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/ostream.hpp"
40
41 class AdjoiningGenerations;
42 class GCHeapSummary;
43 class GCTaskManager;
44 class PSAdaptiveSizePolicy;
45 class PSHeapSummary;
46
47 class ParallelScavengeHeap : public CollectedHeap {
48 friend class VMStructs;
49 private:
50 static PSYoungGen* _young_gen;
51 static PSOldGen* _old_gen;
52
53 // Sizing policy for entire heap
54 static PSAdaptiveSizePolicy* _size_policy;
55 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
56
57 GenerationSizer* _collector_policy;
58
59 // Collection of generations that are adjacent in the
60 // space reserved for the heap.
61 AdjoiningGenerations* _gens;
62 unsigned int _death_march_count;
63
64 // The task manager
65 static GCTaskManager* _gc_task_manager;
66
67 virtual GCServicabilitySupport* create_servicability_support();
68
69 void trace_heap(GCWhen::Type when, const GCTracer* tracer);
70
71 protected:
72 static inline size_t total_invocations();
73 HeapWord* allocate_new_tlab(size_t size);
74
75 inline bool should_alloc_in_eden(size_t size) const;
76 inline void death_march_check(HeapWord* const result, size_t size);
77 HeapWord* mem_allocate_old_gen(size_t size);
78
79 public:
80 ParallelScavengeHeap(GenerationSizer* policy) :
81 CollectedHeap(), _collector_policy(policy), _death_march_count(0) { }
82
83 // For use by VM operations
84 enum CollectionType {
85 Scavenge,
86 MarkSweep
87 };
88
89 virtual Name kind() const {
90 return CollectedHeap::ParallelScavengeHeap;
91 }
92
93 virtual const char* name() const {
94 return "Parallel";
95 }
96
97 virtual CollectorPolicy* collector_policy() const { return _collector_policy; }
98
99 static PSYoungGen* young_gen() { return _young_gen; }
100 static PSOldGen* old_gen() { return _old_gen; }
101
102 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
103
104 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
105
106 static ParallelScavengeHeap* heap();
107
108 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
109
110 AdjoiningGenerations* gens() { return _gens; }
111
112 // Returns JNI_OK on success
113 virtual jint initialize();
114
115 void post_initialize();
116 void update_counters();
117
118 // The alignment used for the various areas
119 size_t space_alignment() { return _collector_policy->space_alignment(); }
120 size_t generation_alignment() { return _collector_policy->gen_alignment(); }
121
122 // Return the (conservative) maximum heap alignment
123 static size_t conservative_max_heap_alignment() {
124 return CollectorPolicy::compute_heap_alignment();
125 }
126
127 size_t capacity() const;
128 size_t used() const;
129
130 // Return "true" if all generations have reached the
131 // maximal committed limit that they can reach, without a garbage
132 // collection.
133 virtual bool is_maximal_no_gc() const;
134
135 // Return true if the reference points to an object that
136 // can be moved in a partial collection. For currently implemented
137 // generational collectors that means during a collection of
138 // the young gen.
139 virtual bool is_scavengable(oop obj);
140 virtual void register_nmethod(nmethod* nm);
141 virtual void verify_nmethod(nmethod* nmethod);
142
143 size_t max_capacity() const;
144
145 // Whether p is in the allocated part of the heap
146 bool is_in(const void* p) const;
147
148 bool is_in_reserved(const void* p) const;
149
150 bool is_in_young(oop p); // reserved part
151 bool is_in_old(oop p); // reserved part
152
153 // Memory allocation. "gc_time_limit_was_exceeded" will
154 // be set to true if the adaptive size policy determine that
155 // an excessive amount of time is being spent doing collections
156 // and caused a NULL to be returned. If a NULL is not returned,
157 // "gc_time_limit_was_exceeded" has an undefined meaning.
158 HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
159
160 // Allocation attempt(s) during a safepoint. It should never be called
161 // to allocate a new TLAB as this allocation might be satisfied out
162 // of the old generation.
163 HeapWord* failed_mem_allocate(size_t size);
164
165 // Support for System.gc()
166 void collect(GCCause::Cause cause);
167
168 // These also should be called by the vm thread at a safepoint (e.g., from a
169 // VM operation).
170 //
171 // The first collects the young generation only, unless the scavenge fails; it
172 // will then attempt a full gc. The second collects the entire heap; if
173 // maximum_compaction is true, it will compact everything and clear all soft
174 // references.
