1 /* 2 * Copyright (c) 2003, 2016, 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 31 // Layout of the file: 32 // header: dump of archive instance plus versioning info, datestamp, etc. 33 // [magic # = 0xF00BABA2] 34 // ... padding to align on page-boundary 35 // read-write space 36 // read-only space 37 // misc data (block offset table, string table, symbols, dictionary, etc.) 38 // tag(666) 39 40 static const int JVM_IDENT_MAX = 256; 41 42 class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC { 43 protected: 44 bool _is_dir; 45 time_t _timestamp; // jar/jimage timestamp, 0 if is directory or other 46 long _filesize; // jar/jimage file size, -1 if is directory, -2 if other 47 Array<char>* _name; 48 Array<u1>* _manifest; 49 50 public: 51 void init(const char* name, TRAPS); 52 void metaspace_pointers_do(MetaspaceClosure* it); 53 bool validate(); 54 55 // The _timestamp only gets set for jar files and "modules" jimage. 56 bool is_jar_or_bootimage() { 57 return _timestamp != 0; 58 } 59 bool is_dir() { return _is_dir; } 60 bool is_jrt() { return ClassLoader::is_jrt(name()); } 61 time_t timestamp() const { return _timestamp; } 62 long filesize() const { return _filesize; } 63 const char* name() const { return _name->data(); } 64 const char* manifest() const { 65 return (_manifest == NULL) ? NULL : (const char*)_manifest->data(); 66 } 67 int manifest_size() const { 68 return (_manifest == NULL) ? 0 : _manifest->length(); 69 } 70 }; 71 72 class FileMapInfo : public CHeapObj<mtInternal> { 73 private: 74 friend class ManifestStream; 75 enum { 76 _invalid_version = -1, 77 _current_version = 3 78 }; 79 80 bool _file_open; 81 int _fd; 82 size_t _file_offset; 83 84 private: 85 static Array<u8>* _classpath_entry_table; 86 static int _classpath_entry_table_size; 87 static size_t _classpath_entry_size; 88 static bool _validating_classpath_entry_table; 89 90 // FileMapHeader describes the shared space data in the file to be 91 // mapped. This structure gets written to a file. It is not a class, so 92 // that the compilers don't add any compiler-private data to it. 93 94 public: 95 struct FileMapHeaderBase : public CHeapObj<mtClass> { 96 virtual bool validate() = 0; 97 virtual void populate(FileMapInfo* info, size_t alignment) = 0; 98 }; 99 struct FileMapHeader : FileMapHeaderBase { 100 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to 101 // avoid read/writing the C++ vtable pointer. 102 static size_t data_size(); 103 char* data() { 104 return ((char*)this) + sizeof(FileMapHeaderBase); 105 } 106 107 int _magic; // identify file type. 108 int _crc; // header crc checksum. 109 int _version; // (from enum, above.) 110 size_t _alignment; // how shared archive should be aligned 111 int _obj_alignment; // value of ObjectAlignmentInBytes 112 int _narrow_oop_shift; // compressed oop encoding shift 113 bool _compact_strings; // value of CompactStrings 114 uintx _max_heap_size; // java max heap size during dumping 115 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode 116 int _narrow_klass_shift; // save narrow klass base and shift 117 address _narrow_klass_base; 118 char* _misc_data_patching_start; 119 char* _read_only_tables_start; 120 address _cds_i2i_entry_code_buffers; 121 size_t _cds_i2i_entry_code_buffers_size; 122 size_t _core_spaces_size; // number of bytes allocated by the core spaces 123 // (mc, md, ro, rw and od). 124 125 struct space_info { 126 int _crc; // crc checksum of the current space 127 size_t _file_offset; // sizeof(this) rounded to vm page size 128 union { 129 char* _base; // copy-on-write base address 130 intx _offset; // offset from the compressed oop encoding base, only used 131 // by string space 132 } _addr; 133 size_t _used; // for setting space top on read 134 bool _read_only; // read only space? 135 bool _allow_exec; // executable code in space? 136 } _space[MetaspaceShared::n_regions]; 137 138 // The following fields are all sanity checks for whether this archive 139 // will function correctly with this JVM and the bootclasspath it's 140 // invoked with. 141 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 142 143 // The _paths_misc_info is a variable-size structure that records "miscellaneous" 144 // information during dumping. It is generated and validated by the 145 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for 146 // detailed description. 147 // 148 // The _paths_misc_info data is stored as a byte array in the archive file header, 149 // immediately after the _header field. This information is used only when 150 // checking the validity of the archive and is deallocated after the archive is loaded. 151 // 152 // Note that the _paths_misc_info does NOT include information for JAR files 153 // that existed during dump time. Their information is stored in _classpath_entry_table. 