Perform a full collection
189 virtual void do_full_collection(bool clear_all_soft_refs);
190
191 bool supports_inline_contig_alloc() const { return !UseNUMA; }
192
193 HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }
194 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
195
196 void ensure_parsability(bool retire_tlabs);
197 void accumulate_statistics_all_tlabs();
198 void resize_all_tlabs();
199
200 bool supports_tlab_allocation() const { return true; }
201
202 size_t tlab_capacity(Thread* thr) const;
203 size_t tlab_used(Thread* thr) const;
204 size_t unsafe_max_tlab_alloc(Thread* thr) const;
205
206 // Can a compiler initialize a new object without store barriers?
207 // This permission only extends from the creation of a new object
208 // via a TLAB up to the first subsequent safepoint.
209 virtual bool can_elide_tlab_store_barriers() const {
210 return true;
211 }
212
213 virtual bool card_mark_must_follow_store() const {
214 return false;
215 }
216
217 // Return true if we don't we need a store barrier for
218 // initializing stores to an object at this address.
219 virtual bool can_elide_initializing_store_barrier(oop new_obj);
220
221 void object_iterate(ObjectClosure* cl);
222 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
223
224 HeapWord* block_start(const void* addr) const;
225 size_t block_size(const HeapWord* addr) const;
226 bool block_is_obj(const HeapWord* addr) const;
227
228 jlong millis_since_last_gc();
229
230 void prepare_for_verify();
231 PSHeapSummary create_ps_heap_summary();
232 virtual void print_on(outputStream* st) const;
233 virtual void print_on_error(outputStream* st) const;
234 virtual void print_gc_threads_on(outputStream* st) const;
235 virtual void gc_threads_do(ThreadClosure* tc) const;
236 virtual void print_tracing_info() const;
237
238 void verify(VerifyOption option /* ignored */);
239
240 // Resize the young generation. The reserved space for the
241 // generation may be expanded in preparation for the resize.
242 void resize_young_gen(size_t eden_size, size_t survivor_size);
243
244 // Resize the old generation. The reserved space for the
245 // generation may be expanded in preparation for the resize.
246 void resize_old_gen(size_t desired_free_space);
247
248 // Save the tops of the spaces in all generations
249 void record_gen_tops_before_GC() PRODUCT_RETURN;
250
251 // Mangle the unused parts of all spaces in the heap
252 void gen_mangle_unused_area() PRODUCT_RETURN;
253
254 // Call these in sequential code around the processing of strong roots.
255 class ParStrongRootsScope : public MarkScope {
256 public:
257 ParStrongRootsScope();
258 ~ParStrongRootsScope();
259 };
260
261 GCMemoryManager* old_gc_manager() const { return _old_manager; }
262 GCMemoryManager* young_gc_manager() const { return _young_manager; }
263 };
264
265 // Simple class for storing info about the heap at the start of GC, to be used
266 // after GC for comparison/printing.
267 class PreGCValues {
268 public:
269 PreGCValues(ParallelScavengeHeap* heap) :
270 _heap_used(heap->used()),
271 _young_gen_used(heap->young_gen()->used_in_bytes()),
272 _old_gen_used(heap->old_gen()->used_in_bytes()),
273 _metadata_used(MetaspaceAux::used_bytes()) { };
274
275 size_t heap_used() const { return _heap_used; }
276 size_t young_gen_used() const { return _young_gen_used; }
277 size_t old_gen_used() const { return _old_gen_used; }
278 size_t metadata_used() const { return _metadata_used; }
279
280 private:
281 size_t _heap_used;
282 size_t _young_gen_used;
283 size_t _old_gen_used;
284 size_t _metadata_used;
285 };
286
287 // Class that can be used to print information about the
288 // adaptive size policy at intervals specified by
289 // AdaptiveSizePolicyOutputInterval. Only print information
290 // if an adaptive size policy is in use.
291 class AdaptiveSizePolicyOutput : AllStatic {
292 static bool enabled() {
293 return UseParallelGC &&
294 UseAdaptiveSizePolicy &&
295 log_is_enabled(Debug, gc, ergo);
296 }
297 public:
298 static void print() {
299 if (enabled()) {
300 ParallelScavengeHeap::heap()->size_policy()->print();
301 }
302 }
303
304 static void print(AdaptiveSizePolicy* size_policy, uint count) {
305 bool do_print =
306 enabled() &&
307 (AdaptiveSizePolicyOutputInterval > 0) &&
308 (count % AdaptiveSizePolicyOutputInterval) == 0;
309
310 if (do_print) {
311 size_policy->print();
312 }
313 }
314 };
315
316 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP