1 /*
2 * Copyright (c) 2003, 2018, 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
43 static const int JVM_IDENT_MAX = 256;
44
45 class SharedClassPathEntry {
46 protected:
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
53 public:
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_modules_image() { return ClassLoader::is_modules_image(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
75 class FileMapInfo : public CHeapObj<mtInternal> {
76 private:
77 friend class ManifestStream;
78 friend class VMStructs;
79 enum {
80 _invalid_version = -1,
81 _current_version = 3
82 };
83
84 bool _file_open;
85 int _fd;
86 size_t _file_offset;
87
88 private:
89 static Array<u8>* _classpath_entry_table;
90 static int _classpath_entry_table_size;
91 static size_t _classpath_entry_size;
92 static bool _validating_classpath_entry_table;
93
94 // FileMapHeader describes the shared space data in the file to be
95 // mapped. This structure gets written to a file. It is not a class, so
96 // that the compilers don't add any compiler-private data to it.
97
98 public:
99 struct FileMapHeaderBase : public CHeapObj<mtClass> {
100 virtual bool validate() = 0;
101 virtual void populate(FileMapInfo* info, size_t alignment) = 0;
102 };
103 struct FileMapHeader : FileMapHeaderBase {
104 // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to
105 // avoid read/writing the C++ vtable pointer.
106 static size_t data_size();
107 char* data() {
108 return ((char*)this) + sizeof(FileMapHeaderBase);
109 }
110
111 int _magic; // identify file type.
112 int _crc; // header crc checksum.
113 int _version; // (from enum, above.)
114 size_t _alignment; // how shared archive should be aligned
115 int _obj_alignment; // value of ObjectAlignmentInBytes
116 address _narrow_oop_base; // compressed oop encoding base
117 int _narrow_oop_shift; // compressed oop encoding shift
118 bool _compact_strings; // value of CompactStrings
119 uintx _max_heap_size; // java max heap size during dumping
120 Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode
121 int _narrow_klass_shift; // save narrow klass base and shift
122 address _narrow_klass_base;
123 char* _misc_data_patching_start;
124 char* _read_only_tables_start;
125 address _cds_i2i_entry_code_buffers;
126 size_t _cds_i2i_entry_code_buffers_size;
127 size_t _core_spaces_size; // number of bytes allocated by the core spaces
128 // (mc, md, ro, rw and od).
129 struct space_info {
130 int _crc; // crc checksum of the current space
131 size_t _file_offset; // sizeof(this) rounded to vm page size
132 union {
133 char* _base; // copy-on-write base address
134 intx _offset; // offset from the compressed oop encoding base, only used
135 // by archive heap space
136 } _addr;
137 size_t _used; // for setting space top on read
138 bool _read_only; // read only space?
139 bool _allow_exec; // executable code in space?
140 } _space[MetaspaceShared::n_regions];
141
142 // The following fields are all sanity checks for whether this archive
143 // will function correctly with this JVM and the bootclasspath it's
144 // invoked with.
145 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm
146
147 // The _paths_misc_info is a variable-size structure that records "miscellaneous"
148 // information during dumping. It is generated and validated by the
149 // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for
150 // detailed description.
151 //
152 // The _paths_misc_info data is stored as a byte array in the archive file header,
153 // immediately after the _header field. This information is used only when
154 // checking the validity of the archive and is deallocated after the archive is loaded.
155 //
156 // Note that the _paths_misc_info does NOT include information for JAR files
157 // that existed during dump time. Their information is stored in _classpath_entry_table.
158 int _paths_misc_info_size;
159
160 // The following is a table of all the class path entries that were used
161 // during dumping. At run time, we require these files to exist and have the same
162 // size/modification time, or else the archive will refuse to load.
163 //
164 // All of these entries must be JAR files. The dumping process would fail if a non-empty
165 // directory was specified in the classpaths. If an empty directory was specified
166 // it is checked by the _paths_misc_info as described above.
167 //
168 // FIXME -- if JAR files in the tail of the list were specified but not used during dumping,
169 // they should be removed from this table, to save space and to avoid spurious
170 // loading failures during runtime.
