1 /*
2 * Copyright (c) 2019, 2022, 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.
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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 #include "utilities/macros.hpp"
34
35 class BootstrapInfo;
36 class ReservedSpace;
37 class VirtualSpace;
38
39 // ArchivePtrMarker is used to mark the location of pointers embedded in a CDS archive. E.g., when an
40 // InstanceKlass k is dumped, we mark the location of the k->_name pointer by effectively calling
41 // mark_pointer(/*ptr_loc=*/&k->_name). It's required that (_prt_base <= ptr_loc < _ptr_end). _ptr_base is
42 // fixed, but _ptr_end can be expanded as more objects are dumped.
43 class ArchivePtrMarker : AllStatic {
44 static CHeapBitMap* _ptrmap;
45 static VirtualSpace* _vs;
46
47 // Once _ptrmap is compacted, we don't allow bit marking anymore. This is to
48 // avoid unintentional copy operations after the bitmap has been finalized and written.
49 static bool _compacted;
50
51 static address* ptr_base() { return (address*)_vs->low(); } // committed lower bound (inclusive)
52 static address* ptr_end() { return (address*)_vs->high(); } // committed upper bound (exclusive)
53
54 public:
55 static void initialize(CHeapBitMap* ptrmap, VirtualSpace* vs);
56 static void mark_pointer(address* ptr_loc);
57 static void clear_pointer(address* ptr_loc);
58 static void compact(address relocatable_base, address relocatable_end);
59 static void compact(size_t max_non_null_offset);
60
61 template <typename T>
62 static void mark_pointer(T* ptr_loc) {
63 mark_pointer((address*)ptr_loc);
64 }
65
66 template <typename T>
67 static void set_and_mark_pointer(T* ptr_loc, T ptr_value) {
68 *ptr_loc = ptr_value;
69 mark_pointer(ptr_loc);
70 }
71
72 static CHeapBitMap* ptrmap() {
73 return _ptrmap;
74 }
75
76 static void reset_map_and_vs() {
77 _ptrmap = nullptr;
78 _vs = nullptr;
79 }
80 };
81
82 // SharedDataRelocator is used to shift pointers in the CDS archive.
83 //
84 // The CDS archive is basically a contiguous block of memory (divided into several regions)
85 // that contains multiple objects. The objects may contain direct pointers that point to other objects
86 // within the archive (e.g., InstanceKlass::_name points to a Symbol in the archive). During dumping, we
87 // built a bitmap that marks the locations of all these pointers (using ArchivePtrMarker, see comments above).
88 //
89 // The contents of the archive assumes that it’s mapped at the default SharedBaseAddress (e.g. 0x800000000).
90 // If the archive ends up being mapped at a different address (e.g. 0x810000000), SharedDataRelocator
91 // is used to shift each marked pointer by a delta (0x10000000 in this example), so that it points to
92 // the actually mapped location of the target object.
93 class SharedDataRelocator: public BitMapClosure {
94 // for all (address** p), where (is_marked(p) && _patch_base <= p && p < _patch_end) { *p += delta; }
95
96 // Patch all pointers within this region that are marked.
97 address* _patch_base;
98 address* _patch_end;
99
100 // Before patching, all pointers must point to this region.
101 address _valid_old_base;
102 address _valid_old_end;
103
104 // After patching, all pointers must point to this region.
105 address _valid_new_base;
106 address _valid_new_end;
107
108 // How much to relocate for each pointer.
