1 /*
2 * Copyright (c) 2003, 2010, 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_MEMORY_FILEMAP_HPP
26 #define SHARE_VM_MEMORY_FILEMAP_HPP
27
28 #include "memory/compactingPermGenGen.hpp"
29 #include "memory/space.hpp"
30
31 // Layout of the file:
32 // header: dump of archive instance plus versioning info, datestamp, etc.
33 // [magic # = 0xF00BABA2]
34 // ... padding to align on page-boundary
35 // read-write space from CompactingPermGenGen
36 // read-only space from CompactingPermGenGen
37 // misc data (block offset table, string table, symbols, dictionary, etc.)
38 // tag(666)
39
40 static const int JVM_SHARED_JARS_MAX = 128;
41 static const int JVM_SPACENAME_MAX = 128;
42 static const int JVM_IDENT_MAX = 256;
43 static const int JVM_ARCH_MAX = 12;
44
45
46
47 class FileMapInfo : public CHeapObj {
48 private:
49 enum {
50 _invalid_version = -1,
51 _current_version = 1
52 };
53
54 bool _file_open;
55 int _fd;
56 long _file_offset;
57
58 // FileMapHeader describes the shared space data in the file to be
59 // mapped. This structure gets written to a file. It is not a class, so
60 // that the compilers don't add any compiler-private data to it.
61
62 struct FileMapHeader {
63 int _magic; // identify file type.
64 int _version; // (from enum, above.)
65 size_t _alignment; // how shared archive should be aligned
66
67 struct space_info {
68 int _file_offset; // sizeof(this) rounded to vm page size
69 char* _base; // copy-on-write base address
70 size_t _capacity; // for validity checking
71 size_t _used; // for setting space top on read
72 bool _read_only; // read only space?
73 bool _allow_exec; // executable code in space?
74 } _space[CompactingPermGenGen::n_regions];
75
76 // The following fields are all sanity checks for whether this archive
77 // will function correctly with this JVM and the bootclasspath it's
78 // invoked with.
79 char _arch[JVM_ARCH_MAX]; // architecture
80 char _jvm_ident[JVM_IDENT_MAX]; // identifier for jvm
81 int _num_jars; // Number of jars in bootclasspath
82
83 // Per jar file data: timestamp, size.
84
85 struct {
86 time_t _timestamp; // jar timestamp.
87 long _filesize; // jar file size.
88 } _jar[JVM_SHARED_JARS_MAX];
89 } _header;
90 const char* _full_path;
91
92 static FileMapInfo* _current_info;
93
94 bool init_from_file(int fd);
95 void align_file_position();
96
97 public:
98 FileMapInfo() {
99 _file_offset = 0;
100 _file_open = false;
101 _header._version = _invalid_version;
102 }
103
104 static int current_version() { return _current_version; }
105 void populate_header(size_t alignment);
106 bool validate();
107 void invalidate();
108 int version() { return _header._version; }
109 size_t alignment() { return _header._alignment; }
110 size_t space_capacity(int i) { return _header._space[i]._capacity; }
111 char* region_base(int i) { return _header._space[i]._base; }
112 struct FileMapHeader* header() { return &_header; }
113
114 static void set_current_info(FileMapInfo* info) { _current_info = info; }
115 static FileMapInfo* current_info() { return _current_info; }
116 static void assert_mark(bool check);
117
118 // File manipulation.
119 bool initialize();
120 bool open_for_read();
121 void open_for_write();
122 void write_header();
123 void write_space(int i, CompactibleSpace* space, bool read_only);
124 void write_region(int region, char* base, size_t size,
125 size_t capacity, bool read_only, bool allow_exec);
126 void write_bytes(const void* buffer, int count);
127 void write_bytes_aligned(const void* buffer, int count);
128 bool map_space(int i, ReservedSpace rs, ContiguousSpace *space);
129 char* map_region(int i, ReservedSpace rs);
130 char* map_region(int i, bool address_must_match);
131 void unmap_region(int i);
132 void close();
133 bool is_open() { return _file_open; }
134
135 // JVM/TI RedefineClasses() support:
136 // Remap the shared readonly space to shared readwrite, private.
137 bool remap_shared_readonly_as_readwrite();
138
139 // Errors.
140 static void fail_stop(const char *msg, ...);
141 void fail_continue(const char *msg, ...);
142
143 // Return true if given address is in the mapped shared space.
144 bool is_in_shared_space(const void* p);
145 };
146
147 #endif // SHARE_VM_MEMORY_FILEMAP_HPP