171 int _classpath_entry_table_size;
172 size_t _classpath_entry_size;
173 Array<u8>* _classpath_entry_table;
174
175 char* region_addr(int idx);
176
177 virtual bool validate();
178 virtual void populate(FileMapInfo* info, size_t alignment);
179 int compute_crc();
180 };
181
182 FileMapHeader * _header;
183
184 const char* _full_path;
185 char* _paths_misc_info;
186
187 static FileMapInfo* _current_info;
188
189 bool init_from_file(int fd);
190 void align_file_position();
191 bool validate_header_impl();
192 static void metaspace_pointers_do(MetaspaceClosure* it);
193
194 public:
195 FileMapInfo();
196 ~FileMapInfo();
197
198 static int current_version() { return _current_version; }
199 int compute_header_crc() { return _header->compute_crc(); }
200 void set_header_crc(int crc) { _header->_crc = crc; }
201 void populate_header(size_t alignment);
202 bool validate_header();
203 void invalidate();
204 int version() { return _header->_version; }
205 size_t alignment() { return _header->_alignment; }
206 Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; }
207 address narrow_oop_base() const { return _header->_narrow_oop_base; }
208 int narrow_oop_shift() const { return _header->_narrow_oop_shift; }
209 uintx max_heap_size() const { return _header->_max_heap_size; }
210 address narrow_klass_base() const { return _header->_narrow_klass_base; }
211 int narrow_klass_shift() const { return _header->_narrow_klass_shift; }
212 struct FileMapHeader* header() { return _header; }
213 char* misc_data_patching_start() { return _header->_misc_data_patching_start; }
214 void set_misc_data_patching_start(char* p) { _header->_misc_data_patching_start = p; }
215 char* read_only_tables_start() { return _header->_read_only_tables_start; }
216 void set_read_only_tables_start(char* p) { _header->_read_only_tables_start = p; }
217
218 address cds_i2i_entry_code_buffers() {
219 return _header->_cds_i2i_entry_code_buffers;
220 }
221 void set_cds_i2i_entry_code_buffers(address addr) {
222 _header->_cds_i2i_entry_code_buffers = addr;
223 }
224 size_t cds_i2i_entry_code_buffers_size() {
225 return _header->_cds_i2i_entry_code_buffers_size;
226 }
227 void set_cds_i2i_entry_code_buffers_size(size_t s) {
228 _header->_cds_i2i_entry_code_buffers_size = s;
229 }
230 void set_core_spaces_size(size_t s) { _header->_core_spaces_size = s; }
231 size_t core_spaces_size() { return _header->_core_spaces_size; }
232
233 static FileMapInfo* current_info() {
234 CDS_ONLY(return _current_info;)
235 NOT_CDS(return NULL;)
236 }
237
238 static void assert_mark(bool check);
239
240 // File manipulation.
241 bool initialize() NOT_CDS_RETURN_(false);
242 bool open_for_read();
243 void open_for_write();
244 void write_header();
245 void write_region(int region, char* base, size_t size,
246 bool read_only, bool allow_exec);
247 size_t write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,
248 int first_region_id, int max_num_regions);
249 void write_bytes(const void* buffer, int count);
250 void write_bytes_aligned(const void* buffer, int count);
251 char* map_region(int i, char** top_ret);
252 void map_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;
253 void fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;
254 void unmap_region(int i);
255 bool verify_region_checksum(int i);
256 void close();
257 bool is_open() { return _file_open; }
258 ReservedSpace reserve_shared_memory();
259
260 // JVM/TI RedefineClasses() support:
261 // Remap the shared readonly space to shared readwrite, private.
262 bool remap_shared_readonly_as_readwrite();
263
264 // Errors.
265 static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);
266 static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);
267
268 bool is_in_shared_region(const void* p, int idx) NOT_CDS_RETURN_(false);
269 void print_shared_spaces() NOT_CDS_RETURN;
270
271 // Stop CDS sharing and unmap CDS regions.
272 static void stop_sharing_and_unmap(const char* msg);
273
274 static void allocate_classpath_entry_table();
275 bool validate_classpath_entry_table();
276
277 static SharedClassPathEntry* shared_classpath(int index) {
278 if (index < 0) {
279 return NULL;
280 }
281 assert(index < _classpath_entry_table_size, "sanity");
282 char* p = (char*)_classpath_entry_table->data();
283 p += _classpath_entry_size * index;
284 return (SharedClassPathEntry*)p;
285 }
286 static const char* shared_classpath_name(int index) {
287 assert(index >= 0, "Sanity");
288 return shared_classpath(index)->name();
289 }
290
291 static int get_number_of_share_classpaths() {
292 return _classpath_entry_table_size;
293 }
294
295 private:
296 bool map_heap_data(MemRegion **heap_mem, int first, int max, int* num,
297 bool is_open = false) NOT_CDS_JAVA_HEAP_RETURN_(false);
298 bool verify_mapped_heap_regions(int first, int num) NOT_CDS_JAVA_HEAP_RETURN_(false);
299 void dealloc_archive_heap_regions(MemRegion* regions, int num) NOT_CDS_JAVA_HEAP_RETURN;
300 };
301
302 #endif // SHARE_VM_MEMORY_FILEMAP_HPP