1 /*
2 * Copyright (c) 1999, 2011, 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
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP
26 #define SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP
27
28 #include "gc_implementation/shared/gcUtil.hpp"
29 #include "oops/typeArrayOop.hpp"
30 #include "runtime/perfData.hpp"
31
32 class GlobalTLABStats;
33
34 // ThreadLocalAllocBuffer: a descriptor for thread-local storage used by
35 // the threads for allocation.
36 // It is thread-private at any time, but maybe multiplexed over
37 // time across multiple threads. The park()/unpark() pair is
38 // used to make it avaiable for such multiplexing.
39 class ThreadLocalAllocBuffer: public CHeapObj {
40 friend class VMStructs;
41 private:
42 HeapWord* _start; // address of TLAB
43 HeapWord* _top; // address after last allocation
44 HeapWord* _pf_top; // allocation prefetch watermark
45 HeapWord* _end; // allocation end (excluding alignment_reserve)
46 size_t _desired_size; // desired size (including alignment_reserve)
47 size_t _refill_waste_limit; // hold onto tlab if free() is larger than this
48
49 static unsigned _target_refills; // expected number of refills between GCs
50
51 unsigned _number_of_refills;
52 unsigned _fast_refill_waste;
53 unsigned _slow_refill_waste;
54 unsigned _gc_waste;
55 unsigned _slow_allocations;
56
57 AdaptiveWeightedAverage _allocation_fraction; // fraction of eden allocated in tlabs
58
59 void accumulate_statistics();
60 void initialize_statistics();
61
62 void set_start(HeapWord* start) { _start = start; }
63 void set_end(HeapWord* end) { _end = end; }
64 void set_top(HeapWord* top) { _top = top; }
65 void set_pf_top(HeapWord* pf_top) { _pf_top = pf_top; }
66 void set_desired_size(size_t desired_size) { _desired_size = desired_size; }
67 void set_refill_waste_limit(size_t waste) { _refill_waste_limit = waste; }
68
69 size_t initial_refill_waste_limit() { return desired_size() / TLABRefillWasteFraction; }
70
71 static int target_refills() { return _target_refills; }
72 size_t initial_desired_size();
73
74 size_t remaining() const { return end() == NULL ? 0 : pointer_delta(hard_end(), top()); }
75
76 // Make parsable and release it.
77 void reset();
78
79 // Resize based on amount of allocation, etc.
80 void resize();
81
82 void invariants() const { assert(top() >= start() && top() <= end(), "invalid tlab"); }
83
84 void initialize(HeapWord* start, HeapWord* top, HeapWord* end);
85
86 void print_stats(const char* tag);
87
88 Thread* myThread();
89
90 // statistics
91
92 int number_of_refills() const { return _number_of_refills; }
93 int fast_refill_waste() const { return _fast_refill_waste; }
94 int slow_refill_waste() const { return _slow_refill_waste; }
95 int gc_waste() const { return _gc_waste; }
96 int slow_allocations() const { return _slow_allocations; }
97
98 static GlobalTLABStats* _global_stats;
99 static GlobalTLABStats* global_stats() { return _global_stats; }
100
101 public:
102 ThreadLocalAllocBuffer() : _allocation_fraction(TLABAllocationWeight) {
103 // do nothing. tlabs must be inited by initialize() calls
104 }
105
106 static const size_t min_size() { return align_object_size(MinTLABSize / HeapWordSize); }
107 static const size_t max_size();
108
109 HeapWord* start() const { return _start; }
110 HeapWord* end() const { return _end; }
111 HeapWord* hard_end() const { return _end + alignment_reserve(); }
112 HeapWord* top() const { return _top; }
113 HeapWord* pf_top() const { return _pf_top; }
114 size_t desired_size() const { return _desired_size; }
115 size_t used() const { return pointer_delta(top(), start()); }
116 size_t used_bytes() const { return pointer_delta(top(), start(), 1); }
117 size_t free() const { return pointer_delta(end(), top()); }
118 // Don't discard tlab if remaining space is larger than this.
119 size_t refill_waste_limit() const { return _refill_waste_limit; }
120
121 // Allocate size HeapWords. The memory is NOT initialized to zero.
122 inline HeapWord* allocate(size_t size);
123
124 // Reserve space at the end of TLAB
125 static size_t end_reserve() {
126 int reserve_size = typeArrayOopDesc::header_size(T_INT);
127 return MAX2(reserve_size, VM_Version::reserve_for_allocation_prefetch());
128 }
129 static size_t alignment_reserve() { return align_object_size(end_reserve()); }
130 static size_t alignment_reserve_in_bytes() { return alignment_reserve() * HeapWordSize; }
131
132 // Return tlab size or remaining space in eden such that the
133 // space is large enough to hold obj_size and necessary fill space.
