Fri, 14 Nov 2014 15:03:39 +0100
8064473: Improved handling of age during object copy in G1
Reviewed-by: brutisso, tschatzl
1 /*
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP
28 #include "oops/markOop.hpp"
29 #include "oops/oop.hpp"
30 #include "runtime/perfData.hpp"
32 /* Copyright (c) 1992-2009 Oracle and/or its affiliates, and Stanford University.
33 See the LICENSE file for license information. */
35 // Age table for adaptive feedback-mediated tenuring (scavenging)
36 //
37 // Note: all sizes are in oops
39 class ageTable VALUE_OBJ_CLASS_SPEC {
40 friend class VMStructs;
42 public:
43 // constants
44 enum { table_size = markOopDesc::max_age + 1 };
46 // instance variables
47 size_t sizes[table_size];
49 // constructor. "global" indicates that this is the global age table
50 // (as opposed to gc-thread-local)
51 ageTable(bool global = true);
53 // clear table
54 void clear();
56 // add entry
57 void add(oop p, size_t oop_size) {
58 add(p->age(), oop_size);
59 }
61 void add(uint age, size_t oop_size) {
62 assert(age > 0 && age < table_size, "invalid age of object");
63 sizes[age] += oop_size;
64 }
66 // Merge another age table with the current one. Used
67 // for parallel young generation gc.
68 void merge(ageTable* subTable);
69 void merge_par(ageTable* subTable);
71 // calculate new tenuring threshold based on age information
72 uint compute_tenuring_threshold(size_t survivor_capacity);
74 private:
75 PerfVariable* _perf_sizes[table_size];
76 };
78 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_AGETABLE_HPP