1 /* 2 * Copyright (c) 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_CLASSFILE_SHAREDPATHSMISCINFO_HPP 26 #define SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP 27 28 #include "runtime/os.hpp" 29 30 // During dumping time, when processing class paths, we build up the dump-time 31 // classpath. The JAR files that exist are stored in the list ClassLoader::_first_entry. 32 // However, we need to store other "misc" information for run-time checking, such as 33 // 34 // + The values of Arguments::get_sysclasspath() used during dumping. 35 // 36 // + The meta-index file(s) used during dumping (incl modification time and size) 37 // 38 // + The class path elements specified during dumping but did not exist -- 39 // these elements must also be specified at run time, and they also must not 40 // exist at run time. 41 // 42 // These misc items are stored in a linear buffer in SharedPathsMiscInfo. 43 // The storage format is stream oriented to minimize its size. 44 // 45 // When writing the information to the archive file, SharedPathsMiscInfo is stored in 46 // the archive file header. At run-time, this information is used only during initialization 47 // (accessed using read() instead of mmap()), and is deallocated afterwards to save space. 48 // 49 // The SharedPathsMiscInfo class is used for both creating the the information (during 50 // dumping time) and validation (at run time). Different constructors are used in the 51 // two situations. See below. 52 53 class SharedPathsMiscInfo : public CHeapObj<mtClass> { 54 protected: 55 char* _buf_start; 56 char* _cur_ptr; 57 char* _end_ptr; 58 int _buf_size; 59 bool _allocated; // was _buf_start allocated by me? 60 void ensure_size(size_t needed_bytes); 61 void add_path(const char* path, int type); 62 63 void write(const void* ptr, size_t size); 64 bool read(void* ptr, size_t size); 65 66 static void trace_class_path(const char* msg, const char* name = NULL) { 67 ClassLoader::trace_class_path(msg, name); 68 } 69 protected: 70 static bool fail(const char* msg, const char* name = NULL); 71 virtual bool check(jint type, const char* path); 72 73 public: 74 enum { 75 INITIAL_BUF_SIZE = 128 76 }; 77 // This constructor is used when creating the misc information (during dump) 78 SharedPathsMiscInfo() { 79 _buf_size = INITIAL_BUF_SIZE; 80 _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass); 81 _allocated = true; 82 } 83 // This constructor is used when validating the misc info (during run time) 84 SharedPathsMiscInfo(char *buff, int size) { 85 _cur_ptr = _buf_start = buff; 86 _end_ptr = _buf_start + size; 87 _buf_size = size; 88 _allocated = false; 89 } 90 ~SharedPathsMiscInfo() { 91 if (_allocated) { 92 FREE_C_HEAP_ARRAY(char, _buf_start, mtClass); 93 } 94 } 95 int get_used_bytes() { 96 return _cur_ptr - _buf_start; 97 } 98 void* buffer() { 99 return _buf_start; 100 } 101 102 // writing -- 103 104 // The path must not exist at run-time 105 void add_nonexist_path(const char* path) { 106 add_path(path, NON_EXIST); 107 } 108 109 // The path must exist and have required size and modification time 110 void add_required_file(const char* path) { 111 add_path(path, REQUIRED); 112 113 struct stat st; 114 if (os::stat(path, &st) != 0) { 115 assert(0, "sanity"); 116 ClassLoader::exit_with_path_failure("failed to os::stat(%s)", path); // should not happen 117 } 118 write_time(st.st_mtime); 119 write_long(st.st_size); 120 } 121 122 // The path must exist, and must contain exactly <num_entries> files/dirs 123 void add_boot_classpath(const char* path) { 124 add_path(path, BOOT); 125 } 126 int write_jint(jint num) { 127 write(&num, sizeof(num)); 128 return 0; 129 } 130 void write_time(time_t t) { 131 write(&t, sizeof(t)); 132 } 133 void write_long(long l) { 134 write(&l, sizeof(l)); 135 } 136 137 bool dump_to_file(int fd) { 138 int n = get_used_bytes(); 139 return (os::write(fd, _buf_start, n) == (size_t)n); 140 } 141 142 // reading -- 143 144 enum { 145 BOOT = 1, 146 NON_EXIST = 2, 147 REQUIRED = 3 148 }; 149 150 virtual const char* type_name(int type) { 151 switch (type) { 152 case BOOT: return "BOOT"; 153 case NON_EXIST: return "NON_EXIST"; 154 case REQUIRED: return "REQUIRED"; 155 default: ShouldNotReachHere(); return "?"; 156 } 157 } 158 159 virtual void print_path(outputStream* out, int type, const char* path) { 160 switch (type) { 161 case BOOT: 162 out->print("Expecting -Dsun.boot.class.path=%s", path); 163 break; 164 case NON_EXIST: 165 out->print("Expecting that %s does not exist", path); 166 break; 167 case REQUIRED: 168 out->print("Expecting that file %s must exist and is not altered", path); 169 break; 170 default: 171 ShouldNotReachHere(); 172 } 173 } 174 175 bool check(); 176 bool read_jint(jint *ptr) { 177 return read(ptr, sizeof(jint)); 178 } 179 bool read_long(long *ptr) { 180 return read(ptr, sizeof(long)); 181 } 182 bool read_time(time_t *ptr) { 183 return read(ptr, sizeof(time_t)); 184 } 185 }; 186 187 #endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP