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src/hotspot/share/gc/shared/ageTable.hpp

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 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_SHARED_AGETABLE_HPP
26 #define SHARE_GC_SHARED_AGETABLE_HPP
27 

28 #include "oops/markWord.hpp"
29 #include "oops/oop.hpp"
30 #include "runtime/perfDataTypes.hpp"
31 
32 /* Copyright (c) 1992, 2021, Oracle and/or its affiliates, and Stanford University.
33    See the LICENSE file for license information. */
34 
35 // Age table for adaptive feedback-mediated tenuring (scavenging)
36 //
37 // Note: all sizes are in oops
38 
39 class AgeTable {
40   friend class VMStructs;
41 
42  public:
43   // constants
44   enum { table_size = markWord::max_age + 1 };
45 
46   // instance variables
47   size_t sizes[table_size];
48 
49   // constructor.  "global" indicates that this is the global age table
50   // (as opposed to gc-thread-local)
51   AgeTable(bool global = true);
52 
53   // clear table
54   void clear();
55 





56   // add entry
57   inline void add(oop p, size_t oop_size);
58 
59   void add(uint age, size_t oop_size) {
60     assert(age > 0 && age < table_size, "invalid age of object");
61     sizes[age] += oop_size;
62   }
63 
64   // Merge another age table with the current one.  Used
65   // for parallel young generation gc.
66   void merge(const AgeTable* subTable);
67 
68   // Calculate new tenuring threshold based on age information.
69   uint compute_tenuring_threshold(size_t desired_survivor_size);
70   void print_age_table(uint tenuring_threshold);
71   void print_on(outputStream* st, uint tenuring_threshold);
72 
73  private:
74   bool _use_perf_data;
75   PerfVariable* _perf_sizes[table_size];
76 };
77 
78 #endif // SHARE_GC_SHARED_AGETABLE_HPP

 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_SHARED_AGETABLE_HPP
26 #define SHARE_GC_SHARED_AGETABLE_HPP
27 
28 #include "memory/allocation.hpp"
29 #include "oops/markWord.hpp"
30 #include "oops/oop.hpp"
31 #include "runtime/perfDataTypes.hpp"
32 
33 /* Copyright (c) 1992, 2021, Oracle and/or its affiliates, and Stanford University.
34    See the LICENSE file for license information. */
35 
36 // Age table for adaptive feedback-mediated tenuring (scavenging)
37 //
38 // Note: all sizes are in oops
39 
40 class AgeTable: public CHeapObj<mtGC> {
41   friend class VMStructs;
42 
43  public:
44   // constants
45   enum { table_size = markWord::max_age + 1 };
46 
47   // instance variables
48   size_t sizes[table_size];
49 
50   // constructor.  "global" indicates that this is the global age table
51   // (as opposed to gc-thread-local)
52   AgeTable(bool global = true);
53 
54   // clear table
55   void clear();
56 
57 #ifndef PRODUCT
58   // check whether it's clear
59   bool is_clear() const;
60 #endif // !PRODUCT
61 
62   // add entry
63   inline void add(oop p, size_t oop_size);
64 
65   void add(uint age, size_t oop_size) {
66     assert(age < table_size, "invalid age of object");
67     sizes[age] += oop_size;
68   }
69 
70   // Merge another age table with the current one.

71   void merge(const AgeTable* subTable);
72 
73   // Calculate new tenuring threshold based on age information.
74   uint compute_tenuring_threshold(size_t desired_survivor_size);
75   void print_age_table(uint tenuring_threshold);
76   void print_on(outputStream* st, uint tenuring_threshold);
77 
78  private:
79   bool _use_perf_data;
80   PerfVariable* _perf_sizes[table_size];
81 };
82 
83 #endif // SHARE_GC_SHARED_AGETABLE_HPP
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