134 // Otherwise return 0;
135 inline size_t compute_size(size_t obj_size);
136
137 // Record slow allocation
138 inline void record_slow_allocation(size_t obj_size);
139
140 // Initialization at startup
141 static void startup_initialization();
142
143 // Make an in-use tlab parsable, optionally also retiring it.
144 void make_parsable(bool retire);
145
146 // Retire in-use tlab before allocation of a new tlab
147 void clear_before_allocation();
148
149 // Accumulate statistics across all tlabs before gc
150 static void accumulate_statistics_before_gc();
151
152 // Resize tlabs for all threads
153 static void resize_all_tlabs();
154
155 void fill(HeapWord* start, HeapWord* top, size_t new_size);
156 void initialize();
157
158 static size_t refill_waste_limit_increment() { return TLABWasteIncrement; }
159
160 // Code generation support
161 static ByteSize start_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _start); }
162 static ByteSize end_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _end ); }
163 static ByteSize top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _top ); }
164 static ByteSize pf_top_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _pf_top ); }
165 static ByteSize size_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _desired_size ); }
166 static ByteSize refill_waste_limit_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _refill_waste_limit ); }
167
168 static ByteSize number_of_refills_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _number_of_refills ); }
169 static ByteSize fast_refill_waste_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _fast_refill_waste ); }
170 static ByteSize slow_allocations_offset() { return byte_offset_of(ThreadLocalAllocBuffer, _slow_allocations ); }
171
172 void verify();
173 };
174
175 class GlobalTLABStats: public CHeapObj {
176 private:
177
178 // Accumulate perfdata in private variables because
179 // PerfData should be write-only for security reasons
180 // (see perfData.hpp)
181 unsigned _allocating_threads;
182 unsigned _total_refills;
183 unsigned _max_refills;
184 size_t _total_allocation;
185 size_t _total_gc_waste;
186 size_t _max_gc_waste;
187 size_t _total_slow_refill_waste;
188 size_t _max_slow_refill_waste;
189 size_t _total_fast_refill_waste;
190 size_t _max_fast_refill_waste;
191 unsigned _total_slow_allocations;
192 unsigned _max_slow_allocations;
193
194 PerfVariable* _perf_allocating_threads;
195 PerfVariable* _perf_total_refills;
196 PerfVariable* _perf_max_refills;
197 PerfVariable* _perf_allocation;
198 PerfVariable* _perf_gc_waste;
199 PerfVariable* _perf_max_gc_waste;
200 PerfVariable* _perf_slow_refill_waste;
201 PerfVariable* _perf_max_slow_refill_waste;
202 PerfVariable* _perf_fast_refill_waste;
203 PerfVariable* _perf_max_fast_refill_waste;
204 PerfVariable* _perf_slow_allocations;
205 PerfVariable* _perf_max_slow_allocations;
206
207 AdaptiveWeightedAverage _allocating_threads_avg;
208
209 public:
210 GlobalTLABStats();
211
212 // Initialize all counters
213 void initialize();
214
215 // Write all perf counters to the perf_counters
216 void publish();
217
218 void print();
219
220 // Accessors
221 unsigned allocating_threads_avg() {
222 return MAX2((unsigned)(_allocating_threads_avg.average() + 0.5), 1U);
223 }
224
225 size_t allocation() {
226 return _total_allocation;
227 }
228
229 // Update methods
230
231 void update_allocating_threads() {
232 _allocating_threads++;
233 }
234 void update_number_of_refills(unsigned value) {
235 _total_refills += value;
236 _max_refills = MAX2(_max_refills, value);
237 }
238 void update_allocation(size_t value) {
239 _total_allocation += value;
240 }
241 void update_gc_waste(size_t value) {
242 _total_gc_waste += value;
243 _max_gc_waste = MAX2(_max_gc_waste, value);
244 }
245 void update_fast_refill_waste(size_t value) {
246 _total_fast_refill_waste += value;
247 _max_fast_refill_waste = MAX2(_max_fast_refill_waste, value);
248 }
249 void update_slow_refill_waste(size_t value) {
250 _total_slow_refill_waste += value;
251 _max_slow_refill_waste = MAX2(_max_slow_refill_waste, value);
252 }
253 void update_slow_allocations(unsigned value) {
254 _total_slow_allocations += value;
255 _max_slow_allocations = MAX2(_max_slow_allocations, value);
256 }
257 };
258
259 #endif // SHARE_VM_MEMORY_THREADLOCALALLOCBUFFER_HPP