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