1 /*
  2  * Copyright (c) 2003, 2024, 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_CDS_FILEMAP_HPP
 26 #define SHARE_CDS_FILEMAP_HPP
 27 
 28 #include "cds/archiveUtils.hpp"
 29 #include "cds/metaspaceShared.hpp"
 30 #include "include/cds.h"
 31 #include "logging/logLevel.hpp"
 32 #include "memory/allocation.hpp"
 33 #include "oops/array.hpp"
 34 #include "oops/compressedOops.hpp"
 35 #include "utilities/align.hpp"
 36 
 37 // To understand the layout of the CDS archive file:
 38 //
 39 // java -Xlog:cds+map=info:file=cds.map:none:filesize=0
 40 // java -Xlog:cds+map=debug:file=cds.map:none:filesize=0
 41 // java -Xlog:cds+map=trace:file=cds.map:none:filesize=0
 42 
 43 static const int JVM_IDENT_MAX = 256;
 44 
 45 class ArchiveHeapInfo;
 46 class BitMapView;
 47 class CHeapBitMap;
 48 class ClassFileStream;
 49 class ClassLoaderData;
 50 class ClassPathEntry;
 51 class outputStream;
 52 
 53 class SharedClassPathEntry : public MetaspaceObj {
 54   enum {
 55     modules_image_entry,
 56     jar_entry,
 57     dir_entry,
 58     non_existent_entry,
 59     unknown_entry
 60   };
 61 
 62   void set_name(const char* name, TRAPS);
 63 
 64   u1     _type;
 65   bool   _is_module_path;
 66   bool   _from_class_path_attr;
 67   time_t _timestamp;          // jar timestamp,  0 if is directory, modules image or other
 68   int64_t      _filesize;     // jar/jimage file size, -1 if is directory, -2 if other
 69   Array<char>* _name;
 70   Array<u1>*   _manifest;
 71 
 72 public:
 73   SharedClassPathEntry() : _type(0), _is_module_path(false),
 74                            _from_class_path_attr(false), _timestamp(0),
 75                            _filesize(0), _name(nullptr), _manifest(nullptr) {}
 76   static int size() {
 77     static_assert(is_aligned(sizeof(SharedClassPathEntry), wordSize), "must be");
 78     return (int)(sizeof(SharedClassPathEntry) / wordSize);
 79   }
 80   void init(bool is_modules_image, bool is_module_path, ClassPathEntry* cpe, TRAPS);
 81   void init_as_non_existent(const char* path, TRAPS);
 82   void metaspace_pointers_do(MetaspaceClosure* it);
 83   MetaspaceObj::Type type() const { return SharedClassPathEntryType; }
 84   bool validate(bool is_class_path = true) const;
 85 
 86   // The _timestamp only gets set for jar files.
 87   bool has_timestamp() const {
 88     return _timestamp != 0;
 89   }
 90   bool is_dir()           const { return _type == dir_entry; }
 91   bool is_modules_image() const { return _type == modules_image_entry; }
 92   bool is_jar()           const { return _type == jar_entry; }
 93   bool is_non_existent()  const { return _type == non_existent_entry; }
 94   bool from_class_path_attr() { return _from_class_path_attr; }
 95   time_t timestamp() const { return _timestamp; }
 96   const char* name() const;
 97   const char* manifest() const {
 98     return (_manifest == nullptr) ? nullptr : (const char*)_manifest->data();
 99   }
100   int manifest_size() const {
101     return (_manifest == nullptr) ? 0 : _manifest->length();
102   }
103   void set_manifest(Array<u1>* manifest) {
104     _manifest = manifest;
105   }
106   bool check_non_existent() const;
107   void copy_from(SharedClassPathEntry* ent, ClassLoaderData* loader_data, TRAPS);
108   bool in_named_module() {
109     return is_modules_image() || // modules image doesn't contain unnamed modules
110            _is_module_path;      // module path doesn't contain unnamed modules
111   }
112 };
113 
114 class SharedPathTable {
115   Array<SharedClassPathEntry*>* _entries;
116 public:
117   SharedPathTable() : _entries(nullptr) {}
118   SharedPathTable(Array<SharedClassPathEntry*>* entries) : _entries(entries) {}
119 
120   void dumptime_init(ClassLoaderData* loader_data, TRAPS);
121   void metaspace_pointers_do(MetaspaceClosure* it);
122 
123   int size() {
124     return _entries == nullptr ? 0 : _entries->length();
125   }
126   SharedClassPathEntry* path_at(int index) {
127     return _entries->at(index);
128   }
129   Array<SharedClassPathEntry*>* table() {return _entries;}
130   void set_table(Array<SharedClassPathEntry*>* table) {_entries = table;}
131 };
132 
133 
134 class FileMapRegion: private CDSFileMapRegion {
135 public:
136   void assert_is_heap_region() const {
137     assert(_is_heap_region, "must be heap region");
138   }
139   void assert_is_not_heap_region() const {
