filemap.hpp revision 13370:731370f39fcd
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 "classfile/classLoader.hpp" 29#include "memory/metaspaceShared.hpp" 30#include "memory/metaspace.hpp" 31#include "memory/universe.hpp" 32#include "utilities/align.hpp" 33 34// Layout of the file: 35// header: dump of archive instance plus versioning info, datestamp, etc. 36// [magic # = 0xF00BABA2] 37// ... padding to align on page-boundary 38// read-write space 39// read-only space 40// misc data (block offset table, string table, symbols, dictionary, etc.) 41// tag(666) 42 43static const int JVM_IDENT_MAX = 256; 44 45class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC { 46protected: 47 bool _is_dir; 48 time_t _timestamp; // jar/jimage timestamp, 0 if is directory or other 49 long _filesize; // jar/jimage file size, -1 if is directory, -2 if other 50 Array<char>* _name; 51 Array<u1>* _manifest; 52 53public: 54 void init(const char* name, TRAPS); 55 void metaspace_pointers_do(MetaspaceClosure* it); 56 bool validate(); 57 58 // The _timestamp only gets set for jar files and "modules" jimage. 59 bool is_jar_or_bootimage() { 60 return _timestamp != 0; 61 } 62 bool is_dir() { return _is_dir; } 63 bool is_jrt() { return ClassLoader::is_jrt(name()); } 64 time_t timestamp() const { return _timestamp; } 65 long filesize() const { return _filesize; } 66 const char* name() const { return _name->data(); } 67 const char* manifest() const { 68 return (_manifest == NULL) ? NULL : (const char*)_manifest->data(); 69 } 70 int manifest_size() const { 71 return (_manifest == NULL) ? 0 : _manifest->length(); 72 } 73}; 74 75class FileMapInfo : public CHeapObj<mtInternal> { 76private: 77 friend class ManifestStream; 78 enum { 79 _invalid_version = -1, 80 _current_version = 3 81 }; 82 83 bool _file_open; 84 int _fd; 85 size_t _file_offset; 86 87private: 88 static Array<u8>* _classpath_entry_table; 89 static int _classpath_entry_table_size; 90 static size_t _classpath_entry_size; 91 static bool _validating_classpath_entry_table; 92 93 // FileMapHeader describes the shared space data in the file to be 94 // mapped. This structure gets written to a file. It is not a class, so 95 // that the compilers don't add any compiler-private data to it. 96 97public: 98 struct FileMapHeaderBase : public CHeapObj<mtClass> { 99 virtual bool validate() = 0; 100 virtual void populate(FileMapInfo* info, size_t alignment) = 0; 101 }; 102 struct FileMapHeader : FileMapHeaderBase { 103 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to 104 // avoid read/writing the C++ vtable pointer. 105 static size_t data_size(); 106 char* data() { 107 return ((char*)this) + sizeof(FileMapHeaderBase); 108 } 109 110 int _magic; // identify file type. 111 int _crc; // header crc checksum. 112 int _version; // (from enum, above.) 113 size_t _alignment; // how shared archive should be aligned 114 int _obj_alignment; // value of ObjectAlignmentInBytes 115 int _narrow_oop_shift; // compressed oop encoding shift 116 bool _compact_strings; // value of CompactStrings 117 uintx _max_heap_size; // java max heap size during dumping 118 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode 119 int _narrow_klass_shift; // save narrow klass base and shift 120 address _narrow_klass_base; 121 char* _misc_data_patching_start; 122 char* _read_only_tables_start; 123 address _cds_i2i_entry_code_buffers; 124 size_t _cds_i2i_entry_code_buffers_size; 125 size_t _core_spaces_size; // number of bytes allocated by the core spaces 126 // (mc, md, ro, rw and od). 127 128 struct space_info { 129 int _crc; // crc checksum of the current space 130 size_t _file_offset; // sizeof(this) rounded to vm page size 131 union { 132 char* _base; // copy-on-write base address 133 intx _offset; // offset from the compressed oop encoding base, only used 134 // by string space 135 } _addr; 136 size_t _used; // for setting space top on read 137 bool _read_only; // read only space? 138 bool _allow_exec; // executable code in space? 139 } _space[MetaspaceShared::n_regions]; 140 141 // The following fields are all sanity checks for whether this archive 142 // will function correctly with this JVM and the bootclasspath it's 143 // invoked with. 144 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 145 146 // The _paths_misc_info is a variable-size structure that records "miscellaneous" 147 // information during dumping. It is generated and validated by the 148 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for 149 // detailed description. 150 // 151 // The _paths_misc_info data is stored as a byte array in the archive file header, 152 // immediately after the _header field. This information is used only when 153 // checking the validity of the archive and is deallocated after the archive is loaded. 154 // 155 // Note that the _paths_misc_info does NOT include information for JAR files 156 // that existed during dump time. Their information is stored in _classpath_entry_table. 