1 /*

     2  * Copyright (c) 2003, 2017, 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 VALUE_OBJ_CLASS_SPEC {

    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_jrt() { return ClassLoader::is_jrt(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   enum {

    79     _invalid_version = -1,

    80     _current_version = 3

    81   };

    82 

    83   bool  _file_open;

    84   int   _fd;

    85   size_t  _file_offset;

    86 

    87 private:

    88   static Array<u8>*            _classpath_entry_table;

    89   static int                   _classpath_entry_table_size;

    90   static size_t                _classpath_entry_size;

    91   static bool                  _validating_classpath_entry_table;

    92 

    93   // FileMapHeader describes the shared space data in the file to be

    94   // mapped.  This structure gets written to a file.  It is not a class, so

    95   // that the compilers don't add any compiler-private data to it.

    96 

    97 public:

    98   struct FileMapHeaderBase : public CHeapObj<mtClass> {

    99     virtual bool validate() = 0;

   100     virtual void populate(FileMapInfo* info, size_t alignment) = 0;

   101   };

   102   struct FileMapHeader : FileMapHeaderBase {

   103     // Use data() and data_size() to memcopy to/from the FileMapHeader. We need to

   104     // avoid read/writing the C++ vtable pointer.

   105     static size_t data_size();

   106     char* data() {

   107       return ((char*)this) + sizeof(FileMapHeaderBase);

   108     }

   109 

   110     int    _magic;                    // identify file type.

   111     int    _crc;                      // header crc checksum.

   112     int    _version;                  // (from enum, above.)

   113     size_t _alignment;                // how shared archive should be aligned

   114     int    _obj_alignment;            // value of ObjectAlignmentInBytes

   115     int    _narrow_oop_shift;         // compressed oop encoding shift

   116     bool   _compact_strings;          // value of CompactStrings

   117     uintx  _max_heap_size;            // java max heap size during dumping

   118     Universe::NARROW_OOP_MODE _narrow_oop_mode; // compressed oop encoding mode

   119     int     _narrow_klass_shift;      // save narrow klass base and shift

   120     address _narrow_klass_base;

   121     char*   _misc_data_patching_start;

   122     char*   _read_only_tables_start;

   123     address _cds_i2i_entry_code_buffers;

   124     size_t  _cds_i2i_entry_code_buffers_size;

   125     size_t  _core_spaces_size;        // number of bytes allocated by the core spaces

   126                                       // (mc, md, ro, rw and od).

   127 

   128     struct space_info {

   129       int    _crc;           // crc checksum of the current space

   130       size_t _file_offset;   // sizeof(this) rounded to vm page size

   131       union {

   132         char*  _base;        // copy-on-write base address

   133         intx   _offset;      // offset from the compressed oop encoding base, only used

   134                              // by string space

   135       } _addr;

   136       size_t _used;          // for setting space top on read

   137       bool   _read_only;     // read only space?

   138       bool   _allow_exec;    // executable code in space?

   139     } _space[MetaspaceShared::n_regions];

   140 

   141     // The following fields are all sanity checks for whether this archive

   142     // will function correctly with this JVM and the bootclasspath it's

   143     // invoked with.

   144     char  _jvm_ident[JVM_IDENT_MAX];      // identifier for jvm

   145 

   146     // The _paths_misc_info is a variable-size structure that records "miscellaneous"

   147     // information during dumping. It is generated and validated by the

   148     // SharedPathsMiscInfo class. See SharedPathsMiscInfo.hpp and sharedClassUtil.hpp for

   149     // detailed description.

   150     //

   151     // The _paths_misc_info data is stored as a byte array in the archive file header,

   152     // immediately after the _header field. This information is used only when

   153     // checking the validity of the archive and is deallocated after the archive is loaded.

   154     //

   155     // Note that the _paths_misc_info does NOT include information for JAR files

   156     // that existed during dump time. Their information is stored in _classpath_entry_table.

   157     int _paths_misc_info_size;

   158 

   159     // The following is a table of all the class path entries that were used

   160     // during dumping. At run time, we require these files to exist and have the same

   161     // size/modification time, or else the archive will refuse to load.

   162     //

   163     // All of these entries must be JAR files. The dumping process would fail if a non-empty

   164     // directory was specified in the classpaths. If an empty directory was specified

   165     // it is checked by the _paths_misc_info as described above.

   166     //

   167     // FIXME -- if JAR files in the tail of the list were specified but not used during dumping,

   168     // they should be removed from this table, to save space and to avoid spurious

   169     // loading failures during runtime.