109 intx _delta;
110
111 public:
112 SharedDataRelocator(address* patch_base, address* patch_end,
113 address valid_old_base, address valid_old_end,
114 address valid_new_base, address valid_new_end, intx delta) :
115 _patch_base(patch_base), _patch_end(patch_end),
116 _valid_old_base(valid_old_base), _valid_old_end(valid_old_end),
117 _valid_new_base(valid_new_base), _valid_new_end(valid_new_end),
118 _delta(delta) {
119 log_debug(cds, reloc)("SharedDataRelocator::_patch_base = " PTR_FORMAT, p2i(_patch_base));
120 log_debug(cds, reloc)("SharedDataRelocator::_patch_end = " PTR_FORMAT, p2i(_patch_end));
121 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_base = " PTR_FORMAT, p2i(_valid_old_base));
122 log_debug(cds, reloc)("SharedDataRelocator::_valid_old_end = " PTR_FORMAT, p2i(_valid_old_end));
123 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_base = " PTR_FORMAT, p2i(_valid_new_base));
124 log_debug(cds, reloc)("SharedDataRelocator::_valid_new_end = " PTR_FORMAT, p2i(_valid_new_end));
125 }
126
127 bool do_bit(size_t offset);
128 };
129
130 class DumpRegion {
131 private:
132 const char* _name;
133 char* _base;
134 char* _top;
135 char* _end;
136 uintx _max_delta;
137 bool _is_packed;
138 ReservedSpace* _rs;
139 VirtualSpace* _vs;
140
141 void commit_to(char* newtop);
142
143 public:
144 DumpRegion(const char* name, uintx max_delta = 0)
145 : _name(name), _base(NULL), _top(NULL), _end(NULL),
146 _max_delta(max_delta), _is_packed(false) {}
147
148 char* expand_top_to(char* newtop);
149 char* allocate(size_t num_bytes);
150
151 void append_intptr_t(intptr_t n, bool need_to_mark = false) NOT_CDS_RETURN;
152
153 char* base() const { return _base; }
154 char* top() const { return _top; }
155 char* end() const { return _end; }
156 size_t reserved() const { return _end - _base; }
157 size_t used() const { return _top - _base; }
158 bool is_packed() const { return _is_packed; }
159 bool is_allocatable() const {
160 return !is_packed() && _base != NULL;
161 }
162
163 void print(size_t total_bytes) const;
164 void print_out_of_space_msg(const char* failing_region, size_t needed_bytes);
165
166 void init(ReservedSpace* rs, VirtualSpace* vs);
167
168 void pack(DumpRegion* next = NULL);
169
170 bool contains(char* p) {
171 return base() <= p && p < top();
172 }
173 };
174
175 // Closure for serializing initialization data out to a data area to be
176 // written to the shared file.
177
178 class WriteClosure : public SerializeClosure {
179 private:
180 DumpRegion* _dump_region;
181
182 public:
183 WriteClosure(DumpRegion* r) {
184 _dump_region = r;
185 }
186
187 void do_ptr(void** p) {
188 _dump_region->append_intptr_t((intptr_t)*p, true);
189 }
190
191 void do_u4(u4* p) {
192 _dump_region->append_intptr_t((intptr_t)(*p));
193 }
194
195 void do_bool(bool *p) {
196 _dump_region->append_intptr_t((intptr_t)(*p));
197 }
198
199 void do_tag(int tag) {
200 _dump_region->append_intptr_t((intptr_t)tag);
201 }
202
203 void do_oop(oop* o);
204 void do_region(u_char* start, size_t size);
205 bool reading() const { return false; }
206 };
207
208 // Closure for serializing initialization data in from a data area
209 // (ptr_array) read from the shared file.
210
211 class ReadClosure : public SerializeClosure {
212 private:
213 intptr_t** _ptr_array;
214
215 inline intptr_t nextPtr() {
216 return *(*_ptr_array)++;
217 }
218
219 public:
220 ReadClosure(intptr_t** ptr_array) { _ptr_array = ptr_array; }
221
222 void do_ptr(void** p);
223 void do_u4(u4* p);
224 void do_bool(bool *p);
225 void do_tag(int tag);
226 void do_oop(oop *p);
227 void do_region(u_char* start, size_t size);
228 bool reading() const { return true; }
229 };
230
231 class ArchiveUtils {
232 public:
233 static void log_to_classlist(BootstrapInfo* bootstrap_specifier, TRAPS) NOT_CDS_RETURN;
234 };
235
236 #endif // SHARE_CDS_ARCHIVEUTILS_HPP