140     assert(!_is_heap_region, "must not be heap region");
141   }
142 
143   static FileMapRegion* cast(CDSFileMapRegion* p) {
144     return (FileMapRegion*)p;
145   }
146 
147   // Accessors
148   int crc()                         const { return _crc; }
149   size_t file_offset()              const { return _file_offset; }
150   size_t mapping_offset()           const { return _mapping_offset; }
151   size_t mapping_end_offset()       const { return _mapping_offset + used_aligned(); }
152   size_t used()                     const { return _used; }
153   size_t used_aligned()             const; // aligned up to MetaspaceShared::core_region_alignment()
154   char*  mapped_base()              const { return _mapped_base; }
155   char*  mapped_end()               const { return mapped_base()        + used_aligned(); }
156   bool   read_only()                const { return _read_only != 0; }
157   bool   allow_exec()               const { return _allow_exec != 0; }
158   bool   mapped_from_file()         const { return _mapped_from_file != 0; }
159   size_t oopmap_offset()            const { assert_is_heap_region();     return _oopmap_offset; }
160   size_t oopmap_size_in_bits()      const { assert_is_heap_region();     return _oopmap_size_in_bits; }
161   size_t ptrmap_offset()            const { return _ptrmap_offset; }
162   size_t ptrmap_size_in_bits()      const { return _ptrmap_size_in_bits; }
163 
164   void set_file_offset(size_t s)     { _file_offset = s; }
165   void set_read_only(bool v)         { _read_only = v; }
166   void set_mapped_base(char* p)      { _mapped_base = p; }
167   void set_mapped_from_file(bool v)  { _mapped_from_file = v; }
168   void init(int region_index, size_t mapping_offset, size_t size, bool read_only,
169             bool allow_exec, int crc);
170   void init_oopmap(size_t offset, size_t size_in_bits);
171   void init_ptrmap(size_t offset, size_t size_in_bits);
172   bool has_ptrmap()                  { return _ptrmap_size_in_bits != 0; }
173 
174   bool check_region_crc(char* base) const;
175   void print(outputStream* st, int region_index);
176 };
177 
178 class FileMapHeader: private CDSFileMapHeaderBase {
179   friend class CDSConstants;
180   friend class VMStructs;
181 
182 private:
183   // The following fields record the states of the VM during dump time.
184   // They are compared with the runtime states to see if the archive
185   // can be used.
186   size_t _core_region_alignment;                  // how shared archive should be aligned
187   int    _obj_alignment;                          // value of ObjectAlignmentInBytes
188   address _narrow_oop_base;                       // compressed oop encoding base
189   int    _narrow_oop_shift;                       // compressed oop encoding shift
190   bool   _compact_strings;                        // value of CompactStrings
191   bool   _compact_headers;                        // value of UseCompactObjectHeaders
192   uintx  _max_heap_size;                          // java max heap size during dumping
193   CompressedOops::Mode _narrow_oop_mode;          // compressed oop encoding mode
194   bool    _compressed_oops;                       // save the flag UseCompressedOops
195   bool    _compressed_class_ptrs;                 // save the flag UseCompressedClassPointers
196   int     _narrow_klass_pointer_bits;             // save number of bits in narrowKlass
197   int     _narrow_klass_shift;                    // save shift width used to pre-compute narrowKlass IDs in archived heap objects
198   size_t  _cloned_vtables_offset;                 // The address of the first cloned vtable
199   size_t  _early_serialized_data_offset;          // Data accessed using {ReadClosure,WriteClosure}::serialize()
200   size_t  _serialized_data_offset;                // Data accessed using {ReadClosure,WriteClosure}::serialize()
201   bool _has_non_jar_in_classpath;                 // non-jar file entry exists in classpath
202   unsigned int _common_app_classpath_prefix_size; // size of the common prefix of app class paths
203                                                   //    0 if no common prefix exists
204 
205   // The following fields are all sanity checks for whether this archive
206   // will function correctly with this JVM and the bootclasspath it's
207   // invoked with.
