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 #ifndef SHARE_GC_Z_ZMARKSTACKENTRY_HPP 25 #define SHARE_GC_Z_ZMARKSTACKENTRY_HPP 26 27 #include "gc/z/zBitField.hpp" 28 #include "memory/allocation.hpp" 29 30 // 31 // Mark stack entry layout 32 // ----------------------- 33 // 34 // Object entry 35 // ------------ 36 // 37 // 6 38 // 3 2 1 0 39 // +---------------------------------------------------------------------+-+-+ 40 // |11111111 11111111 11111111 11111111 11111111 11111111 11111111 111111|1|1| 41 // +---------------------------------------------------------------------+-+-+ 42 // | | | 43 // | 1-1 Partial Array Flag (1-bit) * | 44 // | | 45 // | 0-0 Final Flag (1-bit) * 46 // | 47 // * 63-2 Object Address (62-bits) 48 // 49 // 50 // Partial array entry 51 // ------------------- 52 // 53 // 6 3 3 54 // 3 2 1 2 1 0 55 // +------------------------------------+---------------------------------+-+-+ 56 // |11111111 11111111 11111111 11111111 |11111111 11111111 11111111 111111|1|1| 57 // +------------------------------------+---------------------------------+-+-+ 58 // | | | | 59 // | | 1-1 Partial Array Flag (1-bit) * | 60 // | | | 61 // | | 0-0 Final Flag (1-bit) * 62 // | | 63 // | * 31-2 Partial Array Length (30-bits) 64 // | 65 // * 63-32 Partial Array Address Offset (32-bits) 66 // 67 68 class ZMarkStackEntry { 69 private: 70 typedef ZBitField<uint64_t, bool, 0, 1> field_finalizable; 71 typedef ZBitField<uint64_t, bool, 1, 1> field_partial_array; 72 typedef ZBitField<uint64_t, uintptr_t, 2, 62> field_object_address; 73 typedef ZBitField<uint64_t, size_t, 2, 30> field_partial_array_length; 74 typedef ZBitField<uint64_t, size_t, 32, 32> field_partial_array_offset; 75 76 uint64_t _entry; 77 78 public: 79 ZMarkStackEntry() { 80 // This constructor is intentionally left empty and does not initialize 81 // _entry to allow it to be optimized out when instantiating ZMarkStack, 82 // which has a long array of ZMarkStackEntry elements, but doesn't care 83 // what _entry is initialized to. 84 } 85 86 ZMarkStackEntry(uintptr_t object_address, bool finalizable) : 87 _entry(field_object_address::encode(object_address) | 88 field_partial_array::encode(false) | 89 field_finalizable::encode(finalizable)) {} 90 91 ZMarkStackEntry(size_t partial_array_offset, size_t partial_array_length, bool finalizable) : 92 _entry(field_partial_array_offset::encode(partial_array_offset) | 93 field_partial_array_length::encode(partial_array_length) | 94 field_partial_array::encode(true) | 95 field_finalizable::encode(finalizable)) {} 96 97 bool finalizable() const { 98 return field_finalizable::decode(_entry); 99 } 100 101 bool partial_array() const { 102 return field_partial_array::decode(_entry); 103 } 104 105 size_t partial_array_offset() const { 106 return field_partial_array_offset::decode(_entry); 107 } 108 109 size_t partial_array_length() const { 110 return field_partial_array_length::decode(_entry); 111 } 112 113 uintptr_t object_address() const { 114 return field_object_address::decode(_entry); 115 } 116 }; 117 118 #endif // SHARE_GC_Z_ZMARKSTACKENTRY_HPP | 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 #ifndef SHARE_GC_Z_ZMARKSTACKENTRY_HPP 25 #define SHARE_GC_Z_ZMARKSTACKENTRY_HPP 26 27 #include "gc/z/zBitField.hpp" 28 #include "memory/allocation.hpp" 29 30 // 31 // Mark stack entry layout 32 // ----------------------- 33 // 34 // Object entry 35 // ------------ 36 // 37 // 6 38 // 3 3 2 1 0 39 // +--------------------------------------------------------------------+-+-+-+ 40 // |11111111 11111111 11111111 11111111 11111111 11111111 11111111 11111|1|1|1| 41 // +--------------------------------------------------------------------+-+-+-+ 42 // | | | | 43 // | 2-2 Follow Flag (1-bit) * | | 44 // | | | 45 // | 1-1 Partial Array Flag (1-bit) * | 46 // | | 47 // | 0-0 Final Flag (1-bit) * 48 // | 49 // * 63-3 Object Address (62-bits) 50 // 51 // 52 // Partial array entry 53 // ------------------- 54 // 55 // 6 3 3 56 // 3 2 1 2 1 0 57 // +------------------------------------+---------------------------------+-+-+ 58 // |11111111 11111111 11111111 11111111 |11111111 11111111 11111111 111111|1|1| 59 // +------------------------------------+---------------------------------+-+-+ 60 // | | | | 61 // | | 1-1 Partial Array Flag (1-bit) * | 62 // | | | 63 // | | 0-0 Final Flag (1-bit) * 64 // | | 65 // | * 31-2 Partial Array Length (30-bits) 66 // | 67 // * 63-32 Partial Array Address Offset (32-bits) 68 // 69 70 class ZMarkStackEntry { 71 private: 72 typedef ZBitField<uint64_t, bool, 0, 1> field_finalizable; 73 typedef ZBitField<uint64_t, bool, 1, 1> field_partial_array; 74 typedef ZBitField<uint64_t, bool, 2, 1> field_follow; 75 typedef ZBitField<uint64_t, uintptr_t, 3, 61> field_object_address; 76 typedef ZBitField<uint64_t, size_t, 2, 30> field_partial_array_length; 77 typedef ZBitField<uint64_t, size_t, 32, 32> field_partial_array_offset; 78 79 uint64_t _entry; 80 81 public: 82 ZMarkStackEntry() { 83 // This constructor is intentionally left empty and does not initialize 84 // _entry to allow it to be optimized out when instantiating ZMarkStack, 85 // which has a long array of ZMarkStackEntry elements, but doesn't care 86 // what _entry is initialized to. 87 } 88 89 ZMarkStackEntry(uintptr_t object_address, bool follow, bool finalizable) : 90 _entry(field_object_address::encode(object_address) | 91 field_follow::encode(follow) | 92 field_partial_array::encode(false) | 93 field_finalizable::encode(finalizable)) {} 94 95 ZMarkStackEntry(size_t partial_array_offset, size_t partial_array_length, bool finalizable) : 96 _entry(field_partial_array_offset::encode(partial_array_offset) | 97 field_partial_array_length::encode(partial_array_length) | 98 field_partial_array::encode(true) | 99 field_finalizable::encode(finalizable)) {} 100 101 bool finalizable() const { 102 return field_finalizable::decode(_entry); 103 } 104 105 bool partial_array() const { 106 return field_partial_array::decode(_entry); 107 } 108 109 size_t partial_array_offset() const { 110 return field_partial_array_offset::decode(_entry); 111 } 112 113 size_t partial_array_length() const { 114 return field_partial_array_length::decode(_entry); 115 } 116 117 bool follow() const { 118 return field_follow::decode(_entry); 119 } 120 121 uintptr_t object_address() const { 122 return field_object_address::decode(_entry); 123 } 124 }; 125 126 #endif // SHARE_GC_Z_ZMARKSTACKENTRY_HPP |