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