1 /*
2 * Copyright (c) 2014, 2015, 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 static void trace_class_path(const char* msg, const char* name = NULL) {
68 ClassLoader::trace_class_path(tty, msg, name);
69 }
70 protected:
71 static bool fail(const char* msg, const char* name = NULL);
72 virtual bool check(jint type, const char* path);
73
74 public:
75 enum {
76 INITIAL_BUF_SIZE = 128
77 };
78 // This constructor is used when creating the misc information (during dump)
79 SharedPathsMiscInfo() {
80 _buf_size = INITIAL_BUF_SIZE;
81 _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass);
82 _allocated = true;
83 }
84 // This constructor is used when validating the misc info (during run time)
85 SharedPathsMiscInfo(char *buff, int size) {
86 _cur_ptr = _buf_start = buff;
87 _end_ptr = _buf_start + size;
88 _buf_size = size;
89 _allocated = false;
90 }
91 ~SharedPathsMiscInfo() {
92 if (_allocated) {
93 FREE_C_HEAP_ARRAY(char, _buf_start);
94 }
95 }
96 int get_used_bytes() {
97 return _cur_ptr - _buf_start;
98 }
99 void* buffer() {
100 return _buf_start;
101 }
102
103 // writing --
104
105 // The path must not exist at run-time
106 void add_nonexist_path(const char* path) {
107 add_path(path, NON_EXIST);
108 }
109
110 // The path must exist, and must contain exactly <num_entries> files/dirs
111 void add_boot_classpath(const char* path) {
112 add_path(path, BOOT);
113 }
114 int write_jint(jint num) {
115 write(&num, sizeof(num));
116 return 0;
117 }
118 void write_time(time_t t) {
119 write(&t, sizeof(t));
120 }
121 void write_long(long l) {
122 write(&l, sizeof(l));
123 }
124
125 bool dump_to_file(int fd) {
126 int n = get_used_bytes();
127 return (os::write(fd, _buf_start, n) == (size_t)n);
128 }
129
130 // reading --
131
132 enum {
133 BOOT = 1,
134 NON_EXIST = 2,
135 REQUIRED = 3
136 };
137
138 virtual const char* type_name(int type) {
139 switch (type) {
140 case BOOT: return "BOOT";
141 case NON_EXIST: return "NON_EXIST";
142 case REQUIRED: return "REQUIRED";
143 default: ShouldNotReachHere(); return "?";
144 }
145 }
146
147 virtual void print_path(outputStream* out, int type, const char* path) {
148 switch (type) {
149 case BOOT:
150 out->print("Expecting -Dsun.boot.class.path=%s", path);
151 break;
152 case NON_EXIST:
153 out->print("Expecting that %s does not exist", path);
154 break;
155 case REQUIRED:
156 out->print("Expecting that file %s must exist and is not altered", path);
157 break;
158 default:
159 ShouldNotReachHere();
160 }
161 }
162
163 bool check();
164 bool read_jint(jint *ptr) {
165 return read(ptr, sizeof(jint));
166 }
167 bool read_long(long *ptr) {
168 return read(ptr, sizeof(long));
169 }
170 bool read_time(time_t *ptr) {
171 return read(ptr, sizeof(time_t));
172 }
173 };
174
175 #endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP