filemap.hpp revision 13249:a2753984d2c1
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#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 41static const int JVM_IDENT_MAX = 256; 42 43class Metaspace; 44 45class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC { 46public: 47 const char *_name; 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 51 // The _timestamp only gets set for jar files and "modules" jimage. 52 bool is_jar_or_bootimage() { 53 return _timestamp != 0; 54 } 55 bool is_dir() { 56 return _filesize == -1; 57 } 58 59 bool is_jrt() { 60 return ClassLoader::is_jrt(_name); 61 } 62}; 63 64class FileMapInfo : public CHeapObj<mtInternal> { 65private: 66 friend class ManifestStream; 67 enum { 68 _invalid_version = -1, 69 _current_version = 2 70 }; 71 72 bool _file_open; 73 int _fd; 74 size_t _file_offset; 75 76private: 77 static SharedClassPathEntry* _classpath_entry_table; 78 static int _classpath_entry_table_size; 79 static size_t _classpath_entry_size; 80 static bool _validating_classpath_entry_table; 81 82 // FileMapHeader describes the shared space data in the file to be 83 // mapped. This structure gets written to a file. It is not a class, so 84 // that the compilers don't add any compiler-private data to it. 85 86public: 87 struct FileMapHeaderBase : public CHeapObj<mtClass> { 88 virtual bool validate() = 0; 89 virtual void populate(FileMapInfo* info, size_t alignment) = 0; 90 }; 91 struct FileMapHeader : FileMapHeaderBase { 92 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to 93 // avoid read/writing the C++ vtable pointer. 94 static size_t data_size(); 95 char* data() { 96 return ((char*)this) + sizeof(FileMapHeaderBase); 97 } 98 99 int _magic; // identify file type. 100 int _crc; // header crc checksum. 101 int _version; // (from enum, above.) 102 size_t _alignment; // how shared archive should be aligned 103 int _obj_alignment; // value of ObjectAlignmentInBytes 104 int _narrow_oop_shift; // compressed oop encoding shift 105 bool _compact_strings; // value of CompactStrings 106 uintx _max_heap_size; // java max heap size during dumping 107 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode 108 int _narrow_klass_shift; // save narrow klass base and shift 109 address _narrow_klass_base; 110 char* _misc_data_patching_start; 111 address _cds_i2i_entry_code_buffers; 112 size_t _cds_i2i_entry_code_buffers_size; 113 114 struct space_info { 115 int _crc; // crc checksum of the current space 116 size_t _file_offset; // sizeof(this) rounded to vm page size 117 union { 118 char* _base; // copy-on-write base address 119 intx _offset; // offset from the compressed oop encoding base, only used 120 // by string space 121 } _addr; 122 size_t _capacity; // for validity checking 123 size_t _used; // for setting space top on read 124 bool _read_only; // read only space? 125 bool _allow_exec; // executable code in space? 126 } _space[MetaspaceShared::n_regions]; 127 128 // The following fields are all sanity checks for whether this archive 129 // will function correctly with this JVM and the bootclasspath it's 130 // invoked with. 131 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 132 133 // The _paths_misc_info is a variable-size structure that records "miscellaneous" 134 // information during dumping. It is generated and validated by the 135 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for 136 // detailed description. 137 // 138 // The _paths_misc_info data is stored as a byte array in the archive file header, 139 // immediately after the _header field. This information is used only when 140 // checking the validity of the archive and is deallocated after the archive is loaded. 141 // 142 // Note that the _paths_misc_info does NOT include information for JAR files 143 // that existed during dump time. Their information is stored in _classpath_entry_table. 144 int _paths_misc_info_size; 145 146 // The following is a table of all the class path entries that were used 147 // during dumping. At run time, we require these files to exist and have the same 148 // size/modification time, or else the archive will refuse to load. 149 // 150 // All of these entries must be JAR files. The dumping process would fail if a non-empty 151 // directory was specified in the classpaths. If an empty directory was specified 152 // it is checked by the _paths_misc_info as described above. 153 // 154 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping, 155 // they should be removed from this table, to save space and to avoid spurious 156 // loading failures during runtime. 