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_GC_IMPLEMENTATION_SHARED_PLAB_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_HPP
27
28 #include "gc_implementation/shared/gcUtil.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/atomic.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33 // Forward declarations.
34 class PLABStats;
35
36 // A per-thread allocation buffer used during GC.
37 class PLAB: public CHeapObj<mtGC> {
38 protected:
39 char head[32];
40 size_t _word_sz; // In HeapWord units
41 HeapWord* _bottom;
42 HeapWord* _top;
43 HeapWord* _end; // Last allocatable address + 1
44 HeapWord* _hard_end; // _end + AlignmentReserve
45 // In support of ergonomic sizing of PLAB's
46 size_t _allocated; // in HeapWord units
47 size_t _wasted; // in HeapWord units
48 char tail[32];
49 static size_t AlignmentReserve;
50
51 // Force future allocations to fail and queries for contains()
52 // to return false. Returns the amount of unused space in this PLAB.
53 size_t invalidate() {
54 _end = _hard_end;
55 size_t remaining = pointer_delta(_end, _top); // Calculate remaining space.
56 _top = _end; // Force future allocations to fail.
57 _bottom = _end; // Force future contains() queries to return false.
58 return remaining;
59 }
60
61 // Fill in remaining space with a dummy object and invalidate the PLAB. Returns
62 // the amount of remaining space.
63 size_t retire_internal();
64
65 public:
66 // Initializes the buffer to be empty, but with the given "word_sz".
67 // Must get initialized with "set_buf" for an allocation to succeed.
68 PLAB(size_t word_sz);
69 virtual ~PLAB() {}
70
71 // Minimum PLAB size.
72 static size_t min_size();
73 // Maximum PLAB size.
74 static size_t max_size();
75
76 // If an allocation of the given "word_sz" can be satisfied within the
77 // buffer, do the allocation, returning a pointer to the start of the
78 // allocated block. If the allocation request cannot be satisfied,
79 // return NULL.
80 HeapWord* allocate(size_t word_sz) {
81 HeapWord* res = _top;
82 if (pointer_delta(_end, _top) >= word_sz) {
83 _top = _top + word_sz;
84 return res;
85 } else {
86 return NULL;
87 }
88 }
89
149 size_t _unused; // Unused in last buffer
150 size_t _desired_plab_sz;// Output of filter (below), suitably trimmed and quantized
151 AdaptiveWeightedAverage
152 _filter; // Integrator with decay
153
154 void reset() {
155 _allocated = 0;
156 _wasted = 0;
157 _unused = 0;
158 }
159 public:
160 PLABStats(size_t desired_plab_sz_, unsigned wt) :
161 _allocated(0),
162 _wasted(0),
163 _unused(0),
164 _desired_plab_sz(desired_plab_sz_),
165 _filter(wt)
166 { }
167
168 static const size_t min_size() {
169 return PLAB::min_size();
170 }
171
172 static const size_t max_size() {
173 return PLAB::max_size();
174 }
175
176 size_t desired_plab_sz() {
177 return _desired_plab_sz;
178 }
179
180 // Updates the current desired PLAB size. Computes the new desired PLAB size,
181 // updates _desired_plab_sz and clears sensor accumulators.
182 void adjust_desired_plab_sz(uint no_of_gc_workers);
183
184 void add_allocated(size_t v) {
185 Atomic::add_ptr(v, &_allocated);
186 }
187
188 void add_unused(size_t v) {
189 Atomic::add_ptr(v, &_unused);
190 }
191
192 void add_wasted(size_t v) {
193 Atomic::add_ptr(v, &_wasted);
194 }
195 };
196
197 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_PLAB_HPP
|
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_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
27
28 #include "gc_implementation/shared/gcUtil.hpp"
29 #include "memory/allocation.hpp"
30 #include "runtime/atomic.hpp"
31 #include "utilities/globalDefinitions.hpp"
32
33 // Forward declarations.
34 class PLABStats;
35
36 // A per-thread allocation buffer used during GC.
37 class ParGCAllocBuffer: public CHeapObj<mtGC> {
38 protected:
39 char head[32];
40 size_t _word_sz; // In HeapWord units
41 HeapWord* _bottom;
42 HeapWord* _top;
43 HeapWord* _end; // Last allocatable address + 1
44 HeapWord* _hard_end; // _end + AlignmentReserve
45 // In support of ergonomic sizing of PLAB's
46 size_t _allocated; // in HeapWord units
47 size_t _wasted; // in HeapWord units
48 char tail[32];
49 static size_t AlignmentReserve;
50
51 // Force future allocations to fail and queries for contains()
52 // to return false. Returns the amount of unused space in this PLAB.
53 size_t invalidate() {
54 _end = _hard_end;
55 size_t remaining = pointer_delta(_end, _top); // Calculate remaining space.
56 _top = _end; // Force future allocations to fail.
57 _bottom = _end; // Force future contains() queries to return false.
58 return remaining;
59 }
60
61 // Fill in remaining space with a dummy object and invalidate the PLAB. Returns
62 // the amount of remaining space.
63 size_t retire_internal();
64
65 public:
66 // Initializes the buffer to be empty, but with the given "word_sz".
67 // Must get initialized with "set_buf" for an allocation to succeed.
68 ParGCAllocBuffer(size_t word_sz);
69 virtual ~ParGCAllocBuffer() {}
70
71 // Minimum PLAB size.
72 static size_t min_size();
73 // Maximum PLAB size.
74 static size_t max_size();
75
76 // If an allocation of the given "word_sz" can be satisfied within the
77 // buffer, do the allocation, returning a pointer to the start of the
78 // allocated block. If the allocation request cannot be satisfied,
79 // return NULL.
80 HeapWord* allocate(size_t word_sz) {
81 HeapWord* res = _top;
82 if (pointer_delta(_end, _top) >= word_sz) {
83 _top = _top + word_sz;
84 return res;
85 } else {
86 return NULL;
87 }
88 }
89
149 size_t _unused; // Unused in last buffer
150 size_t _desired_plab_sz;// Output of filter (below), suitably trimmed and quantized
151 AdaptiveWeightedAverage
152 _filter; // Integrator with decay
153
154 void reset() {
155 _allocated = 0;
156 _wasted = 0;
157 _unused = 0;
158 }
159 public:
160 PLABStats(size_t desired_plab_sz_, unsigned wt) :
161 _allocated(0),
162 _wasted(0),
163 _unused(0),
164 _desired_plab_sz(desired_plab_sz_),
165 _filter(wt)
166 { }
167
168 static const size_t min_size() {
169 return ParGCAllocBuffer::min_size();
170 }
171
172 static const size_t max_size() {
173 return ParGCAllocBuffer::max_size();
174 }
175
176 size_t desired_plab_sz() {
177 return _desired_plab_sz;
178 }
179
180 // Updates the current desired PLAB size. Computes the new desired PLAB size,
181 // updates _desired_plab_sz and clears sensor accumulators.
182 void adjust_desired_plab_sz(uint no_of_gc_workers);
183
184 void add_allocated(size_t v) {
185 Atomic::add_ptr(v, &_allocated);
186 }
187
188 void add_unused(size_t v) {
189 Atomic::add_ptr(v, &_unused);
190 }
191
192 void add_wasted(size_t v) {
193 Atomic::add_ptr(v, &_wasted);
194 }
195 };
196
197 #endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PARGCALLOCBUFFER_HPP
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