1 /* 2 * Copyright (c) 2014, 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_CLASSFILE_SHAREDPATHSMISCINFO_HPP 26 #define SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP 27 28 #include "classfile/classLoader.hpp" 29 #include "runtime/os.hpp" 30 31 class outputStream; 32 // During dumping time, when processing class paths, we build up the dump-time 33 // classpath. The JAR files that exist are stored in the list ClassLoader::_first_append_entry. 34 // However, we need to store other "misc" information for run-time checking, such as 35 // 36 // + The values of Arguments::get_sysclasspath() used during dumping. 37 // 38 // + The meta-index file(s) used during dumping (incl modification time and size) 39 // 40 // + The class path elements specified during dumping but did not exist -- 41 // these elements must also be specified at run time, and they also must not 42 // exist at run time. 43 // 44 // These misc items are stored in a linear buffer in SharedPathsMiscInfo. 45 // The storage format is stream oriented to minimize its size. 46 // 47 // When writing the information to the archive file, SharedPathsMiscInfo is stored in 48 // the archive file header. At run-time, this information is used only during initialization 49 // (accessed using read() instead of mmap()), and is deallocated afterwards to save space. 50 // 51 // The SharedPathsMiscInfo class is used for both creating the the information (during 52 // dumping time) and validation (at run time). Different constructors are used in the 53 // two situations. See below. 54 55 class SharedPathsMiscInfo : public CHeapObj<mtClass> { 56 protected: 57 char* _buf_start; 58 char* _cur_ptr; 59 char* _end_ptr; 60 int _buf_size; 61 bool _allocated; // was _buf_start allocated by me? 62 void ensure_size(size_t needed_bytes); 63 void add_path(const char* path, int type); 64 65 void write(const void* ptr, size_t size); 66 bool read(void* ptr, size_t size); 67 68 protected: 69 static bool fail(const char* msg, const char* name = NULL); 70 virtual bool check(jint type, const char* path); 71 72 public: 73 enum { 74 INITIAL_BUF_SIZE = 128 75 }; 76 // This constructor is used when creating the misc information (during dump) 77 SharedPathsMiscInfo() { 78 _buf_size = INITIAL_BUF_SIZE; 79 _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass); 80 _allocated = true; 81 } 82 // This constructor is used when validating the misc info (during run time) 83 SharedPathsMiscInfo(char *buff, int size) { 84 _cur_ptr = _buf_start = buff; 85 _end_ptr = _buf_start + size; 86 _buf_size = size; 87 _allocated = false; 88 } 89 ~SharedPathsMiscInfo() { 90 if (_allocated) { 91 FREE_C_HEAP_ARRAY(char, _buf_start); 92 } 93 } 94 int get_used_bytes() { 95 return _cur_ptr - _buf_start; 96 } 97 void* buffer() { 98 return _buf_start; 99 } 100 101 // writing -- 102 103 // The path must not exist at run-time 104 void add_nonexist_path(const char* path) { 105 add_path(path, NON_EXIST); 106 } 107 108 // The path must exist, and must contain exactly <num_entries> files/dirs 109 void add_boot_classpath(const char* path) { 110 add_path(path, BOOT); 111 } 112 int write_jint(jint num) { 113 write(&num, sizeof(num)); 114 return 0; 115 } 116 void write_time(time_t t) { 117 write(&t, sizeof(t)); 118 } 119 void write_long(long l) { 120 write(&l, sizeof(l)); 121 } 122 123 bool dump_to_file(int fd) { 124 int n = get_used_bytes(); 125 return (os::write(fd, _buf_start, n) == (size_t)n); 126 } 127 128 // reading -- 129 130 enum { 131 BOOT = 1, 132 NON_EXIST = 2 133 }; 134 135 virtual const char* type_name(int type) { 136 switch (type) { 137 case BOOT: return "BOOT"; 138 case NON_EXIST: return "NON_EXIST"; 139 default: ShouldNotReachHere(); return "?"; 140 } 141 } 142 143 virtual void print_path(outputStream* os, int type, const char* path); 144 145 bool check(); 146 bool read_jint(jint *ptr) { 147 return read(ptr, sizeof(jint)); 148 } 149 bool read_long(long *ptr) { 150 return read(ptr, sizeof(long)); 151 } 152 bool read_time(time_t *ptr) { 153 return read(ptr, sizeof(time_t)); 154 } 155 }; 156 157 #endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP