1 /*
  2  * Copyright (c) 2025, 2026, 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_CDS_AOTSTREAMEDHEAPWRITER_HPP
 26 #define SHARE_CDS_AOTSTREAMEDHEAPWRITER_HPP
 27 
 28 #include "cds/aotMapLogger.hpp"
 29 #include "cds/heapShared.hpp"
 30 #include "memory/allocation.hpp"
 31 #include "memory/allStatic.hpp"
 32 #include "oops/oopHandle.hpp"
 33 #include "utilities/bitMap.hpp"
 34 #include "utilities/exceptions.hpp"
 35 #include "utilities/growableArray.hpp"
 36 #include "utilities/macros.hpp"
 37 #include "utilities/resizableHashTable.hpp"
 38 
 39 class MemRegion;
 40 
 41 #if INCLUDE_CDS_JAVA_HEAP
 42 class AOTStreamedHeapWriter : AllStatic {
 43   class EmbeddedOopMapper;
 44   static GrowableArrayCHeap<u1, mtClassShared>* _buffer;
 45 
 46   // The number of bytes that have written into _buffer (may be smaller than _buffer->length()).
 47   static size_t _buffer_used;
 48 
 49   // The bottom of the copy of Heap::roots() inside this->_buffer.
 50   static size_t _roots_offset;
 51 
 52   // Offset to the forwarding information
 53   static size_t _forwarding_offset;
 54 
 55   // Offset to dfs bounds information
 56   static size_t _root_highest_object_index_table_offset;
 57 
 58   static GrowableArrayCHeap<oop, mtClassShared>* _source_objs;
 59 
 60   typedef ResizeableHashTable<size_t, OopHandle,
 61                               AnyObj::C_HEAP,
 62                               mtClassShared> BufferOffsetToSourceObjectTable;
 63 
 64   static BufferOffsetToSourceObjectTable* _buffer_offset_to_source_obj_table;
 65 
 66   typedef ResizeableHashTable<void*, int,
 67                               AnyObj::C_HEAP,
 68                               mtClassShared> SourceObjectToDFSOrderTable;
 69   static SourceObjectToDFSOrderTable* _dfs_order_table;
 70 
 71   static int* _roots_highest_dfs;
 72   static size_t* _dfs_to_archive_object_table;
 73 
 74   static int cmp_dfs_order(oop* o1, oop* o2);
 75 
 76   static void allocate_buffer();
 77   static void ensure_buffer_space(size_t min_bytes);
 78 
 79   // Both Java bytearray and GrowableArraty use int indices and lengths. Do a safe typecast with range check
 80   static int to_array_index(size_t i) {
 81     assert(i <= (size_t)max_jint, "must be");
 82     return (int)i;
 83   }
 84   static int to_array_length(size_t n) {
 85     return to_array_index(n);
 86   }
 87 
 88   template <typename T> static T offset_to_buffered_address(size_t offset) {
 89     return (T)(_buffer->adr_at(to_array_index(offset)));
 90   }
 91 
 92   static address buffer_bottom() {
 93     return offset_to_buffered_address<address>(0);
 94   }
 95 
 96   // The exclusive end of the last object that was copied into the buffer.
 97   static address buffer_top() {
 98     return buffer_bottom() + _buffer_used;
 99   }
100 
101   static bool in_buffer(address buffered_addr) {
102     return (buffer_bottom() <= buffered_addr) && (buffered_addr < buffer_top());
103   }
104 
105   static size_t buffered_address_to_offset(address buffered_addr) {
106     assert(in_buffer(buffered_addr), "sanity");
107     return buffered_addr - buffer_bottom();
108   }
109 
110   static void order_source_objs(GrowableArrayCHeap<oop, mtClassShared>* roots);
111   static void copy_roots_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots);
112   static void copy_source_objs_to_buffer(GrowableArrayCHeap<oop, mtClassShared>* roots);
113   static size_t copy_one_source_obj_to_buffer(oop src_obj);
114 
115   template <typename T>
116   static void write(T value);
117   static void copy_forwarding_to_buffer();
118   static void copy_roots_max_dfs_to_buffer(int roots_length);
119 
120   static void map_embedded_oops(ArchiveStreamedHeapInfo* info);
121   static bool is_in_requested_range(oop o);
122   static oop requested_obj_from_buffer_offset(size_t offset);
123 
124   static oop load_oop_from_buffer(oop* buffered_addr);
125   static oop load_oop_from_buffer(narrowOop* buffered_addr);
126   inline static void store_oop_in_buffer(oop* buffered_addr, int dfs_index);
127   inline static void store_oop_in_buffer(narrowOop* buffered_addr, int dfs_index);
128 
129   template <typename T> static void mark_oop_pointer(T* buffered_addr, CHeapBitMap* oopmap);
130   template <typename T> static void map_oop_field_in_buffer(oop obj, T* field_addr_in_buffer, CHeapBitMap* oopmap);
131 
132   static void update_header_for_buffered_addr(address buffered_addr, oop src_obj, Klass* src_klass);
133 
134   static void populate_archive_heap_info(ArchiveStreamedHeapInfo* info);
135 
136 public:
137   static void init() NOT_CDS_JAVA_HEAP_RETURN;
138 
139   static void delete_tables_with_raw_oops();
140   static void add_source_obj(oop src_obj);
141   static void write(GrowableArrayCHeap<oop, mtClassShared>*, ArchiveStreamedHeapInfo* heap_info);
142   static address buffered_heap_roots_addr() {
143     return offset_to_buffered_address<address>(_roots_offset);
144   }
145 
146   static size_t buffered_addr_to_buffered_offset(address buffered_addr) {
147     assert(buffered_addr != nullptr, "should not be null");
148     return size_t(buffered_addr) - size_t(buffer_bottom());
149   }
150 
151   static size_t source_obj_to_buffered_offset(oop src_obj);
152   static address source_obj_to_buffered_addr(oop src_obj);
153 
154   static oop buffered_offset_to_source_obj(size_t buffered_offset);
155   static oop buffered_addr_to_source_obj(address buffered_addr);
156 
157   static AOTMapLogger::OopDataIterator* oop_iterator(ArchiveStreamedHeapInfo* heap_info);
158 };
159 #endif // INCLUDE_CDS_JAVA_HEAP
160 #endif // SHARE_CDS_AOTSTREAMEDHEAPWRITER_HPP