filemap.hpp revision 10844:c04ff0bb5b8e
1/* 2 * Copyright (c) 2003, 2015, 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 40static const int JVM_IDENT_MAX = 256; 41 42class Metaspace; 43 44class SharedClassPathEntry VALUE_OBJ_CLASS_SPEC { 45public: 46 const char *_name; 47 time_t _timestamp; // jar/jimage timestamp, 0 if is directory or other 48 long _filesize; // jar/jimage file size, -1 if is directory, -2 if other 49 50 // The _timestamp only gets set for jar files and "modules" jimage. 51 bool is_jar_or_bootimage() { 52 return _timestamp != 0; 53 } 54 bool is_dir() { 55 return _filesize == -1; 56 } 57 58 bool is_jrt() { 59 return ClassLoader::is_jrt(_name); 60 } 61}; 62 63class FileMapInfo : public CHeapObj<mtInternal> { 64private: 65 friend class ManifestStream; 66 enum { 67 _invalid_version = -1, 68 _current_version = 2 69 }; 70 71 bool _file_open; 72 int _fd; 73 size_t _file_offset; 74 75private: 76 static SharedClassPathEntry* _classpath_entry_table; 77 static int _classpath_entry_table_size; 78 static size_t _classpath_entry_size; 79 static bool _validating_classpath_entry_table; 80 81 // FileMapHeader describes the shared space data in the file to be 82 // mapped. This structure gets written to a file. It is not a class, so 83 // that the compilers don't add any compiler-private data to it. 84 85public: 86 struct FileMapHeaderBase : public CHeapObj<mtClass> { 87 virtual bool validate() = 0; 88 virtual void populate(FileMapInfo* info, size_t alignment) = 0; 89 }; 90 struct FileMapHeader : FileMapHeaderBase { 91 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to 92 // avoid read/writing the C++ vtable pointer. 93 static size_t data_size(); 94 char* data() { 95 return ((char*)this) + sizeof(FileMapHeaderBase); 96 } 97 98 int _magic; // identify file type. 99 int _crc; // header crc checksum. 100 int _version; // (from enum, above.) 101 size_t _alignment; // how shared archive should be aligned 102 int _obj_alignment; // value of ObjectAlignmentInBytes 103 int _narrow_oop_shift; // compressed oop encoding shift 104 bool _compact_strings; // value of CompactStrings 105 uintx _max_heap_size; // java max heap size during dumping 106 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode 107 int _narrow_klass_shift; // save narrow klass base and shift 108 address _narrow_klass_base; 109 char* _misc_data_patching_start; 110 address _cds_i2i_entry_code_buffers; 111 size_t _cds_i2i_entry_code_buffers_size; 112 113 struct space_info { 114 int _crc; // crc checksum of the current space 115 size_t _file_offset; // sizeof(this) rounded to vm page size 116 union { 117 char* _base; // copy-on-write base address 118 intx _offset; // offset from the compressed oop encoding base, only used 119 // by string space 120 } _addr; 121 size_t _capacity; // for validity checking 122 size_t _used; // for setting space top on read 123 bool _read_only; // read only space? 124 bool _allow_exec; // executable code in space? 125 } _space[MetaspaceShared::n_regions]; 126 127 // The following fields are all sanity checks for whether this archive 128 // will function correctly with this JVM and the bootclasspath it's 129 // invoked with. 130 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 131 132 // The _paths_misc_info is a variable-size structure that records "miscellaneous" 133 // information during dumping. It is generated and validated by the 134 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for 135 // detailed description. 136 // 137 // The _paths_misc_info data is stored as a byte array in the archive file header, 138 // immediately after the _header field. This information is used only when 139 // checking the validity of the archive and is deallocated after the archive is loaded. 140 // 141 // Note that the _paths_misc_info does NOT include information for JAR files 142 // that existed during dump time. Their information is stored in _classpath_entry_table. 143 int _paths_misc_info_size; 144 145 // The following is a table of all the class path entries that were used 146 // during dumping. At run time, we require these files to exist and have the same 147 // size/modification time, or else the archive will refuse to load. 148 // 149 // All of these entries must be JAR files. The dumping process would fail if a non-empty 150 // directory was specified in the classpaths. If an empty directory was specified 151 // it is checked by the _paths_misc_info as described above. 