1 /*
2 * Copyright Amazon.com Inc. 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
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALHEAP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALHEAP
27
28 #include "gc/shenandoah/shenandoahHeap.hpp"
29
30 class ShenandoahRegulatorThread;
31 class ShenandoahGenerationalControlThread;
32
33 class ShenandoahGenerationalHeap : public ShenandoahHeap {
34 public:
35 explicit ShenandoahGenerationalHeap(ShenandoahCollectorPolicy* policy);
36
37 static ShenandoahGenerationalHeap* heap();
38
39 void print_init_logger() const override;
40 size_t unsafe_max_tlab_alloc(Thread *thread) const override;
41
42 // ---------- Evacuations and Promotions
43 //
44 oop evacuate_object(oop p, Thread* thread) override;
45 oop try_evacuate_object(oop p, Thread* thread, ShenandoahHeapRegion* from_region, ShenandoahAffiliation target_gen);
46
47 size_t plab_min_size() const { return _min_plab_size; }
48 size_t plab_max_size() const { return _max_plab_size; }
49
50 void retire_plab(PLAB* plab);
51 void retire_plab(PLAB* plab, Thread* thread);
52
53 private:
54 HeapWord* allocate_from_plab(Thread* thread, size_t size, bool is_promotion);
55 HeapWord* allocate_from_plab_slow(Thread* thread, size_t size, bool is_promotion);
56 HeapWord* allocate_new_plab(size_t min_size, size_t word_size, size_t* actual_size);
57
58 const size_t _min_plab_size;
59 const size_t _max_plab_size;
60
61 static size_t calculate_min_plab();
62 static size_t calculate_max_plab();
63
64 public:
65 // ---------- Serviceability
66 //
67 void initialize_serviceability() override;
68 GrowableArray<MemoryPool*> memory_pools() override;
69
70 ShenandoahRegulatorThread* regulator_thread() const { return _regulator_thread; }
71
72 void gc_threads_do(ThreadClosure* tcl) const override;
73
74 void stop() override;
75
76 // Used for logging the result of a region transfer outside the heap lock
77 struct TransferResult {
78 bool success;
79 size_t region_count;
80 const char* region_destination;
81
82 void print_on(const char* when, outputStream* ss) const;
83 };
84
85 // Zeros out the evacuation and promotion reserves
86 void reset_generation_reserves();
87
88 // Computes the optimal size for the old generation, represented as a surplus or deficit of old regions
89 void compute_old_generation_balance(size_t old_xfer_limit, size_t old_cset_regions);
90
91 // Transfers surplus old regions to young, or takes regions from young to satisfy old region deficit
92 TransferResult balance_generations();
93
94 void coalesce_and_fill_old_regions(bool concurrent);
95
96 private:
97 void initialize_controller() override;
98
99 ShenandoahRegulatorThread* _regulator_thread;
100
101 MemoryPool* _young_gen_memory_pool;
102 MemoryPool* _old_gen_memory_pool;
103 };
104
105 #endif //SHARE_GC_SHENANDOAH_SHENANDOAHGENERATIONALHEAP