208   char  _jvm_ident[JVM_IDENT_MAX];  // identifier string of the jvm that created this dump
209 
210   // The following is a table of all the boot/app/module path entries that were used
211   // during dumping. At run time, we validate these entries according to their
212   // SharedClassPathEntry::_type. See:
213   //      check_nonempty_dir_in_shared_path_table()
214   //      validate_shared_path_table()
215   //      validate_non_existent_class_paths()
216   size_t _shared_path_table_offset;
217 
218   jshort _app_class_paths_start_index;  // Index of first app classpath entry
219   jshort _app_module_paths_start_index; // Index of first module path entry
220   jshort _max_used_path_index;          // max path index referenced during CDS dump
221   int    _num_module_paths;             // number of module path entries
222   bool   _verify_local;                 // BytecodeVerificationLocal setting
223   bool   _verify_remote;                // BytecodeVerificationRemote setting
224   bool   _has_platform_or_app_classes;  // Archive contains app classes
225   char*  _requested_base_address;       // Archive relocation is not necessary if we map with this base address.
226   char*  _mapped_base_address;          // Actual base address where archive is mapped.
227 
228   bool   _allow_archiving_with_java_agent; // setting of the AllowArchivingWithJavaAgent option
229   bool   _use_optimized_module_handling;// No module-relation VM options were specified, so we can skip
230                                         // some expensive operations.
231   bool   _has_aot_linked_classes;       // Was the CDS archive created with -XX:+AOTClassLinking
232   bool   _has_full_module_graph;        // Does this CDS archive contain the full archived module graph?
233   bool   _has_archived_invokedynamic;   // Does the archive have aot-linked invokedynamic CP entries?
234   bool   _has_archived_packages;
235   bool   _has_archived_protection_domains;
236   int    _gc_kind;                      // Universe::heap()->kind();
237   char   _gc_name[32];                  // Universe::heap()->name();
238   size_t _ptrmap_size_in_bits;          // Size of pointer relocation bitmap
239   HeapRootSegments _heap_root_segments; // Heap root segments info
240   size_t _heap_oopmap_start_pos;        // The first bit in the oopmap corresponds to this position in the heap.
241   size_t _heap_ptrmap_start_pos;        // The first bit in the ptrmap corresponds to this position in the heap.
242   size_t _rw_ptrmap_start_pos;          // The first bit in the ptrmap corresponds to this position in the rw region
243   size_t _ro_ptrmap_start_pos;          // The first bit in the ptrmap corresponds to this position in the ro region
244   char* from_mapped_offset(size_t offset) const {
245     return mapped_base_address() + offset;
246   }
247   void set_as_offset(char* p, size_t *offset);
248 public:
249   // Accessors -- fields declared in GenericCDSFileMapHeader
250   unsigned int magic()                            const { return _generic_header._magic;                    }
251   int crc()                                       const { return _generic_header._crc;                      }
252   int version()                                   const { return _generic_header._version;                  }
253   unsigned int header_size()                      const { return _generic_header._header_size;              }
254   unsigned int base_archive_name_offset()         const { return _generic_header._base_archive_name_offset; }
255   unsigned int base_archive_name_size()           const { return _generic_header._base_archive_name_size;   }
256   unsigned int common_app_classpath_prefix_size() const { return _common_app_classpath_prefix_size;         }
257 
258   void set_magic(unsigned int m)                            { _generic_header._magic = m;                    }
259   void set_crc(int crc_value)                               { _generic_header._crc = crc_value;              }
260   void set_version(int v)                                   { _generic_header._version = v;                  }
261   void set_header_size(unsigned int s)                      { _generic_header._header_size = s;              }
262   void set_base_archive_name_offset(unsigned int s)         { _generic_header._base_archive_name_offset = s; }
263   void set_base_archive_name_size(unsigned int s)           { _generic_header._base_archive_name_size = s;   }
264   void set_common_app_classpath_prefix_size(unsigned int s) { _common_app_classpath_prefix_size = s;         }
265 
266   bool is_static()                         const { return magic() == CDS_ARCHIVE_MAGIC; }
267   size_t core_region_alignment()           const { return _core_region_alignment; }
268   int obj_alignment()                      const { return _obj_alignment; }
269   address narrow_oop_base()                const { return _narrow_oop_base; }
270   int narrow_oop_shift()                   const { return _narrow_oop_shift; }
271   bool compact_strings()                   const { return _compact_strings; }
272   bool compact_headers()                   const { return _compact_headers; }
273   uintx max_heap_size()                    const { return _max_heap_size; }
274   CompressedOops::Mode narrow_oop_mode()   const { return _narrow_oop_mode; }
