1 /*
2 * Copyright (c) 2019, 2021, 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_CDS_ARCHIVEUTILS_HPP
26 #define SHARE_CDS_ARCHIVEUTILS_HPP
27
28 #include "logging/log.hpp"
29 #include "memory/iterator.hpp"
30 #include "memory/virtualspace.hpp"
31 #include "utilities/bitMap.hpp"
32 #include "utilities/exceptions.hpp"
33
34 class BootstrapInfo;
35 class ReservedSpace;
36 class VirtualSpace;
37
38 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
39 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
40 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
41 // fixed, but _ptr_end can be expanded as more objects are dumped.
42 class ArchivePtrMarker : AllStatic {
43 static CHeapBitMap* _ptrmap;
44 static VirtualSpace* _vs;
45
46 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
47 // avoid unintentional copy operations after the bitmap has been finalized and written.
48 static bool _compacted;
49
50 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
51 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
52
53 public:
54 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
55 static void mark_pointer(address* ptr_loc);
56 static void clear_pointer(address* ptr_loc);
57 static void compact(address relocatable_base, address relocatable_end);
58 static void compact(size_t max_non_null_offset);
59
60 template <typename T>
61 static void mark_pointer(T* ptr_loc) {
62 mark_pointer((address*)ptr_loc);
63 }
64
65 template <typename T>
66 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
67 *ptr_loc = ptr_value;
68 mark_pointer(ptr_loc);
69 }
70
71 static CHeapBitMap* ptrmap() {
72 return _ptrmap;
73 }
74
75 static void reset_map_and_vs() {
76 _ptrmap = nullptr;
77 _vs = nullptr;
78 }
79 };
80
81 // SharedDataRelocator is used to shift pointers in the CDS archive.
82 //
83 // The CDS archive is basically a contiguous block of memory (divided into several regions)
84 // that contains multiple objects. The objects may contain direct pointers that point to other objects
85 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
86 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
87 //
88 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
89 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
90 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
91 // the actually mapped location of the target object.
92 class SharedDataRelocator: public BitMapClosure {
93 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
94
95 // Patch all pointers within this region that are marked.
96 address* _patch_base;
97 address* _patch_end;
98
99 // Before patching, all pointers must point to this region.
100 address _valid_old_base;
101 address _valid_old_end;
102
103 // After patching, all pointers must point to this region.
104 address _valid_new_base;
105 address _valid_new_end;
106
107 // How much to relocate for each pointer.
108 intx _delta;
109
110 public:
111 SharedDataRelocator(address* patch_base, address* patch_end,
112 address valid_old_base, address valid_old_end,
113 address valid_new_base, address valid_new_end, intx delta) :
114 _patch_base(patch_base), _patch_end(patch_end),
115 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
116 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
117 _delta(delta) {
118 log_debug(cds, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
119 log_debug(cds, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
120 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
121 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
122 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
123 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
124 }
125
126 bool do_bit(size_t offset);
127 };
128
129 class DumpRegion {
130 private:
131 const char* _name;
132 char* _base;
133 char* _top;
134 char* _end;
135 uintx _max_delta;
136 bool _is_packed;
137 ReservedSpace* _rs;
138 VirtualSpace* _vs;
139
140 void commit_to(char* newtop);
141
142 public:
143 DumpRegion(const char* name, uintx max_delta = 0)
144 : _name(name), _base(NULL), _top(NULL), _end(NULL),
145 _max_delta(max_delta), _is_packed(false) {}
146
147 char* expand_top_to(char* newtop);
148 char* allocate(size_t num_bytes);
149
150 void append_intptr_t(intptr_t n, bool need_to_mark = false);
151
152 char* base() const { return _base; }
153 char* top() const { return _top; }
154 char* end() const { return _end; }
155 size_t reserved() const { return _end - _base; }
156 size_t used() const { return _top - _base; }
157 bool is_packed() const { return _is_packed; }
158 bool is_allocatable() const {
159 return !is_packed() && _base != NULL;
160 }
161
162 void print(size_t total_bytes) const;
163 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
164
165 void init(ReservedSpace* rs, VirtualSpace* vs);
166
167 void pack(DumpRegion* next = NULL);
168
169 bool contains(char* p) {
170 return base() <= p && p < top();
171 }
172 };
173
174 // Closure for serializing initialization data out to a data area to be
175 // written to the shared file.
176
177 class WriteClosure : public SerializeClosure {
178 private:
179 DumpRegion* _dump_region;
180
181 public:
182 WriteClosure(DumpRegion* r) {
183 _dump_region = r;
184 }
185
186 void do_ptr(void** p) {
187 _dump_region->append_intptr_t((intptr_t)*p, true);
188 }
189
190 void do_u4(u4* p) {
191 _dump_region->append_intptr_t((intptr_t)(*p));
192 }
193
194 void do_bool(bool *p) {
195 _dump_region->append_intptr_t((intptr_t)(*p));
196 }
197
198 void do_tag(int tag) {
199 _dump_region->append_intptr_t((intptr_t)tag);
200 }
201
202 void do_oop(oop* o);
203 void do_region(u_char* start, size_t size);
204 bool reading() const { return false; }
205 };
206
207 // Closure for serializing initialization data in from a data area
208 // (ptr_array) read from the shared file.
209
210 class ReadClosure : public SerializeClosure {
211 private:
212 intptr_t** _ptr_array;
213
214 inline intptr_t nextPtr() {
215 return *(*_ptr_array)++;
216 }
217
218 public:
219 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
220
221 void do_ptr(void** p);
222 void do_u4(u4* p);
223 void do_bool(bool *p);
224 void do_tag(int tag);
225 void do_oop(oop *p);
226 void do_region(u_char* start, size_t size);
227 bool reading() const { return true; }
228 };
229
230 class ArchiveUtils {
231 public:
232 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
233 };
234
235 #endif // SHARE_CDS_ARCHIVEUTILS_HPP