1 /* 2 * Copyright (c) 2003, 2017, 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_VM_MEMORY_FILEMAP_HPP 26 #define SHARE_VM_MEMORY_FILEMAP_HPP 27 28 #include "memory/metaspaceShared.hpp" 29 #include "memory/metaspace.hpp" 30 #include "utilities/align.hpp" 31 32 // Layout of the file: 33 // header: dump of archive instance plus versioning info, datestamp, etc. 34 // [magic # = 0xF00BABA2] 35 // ... padding to align on page-boundary 36 // read-write space 37 // read-only space 38 // misc data (block offset table, string table, symbols, dictionary, etc.) 39 // tag(666) 40 41 static const int JVM_IDENT_MAX = 256; 42 43 class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC { 44 protected: 45 bool _is_dir; 46 time_t _timestamp; // jar/jimage timestamp, 0 if is directory or other 47 long _filesize; // jar/jimage file size, -1 if is directory, -2 if other 48 Array<char>* _name; 49 Array<u1>* _manifest; 50 51 public: 52 void init(const char* name, TRAPS); 53 void metaspace_pointers_do(MetaspaceClosure* it); 54 bool validate(); 55 56 // The _timestamp only gets set for jar files and "modules" jimage. 57 bool is_jar_or_bootimage() { 58 return _timestamp != 0; 59 } 60 bool is_dir() { return _is_dir; } 61 bool is_jrt() { return ClassLoader::is_jrt(name()); } 62 time_t timestamp() const { return _timestamp; } 63 long filesize() const { return _filesize; } 64 const char* name() const { return _name->data(); } 65 const char* manifest() const { 66 return (_manifest == NULL) ? NULL : (const char*)_manifest->data(); 67 } 68 int manifest_size() const { 69 return (_manifest == NULL) ? 0 : _manifest->length(); 70 } 71 }; 72 73 class FileMapInfo : public CHeapObj<mtInternal> { 74 private: 75 friend class ManifestStream; 76 enum { 77 _invalid_version = -1, 78 _current_version = 3 79 }; 80 81 bool _file_open; 82 int _fd; 83 size_t _file_offset; 84 85 private: 86 static Array<u8>* _classpath_entry_table; 87 static int _classpath_entry_table_size; 88 static size_t _classpath_entry_size; 89 static bool _validating_classpath_entry_table; 90 91 // FileMapHeader describes the shared space data in the file to be 92 // mapped. This structure gets written to a file. It is not a class, so 93 // that the compilers don't add any compiler-private data to it. 94 95 public: 96 struct FileMapHeaderBase : public CHeapObj<mtClass> { 97 virtual bool validate() = 0; 98 virtual void populate(FileMapInfo* info, size_t alignment) = 0; 99 }; 100 struct FileMapHeader : FileMapHeaderBase { 101 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to 102 // avoid read/writing the C++ vtable pointer. 103 static size_t data_size(); 104 char* data() { 105 return ((char*)this) + sizeof(FileMapHeaderBase); 106 } 107 108 int _magic; // identify file type. 109 int _crc; // header crc checksum. 110 int _version; // (from enum, above.) 111 size_t _alignment; // how shared archive should be aligned 112 int _obj_alignment; // value of ObjectAlignmentInBytes 113 int _narrow_oop_shift; // compressed oop encoding shift 114 bool _compact_strings; // value of CompactStrings 115 uintx _max_heap_size; // java max heap size during dumping 116 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode 117 int _narrow_klass_shift; // save narrow klass base and shift 118 address _narrow_klass_base; 119 char* _misc_data_patching_start; 120 char* _read_only_tables_start; 121 address _cds_i2i_entry_code_buffers; 122 size_t _cds_i2i_entry_code_buffers_size; 123 size_t _core_spaces_size; // number of bytes allocated by the core spaces 124 // (mc, md, ro, rw and od). 125 126 struct space_info { 127 int _crc; // crc checksum of the current space 128 size_t _file_offset; // sizeof(this) rounded to vm page size 129 union { 130 char* _base; // copy-on-write base address 131 intx _offset; // offset from the compressed oop encoding base, only used 132 // by string space 133 } _addr; 134 size_t _used; // for setting space top on read 135 bool _read_only; // read only space? 136 bool _allow_exec; // executable code in space? 137 } _space[MetaspaceShared::n_regions]; 138 139 // The following fields are all sanity checks for whether this archive 140 // will function correctly with this JVM and the bootclasspath it's 141 // invoked with. 142 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 143 144 // The _paths_misc_info is a variable-size structure that records "miscellaneous" 145 // information during dumping. It is generated and validated by the 146 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for 147 // detailed description. 148 // 149 // The _paths_misc_info data is stored as a byte array in the archive file header, 150 // immediately after the _header field. This information is used only when 151 // checking the validity of the archive and is deallocated after the archive is loaded. 152 // 153 // Note that the _paths_misc_info does NOT include information for JAR files 154 // that existed during dump time. Their information is stored in _classpath_entry_table. 