1 /*
2 * Copyright (c) 2020, 2024, 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
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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 *
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23 */
24
25 #ifndef SHARE_CDS_ARCHIVEBUILDER_HPP
26 #define SHARE_CDS_ARCHIVEBUILDER_HPP
27
28 #include "cds/archiveUtils.hpp"
29 #include "cds/dumpAllocStats.hpp"
30 #include "memory/metaspaceClosure.hpp"
31 #include "oops/array.hpp"
32 #include "oops/klass.hpp"
33 #include "runtime/os.hpp"
34 #include "utilities/bitMap.hpp"
35 #include "utilities/growableArray.hpp"
36 #include "utilities/resizeableResourceHash.hpp"
37 #include "utilities/resourceHash.hpp"
38
39 class ArchiveHeapInfo;
40 class CHeapBitMap;
41 class FileMapInfo;
42 class Klass;
43 class MemRegion;
44 class Symbol;
45
46 // Metaspace::allocate() requires that all blocks must be aligned with KlassAlignmentInBytes.
47 // We enforce the same alignment rule in blocks allocated from the shared space.
48 const int SharedSpaceObjectAlignment = KlassAlignmentInBytes;
49
50 // Overview of CDS archive creation (for both static and dynamic dump):
51 //
52 // [1] Load all classes (static dump: from the classlist, dynamic dump: as part of app execution)
53 // [2] Allocate "output buffer"
54 // [3] Copy contents of the 2 "core" regions (rw/ro) into the output buffer.
55 // - allocate the cpp vtables in rw (static dump only)
56 // - memcpy the MetaspaceObjs into rw/ro:
57 // dump_rw_region();
58 // dump_ro_region();
59 // - fix all the pointers in the MetaspaceObjs to point to the copies
60 // relocate_metaspaceobj_embedded_pointers()
61 // [4] Copy symbol table, dictionary, etc, into the ro region
62 // [5] Relocate all the pointers in rw/ro, so that the archive can be mapped to
63 // the "requested" location without runtime relocation. See relocate_to_requested()
64 //
65 // "source" vs "buffered" vs "requested"
66 //
67 // The ArchiveBuilder deals with three types of addresses.
68 //
69 // "source": These are the addresses of objects created in step [1] above. They are the actual
70 // InstanceKlass*, Method*, etc, of the Java classes that are loaded for executing
71 // Java bytecodes in the JVM process that's dumping the CDS archive.
72 //
73 // It may be necessary to contiue Java execution after ArchiveBuilder is finished.
74 // Therefore, we don't modify any of the "source" objects.
75 //
76 // "buffered": The "source" objects that are deemed archivable are copied into a temporary buffer.
77 // Objects in the buffer are modified in steps [2, 3, 4] (e.g., unshareable info is
78 // removed, pointers are relocated, etc) to prepare them to be loaded at runtime.
79 //
80 // "requested": These are the addreses where the "buffered" objects should be loaded at runtime.
81 // When the "buffered" objects are written into the archive file, their addresses
82 // are adjusted in step [5] such that the lowest of these objects would be mapped
83 // at SharedBaseAddress.
84 //
85 // Translation between "source" and "buffered" addresses is done with two hashtables:
86 // _src_obj_table : "source" -> "buffered"
87 // _buffered_to_src_table : "buffered" -> "source"
88 //
89 // Translation between "buffered" and "requested" addresses is done with a simple shift:
90 // buffered_address + _buffer_to_requested_delta == requested_address
91 //
92 class ArchiveBuilder : public StackObj {
93 protected:
94 DumpRegion* _current_dump_region;
95 address _buffer_bottom; // for writing the contents of rw/ro regions
96 address _last_verified_top;
97 int _num_dump_regions_used;
98 size_t _other_region_used_bytes;
99
100 // These are the addresses where we will request the static and dynamic archives to be
101 // mapped at run time. If the request fails (due to ASLR), we will map the archives at
102 // os-selected addresses.
103 address _requested_static_archive_bottom; // This is determined solely by the value of
104 // SharedBaseAddress during -Xshare:dump.
105 address _requested_static_archive_top;
106 address _requested_dynamic_archive_bottom; // Used only during dynamic dump. It's placed
107 // immediately above _requested_static_archive_top.
108 address _requested_dynamic_archive_top;
109
110 // (Used only during dynamic dump) where the static archive is actually mapped. This
111 // may be different than _requested_static_archive_{bottom,top} due to ASLR
112 address _mapped_static_archive_bottom;
113 address _mapped_static_archive_top;
114
115 intx _buffer_to_requested_delta;
116
117 DumpRegion* current_dump_region() const { return _current_dump_region; }
118
119 public:
120 enum FollowMode {
121 make_a_copy, point_to_it, set_to_null
122 };
123
124 private:
125 class SourceObjInfo {
126 uintx _ptrmap_start; // The bit-offset of the start of this object (inclusive)
127 uintx _ptrmap_end; // The bit-offset of the end of this object (exclusive)
128 bool _read_only;
129 bool _has_embedded_pointer;
130 FollowMode _follow_mode;
131 int _size_in_bytes;
132 int _id; // Each object has a unique serial ID, starting from zero. The ID is assigned
133 // when the object is added into _source_objs.
