filemap.hpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 2003, 2012, 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 30// Layout of the file: 31// header: dump of archive instance plus versioning info, datestamp, etc. 32// [magic # = 0xF00BABA2] 33// ... padding to align on page-boundary 34// read-write space from CompactingPermGenGen 35// read-only space from CompactingPermGenGen 36// misc data (block offset table, string table, symbols, dictionary, etc.) 37// tag(666) 38 39static const int JVM_SHARED_JARS_MAX = 128; 40static const int JVM_SPACENAME_MAX = 128; 41static const int JVM_IDENT_MAX = 256; 42static const int JVM_ARCH_MAX = 12; 43 44 45class Metaspace; 46 47class FileMapInfo : public CHeapObj<mtInternal> { 48private: 49 enum { 50 _invalid_version = -1, 51 _current_version = 1 52 }; 53 54 bool _file_open; 55 int _fd; 56 long _file_offset; 57 58 // FileMapHeader describes the shared space data in the file to be 59 // mapped. This structure gets written to a file. It is not a class, so 60 // that the compilers don't add any compiler-private data to it. 61 62 struct FileMapHeader { 63 int _magic; // identify file type. 64 int _version; // (from enum, above.) 65 size_t _alignment; // how shared archive should be aligned 66 67 struct space_info { 68 int _file_offset; // sizeof(this) rounded to vm page size 69 char* _base; // copy-on-write base address 70 size_t _capacity; // for validity checking 71 size_t _used; // for setting space top on read 72 bool _read_only; // read only space? 73 bool _allow_exec; // executable code in space? 74 } _space[MetaspaceShared::n_regions]; 75 76 // The following fields are all sanity checks for whether this archive 77 // will function correctly with this JVM and the bootclasspath it's 78 // invoked with. 79 char _arch[JVM_ARCH_MAX]; // architecture 80 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 81 int _num_jars; // Number of jars in bootclasspath 82 83 // Per jar file data: timestamp, size. 84 85 struct { 86 time_t _timestamp; // jar timestamp. 87 long _filesize; // jar file size. 88 } _jar[JVM_SHARED_JARS_MAX]; 89 } _header; 90 const char* _full_path; 91 92 static FileMapInfo* _current_info; 93 94 bool init_from_file(int fd); 95 void align_file_position(); 96 97public: 98 FileMapInfo() { 99 _file_offset = 0; 100 _file_open = false; 101 _header._version = _invalid_version; 102 } 103 104 static int current_version() { return _current_version; } 105 void populate_header(size_t alignment); 106 bool validate(); 107 void invalidate(); 108 int version() { return _header._version; } 109 size_t alignment() { return _header._alignment; } 110 size_t space_capacity(int i) { return _header._space[i]._capacity; } 111 char* region_base(int i) { return _header._space[i]._base; } 112 struct FileMapHeader* header() { return &_header; } 113 114 static void set_current_info(FileMapInfo* info) { _current_info = info; } 115 static FileMapInfo* current_info() { return _current_info; } 116 static void assert_mark(bool check); 117 118 // File manipulation. 119 bool initialize(); 120 bool open_for_read(); 121 void open_for_write(); 122 void write_header(); 123 void write_space(int i, Metaspace* space, bool read_only); 124 void write_region(int region, char* base, size_t size, 125 size_t capacity, bool read_only, bool allow_exec); 126 void write_bytes(const void* buffer, int count); 127 void write_bytes_aligned(const void* buffer, int count); 128 char* map_region(int i, ReservedSpace rs); 129 char* map_region(int i); 130 void unmap_region(int i); 131 void close(); 132 bool is_open() { return _file_open; } 133 ReservedSpace reserve_shared_memory(); 134 135 // JVM/TI RedefineClasses() support: 136 // Remap the shared readonly space to shared readwrite, private. 137 bool remap_shared_readonly_as_readwrite(); 138 139 // Errors. 140 static void fail_stop(const char *msg, ...); 141 void fail_continue(const char *msg, ...); 142 143 // Return true if given address is in the mapped shared space. 144 bool is_in_shared_space(const void* p); 145}; 146 147#endif // SHARE_VM_MEMORY_FILEMAP_HPP 148