1 /*
2 * Copyright (c) 2014, 2016, 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 // During dumping time, when processing class paths, we build up the dump-time
32 // classpath. The JAR files that exist are stored in the list ClassLoader::_first_entry.
33 // However, we need to store other "misc" information for run-time checking, such as
34 //
35 // + The values of Arguments::get_sysclasspath() used during dumping.
36 //
37 // + The meta-index file(s) used during dumping (incl modification time and size)
38 //
39 // + The class path elements specified during dumping but did not exist --
40 // these elements must also be specified at run time, and they also must not
41 // exist at run time.
42 //
43 // These misc items are stored in a linear buffer in SharedPathsMiscInfo.
44 // The storage format is stream oriented to minimize its size.
45 //
46 // When writing the information to the archive file, SharedPathsMiscInfo is stored in
47 // the archive file header. At run-time, this information is used only during initialization
48 // (accessed using read() instead of mmap()), and is deallocated afterwards to save space.
49 //
50 // The SharedPathsMiscInfo class is used for both creating the the information (during
51 // dumping time) and validation (at run time). Different constructors are used in the
52 // two situations. See below.
53
54 class SharedPathsMiscInfo : public CHeapObj<mtClass> {
55 protected:
56 char* _buf_start;
57 char* _cur_ptr;
58 char* _end_ptr;
59 int _buf_size;
60 bool _allocated; // was _buf_start allocated by me?
61 void ensure_size(size_t needed_bytes);
62 void add_path(const char* path, int type);
63
64 void write(const void* ptr, size_t size);
65 bool read(void* ptr, size_t size);
66
67 protected:
68 static bool fail(const char* msg, const char* name = NULL);
69 virtual bool check(jint type, const char* path);
70
71 public:
72 enum {
73 INITIAL_BUF_SIZE = 128
74 };
75 // This constructor is used when creating the misc information (during dump)
76 SharedPathsMiscInfo() {
77 _buf_size = INITIAL_BUF_SIZE;
78 _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass);
79 _allocated = true;
80 }
81 // This constructor is used when validating the misc info (during run time)
82 SharedPathsMiscInfo(char *buff, int size) {
83 _cur_ptr = _buf_start = buff;
84 _end_ptr = _buf_start + size;
85 _buf_size = size;
86 _allocated = false;
87 }
88 ~SharedPathsMiscInfo() {
89 if (_allocated) {
90 FREE_C_HEAP_ARRAY(char, _buf_start);
91 }
92 }
93 int get_used_bytes() {
94 return _cur_ptr - _buf_start;
95 }
96 void* buffer() {
97 return _buf_start;
98 }
99
100 // writing --
101
102 // The path must not exist at run-time
103 void add_nonexist_path(const char* path) {
104 add_path(path, NON_EXIST);
105 }
106
107 // The path must exist, and must contain exactly <num_entries> files/dirs
108 void add_boot_classpath(const char* path) {
109 add_path(path, BOOT);
110 }
111 int write_jint(jint num) {
112 write(&num, sizeof(num));
113 return 0;
114 }
115 void write_time(time_t t) {
116 write(&t, sizeof(t));
117 }
118 void write_long(long l) {
119 write(&l, sizeof(l));
120 }
121
122 bool dump_to_file(int fd) {
123 int n = get_used_bytes();
124 return (os::write(fd, _buf_start, n) == (size_t)n);
125 }
126
127 // reading --
128
129 enum {
130 BOOT = 1,
131 NON_EXIST = 2,
132 REQUIRED = 3
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 case REQUIRED: return "REQUIRED";
140 default: ShouldNotReachHere(); return "?";
141 }
142 }
143
144 virtual void print_path(int type, const char* path) {
145 ResourceMark rm;
146 outputStream* out = LogHandle(classpath)::info_stream();
147 switch (type) {
148 case BOOT:
149 out->print("Expecting -Dsun.boot.class.path=%s", path);
150 break;
151 case NON_EXIST:
152 out->print("Expecting that %s does not exist", path);
153 break;
154 case REQUIRED:
155 out->print("Expecting that file %s must exist and is not altered", path);
156 break;
157 default:
158 ShouldNotReachHere();
159 }
160 }
161
162 bool check();
163 bool read_jint(jint *ptr) {
164 return read(ptr, sizeof(jint));
165 }
166 bool read_long(long *ptr) {
167 return read(ptr, sizeof(long));
168 }
169 bool read_time(time_t *ptr) {
170 return read(ptr, sizeof(time_t));
171 }
172 };
173
174 #endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP