Sat, 23 Nov 2013 12:25:13 +0100
8028128: Add a type safe alternative for working with counter based data
Reviewed-by: dholmes, egahlin
1 /*
2 * Copyright (c) 2001, 2013, 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
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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.
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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23 */
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP
28 #include "gc_implementation/parallelScavenge/generationSizer.hpp"
29 #include "gc_implementation/parallelScavenge/objectStartArray.hpp"
30 #include "gc_implementation/parallelScavenge/psGCAdaptivePolicyCounters.hpp"
31 #include "gc_implementation/parallelScavenge/psOldGen.hpp"
32 #include "gc_implementation/parallelScavenge/psYoungGen.hpp"
33 #include "gc_implementation/shared/gcPolicyCounters.hpp"
34 #include "gc_implementation/shared/gcWhen.hpp"
35 #include "gc_interface/collectedHeap.inline.hpp"
36 #include "memory/collectorPolicy.hpp"
37 #include "utilities/ostream.hpp"
39 class AdjoiningGenerations;
40 class GCHeapSummary;
41 class GCTaskManager;
42 class PSAdaptiveSizePolicy;
43 class PSHeapSummary;
45 class ParallelScavengeHeap : public CollectedHeap {
46 friend class VMStructs;
47 private:
48 static PSYoungGen* _young_gen;
49 static PSOldGen* _old_gen;
51 // Sizing policy for entire heap
52 static PSAdaptiveSizePolicy* _size_policy;
53 static PSGCAdaptivePolicyCounters* _gc_policy_counters;
55 static ParallelScavengeHeap* _psh;
57 GenerationSizer* _collector_policy;
59 // Collection of generations that are adjacent in the
60 // space reserved for the heap.
61 AdjoiningGenerations* _gens;
62 unsigned int _death_march_count;
64 // The task manager
65 static GCTaskManager* _gc_task_manager;
67 void trace_heap(GCWhen::Type when, GCTracer* tracer);
69 protected:
70 static inline size_t total_invocations();
71 HeapWord* allocate_new_tlab(size_t size);
73 inline bool should_alloc_in_eden(size_t size) const;
74 inline void death_march_check(HeapWord* const result, size_t size);
75 HeapWord* mem_allocate_old_gen(size_t size);
77 public:
78 ParallelScavengeHeap() : CollectedHeap(), _death_march_count(0) { }
80 // For use by VM operations
81 enum CollectionType {
82 Scavenge,
83 MarkSweep
84 };
86 ParallelScavengeHeap::Name kind() const {
87 return CollectedHeap::ParallelScavengeHeap;
88 }
90 virtual CollectorPolicy* collector_policy() const { return (CollectorPolicy*) _collector_policy; }
92 static PSYoungGen* young_gen() { return _young_gen; }
93 static PSOldGen* old_gen() { return _old_gen; }
95 virtual PSAdaptiveSizePolicy* size_policy() { return _size_policy; }
97 static PSGCAdaptivePolicyCounters* gc_policy_counters() { return _gc_policy_counters; }
99 static ParallelScavengeHeap* heap();
101 static GCTaskManager* const gc_task_manager() { return _gc_task_manager; }
103 AdjoiningGenerations* gens() { return _gens; }
105 // Returns JNI_OK on success
106 virtual jint initialize();
108 void post_initialize();
109 void update_counters();
111 // The alignment used for the various areas
112 size_t space_alignment() { return _collector_policy->space_alignment(); }
113 size_t generation_alignment() { return _collector_policy->gen_alignment(); }
115 // Return the (conservative) maximum heap alignment
116 static size_t conservative_max_heap_alignment() {
117 return CollectorPolicy::compute_heap_alignment();
118 }
120 size_t capacity() const;
121 size_t used() const;
123 // Return "true" if all generations have reached the
124 // maximal committed limit that they can reach, without a garbage
125 // collection.
126 virtual bool is_maximal_no_gc() const;
128 // Return true if the reference points to an object that
129 // can be moved in a partial collection. For currently implemented
130 // generational collectors that means during a collection of
131 // the young gen.
132 virtual bool is_scavengable(const void* addr);
134 // Does this heap support heap inspection? (+PrintClassHistogram)
135 bool supports_heap_inspection() const { return true; }
137 size_t max_capacity() const;
139 // Whether p is in the allocated part of the heap
140 bool is_in(const void* p) const;
142 bool is_in_reserved(const void* p) const;
144 #ifdef ASSERT
145 virtual bool is_in_partial_collection(const void *p);
146 #endif
148 bool is_in_young(oop p); // reserved part
149 bool is_in_old(oop p); // reserved part
151 // Memory allocation. "gc_time_limit_was_exceeded" will
152 // be set to true if the adaptive size policy determine that
153 // an excessive amount of time is being spent doing collections
154 // and caused a NULL to be returned. If a NULL is not returned,
155 // "gc_time_limit_was_exceeded" has an undefined meaning.
156 HeapWord* mem_allocate(size_t size, bool* gc_overhead_limit_was_exceeded);
158 // Allocation attempt(s) during a safepoint. It should never be called
159 // to allocate a new TLAB as this allocation might be satisfied out
160 // of the old generation.
161 HeapWord* failed_mem_allocate(size_t size);
163 // Support for System.gc()
164 void collect(GCCause::Cause cause);
166 // These also should be called by the vm thread at a safepoint (e.g., from a
167 // VM operation).
168 //
169 // The first collects the young generation only, unless the scavenge fails; it
170 // will then attempt a full gc. The second collects the entire heap; if
171 // maximum_compaction is true, it will compact everything and clear all soft
172 // references.
173 inline void invoke_scavenge();
175 // Perform a full collection
176 virtual void do_full_collection(bool clear_all_soft_refs);
178 bool supports_inline_contig_alloc() const { return !UseNUMA; }
180 HeapWord** top_addr() const { return !UseNUMA ? young_gen()->top_addr() : (HeapWord**)-1; }
181 HeapWord** end_addr() const { return !UseNUMA ? young_gen()->end_addr() : (HeapWord**)-1; }
183 void ensure_parsability(bool retire_tlabs);
184 void accumulate_statistics_all_tlabs();
185 void resize_all_tlabs();
187 size_t unsafe_max_alloc();
189 bool supports_tlab_allocation() const { return true; }
191 size_t tlab_capacity(Thread* thr) const;
192 size_t unsafe_max_tlab_alloc(Thread* thr) const;
194 // Can a compiler initialize a new object without store barriers?
195 // This permission only extends from the creation of a new object
196 // via a TLAB up to the first subsequent safepoint.
197 virtual bool can_elide_tlab_store_barriers() const {
198 return true;
199 }
201 virtual bool card_mark_must_follow_store() const {
202 return false;
203 }
205 // Return true if we don't we need a store barrier for
206 // initializing stores to an object at this address.
207 virtual bool can_elide_initializing_store_barrier(oop new_obj);
209 void oop_iterate(ExtendedOopClosure* cl);
210 void object_iterate(ObjectClosure* cl);
211 void safe_object_iterate(ObjectClosure* cl) { object_iterate(cl); }
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;
217 jlong millis_since_last_gc();
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;
227 void verify(bool silent, VerifyOption option /* ignored */);
229 void print_heap_change(size_t prev_used);
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);
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);
239 // Save the tops of the spaces in all generations
240 void record_gen_tops_before_GC() PRODUCT_RETURN;
242 // Mangle the unused parts of all spaces in the heap
243 void gen_mangle_unused_area() PRODUCT_RETURN;
245 // Call these in sequential code around the processing of strong roots.
246 class ParStrongRootsScope : public MarkingCodeBlobClosure::MarkScope {
247 public:
248 ParStrongRootsScope();
249 ~ParStrongRootsScope();
250 };
251 };
253 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PARALLELSCAVENGEHEAP_HPP