152 // 153 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping, 154 // they should be removed from this table, to save space and to avoid spurious 155 // loading failures during runtime. 156 int _classpath_entry_table_size; 157 size_t _classpath_entry_size; 158 SharedClassPathEntry* _classpath_entry_table; 159 160 char* region_addr(int idx); 161 162 virtual bool validate(); 163 virtual void populate(FileMapInfo* info, size_t alignment); 164 int compute_crc(); 165 }; 166 167 FileMapHeader * _header; 168 169 const char* _full_path; 170 char* _paths_misc_info; 171 172 static FileMapInfo* _current_info; 173 174 bool init_from_file(int fd); 175 void align_file_position(); 176 bool validate_header_impl(); 177 178public: 179 FileMapInfo(); 180 ~FileMapInfo(); 181 182 static int current_version() { return _current_version; } 183 int compute_header_crc() { return _header->compute_crc(); } 184 void set_header_crc(int crc) { _header->_crc = crc; } 185 void populate_header(size_t alignment); 186 bool validate_header(); 187 void invalidate(); 188 int version() { return _header->_version; } 189 size_t alignment() { return _header->_alignment; } 190 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; } 191 int narrow_oop_shift() { return _header->_narrow_oop_shift; } 192 uintx max_heap_size() { return _header->_max_heap_size; } 193 address narrow_klass_base() const { return _header->_narrow_klass_base; } 194 int narrow_klass_shift() const { return _header->_narrow_klass_shift; } 195 size_t space_capacity(int i) { return _header->_space[i]._capacity; } 196 struct FileMapHeader* header() { return _header; } 197 char* misc_data_patching_start() { return _header->_misc_data_patching_start; } 198 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; } 199 200 address cds_i2i_entry_code_buffers() { 201 return _header->_cds_i2i_entry_code_buffers; 202 } 203 void set_cds_i2i_entry_code_buffers(address addr) { 204 _header->_cds_i2i_entry_code_buffers = addr; 205 } 206 size_t cds_i2i_entry_code_buffers_size() { 207 return _header->_cds_i2i_entry_code_buffers_size; 208 } 209 void set_cds_i2i_entry_code_buffers_size(size_t s) { 210 _header->_cds_i2i_entry_code_buffers_size = s; 211 } 212 213 static FileMapInfo* current_info() { 214 CDS_ONLY(return _current_info;) 215 NOT_CDS(return NULL;) 216 } 217 218 static void assert_mark(bool check); 219 220 // File manipulation. 221 bool initialize() NOT_CDS_RETURN_(false); 222 bool open_for_read(); 223 void open_for_write(); 224 void write_header(); 225 void write_space(int i, Metaspace* space, bool read_only); 226 void write_region(int region, char* base, size_t size, 227 size_t capacity, bool read_only, bool allow_exec); 228 void write_string_regions(GrowableArray<MemRegion> *regions); 229 void write_bytes(const void* buffer, int count); 230 void write_bytes_aligned(const void* buffer, int count); 231 char* map_region(int i); 232 bool map_string_regions(); 233 bool verify_string_regions(); 234 void fixup_string_regions(); 235 void unmap_region(int i); 236 void dealloc_string_regions(); 237 bool verify_region_checksum(int i); 238 void close(); 239 bool is_open() { return _file_open; } 240 ReservedSpace reserve_shared_memory(); 241 242 // JVM/TI RedefineClasses() support: 243 // Remap the shared readonly space to shared readwrite, private. 244 bool remap_shared_readonly_as_readwrite(); 245 246 // Errors. 247 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 248 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2); 249 250 // Return true if given address is in the mapped shared space. 251 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 252 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false); 253 void print_shared_spaces() NOT_CDS_RETURN; 254 255 static size_t shared_spaces_size() { 256 return align_size_up(SharedReadOnlySize + SharedReadWriteSize + 257 SharedMiscDataSize + SharedMiscCodeSize, 258 os::vm_allocation_granularity()); 259 } 260 261 // Stop CDS sharing and unmap CDS regions. 262 static void stop_sharing_and_unmap(const char* msg); 263 264 static void allocate_classpath_entry_table(); 265 bool validate_classpath_entry_table(); 266 267 static SharedClassPathEntry* shared_classpath(int index) { 268 char* p = (char*)_classpath_entry_table; 269 p += _classpath_entry_size * index; 270 return (SharedClassPathEntry*)p; 271 } 272 static const char* shared_classpath_name(int index) { 273 return shared_classpath(index)->_name; 274 } 275 276 static int get_number_of_share_classpaths() { 277 return _classpath_entry_table_size; 278 } 279}; 280 281#endif // SHARE_VM_MEMORY_FILEMAP_HPP 282