175 inline void invoke_scavenge();
176
177 // Perform a full collection
178 virtual void do_full_collection(bool clear_all_soft_refs);
179
180 bool supports_inline_contig_alloc() const { return !UseNUMA; }
181
182 HeapWord* volatile* top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord* volatile*)-1; }
183 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
184
185 void ensure_parsability(bool retire_tlabs);
186 void accumulate_statistics_all_tlabs();
187 void resize_all_tlabs();
188
189 bool supports_tlab_allocation() const { return true; }
190
191 size_t tlab_capacity(Thread* thr) const;
192 size_t tlab_used(Thread* thr) const;
193 size_t unsafe_max_tlab_alloc(Thread* thr) const;
194
195 // Can a compiler initialize a new object without store barriers?
196 // This permission only extends from the creation of a new object
197 // via a TLAB up to the first subsequent safepoint.
198 virtual bool can_elide_tlab_store_barriers() const {
199 return true;
200 }
201
202 virtual bool card_mark_must_follow_store() const {
203 return false;
204 }
205
206 // Return true if we don't we need a store barrier for
207 // initializing stores to an object at this address.
208 virtual bool can_elide_initializing_store_barrier(oop new_obj);
209
210 void object_iterate(ObjectClosure* cl);
211 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
212
213 HeapWord* block_start(const void* addr) const;
214 size_t block_size(const HeapWord* addr) const;
215 bool block_is_obj(const HeapWord* addr) const;
216
217 jlong millis_since_last_gc();
218
219 void prepare_for_verify();
220 PSHeapSummary create_ps_heap_summary();
221 virtual void print_on(outputStream* st) const;
222 virtual void print_on_error(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(VerifyOption option /* ignored */);
228
229 // Resize the young generation. The reserved space for the
230 // generation may be expanded in preparation for the resize.
231 void resize_young_gen(size_t eden_size, size_t survivor_size);
232
233 // Resize the old generation. The reserved space for the
234 // generation may be expanded in preparation for the resize.
235 void resize_old_gen(size_t desired_free_space);
236
237 // Save the tops of the spaces in all generations
238 void record_gen_tops_before_GC() PRODUCT_RETURN;
239
240 // Mangle the unused parts of all spaces in the heap
241 void gen_mangle_unused_area() PRODUCT_RETURN;
242
243 // Call these in sequential code around the processing of strong roots.
244 class ParStrongRootsScope : public MarkScope {
245 public:
246 ParStrongRootsScope();
247 ~ParStrongRootsScope();
248 };
249 };
250
251 // Simple class for storing info about the heap at the start of GC, to be used
252 // after GC for comparison/printing.
253 class PreGCValues {
254 public:
255 PreGCValues(ParallelScavengeHeap* heap) :
256 _heap_used(heap->used()),
257 _young_gen_used(heap->young_gen()->used_in_bytes()),
258 _old_gen_used(heap->old_gen()->used_in_bytes()),
259 _metadata_used(MetaspaceAux::used_bytes()) { };
260
261 size_t heap_used() const { return _heap_used; }
262 size_t young_gen_used() const { return _young_gen_used; }
263 size_t old_gen_used() const { return _old_gen_used; }
264 size_t metadata_used() const { return _metadata_used; }
265
266 private:
267 size_t _heap_used;
268 size_t _young_gen_used;
269 size_t _old_gen_used;
270 size_t _metadata_used;
271 };
272
273 // Class that can be used to print information about the
274 // adaptive size policy at intervals specified by
275 // AdaptiveSizePolicyOutputInterval. Only print information
276 // if an adaptive size policy is in use.
277 class AdaptiveSizePolicyOutput : AllStatic {
278 static bool enabled() {
279 return UseParallelGC &&
280 UseAdaptiveSizePolicy &&
281 log_is_enabled(Debug, gc, ergo);
282 }
283 public:
284 static void print() {
285 if (enabled()) {
286 ParallelScavengeHeap::heap()->size_policy()->print();
287 }
288 }
289
290 static void print(AdaptiveSizePolicy* size_policy, uint count) {
291 bool do_print =
292 enabled() &&
293 (AdaptiveSizePolicyOutputInterval > 0) &&
294 (count % AdaptiveSizePolicyOutputInterval) == 0;
295
296 if (do_print) {
297 size_policy->print();
298 }
299 }
300 };
301
302 #endif // SHARE_VM_GC_PARALLEL_PARALLELSCAVENGEHEAP_HPP