157 int _paths_misc_info_size; 158 159 // The following is a table of all the class path entries that were used 160 // during dumping. At run time, we require these files to exist and have the same 161 // size/modification time, or else the archive will refuse to load. 162 // 163 // All of these entries must be JAR files. The dumping process would fail if a non-empty 164 // directory was specified in the classpaths. If an empty directory was specified 165 // it is checked by the _paths_misc_info as described above. 166 // 167 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping, 168 // they should be removed from this table, to save space and to avoid spurious 169 // loading failures during runtime. 170 int _classpath_entry_table_size; 171 size_t _classpath_entry_size; 172 Array<u8>* _classpath_entry_table; 173 174 char* region_addr(int idx); 175 176 virtual bool validate(); 177 virtual void populate(FileMapInfo* info, size_t alignment); 178 int compute_crc(); 179 }; 180 181 FileMapHeader * _header; 182 183 const char* _full_path; 184 char* _paths_misc_info; 185 186 static FileMapInfo* _current_info; 187 188 bool init_from_file(int fd); 189 void align_file_position(); 190 bool validate_header_impl(); 191 static void metaspace_pointers_do(MetaspaceClosure* it); 192 193public: 194 FileMapInfo(); 195 ~FileMapInfo(); 196 197 static int current_version() { return _current_version; } 198 int compute_header_crc() { return _header->compute_crc(); } 199 void set_header_crc(int crc) { _header->_crc = crc; } 200 void populate_header(size_t alignment); 201 bool validate_header(); 202 void invalidate(); 203 int version() { return _header->_version; } 204 size_t alignment() { return _header->_alignment; } 205 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; } 206 int narrow_oop_shift() { return _header->_narrow_oop_shift; } 207 uintx max_heap_size() { return _header->_max_heap_size; } 208 address narrow_klass_base() const { return _header->_narrow_klass_base; } 209 int narrow_klass_shift() const { return _header->_narrow_klass_shift; } 210 struct FileMapHeader* header() { return _header; } 211 char* misc_data_patching_start() { return _header->_misc_data_patching_start; } 212 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; } 213 char* read_only_tables_start() { return _header->_read_only_tables_start; } 214 void set_read_only_tables_start(char* p) { _header->_read_only_tables_start = p; } 215 216 address cds_i2i_entry_code_buffers() { 217 return _header->_cds_i2i_entry_code_buffers; 218 } 219 void set_cds_i2i_entry_code_buffers(address addr) { 220 _header->_cds_i2i_entry_code_buffers = addr; 221 } 222 size_t cds_i2i_entry_code_buffers_size() { 223 return _header->_cds_i2i_entry_code_buffers_size; 224 } 225 void set_cds_i2i_entry_code_buffers_size(size_t s) { 226 _header->_cds_i2i_entry_code_buffers_size = s; 227 } 228 void set_core_spaces_size(size_t s) { _header->_core_spaces_size = s; } 229 size_t core_spaces_size() { return _header->_core_spaces_size; } 230 231 static FileMapInfo* current_info() { 232 CDS_ONLY(return _current_info;) 233 NOT_CDS(return NULL;) 234 } 235 236 static void assert_mark(bool check); 237 238 // File manipulation. 239 bool initialize() NOT_CDS_RETURN_(false); 240 bool open_for_read(); 241 void open_for_write(); 242 void write_header(); 243 void write_region(int region, char* base, size_t size, 244 bool read_only, bool allow_exec); 245 void write_string_regions(GrowableArray<MemRegion> *regions, 246 char** s0_start, char** s0_top, char** s0_end, 247 char** s1_start, char** s1_top, char** s1_end); 248 void write_bytes(const void* buffer, int count); 249 void write_bytes_aligned(const void* buffer, int count); 250 char* map_region(int i); 251 bool map_string_regions(); 252 bool verify_string_regions(); 253 void fixup_string_regions(); 254 void unmap_region(int i); 255 void dealloc_string_regions(); 256 bool verify_region_checksum(int i); 257 void close(); 258 bool is_open() { return _file_open; } 259 ReservedSpace reserve_shared_memory(); 260 261 // JVM/TI RedefineClasses() support: 262 // Remap the shared readonly space to shared readwrite, private. 263 bool remap_shared_readonly_as_readwrite(); 264 265 // Errors. 266 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 267 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 268 269 // Return true if given address is in the mapped shared space. 270 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 271 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false); 272 void print_shared_spaces() NOT_CDS_RETURN; 273 274 // Stop CDS sharing and unmap CDS regions. 275 static void stop_sharing_and_unmap(const char* msg); 276 277 static void allocate_classpath_entry_table(); 278 bool validate_classpath_entry_table(); 279 280 static SharedClassPathEntry* shared_classpath(int index) { 281 if (index < 0) { 282 return NULL; 283 } 284 assert(index < _classpath_entry_table_size, "sanity"); 285 char* p = (char*)_classpath_entry_table->data(); 286 p += _classpath_entry_size * index; 287 return (SharedClassPathEntry*)p; 288 } 289 static const char* shared_classpath_name(int index) { 290 assert(index >= 0, "Sanity"); 291 return shared_classpath(index)->name(); 292 } 293 294 static int get_number_of_share_classpaths() { 295 return _classpath_entry_table_size; 296 } 297}; 298 299#endif // SHARE_VM_MEMORY_FILEMAP_HPP 300