   170     int _classpath_entry_table_size;

   171     size_t _classpath_entry_size;

   172     Array<u8>* _classpath_entry_table;

   173 

   174     char* region_addr(int idx);

   175 

   176     virtual bool validate();

   177     virtual void populate(FileMapInfo* info, size_t alignment);

   178     int compute_crc();

   179   };

   180 

   181   FileMapHeader * _header;

   182 

   183   const char* _full_path;

   184   char* _paths_misc_info;

   185 

   186   static FileMapInfo* _current_info;

   187 

   188   bool  init_from_file(int fd);

   189   void  align_file_position();

   190   bool  validate_header_impl();

   191   static void metaspace_pointers_do(MetaspaceClosure* it);

   192 

   193 public:

   194   FileMapInfo();

   195   ~FileMapInfo();

   196 

   197   static int current_version()        { return _current_version; }

   198   int    compute_header_crc()         { return _header->compute_crc(); }

   199   void   set_header_crc(int crc)      { _header->_crc = crc; }

   200   void   populate_header(size_t alignment);

   201   bool   validate_header();

   202   void   invalidate();

   203   int    version()                    { return _header->_version; }

   204   size_t alignment()                  { return _header->_alignment; }

   205   Universe::NARROW_OOP_MODE narrow_oop_mode() { return _header->_narrow_oop_mode; }

   206   int    narrow_oop_shift()           { return _header->_narrow_oop_shift; }

   207   uintx  max_heap_size()              { return _header->_max_heap_size; }

   208   address narrow_klass_base() const   { return _header->_narrow_klass_base; }

   209   int     narrow_klass_shift() const  { return _header->_narrow_klass_shift; }

   210   struct FileMapHeader* header()      { return _header; }

   211   char* misc_data_patching_start()            { return _header->_misc_data_patching_start; }

   212   void set_misc_data_patching_start(char* p)  { _header->_misc_data_patching_start = p; }

   213   char* read_only_tables_start()              { return _header->_read_only_tables_start; }

   214   void set_read_only_tables_start(char* p)    { _header->_read_only_tables_start = p; }

   215 

   216   address cds_i2i_entry_code_buffers() {

   217     return _header->_cds_i2i_entry_code_buffers;

   218   }

   219   void set_cds_i2i_entry_code_buffers(address addr) {

   220     _header->_cds_i2i_entry_code_buffers = addr;

   221   }

   222   size_t cds_i2i_entry_code_buffers_size() {

   223     return _header->_cds_i2i_entry_code_buffers_size;

   224   }

   225   void set_cds_i2i_entry_code_buffers_size(size_t s) {

   226     _header->_cds_i2i_entry_code_buffers_size = s;

   227   }

   228   void set_core_spaces_size(size_t s)    {  _header->_core_spaces_size = s; }

   229   size_t core_spaces_size()              { return _header->_core_spaces_size; }

   230 

   231   static FileMapInfo* current_info() {

   232     CDS_ONLY(return _current_info;)

   233     NOT_CDS(return NULL;)

   234   }

   235 

   236   static void assert_mark(bool check);

   237 

   238   // File manipulation.

   239   bool  initialize() NOT_CDS_RETURN_(false);

   240   bool  open_for_read();

   241   void  open_for_write();

   242   void  write_header();

   243   void  write_region(int region, char* base, size_t size,

   244                      bool read_only, bool allow_exec);

   245   size_t write_archive_heap_regions(GrowableArray<MemRegion> *heap_mem,

   246                                     int first_region_id, int max_num_regions);

   247   void  write_bytes(const void* buffer, int count);

   248   void  write_bytes_aligned(const void* buffer, int count);

   249   char* map_region(int i);

   250   void  map_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;

   251   void  fixup_mapped_heap_regions() NOT_CDS_JAVA_HEAP_RETURN;

   252   void  unmap_region(int i);

   253   bool  verify_region_checksum(int i);

   254   void  close();

   255   bool  is_open() { return _file_open; }

   256   ReservedSpace reserve_shared_memory();

   257 

   258   // JVM/TI RedefineClasses() support:

   259   // Remap the shared readonly space to shared readwrite, private.

   260   bool  remap_shared_readonly_as_readwrite();

   261 

   262   // Errors.

   263   static void fail_stop(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);

   264   static void fail_continue(const char *msg, ...) ATTRIBUTE_PRINTF(1, 2);

   265 

   266   // Return true if given address is in the mapped shared space.

   267   bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false);

   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