154 int _paths_misc_info_size; 155 156 // The following is a table of all the class path entries that were used 157 // during dumping. At run time, we require these files to exist and have the same 158 // size/modification time, or else the archive will refuse to load. 159 // 160 // All of these entries must be JAR files. The dumping process would fail if a non-empty 161 // directory was specified in the classpaths. If an empty directory was specified 162 // it is checked by the _paths_misc_info as described above. 163 // 164 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping, 165 // they should be removed from this table, to save space and to avoid spurious 166 // loading failures during runtime. 167 int _classpath_entry_table_size; 168 size_t _classpath_entry_size; 169 Array<u8>* _classpath_entry_table; 170 171 char* region_addr(int idx); 172 173 virtual bool validate(); 174 virtual void populate(FileMapInfo* info, size_t alignment); 175 int compute_crc(); 176 }; 177 178 FileMapHeader * _header; 179 180 const char* _full_path; 181 char* _paths_misc_info; 182 183 static FileMapInfo* _current_info; 184 185 bool init_from_file(int fd); 186 void align_file_position(); 187 bool validate_header_impl(); 188 static void metaspace_pointers_do(MetaspaceClosure* it); 189 190 public: 191 FileMapInfo(); 192 ~FileMapInfo(); 193 194 static int current_version() { return _current_version; } 195 int compute_header_crc() { return _header->compute_crc(); } 196 void set_header_crc(int crc) { _header->_crc = crc; } 197 void populate_header(size_t alignment); 198 bool validate_header(); 199 void invalidate(); 200 int version() { return _header->_version; } 201 size_t alignment() { return _header->_alignment; } 202 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; } 203 int narrow_oop_shift() { return _header->_narrow_oop_shift; } 204 uintx max_heap_size() { return _header->_max_heap_size; } 205 address narrow_klass_base() const { return _header->_narrow_klass_base; } 206 int narrow_klass_shift() const { return _header->_narrow_klass_shift; } 207 struct FileMapHeader* header() { return _header; } 208 char* misc_data_patching_start() { return _header->_misc_data_patching_start; } 209 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; } 210 char* read_only_tables_start() { return _header->_read_only_tables_start; } 211 void set_read_only_tables_start(char* p) { _header->_read_only_tables_start = p; } 212 213 address cds_i2i_entry_code_buffers() { 214 return _header->_cds_i2i_entry_code_buffers; 215 } 216 void set_cds_i2i_entry_code_buffers(address addr) { 217 _header->_cds_i2i_entry_code_buffers = addr; 218 } 219 size_t cds_i2i_entry_code_buffers_size() { 220 return _header->_cds_i2i_entry_code_buffers_size; 221 } 222 void set_cds_i2i_entry_code_buffers_size(size_t s) { 223 _header->_cds_i2i_entry_code_buffers_size = s; 224 } 225 void set_core_spaces_size(size_t s) { _header->_core_spaces_size = s; } 226 size_t core_spaces_size() { return _header->_core_spaces_size; } 227 228 static FileMapInfo* current_info() { 229 CDS_ONLY(return _current_info;) 230 NOT_CDS(return NULL;) 231 } 232 233 static void assert_mark(bool check); 234 235 // File manipulation. 236 bool initialize() NOT_CDS_RETURN_(false); 237 bool open_for_read(); 238 void open_for_write(); 239 void write_header(); 240 void write_region(int region, char* base, size_t size, 241 bool read_only, bool allow_exec); 242 void write_string_regions(GrowableArray<MemRegion> *regions); 243 void write_bytes(const void* buffer, int count); 244 void write_bytes_aligned(const void* buffer, int count); 245 char* map_region(int i); 246 bool map_string_regions(); 247 bool verify_string_regions(); 248 void fixup_string_regions(); 249 void unmap_region(int i); 250 void dealloc_string_regions(); 251 bool verify_region_checksum(int i); 252 void close(); 253 bool is_open() { return _file_open; } 254 ReservedSpace reserve_shared_memory(); 255 256 // JVM/TI RedefineClasses() support: 257 // Remap the shared readonly space to shared readwrite, private. 258 bool remap_shared_readonly_as_readwrite(); 259 260 // Errors. 261 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 262 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 263 264 // Return true if given address is in the mapped shared space. 265 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 266 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false); 267 void print_shared_spaces() NOT_CDS_RETURN; 268 269 // Stop CDS sharing and unmap CDS regions. 270 static void stop_sharing_and_unmap(const char* msg); 271 272 static void allocate_classpath_entry_table(); 273 bool validate_classpath_entry_table(); 274 275 static SharedClassPathEntry* shared_classpath(int index) { 276 if (index < 0) { 277 return NULL; 278 } 279 assert(index < _classpath_entry_table_size, "sanity"); 280 char* p = (char*)_classpath_entry_table->data(); 281 p += _classpath_entry_size * index; 282 return (SharedClassPathEntry*)p; 283 } 284 static const char* shared_classpath_name(int index) { 285 assert(index >= 0, "Sanity"); 286 return shared_classpath(index)->name(); 287 } 288 289 static int get_number_of_share_classpaths() { 290 return _classpath_entry_table_size; 291 } 292 }; 293 294 #endif // SHARE_VM_MEMORY_FILEMAP_HPP