134 MetaspaceObj::Type _msotype;
135 address _source_addr; // The source object to be copied.
136 address _buffered_addr; // The copy of this object insider the buffer.
137 public:
138 SourceObjInfo(MetaspaceClosure::Ref* ref, bool read_only, FollowMode follow_mode) :
139 _ptrmap_start(0), _ptrmap_end(0), _read_only(read_only), _has_embedded_pointer(false), _follow_mode(follow_mode),
140 _size_in_bytes(ref->size() * BytesPerWord), _id(0), _msotype(ref->msotype()),
141 _source_addr(ref->obj()) {
142 if (follow_mode == point_to_it) {
143 _buffered_addr = ref->obj();
144 } else {
145 _buffered_addr = nullptr;
146 }
147 }
148
149 // This constructor is only used for regenerated objects (created by LambdaFormInvokers, etc).
150 // src = address of a Method or InstanceKlass that has been regenerated.
151 // renegerated_obj_info = info for the regenerated version of src.
152 SourceObjInfo(address src, SourceObjInfo* renegerated_obj_info) :
153 _ptrmap_start(0), _ptrmap_end(0), _read_only(false),
154 _follow_mode(renegerated_obj_info->_follow_mode),
155 _size_in_bytes(0), _msotype(renegerated_obj_info->_msotype),
156 _source_addr(src), _buffered_addr(renegerated_obj_info->_buffered_addr) {}
157
158 bool should_copy() const { return _follow_mode == make_a_copy; }
159 void set_buffered_addr(address addr) {
160 assert(should_copy(), "must be");
161 assert(_buffered_addr == nullptr, "cannot be copied twice");
162 assert(addr != nullptr, "must be a valid copy");
163 _buffered_addr = addr;
164 }
165 void set_ptrmap_start(uintx v) { _ptrmap_start = v; }
166 void set_ptrmap_end(uintx v) { _ptrmap_end = v; }
167 uintx ptrmap_start() const { return _ptrmap_start; } // inclusive
168 uintx ptrmap_end() const { return _ptrmap_end; } // exclusive
169 bool read_only() const { return _read_only; }
170 bool has_embedded_pointer() const { return _has_embedded_pointer; }
171 void set_has_embedded_pointer() { _has_embedded_pointer = true; }
172 int size_in_bytes() const { return _size_in_bytes; }
173 int id() const { return _id; }
174 void set_id(int i) { _id = i; }
175 address source_addr() const { return _source_addr; }
176 address buffered_addr() const {
177 if (_follow_mode != set_to_null) {
178 assert(_buffered_addr != nullptr, "must be initialized");
179 }
180 return _buffered_addr;
181 }
182 MetaspaceObj::Type msotype() const { return _msotype; }
183 };
184
185 class SourceObjList {
186 uintx _total_bytes;
187 GrowableArray<SourceObjInfo*>* _objs; // Source objects to be archived
188 CHeapBitMap _ptrmap; // Marks the addresses of the pointer fields
189 // in the source objects
190 public:
191 SourceObjList();
192 ~SourceObjList();
193
194 GrowableArray<SourceObjInfo*>* objs() const { return _objs; }
195
196 void append(SourceObjInfo* src_info);
197 void remember_embedded_pointer(SourceObjInfo* pointing_obj, MetaspaceClosure::Ref* ref);
198 void relocate(int i, ArchiveBuilder* builder);
199
200 // convenience accessor
201 SourceObjInfo* at(int i) const { return objs()->at(i); }
202 };
203
204 class CDSMapLogger;
205
206 static const int INITIAL_TABLE_SIZE = 15889;
207 static const int MAX_TABLE_SIZE = 1000000;
208
209 ReservedSpace _shared_rs;
210 VirtualSpace _shared_vs;
211
212 DumpRegion _rw_region;
213 DumpRegion _ro_region;
214
215 // Combined bitmap to track pointers in both RW and RO regions. This is updated
216 // as objects are copied into RW and RO.
217 CHeapBitMap _ptrmap;
218
219 // _ptrmap is split into these two bitmaps which are written into the archive.
