1 /*
2 * Copyright (c) 2003, 2006, 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 // Layout of the file:
26 // header: dump of archive instance plus versioning info, datestamp, etc.
27 // [magic # = 0xF00BABA2]
28 // ... padding to align on page-boundary
29 // read-write space from CompactingPermGenGen
30 // read-only space from CompactingPermGenGen
31 // misc data (block offset table, string table, symbols, dictionary, etc.)
32 // tag(666)
33
34 static const int JVM_SHARED_JARS_MAX = 128;
35 static const int JVM_SPACENAME_MAX = 128;
36 static const int JVM_IDENT_MAX = 256;
37 static const int JVM_ARCH_MAX = 12;
38
39
40
41 class FileMapInfo : public CHeapObj {
42 private:
43 enum {
44 _invalid_version = -1,
45 _current_version = 1
46 };
47
48 bool _file_open;
49 int _fd;
50 long _file_offset;
51
52 // FileMapHeader describes the shared space data in the file to be
53 // mapped. This structure gets written to a file. It is not a class, so
54 // that the compilers don't add any compiler-private data to it.
55
56 struct FileMapHeader {
57 int _magic; // identify file type.
58 int _version; // (from enum, above.)
59 size_t _alignment; // how shared archive should be aligned
60
61 struct space_info {
62 int _file_offset; // sizeof(this) rounded to vm page size
63 char* _base; // copy-on-write base address
64 size_t _capacity; // for validity checking
65 size_t _used; // for setting space top on read
66 bool _read_only; // read only space?
67 bool _allow_exec; // executable code in space?
68 } _space[CompactingPermGenGen::n_regions];
69
70 // The following fields are all sanity checks for whether this archive
71 // will function correctly with this JVM and the bootclasspath it's
72 // invoked with.
73 char _arch[JVM_ARCH_MAX]; // architecture
74 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm
75 int _num_jars; // Number of jars in bootclasspath
76
77 // Per jar file data: timestamp, size.
78
79 struct {
80 time_t _timestamp; // jar timestamp.
81 long _filesize; // jar file size.
82 } _jar[JVM_SHARED_JARS_MAX];
83 } _header;
84 const char* _full_path;
85
86 static FileMapInfo* _current_info;
87
88 bool init_from_file(int fd);
89 void align_file_position();
90
91 public:
92 FileMapInfo() {
93 _file_offset = 0;
94 _file_open = false;
95 _header._version = _invalid_version;
96 }
97
98 static int current_version() { return _current_version; }
99 void populate_header(size_t alignment);
100 bool validate();
101 void invalidate();
102 int version() { return _header._version; }
103 size_t alignment() { return _header._alignment; }
104 size_t space_capacity(int i) { return _header._space[i]._capacity; }
105 char* region_base(int i) { return _header._space[i]._base; }
106 struct FileMapHeader* header() { return &_header; }
107
108 static void set_current_info(FileMapInfo* info) { _current_info = info; }
109 static FileMapInfo* current_info() { return _current_info; }
110 static void assert_mark(bool check);
111
112 // File manipulation.
113 bool initialize();
114 bool open_for_read();
115 void open_for_write();
116 void write_header();
117 void write_space(int i, CompactibleSpace* space, bool read_only);
118 void write_region(int region, char* base, size_t size,
119 size_t capacity, bool read_only, bool allow_exec);
120 void write_bytes(const void* buffer, int count);
121 void write_bytes_aligned(const void* buffer, int count);
122 bool map_space(int i, ReservedSpace rs, ContiguousSpace *space);
123 char* map_region(int i, ReservedSpace rs);
124 char* map_region(int i, bool address_must_match);
125 void unmap_region(int i);
126 void close();
127 bool is_open() { return _file_open; }
128
129 // JVM/TI RedefineClasses() support:
130 // Remap the shared readonly space to shared readwrite, private.
131 bool remap_shared_readonly_as_readwrite();
132
133 // Errors.
134 static void fail_stop(const char *msg, ...);
135 void fail_continue(const char *msg, ...);
136
137 // Return true if given address is in the mapped shared space.
138 bool is_in_shared_space(const void* p);
139 };