155 int _paths_misc_info_size; 156 157 // The following is a table of all the class path entries that were used 158 // during dumping. At run time, we require these files to exist and have the same 159 // size/modification time, or else the archive will refuse to load. 160 // 161 // All of these entries must be JAR files. The dumping process would fail if a non-empty 162 // directory was specified in the classpaths. If an empty directory was specified 163 // it is checked by the _paths_misc_info as described above. 164 // 165 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping, 166 // they should be removed from this table, to save space and to avoid spurious 167 // loading failures during runtime. 168 int _classpath_entry_table_size; 169 size_t _classpath_entry_size; 170 Array<u8>* _classpath_entry_table; 171 172 char* region_addr(int idx); 173 174 virtual bool validate(); 175 virtual void populate(FileMapInfo* info, size_t alignment); 176 int compute_crc(); 177 }; 178 179 FileMapHeader * _header; 180 181 const char* _full_path; 182 char* _paths_misc_info; 183 184 static FileMapInfo* _current_info; 185 186 bool init_from_file(int fd); 187 void align_file_position(); 188 bool validate_header_impl(); 189 static void metaspace_pointers_do(MetaspaceClosure* it); 190 191 public: 192 FileMapInfo(); 193 ~FileMapInfo(); 194 195 static int current_version() { return _current_version; } 196 int compute_header_crc() { return _header->compute_crc(); } 197 void set_header_crc(int crc) { _header->_crc = crc; } 198 void populate_header(size_t alignment); 199 bool validate_header(); 200 void invalidate(); 201 int version() { return _header->_version; } 202 size_t alignment() { return _header->_alignment; } 203 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; } 204 int narrow_oop_shift() { return _header->_narrow_oop_shift; } 205 uintx max_heap_size() { return _header->_max_heap_size; } 206 address narrow_klass_base() const { return _header->_narrow_klass_base; } 207 int narrow_klass_shift() const { return _header->_narrow_klass_shift; } 208 struct FileMapHeader* header() { return _header; } 209 char* misc_data_patching_start() { return _header->_misc_data_patching_start; } 210 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; } 211 char* read_only_tables_start() { return _header->_read_only_tables_start; } 212 void set_read_only_tables_start(char* p) { _header->_read_only_tables_start = p; } 213 214 address cds_i2i_entry_code_buffers() { 215 return _header->_cds_i2i_entry_code_buffers; 216 } 217 void set_cds_i2i_entry_code_buffers(address addr) { 218 _header->_cds_i2i_entry_code_buffers = addr; 219 } 220 size_t cds_i2i_entry_code_buffers_size() { 221 return _header->_cds_i2i_entry_code_buffers_size; 222 } 223 void set_cds_i2i_entry_code_buffers_size(size_t s) { 224 _header->_cds_i2i_entry_code_buffers_size = s; 225 } 226 void set_core_spaces_size(size_t s) { _header->_core_spaces_size = s; } 227 size_t core_spaces_size() { return _header->_core_spaces_size; } 228 229 static FileMapInfo* current_info() { 230 CDS_ONLY(return _current_info;) 231 NOT_CDS(return NULL;) 232 } 233 234 static void assert_mark(bool check); 235 236 // File manipulation. 237 bool initialize() NOT_CDS_RETURN_(false); 238 bool open_for_read(); 239 void open_for_write(); 240 void write_header(); 241 void write_region(int region, char* base, size_t size, 242 bool read_only, bool allow_exec); 243 void write_string_regions(GrowableArray<MemRegion> *regions, 244 char** s0_start, char** s0_top, char** s0_end, 245 char** s1_start, char** s1_top, char** s1_end); 246 void write_bytes(const void* buffer, int count); 247 void write_bytes_aligned(const void* buffer, int count); 248 char* map_region(int i); 249 bool map_string_regions(); 250 bool verify_string_regions(); 251 void fixup_string_regions(); 252 void unmap_region(int i); 253 void dealloc_string_regions(); 254 bool verify_region_checksum(int i); 255 void close(); 256 bool is_open() { return _file_open; } 257 ReservedSpace reserve_shared_memory(); 258 259 // JVM/TI RedefineClasses() support: 260 // Remap the shared readonly space to shared readwrite, private. 261 bool remap_shared_readonly_as_readwrite(); 262 263 // Errors. 264 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 265 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 266 267 // Return true if given address is in the mapped shared space. 268 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 269 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false); 270 void print_shared_spaces() NOT_CDS_RETURN; 271 272 // Stop CDS sharing and unmap CDS regions. 273 static void stop_sharing_and_unmap(const char* msg); 274 275 static void allocate_classpath_entry_table(); 276 bool validate_classpath_entry_table(); 277 278 static SharedClassPathEntry* shared_classpath(int index) { 279 if (index < 0) { 280 return NULL; 281 } 282 assert(index < _classpath_entry_table_size, "sanity"); 283 char* p = (char*)_classpath_entry_table->data(); 284 p += _classpath_entry_size * index; 285 return (SharedClassPathEntry*)p; 286 } 287 static const char* shared_classpath_name(int index) { 288 assert(index >= 0, "Sanity"); 289 return shared_classpath(index)->name(); 290 } 291 292 static int get_number_of_share_classpaths() { 293 return _classpath_entry_table_size; 294 } 295 }; 296 297 #endif // SHARE_VM_MEMORY_FILEMAP_HPP