1 /*
2 * Copyright (c) 2014, 2019, 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_CLASSFILE_SHAREDPATHSMISCINFO_HPP
26 #define SHARE_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 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 private:
55 int _app_offset;
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 bool check(jint type, const char* path, bool is_static);
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 // This constructor is used when validating the misc info (during run time)
79 SharedPathsMiscInfo(char *buff, int size) {
80 _app_offset = 0;
81 _cur_ptr = _buf_start = buff;
82 _end_ptr = _buf_start + size;
83 _buf_size = size;
84 _allocated = false;
85 }
86 ~SharedPathsMiscInfo();
87
88 int get_used_bytes() {
89 return _cur_ptr - _buf_start;
90 }
91 void* buffer() {
92 return _buf_start;
93 }
94
95 // writing --
96
97 // The path must not exist at run-time
98 void add_nonexist_path(const char* path) {
99 add_path(path, NON_EXIST);
100 }
101
102 // The path must exist, and must contain exactly <num_entries> files/dirs
103 void add_boot_classpath(const char* path) {
104 add_path(path, BOOT_PATH);
105 }
106
107 void add_app_classpath(const char* path) {
108 add_path(path, APP_PATH);
109 }
110 void record_app_offset() {
111 _app_offset = get_used_bytes();
112 }
113 void pop_app() {
114 _cur_ptr = _buf_start + _app_offset;
115 write_jint(0);
116 }
117
118 int write_jint(jint num) {
119 write(&num, sizeof(num));
120 return 0;
121 }
122 void write_time(time_t t) {
123 write(&t, sizeof(t));
124 }
125 void write_long(long l) {
126 write(&l, sizeof(l));
127 }
128
129 bool dump_to_file(int fd) {
130 int n = get_used_bytes();
131 return (os::write(fd, _buf_start, n) == (size_t)n);
132 }
133
134 // reading --
135
136 private:
137 enum {
138 BOOT_PATH = 1,
139 APP_PATH = 2,
140 NON_EXIST = 3
141 };
142
143 const char* type_name(int type) {
144 switch (type) {
145 case BOOT_PATH: return "BOOT";
146 case APP_PATH: return "APP";
147 case NON_EXIST: return "NON_EXIST";
148 default: ShouldNotReachHere(); return "?";
149 }
150 }
151
152 void print_path(outputStream* os, int type, const char* path);
153
154 bool read_jint(jint *ptr) {
155 return read(ptr, sizeof(jint));
156 }
157 bool read_long(long *ptr) {
158 return read(ptr, sizeof(long));
159 }
160 bool read_time(time_t *ptr) {
161 return read(ptr, sizeof(time_t));
162 }
163
164 public:
165 bool check(bool is_static);
166 };
167
168 #endif // SHARE_CLASSFILE_SHAREDPATHSMISCINFO_HPP