275   char* cloned_vtables()                   const { return from_mapped_offset(_cloned_vtables_offset); }
276   char* early_serialized_data()            const { return from_mapped_offset(_early_serialized_data_offset); }
277   char* serialized_data()                  const { return from_mapped_offset(_serialized_data_offset); }
278   const char* jvm_ident()                  const { return _jvm_ident; }
279   char* requested_base_address()           const { return _requested_base_address; }
280   char* mapped_base_address()              const { return _mapped_base_address; }
281   bool has_platform_or_app_classes()       const { return _has_platform_or_app_classes; }
282   bool has_non_jar_in_classpath()          const { return _has_non_jar_in_classpath; }
283   bool has_aot_linked_classes()            const { return _has_aot_linked_classes; }
284   int gc_kind()                            const { return _gc_kind; }
285   const char* gc_name()                    const { return _gc_name; }
286   size_t ptrmap_size_in_bits()             const { return _ptrmap_size_in_bits; }
287   bool compressed_oops()                   const { return _compressed_oops; }
288   bool compressed_class_pointers()         const { return _compressed_class_ptrs; }
289   int narrow_klass_pointer_bits()          const { return _narrow_klass_pointer_bits; }
290   int narrow_klass_shift()                 const { return _narrow_klass_shift; }
291   HeapRootSegments heap_root_segments()    const { return _heap_root_segments; }
292   bool has_full_module_graph()             const { return _has_full_module_graph; }
293   size_t heap_oopmap_start_pos()           const { return _heap_oopmap_start_pos; }
294   size_t heap_ptrmap_start_pos()           const { return _heap_ptrmap_start_pos; }
295   size_t rw_ptrmap_start_pos()             const { return _rw_ptrmap_start_pos; }
296   size_t ro_ptrmap_start_pos()             const { return _ro_ptrmap_start_pos; }
297   // FIXME: These should really return int
298   jshort max_used_path_index()             const { return _max_used_path_index; }
299   jshort app_module_paths_start_index()    const { return _app_module_paths_start_index; }
300   jshort app_class_paths_start_index()     const { return _app_class_paths_start_index; }
301   int    num_module_paths()                const { return _num_module_paths; }
302 
303   void set_has_platform_or_app_classes(bool v)   { _has_platform_or_app_classes = v; }
304   void set_cloned_vtables(char* p)               { set_as_offset(p, &_cloned_vtables_offset); }
305   void set_early_serialized_data(char* p)        { set_as_offset(p, &_early_serialized_data_offset); }
306   void set_serialized_data(char* p)              { set_as_offset(p, &_serialized_data_offset); }
307   void set_mapped_base_address(char* p)          { _mapped_base_address = p; }
308   void set_heap_root_segments(HeapRootSegments segments) { _heap_root_segments = segments; }
309   void set_heap_oopmap_start_pos(size_t n)       { _heap_oopmap_start_pos = n; }
310   void set_heap_ptrmap_start_pos(size_t n)       { _heap_ptrmap_start_pos = n; }
311   void set_rw_ptrmap_start_pos(size_t n)         { _rw_ptrmap_start_pos = n; }
312   void set_ro_ptrmap_start_pos(size_t n)         { _ro_ptrmap_start_pos = n; }
313   void copy_base_archive_name(const char* name);
314 
315   void set_shared_path_table(SharedPathTable table) {
316     set_as_offset((char*)table.table(), &_shared_path_table_offset);
317   }
318 
319   void set_requested_base(char* b) {
320     _requested_base_address = b;
321     _mapped_base_address = nullptr;
322   }
323 
324   SharedPathTable shared_path_table() const {
325     return SharedPathTable((Array<SharedClassPathEntry*>*)
326                            from_mapped_offset(_shared_path_table_offset));
327   }
328 
329   bool validate();
330   int compute_crc();
331 
332   FileMapRegion* region_at(int i) {
333     assert(is_valid_region(i), "invalid region");
334     return FileMapRegion::cast(&_regions[i]);
335   }
336 
337   void populate(FileMapInfo *info, size_t core_region_alignment, size_t header_size,
338                 size_t base_archive_name_size, size_t base_archive_name_offset,
339                 size_t common_app_classpath_size);
340   static bool is_valid_region(int region) {
341     return (0 <= region && region < NUM_CDS_REGIONS);
342   }
343 
344   void print(outputStream* st);
345 };
346 
347 class FileMapInfo : public CHeapObj<mtInternal> {
348 private:
349   friend class ManifestStream;
350   friend class VMStructs;
351   friend class ArchiveBuilder;
352   friend class CDSOffsets;
353   friend class FileMapHeader;
354 
355   bool           _is_static;
356   bool           _file_open;
357   bool           _is_mapped;
358   int            _fd;
359   size_t         _file_offset;
360   const char*    _full_path;
361   const char*    _base_archive_name;
362   FileMapHeader* _header;
363 
364   static SharedPathTable       _shared_path_table;
365   static bool                  _validating_shared_path_table;
366 
367   // FileMapHeader describes the shared space data in the file to be
368   // mapped.  This structure gets written to a file.  It is not a class, so
369   // that the compilers don't add any compiler-private data to it.
370 
371   static FileMapInfo* _current_info;
372   static FileMapInfo* _dynamic_archive_info;
373   static bool _heap_pointers_need_patching;
374   static bool _memory_mapping_failed;
375   static GrowableArray<const char*>* _non_existent_class_paths;
376 
377 public:
378   FileMapHeader *header() const       { return _header; }
379   static bool get_base_archive_name_from_header(const char* archive_name,
380                                                 char** base_archive_name);
381   static SharedPathTable shared_path_table() {
382     return _shared_path_table;
383   }
384 
385   bool init_from_file(int fd);
386   static void metaspace_pointers_do(MetaspaceClosure* it) {
387     _shared_path_table.metaspace_pointers_do(it);
388   }
389 
390   void log_paths(const char* msg, int start_idx, int end_idx);
391 
392   FileMapInfo(const char* full_apth, bool is_static);
393   ~FileMapInfo();
394 
395   // Accessors
396   int    compute_header_crc()  const { return header()->compute_crc(); }
397   void   set_header_crc(int crc)     { header()->set_crc(crc); }
398   int    region_crc(int i)     const { return region_at(i)->crc(); }
399   void   populate_header(size_t core_region_alignment);
400   bool   validate_header();
401   void   invalidate();
402   int    crc()                 const { return header()->crc(); }
403   int    version()             const { return header()->version(); }
404   unsigned int magic()         const { return header()->magic(); }
405   address narrow_oop_base()    const { return header()->narrow_oop_base(); }
406   int     narrow_oop_shift()   const { return header()->narrow_oop_shift(); }
407   uintx   max_heap_size()      const { return header()->max_heap_size(); }
408   HeapRootSegments heap_root_segments() const { return header()->heap_root_segments(); }
409   size_t  core_region_alignment() const { return header()->core_region_alignment(); }
410   size_t  heap_oopmap_start_pos() const { return header()->heap_oopmap_start_pos(); }
411   size_t  heap_ptrmap_start_pos() const { return header()->heap_ptrmap_start_pos(); }
412 
413   CompressedOops::Mode narrow_oop_mode()      const { return header()->narrow_oop_mode(); }
414   jshort app_module_paths_start_index()       const { return header()->app_module_paths_start_index(); }
415   jshort app_class_paths_start_index()        const { return header()->app_class_paths_start_index(); }
416 
417   char* cloned_vtables()                      const { return header()->cloned_vtables(); }
418   void  set_cloned_vtables(char* p)           const { header()->set_cloned_vtables(p); }
419   char* early_serialized_data()               const { return header()->early_serialized_data(); }
420   void  set_early_serialized_data(char* p)    const { header()->set_early_serialized_data(p); }
421   char* serialized_data()                     const { return header()->serialized_data(); }
422   void  set_serialized_data(char* p)          const { header()->set_serialized_data(p); }
423 
424   bool  is_file_position_aligned() const;
425   void  align_file_position();
426 
427   bool is_static()                            const { return _is_static; }
428   bool is_mapped()                            const { return _is_mapped; }
429   void set_is_mapped(bool v)                        { _is_mapped = v; }
430   const char* full_path()                     const { return _full_path; }
431 
432   void set_requested_base(char* b)                  { header()->set_requested_base(b); }
433   char* requested_base_address()           const    { return header()->requested_base_address(); }
434 
435   class DynamicArchiveHeader* dynamic_header() const {
436     assert(!is_static(), "must be");
437     return (DynamicArchiveHeader*)header();
438   }
439 
440   void set_has_platform_or_app_classes(bool v) {
441     header()->set_has_platform_or_app_classes(v);
442   }
443   bool has_platform_or_app_classes() const {
444     return header()->has_platform_or_app_classes();
445   }
446 
447   static FileMapInfo* current_info() {
448     CDS_ONLY(return _current_info;)
449     NOT_CDS(return nullptr;)
450   }
451 
452   static void set_current_info(FileMapInfo* info) {
453     CDS_ONLY(_current_info = info;)
454   }
455 
456   static FileMapInfo* dynamic_info() {
457     CDS_ONLY(return _dynamic_archive_info;)
458     NOT_CDS(return nullptr;)
459   }
460 
461   static void assert_mark(bool check);
462 
463   // File manipulation.
464   bool  initialize() NOT_CDS_RETURN_(false);
465   bool  open_for_read();
466   void  open_for_write();
467   void  write_header();
468   void  write_region(int region, char* base, size_t size,
469                      bool read_only, bool allow_exec);
470   size_t remove_bitmap_zeros(CHeapBitMap* map);
471   char* write_bitmap_region(CHeapBitMap* rw_ptrmap, CHeapBitMap* ro_ptrmap,
472                             CHeapBitMap* cc_ptrmap, ArchiveHeapInfo* heap_info,
473                             size_t &size_in_bytes);
474   size_t write_heap_region(ArchiveHeapInfo* heap_info);
475   void  write_bytes(const void* buffer, size_t count);
476   void  write_bytes_aligned(const void* buffer, size_t count);
477   size_t  read_bytes(void* buffer, size_t count);
478   static size_t readonly_total();
479   MapArchiveResult map_regions(int regions[], int num_regions, char* mapped_base_address, ReservedSpace rs);
480   void  unmap_regions(int regions[], int num_regions);
481   void  map_or_load_heap_region() NOT_CDS_JAVA_HEAP_RETURN;
482   void  fixup_mapped_heap_region() NOT_CDS_JAVA_HEAP_RETURN;
483   void  patch_heap_embedded_pointers() NOT_CDS_JAVA_HEAP_RETURN;
484   bool  has_heap_region()  NOT_CDS_JAVA_HEAP_RETURN_(false);
485   MemRegion get_heap_region_requested_range() NOT_CDS_JAVA_HEAP_RETURN_(MemRegion());
486   bool  read_region(int i, char* base, size_t size, bool do_commit);
487   char* map_bitmap_region();
488   bool map_cached_code_region(ReservedSpace rs);
489   void  unmap_region(int i);
490   void  close();
491   bool  is_open() { return _file_open; }
492   ReservedSpace reserve_shared_memory();
493 
494   // JVM/TI RedefineClasses() support:
495   // Remap the shared readonly space to shared readwrite, private.
496   bool  remap_shared_readonly_as_readwrite();
497 
498   static bool memory_mapping_failed() {
499     CDS_ONLY(return _memory_mapping_failed;)
500     NOT_CDS(return false;)
501   }
502 
503   static void allocate_shared_path_table(TRAPS);
504   static int add_shared_classpaths(int i, const char* which, ClassPathEntry *cpe, TRAPS);
505   static void check_nonempty_dir_in_shared_path_table();
506   bool check_module_paths();
507   bool validate_shared_path_table();
508   bool validate_non_existent_class_paths();
509   bool validate_aot_class_linking();
510   static void set_shared_path_table(FileMapInfo* info) {
511     _shared_path_table = info->header()->shared_path_table();
512   }
513   static void update_jar_manifest(ClassPathEntry *cpe, SharedClassPathEntry* ent, TRAPS);
514   static int num_non_existent_class_paths();
515   static void record_non_existent_class_path_entry(const char* path);
516 
517 #if INCLUDE_JVMTI
518   // Caller needs a ResourceMark because parts of the returned cfs are resource-allocated.
