filemap.hpp revision 1472:c18cbe5936b8
1/* 2 * Copyright (c) 2003, 2006, 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// Layout of the file: 26// header: dump of archive instance plus versioning info, datestamp, etc. 27// [magic # = 0xF00BABA2] 28// ... padding to align on page-boundary 29// read-write space from CompactingPermGenGen 30// read-only space from CompactingPermGenGen 31// misc data (block offset table, string table, symbols, dictionary, etc.) 32// tag(666) 33 34static const int JVM_SHARED_JARS_MAX = 128; 35static const int JVM_SPACENAME_MAX = 128; 36static const int JVM_IDENT_MAX = 256; 37static const int JVM_ARCH_MAX = 12; 38 39 40 41class FileMapInfo : public CHeapObj { 42private: 43 enum { 44 _invalid_version = -1, 45 _current_version = 1 46 }; 47 48 bool _file_open; 49 int _fd; 50 long _file_offset; 51 52 // FileMapHeader describes the shared space data in the file to be 53 // mapped. This structure gets written to a file. It is not a class, so 54 // that the compilers don't add any compiler-private data to it. 55 56 struct FileMapHeader { 57 int _magic; // identify file type. 58 int _version; // (from enum, above.) 59 size_t _alignment; // how shared archive should be aligned 60 61 struct space_info { 62 int _file_offset; // sizeof(this) rounded to vm page size 63 char* _base; // copy-on-write base address 64 size_t _capacity; // for validity checking 65 size_t _used; // for setting space top on read 66 bool _read_only; // read only space? 67 bool _allow_exec; // executable code in space? 68 } _space[CompactingPermGenGen::n_regions]; 69 70 // The following fields are all sanity checks for whether this archive 71 // will function correctly with this JVM and the bootclasspath it's 72 // invoked with. 73 char _arch[JVM_ARCH_MAX]; // architecture 74 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 75 int _num_jars; // Number of jars in bootclasspath 76 77 // Per jar file data: timestamp, size. 78 79 struct { 80 time_t _timestamp; // jar timestamp. 81 long _filesize; // jar file size. 82 } _jar[JVM_SHARED_JARS_MAX]; 83 } _header; 84 const char* _full_path; 85 86 static FileMapInfo* _current_info; 87 88 bool init_from_file(int fd); 89 void align_file_position(); 90 91public: 92 FileMapInfo() { 93 _file_offset = 0; 94 _file_open = false; 95 _header._version = _invalid_version; 96 } 97 98 static int current_version() { return _current_version; } 99 void populate_header(size_t alignment); 100 bool validate(); 101 void invalidate(); 102 int version() { return _header._version; } 103 size_t alignment() { return _header._alignment; } 104 size_t space_capacity(int i) { return _header._space[i]._capacity; } 105 char* region_base(int i) { return _header._space[i]._base; } 106 struct FileMapHeader* header() { return &_header; } 107 108 static void set_current_info(FileMapInfo* info) { _current_info = info; } 109 static FileMapInfo* current_info() { return _current_info; } 110 static void assert_mark(bool check); 111 112 // File manipulation. 113 bool initialize(); 114 bool open_for_read(); 115 void open_for_write(); 116 void write_header(); 117 void write_space(int i, CompactibleSpace* space, bool read_only); 118 void write_region(int region, char* base, size_t size, 119 size_t capacity, bool read_only, bool allow_exec); 120 void write_bytes(const void* buffer, int count); 121 void write_bytes_aligned(const void* buffer, int count); 122 bool map_space(int i, ReservedSpace rs, ContiguousSpace *space); 123 char* map_region(int i, ReservedSpace rs); 124 char* map_region(int i, bool address_must_match); 125 void unmap_region(int i); 126 void close(); 127 bool is_open() { return _file_open; } 128 129 // JVM/TI RedefineClasses() support: 130 // Remap the shared readonly space to shared readwrite, private. 131 bool remap_shared_readonly_as_readwrite(); 132 133 // Errors. 134 static void fail_stop(const char *msg, ...); 135 void fail_continue(const char *msg, ...); 136 137 // Return true if given address is in the mapped shared space. 138 bool is_in_shared_space(const void* p); 139}; 140