1 /* 2 * Copyright (c) 2019, 2022, 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_ARCHIVEUTILS_HPP 26 #define SHARE_CDS_ARCHIVEUTILS_HPP 27 28 #include "logging/log.hpp" 29 #include "memory/iterator.hpp" 30 #include "memory/virtualspace.hpp" 31 #include "utilities/bitMap.hpp" 32 #include "utilities/exceptions.hpp" 33 #include "utilities/macros.hpp" 34 35 class BootstrapInfo; 36 class ReservedSpace; 37 class VirtualSpace; 38 39 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an 40 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling 41 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is 42 // fixed, but _ptr_end can be expanded as more objects are dumped. 43 class ArchivePtrMarker : AllStatic { 44 static CHeapBitMap* _ptrmap; 45 static VirtualSpace* _vs; 46 47 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to 48 // avoid unintentional copy operations after the bitmap has been finalized and written. 49 static bool _compacted; 50 51 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive) 52 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive) 53 54 public: 55 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs); 56 static void mark_pointer(address* ptr_loc); 57 static void clear_pointer(address* ptr_loc); 58 static void compact(address relocatable_base, address relocatable_end); 59 static void compact(size_t max_non_null_offset); 60 61 template <typename T> 62 static void mark_pointer(T* ptr_loc) { 63 mark_pointer((address*)ptr_loc); 64 } 65 66 template <typename T> 67 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) { 68 *ptr_loc = ptr_value; 69 mark_pointer(ptr_loc); 70 } 71 72 static CHeapBitMap* ptrmap() { 73 return _ptrmap; 74 } 75 76 static void reset_map_and_vs() { 77 _ptrmap = nullptr; 78 _vs = nullptr; 79 } 80 }; 81 82 // SharedDataRelocator is used to shift pointers in the CDS archive. 83 // 84 // The CDS archive is basically a contiguous block of memory (divided into several regions) 85 // that contains multiple objects. The objects may contain direct pointers that point to other objects 86 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we 87 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above). 88 // 89 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000). 90 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator 91 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to 92 // the actually mapped location of the target object. 93 class SharedDataRelocator: public BitMapClosure { 94 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; } 95 96 // Patch all pointers within this region that are marked. 97 address* _patch_base; 98 address* _patch_end; 99 100 // Before patching, all pointers must point to this region. 101 address _valid_old_base; 102 address _valid_old_end; 103 104 // After patching, all pointers must point to this region. 105 address _valid_new_base; 106 address _valid_new_end; 107 108 // How much to relocate for each pointer. 109 intx _delta; 110 111 public: 112 SharedDataRelocator(address* patch_base, address* patch_end, 113 address valid_old_base, address valid_old_end, 114 address valid_new_base, address valid_new_end, intx delta) : 115 _patch_base(patch_base), _patch_end(patch_end), 116 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end), 117 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end), 118 _delta(delta) { 119 log_debug(cds, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base)); 120 log_debug(cds, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end)); 121 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base)); 122 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end)); 123 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base)); 124 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end)); 125 } 126 127 bool do_bit(size_t offset); 128 }; 129 130 class DumpRegion { 131 private: 132 const char* _name; 133 char* _base; 134 char* _top; 135 char* _end; 136 uintx _max_delta; 137 bool _is_packed; 138 ReservedSpace* _rs; 139 VirtualSpace* _vs; 140 141 void commit_to(char* newtop); 142 143 public: 144 DumpRegion(const char* name, uintx max_delta = 0) 145 : _name(name), _base(NULL), _top(NULL), _end(NULL), 146 _max_delta(max_delta), _is_packed(false) {} 147 148 char* expand_top_to(char* newtop); 149 char* allocate(size_t num_bytes); 150 151 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN; 152 153 char* base() const { return _base; } 154 char* top() const { return _top; } 155 char* end() const { return _end; } 156 size_t reserved() const { return _end - _base; } 157 size_t used() const { return _top - _base; } 158 bool is_packed() const { return _is_packed; } 159 bool is_allocatable() const { 160 return !is_packed() && _base != NULL; 161 } 162 163 void print(size_t total_bytes) const; 164 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes); 165 166 void init(ReservedSpace* rs, VirtualSpace* vs); 167 168 void pack(DumpRegion* next = NULL); 169 170 bool contains(char* p) { 171 return base() <= p && p < top(); 172 } 173 }; 174 175 // Closure for serializing initialization data out to a data area to be 176 // written to the shared file. 177 178 class WriteClosure : public SerializeClosure { 179 private: 180 DumpRegion* _dump_region; 181 182 public: 183 WriteClosure(DumpRegion* r) { 184 _dump_region = r; 185 } 186 187 void do_ptr(void** p) { 188 _dump_region->append_intptr_t((intptr_t)*p, true); 189 } 190 191 void do_u4(u4* p) { 192 _dump_region->append_intptr_t((intptr_t)(*p)); 193 } 194 195 void do_bool(bool *p) { 196 _dump_region->append_intptr_t((intptr_t)(*p)); 197 } 198 199 void do_tag(int tag) { 200 _dump_region->append_intptr_t((intptr_t)tag); 201 } 202 203 void do_oop(oop* o); 204 void do_region(u_char* start, size_t size); 205 bool reading() const { return false; } 206 }; 207 208 // Closure for serializing initialization data in from a data area 209 // (ptr_array) read from the shared file. 210 211 class ReadClosure : public SerializeClosure { 212 private: 213 intptr_t** _ptr_array; 214 215 inline intptr_t nextPtr() { 216 return *(*_ptr_array)++; 217 } 218 219 public: 220 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; } 221 222 void do_ptr(void** p); 223 void do_u4(u4* p); 224 void do_bool(bool *p); 225 void do_tag(int tag); 226 void do_oop(oop *p); 227 void do_region(u_char* start, size_t size); 228 bool reading() const { return true; } 229 }; 230 231 class ArchiveUtils { 232 public: 233 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN; 234 }; 235 236 #endif // SHARE_CDS_ARCHIVEUTILS_HPP