519   static ClassFileStream* open_stream_for_jvmti(InstanceKlass* ik, Handle class_loader, TRAPS);
520 #endif
521 
522   static SharedClassPathEntry* shared_path(int index) {
523     return _shared_path_table.path_at(index);
524   }
525 
526   static const char* shared_path_name(int index) {
527     assert(index >= 0, "Sanity");
528     return shared_path(index)->name();
529   }
530 
531   static int get_number_of_shared_paths() {
532     return _shared_path_table.size();
533   }
534 
535   static int get_module_shared_path_index(Symbol* location) NOT_CDS_RETURN_(-1);
536 
537   // The offset of the first core region in the archive, relative to SharedBaseAddress
538   size_t mapping_base_offset() const { return first_core_region()->mapping_offset();    }
539   // The offset of the (exclusive) end of the last core region in this archive, relative to SharedBaseAddress
540   size_t mapping_end_offset()  const { return last_core_region()->mapping_end_offset(); }
541 
542   char* mapped_base()    const { return first_core_region()->mapped_base(); }
543   char* mapped_end()     const { return last_core_region()->mapped_end();   }
544 
545   // Non-zero if the archive needs to be mapped a non-default location due to ASLR.
546   intx relocation_delta() const {
547     return header()->mapped_base_address() - header()->requested_base_address();
548   }
549 
550   FileMapRegion* first_core_region() const;
551   FileMapRegion* last_core_region()  const;
552 
553   FileMapRegion* region_at(int i) const {
554     return header()->region_at(i);
555   }
556 
557   BitMapView bitmap_view(int region_index, bool is_oopmap);
558   BitMapView oopmap_view(int region_index);
559   BitMapView ptrmap_view(int region_index);
560 
561   void print(outputStream* st) const;
562 
563   const char* vm_version() {
564     return header()->jvm_ident();
565   }
566 
567  private:
568   void  seek_to_position(size_t pos);
569   char* skip_first_path_entry(const char* path) NOT_CDS_RETURN_(nullptr);
570   int   num_paths(const char* path) NOT_CDS_RETURN_(0);
571   bool  check_paths_existence(const char* paths) NOT_CDS_RETURN_(false);
572   GrowableArray<const char*>* create_dumptime_app_classpath_array() NOT_CDS_RETURN_(nullptr);
573   GrowableArray<const char*>* create_path_array(const char* path) NOT_CDS_RETURN_(nullptr);
574   bool  classpath_failure(const char* msg, const char* name) NOT_CDS_RETURN_(false);
575   unsigned int longest_common_app_classpath_prefix_len(int num_paths,
576                                                        GrowableArray<const char*>* rp_array)
577                                                        NOT_CDS_RETURN_(0);
578   bool  check_paths(int shared_path_start_idx, int num_paths,
579                     GrowableArray<const char*>* rp_array,
580                     unsigned int dumptime_prefix_len,
581                     unsigned int runtime_prefix_len) NOT_CDS_RETURN_(false);
582   void  extract_module_paths(const char* runtime_path, GrowableArray<const char*>* module_paths);
583   bool  validate_boot_class_paths() NOT_CDS_RETURN_(false);
584   bool  validate_app_class_paths(int shared_app_paths_len) NOT_CDS_RETURN_(false);
585   bool  map_heap_region_impl() NOT_CDS_JAVA_HEAP_RETURN_(false);
586   void  dealloc_heap_region() NOT_CDS_JAVA_HEAP_RETURN;
587   bool  can_use_heap_region();
588   bool  load_heap_region() NOT_CDS_JAVA_HEAP_RETURN_(false);
589   bool  map_heap_region() NOT_CDS_JAVA_HEAP_RETURN_(false);
590   void  init_heap_region_relocation();
591   MapArchiveResult map_region(int i, intx addr_delta, char* mapped_base_address, ReservedSpace rs);
592   bool  relocate_pointers_in_core_regions(intx addr_delta);
593   void  relocate_pointers_in_cached_code_region();
594   static MemRegion _mapped_heap_memregion;
595 
596 public:
597   address heap_region_dumptime_address() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
598   address heap_region_requested_address() NOT_CDS_JAVA_HEAP_RETURN_(nullptr);
599   narrowOop encoded_heap_region_dumptime_address();
600 
601 private:
602 
603 #if INCLUDE_JVMTI
604   static ClassPathEntry** _classpath_entries_for_jvmti;
605   static ClassPathEntry* get_classpath_entry_for_jvmti(int i, TRAPS);
606 #endif
607 };
608 
609 #endif // SHARE_CDS_FILEMAP_HPP