1 /* 2 * Copyright (c) 2003, 2014, 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 #include "memory/metaspace.hpp" 30 31 // Layout of the file: 32 // header: dump of archive instance plus versioning info, datestamp, etc. 33 // [magic # = 0xF00BABA2] 34 // ... padding to align on page-boundary 35 // read-write space 36 // read-only space 37 // misc data (block offset table, string table, symbols, dictionary, etc.) 38 // tag(666) 39 40 static const int JVM_SHARED_JARS_MAX = 128; 41 static const int JVM_SPACENAME_MAX = 128; 42 static const int JVM_IDENT_MAX = 256; 43 static const int JVM_ARCH_MAX = 12; 44 45 46 class Metaspace; 47 48 class FileMapInfo : public CHeapObj<mtInternal> { 49 private: 50 enum { 51 _invalid_version = -1, 52 _current_version = 1 53 }; 54 55 bool _file_open; 56 int _fd; 57 long _file_offset; 58 59 // FileMapHeader describes the shared space data in the file to be 60 // mapped. This structure gets written to a file. It is not a class, so 61 // that the compilers don't add any compiler-private data to it. 62 63 struct FileMapHeader { 64 int _magic; // identify file type. 65 int _version; // (from enum, above.) 66 size_t _alignment; // how shared archive should be aligned 67 int _obj_alignment; // value of ObjectAlignmentInBytes 68 69 struct space_info { 70 int _file_offset; // sizeof(this) rounded to vm page size 71 char* _base; // copy-on-write base address 72 size_t _capacity; // for validity checking 73 size_t _used; // for setting space top on read 74 bool _read_only; // read only space? 75 bool _allow_exec; // executable code in space? 76 } _space[MetaspaceShared::n_regions]; 77 78 // The following fields are all sanity checks for whether this archive 79 // will function correctly with this JVM and the bootclasspath it's 80 // invoked with. 81 char _arch[JVM_ARCH_MAX]; // architecture 82 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm 83 int _num_jars; // Number of jars in bootclasspath 84 85 // Per jar file data: timestamp, size. 86 87 struct { 88 time_t _timestamp; // jar timestamp. 89 long _filesize; // jar file size. 90 } _jar[JVM_SHARED_JARS_MAX]; 91 } _header; 92 const char* _full_path; 93 94 static FileMapInfo* _current_info; 95 96 bool init_from_file(int fd); 97 void align_file_position(); 98 99 public: 100 FileMapInfo() { 101 _file_offset = 0; 102 _file_open = false; 103 _header._version = _invalid_version; 104 } 105 106 static int current_version() { return _current_version; } 107 void populate_header(size_t alignment); 108 bool validate(); 109 void invalidate(); 110 int version() { return _header._version; } 111 size_t alignment() { return _header._alignment; } 112 size_t space_capacity(int i) { return _header._space[i]._capacity; } 113 char* region_base(int i) { return _header._space[i]._base; } 114 struct FileMapHeader* header() { return &_header; } 115 116 static void set_current_info(FileMapInfo* info) { 117 CDS_ONLY(_current_info = info;) 118 } 119 120 static FileMapInfo* current_info() { 121 CDS_ONLY(return _current_info;) 122 NOT_CDS(return NULL;) 123 } 124 125 static void assert_mark(bool check); 126 127 // File manipulation. 128 bool initialize() NOT_CDS_RETURN_(false); 129 bool open_for_read(); 130 void open_for_write(); 131 void write_header(); 132 void write_space(int i, Metaspace* space, bool read_only); 133 void write_region(int region, char* base, size_t size, 134 size_t capacity, bool read_only, bool allow_exec); 135 void write_bytes(const void* buffer, int count); 136 void write_bytes_aligned(const void* buffer, int count); 137 char* map_region(int i); 138 void unmap_region(int i); 139 void close(); 140 bool is_open() { return _file_open; } 141 ReservedSpace reserve_shared_memory(); 142 143 // JVM/TI RedefineClasses() support: 144 // Remap the shared readonly space to shared readwrite, private. 145 bool remap_shared_readonly_as_readwrite(); 146 147 // Errors. 148 static void fail_stop(const char *msg, ...); 149 void fail_continue(const char *msg, ...); 150 151 // Return true if given address is in the mapped shared space. 152 bool is_in_shared_space(const void* p) NOT_CDS_RETURN_(false); 153 void print_shared_spaces() NOT_CDS_RETURN; 154 155 static size_t shared_spaces_size() { 156 return align_size_up(SharedReadOnlySize + SharedReadWriteSize + 157 SharedMiscDataSize + SharedMiscCodeSize, 158 os::vm_allocation_granularity()); 159 } 160 161 // Stop CDS sharing and unmap CDS regions. 162 static void stop_sharing_and_unmap(const char* msg); 163 }; 164 165 #endif // SHARE_VM_MEMORY_FILEMAP_HPP