220 CHeapBitMap _rw_ptrmap; // marks pointers in the RW region
221 CHeapBitMap _ro_ptrmap; // marks pointers in the RO region
222
223 SourceObjList _rw_src_objs; // objs to put in rw region
224 SourceObjList _ro_src_objs; // objs to put in ro region
225 ResizeableResourceHashtable<address, SourceObjInfo, AnyObj::C_HEAP, mtClassShared> _src_obj_table;
226 ResizeableResourceHashtable<address, address, AnyObj::C_HEAP, mtClassShared> _buffered_to_src_table;
227 GrowableArray<Klass*>* _klasses;
228 GrowableArray<Symbol*>* _symbols;
229 unsigned int _entropy_seed;
230
231 // statistics
232 DumpAllocStats _alloc_stats;
233 size_t _total_heap_region_size;
234
235 void print_region_stats(FileMapInfo *map_info, ArchiveHeapInfo* heap_info);
236 void print_bitmap_region_stats(size_t size, size_t total_size);
237 void print_heap_region_stats(ArchiveHeapInfo* heap_info, size_t total_size);
238
239 // For global access.
240 static ArchiveBuilder* _current;
241
242 public:
243 // Use this when you allocate space outside of ArchiveBuilder::dump_{rw,ro}_region.
244 // These are usually for misc tables that are allocated in the RO space.
245 class OtherROAllocMark {
246 char* _oldtop;
247 public:
248 OtherROAllocMark() {
249 _oldtop = _current->_ro_region.top();
250 }
251 ~OtherROAllocMark();
252 };
253
254 private:
255 FollowMode get_follow_mode(MetaspaceClosure::Ref *ref);
256
257 void iterate_sorted_roots(MetaspaceClosure* it);
258 void sort_klasses();
259 static int compare_symbols_by_address(Symbol** a, Symbol** b);
260 static int compare_klass_by_name(Klass** a, Klass** b);
261
262 void make_shallow_copies(DumpRegion *dump_region, const SourceObjList* src_objs);
263 void make_shallow_copy(DumpRegion *dump_region, SourceObjInfo* src_info);
264
265 void relocate_embedded_pointers(SourceObjList* src_objs);
266
267 bool is_excluded(Klass* k);
268 void clean_up_src_obj_table();
269
270 protected:
271 virtual void iterate_roots(MetaspaceClosure* it) = 0;
272
273 // Conservative estimate for number of bytes needed for:
274 size_t _estimated_metaspaceobj_bytes; // all archived MetaspaceObj's.
275 size_t _estimated_hashtable_bytes; // symbol table and dictionaries
276
277 static const int _total_dump_regions = 2;
278
279 size_t estimate_archive_size();
280
281 void start_dump_region(DumpRegion* next);
282 void verify_estimate_size(size_t estimate, const char* which);
283
284 public:
285 address reserve_buffer();
286
287 address buffer_bottom() const { return _buffer_bottom; }
288 address buffer_top() const { return (address)current_dump_region()->top(); }
289 address requested_static_archive_bottom() const { return _requested_static_archive_bottom; }
290 address mapped_static_archive_bottom() const { return _mapped_static_archive_bottom; }
291 intx buffer_to_requested_delta() const { return _buffer_to_requested_delta; }
292
293 bool is_in_buffer_space(address p) const {
294 return (buffer_bottom() <= p && p < buffer_top());
295 }
296
297 template <typename T> bool is_in_requested_static_archive(T p) const {
298 return _requested_static_archive_bottom <= (address)p && (address)p < _requested_static_archive_top;
299 }
300
301 template <typename T> bool is_in_mapped_static_archive(T p) const {
302 return _mapped_static_archive_bottom <= (address)p && (address)p < _mapped_static_archive_top;
303 }
304
305 template <typename T> bool is_in_buffer_space(T obj) const {
306 return is_in_buffer_space(address(obj));
307 }
308
309 template <typename T> T to_requested(T obj) const {
310 assert(is_in_buffer_space(obj), "must be");
311 return (T)(address(obj) + _buffer_to_requested_delta);
312 }
313
314 static intx get_buffer_to_requested_delta() {
315 return current()->buffer_to_requested_delta();
316 }
317
318 inline static u4 to_offset_u4(uintx offset) {
319 guarantee(offset <= MAX_SHARED_DELTA, "must be 32-bit offset " INTPTR_FORMAT, offset);
320 return (u4)offset;
321 }
322
323 public:
324 static const uintx MAX_SHARED_DELTA = 0x7FFFFFFF;
325
326 // The address p points to an object inside the output buffer. When the archive is mapped
327 // at the requested address, what's the offset of this object from _requested_static_archive_bottom?
328 uintx buffer_to_offset(address p) const;
329
330 // Same as buffer_to_offset, except that the address p points to either (a) an object
331 // inside the output buffer, or (b), an object in the currently mapped static archive.