157 int _classpath_entry_table_size; 158 size_t _classpath_entry_size; 159 SharedClassPathEntry* _classpath_entry_table; 160 161 char* region_addr(int idx); 162 163 virtual bool validate(); 164 virtual void populate(FileMapInfo* info, size_t alignment); 165 int compute_crc(); 166 }; 167 168 FileMapHeader * _header; 169 170 const char* _full_path; 171 char* _paths_misc_info; 172 173 static FileMapInfo* _current_info; 174 175 bool init_from_file(int fd); 176 void align_file_position(); 177 bool validate_header_impl(); 178 179public: 180 FileMapInfo(); 181 ~FileMapInfo(); 182 183 static int current_version() { return _current_version; } 184 int compute_header_crc() { return _header->compute_crc(); } 185 void set_header_crc(int crc) { _header->_crc = crc; } 186 void populate_header(size_t alignment); 187 bool validate_header(); 188 void invalidate(); 189 int version() { return _header->_version; } 190 size_t alignment() { return _header->_alignment; } 191 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; } 192 int narrow_oop_shift() { return _header->_narrow_oop_shift; } 193 uintx max_heap_size() { return _header->_max_heap_size; } 194 address narrow_klass_base() const { return _header->_narrow_klass_base; } 195 int narrow_klass_shift() const { return _header->_narrow_klass_shift; } 196 size_t space_capacity(int i) { return _header->_space[i]._capacity; } 197 struct FileMapHeader* header() { return _header; } 198 char* misc_data_patching_start() { return _header->_misc_data_patching_start; } 199 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; } 200 201 address cds_i2i_entry_code_buffers() { 202 return _header->_cds_i2i_entry_code_buffers; 203 } 204 void set_cds_i2i_entry_code_buffers(address addr) { 205 _header->_cds_i2i_entry_code_buffers = addr; 206 } 207 size_t cds_i2i_entry_code_buffers_size() { 208 return _header->_cds_i2i_entry_code_buffers_size; 209 } 210 void set_cds_i2i_entry_code_buffers_size(size_t s) { 211 _header->_cds_i2i_entry_code_buffers_size = s; 212 } 213 214 static FileMapInfo* current_info() { 215 CDS_ONLY(return _current_info;) 216 NOT_CDS(return NULL;) 217 } 218 219 static void assert_mark(bool check); 220 221 // File manipulation. 222 bool initialize() NOT_CDS_RETURN_(false); 223 bool open_for_read(); 224 void open_for_write(); 225 void write_header(); 226 void write_space(int i, Metaspace* space, bool read_only); 227 void write_region(int region, char* base, size_t size, 228 size_t capacity, bool read_only, bool allow_exec); 229 void write_string_regions(GrowableArray<MemRegion> *regions); 230 void write_bytes(const void* buffer, int count); 231 void write_bytes_aligned(const void* buffer, int count); 232 char* map_region(int i); 233 bool map_string_regions(); 234 bool verify_string_regions(); 235 void fixup_string_regions(); 236 void unmap_region(int i); 237 void dealloc_string_regions(); 238 bool verify_region_checksum(int i); 239 void close(); 240 bool is_open() { return _file_open; } 241 ReservedSpace reserve_shared_memory(); 242 243 // JVM/TI RedefineClasses() support: 244 // Remap the shared readonly space to shared readwrite, private. 245 bool remap_shared_readonly_as_readwrite(); 246 247 // Errors. 248 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 249 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 250 251 // Return true if given address is in the mapped shared space. 252 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 253 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false); 254 void print_shared_spaces() NOT_CDS_RETURN; 255 256 // The ro+rw+md+mc spaces size 257 static size_t core_spaces_size() { 258 return align_up((SharedReadOnlySize + SharedReadWriteSize + 259 SharedMiscDataSize + SharedMiscCodeSize), 260 os::vm_allocation_granularity()); 261 } 262 263 // The estimated optional space size. 264 // 265 // Currently the optional space only has archived class bytes. 266 // The core_spaces_size is the size of all class metadata, which is a good 267 // estimate of the total class bytes to be archived. Only the portion 268 // containing data is written out to the archive and mapped at runtime. 269 // There is no memory waste due to unused portion in optional space. 270 static size_t optional_space_size() { 271 return core_spaces_size(); 272 } 273 274 // Total shared_spaces size includes the ro, rw, md, mc and od spaces 275 static size_t shared_spaces_size() { 276 return core_spaces_size() + optional_space_size(); 277 } 278 279 // Stop CDS sharing and unmap CDS regions. 280 static void stop_sharing_and_unmap(const char* msg); 281 282 static void allocate_classpath_entry_table(); 283 bool validate_classpath_entry_table(); 284 285 static SharedClassPathEntry* shared_classpath(int index) { 286 if (index < 0) { 287 return NULL; 288 } 289 char* p = (char*)_classpath_entry_table; 290 p += _classpath_entry_size * index; 291 return (SharedClassPathEntry*)p; 292 } 293 static const char* shared_classpath_name(int index) { 294 assert(index >= 0, "Sanity"); 295 return shared_classpath(index)->_name; 296 } 297 298 static int get_number_of_share_classpaths() { 299 return _classpath_entry_table_size; 300 } 301}; 302 303#endif // SHARE_VM_MEMORY_FILEMAP_HPP 304