332 uintx any_to_offset(address p) const;
333
334 template <typename T>
335 u4 buffer_to_offset_u4(T p) const {
336 uintx offset = buffer_to_offset((address)p);
337 return to_offset_u4(offset);
338 }
339
340 template <typename T>
341 u4 any_to_offset_u4(T p) const {
342 uintx offset = any_to_offset((address)p);
343 return to_offset_u4(offset);
344 }
345
346 static void assert_is_vm_thread() PRODUCT_RETURN;
347
348 public:
349 ArchiveBuilder();
350 ~ArchiveBuilder();
351
352 int entropy();
353 void gather_klasses_and_symbols();
354 void gather_source_objs();
355 bool gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool read_only);
356 bool gather_one_source_obj(MetaspaceClosure::Ref* ref, bool read_only);
357 void remember_embedded_pointer_in_enclosing_obj(MetaspaceClosure::Ref* ref);
358 static void serialize_dynamic_archivable_items(SerializeClosure* soc);
359
360 DumpRegion* rw_region() { return &_rw_region; }
361 DumpRegion* ro_region() { return &_ro_region; }
362
363 static char* rw_region_alloc(size_t num_bytes) {
364 return current()->rw_region()->allocate(num_bytes);
365 }
366 static char* ro_region_alloc(size_t num_bytes) {
367 return current()->ro_region()->allocate(num_bytes);
368 }
369
370 template <typename T>
371 static Array<T>* new_ro_array(int length) {
372 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
373 Array<T>* array = (Array<T>*)ro_region_alloc(byte_size);
374 array->initialize(length);
375 return array;
376 }
377
378 template <typename T>
379 static Array<T>* new_rw_array(int length) {
380 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
381 Array<T>* array = (Array<T>*)rw_region_alloc(byte_size);
382 array->initialize(length);
383 return array;
384 }
385
386 template <typename T>
387 static size_t ro_array_bytesize(int length) {
388 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
389 return align_up(byte_size, SharedSpaceObjectAlignment);
390 }
391
392 char* ro_strdup(const char* s);
393
394 static int compare_src_objs(SourceObjInfo** a, SourceObjInfo** b);
395 void sort_metadata_objs();
396 void dump_rw_metadata();
397 void dump_ro_metadata();
398 void relocate_metaspaceobj_embedded_pointers();
399 void record_regenerated_object(address orig_src_obj, address regen_src_obj);
400 void make_klasses_shareable();
401 void relocate_to_requested();
402 void write_archive(FileMapInfo* mapinfo, ArchiveHeapInfo* heap_info);
403 void write_region(FileMapInfo* mapinfo, int region_idx, DumpRegion* dump_region,
404 bool read_only, bool allow_exec);
405
406 void write_pointer_in_buffer(address* ptr_location, address src_addr);
407 template <typename T> void write_pointer_in_buffer(T* ptr_location, T src_addr) {
408 write_pointer_in_buffer((address*)ptr_location, (address)src_addr);
409 }
410
411 address get_buffered_addr(address src_addr) const;
412 template <typename T> T get_buffered_addr(T src_addr) const {
413 return (T)get_buffered_addr((address)src_addr);
414 }
415
416 address get_source_addr(address buffered_addr) const;
417 template <typename T> T get_source_addr(T buffered_addr) const {
418 return (T)get_source_addr((address)buffered_addr);
419 }
420
421 // All klasses and symbols that will be copied into the archive
422 GrowableArray<Klass*>* klasses() const { return _klasses; }
423 GrowableArray<Symbol*>* symbols() const { return _symbols; }
424
425 static bool is_active() {
426 return (_current != nullptr);
427 }
428
429 static ArchiveBuilder* current() {
430 assert_is_vm_thread();
431 assert(_current != nullptr, "ArchiveBuilder must be active");
432 return _current;
433 }
434
435 static DumpAllocStats* alloc_stats() {
436 return &(current()->_alloc_stats);
437 }
438
439 static CompactHashtableStats* symbol_stats() {
440 return alloc_stats()->symbol_stats();
441 }
442
443 static CompactHashtableStats* string_stats() {
444 return alloc_stats()->string_stats();
445 }
446
447 narrowKlass get_requested_narrow_klass(Klass* k);
448
449 static Klass* get_buffered_klass(Klass* src_klass) {
450 Klass* klass = (Klass*)current()->get_buffered_addr((address)src_klass);
451 assert(klass != nullptr && klass->is_klass(), "must be");
452 return klass;
453 }
454
455 static Symbol* get_buffered_symbol(Symbol* src_symbol) {
456 return (Symbol*)current()->get_buffered_addr((address)src_symbol);
457 }
458
459 void print_stats();
460 void report_out_of_space(const char* name, size_t needed_bytes);
461 };
462
463 #endif // SHARE_CDS_ARCHIVEBUILDER_HPP