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.
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5 * This code is free software; you can redistribute it and/or modify it
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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13 * accompanied this code).
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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/metaspace.hpp"
31 #include "memory/metaspaceClosure.hpp"
32 #include "memory/reservedSpace.hpp"
33 #include "memory/virtualspace.hpp"
34 #include "oops/array.hpp"
35 #include "oops/klass.hpp"
36 #include "runtime/os.hpp"
37 #include "utilities/bitMap.hpp"
38 #include "utilities/growableArray.hpp"
39 #include "utilities/resizeableResourceHash.hpp"
40 #include "utilities/resourceHash.hpp"
41
42 class ArchiveHeapInfo;
43 class CHeapBitMap;
44 class FileMapInfo;
45 class Klass;
46 class MemRegion;
47 class Symbol;
48
49 // The minimum alignment for non-Klass objects inside the CDS archive. Klass objects need
50 // to follow CompressedKlassPointers::klass_alignment_in_bytes().
51 constexpr size_t SharedSpaceObjectAlignment = Metaspace::min_allocation_alignment_bytes;
52
53 // Overview of CDS archive creation (for both static and dynamic dump):
54 //
55 // [1] Load all classes (static dump: from the classlist, dynamic dump: as part of app execution)
56 // [2] Allocate "output buffer"
57 // [3] Copy contents of the 2 "core" regions (rw/ro) into the output buffer.
58 // - allocate the cpp vtables in rw (static dump only)
59 // - memcpy the MetaspaceObjs into rw/ro:
60 // dump_rw_region();
61 // dump_ro_region();
62 // - fix all the pointers in the MetaspaceObjs to point to the copies
63 // relocate_metaspaceobj_embedded_pointers()
64 // [4] Copy symbol table, dictionary, etc, into the ro region
65 // [5] Relocate all the pointers in rw/ro, so that the archive can be mapped to
66 // the "requested" location without runtime relocation. See relocate_to_requested()
67 //
68 // "source" vs "buffered" vs "requested"
69 //
70 // The ArchiveBuilder deals with three types of addresses.
71 //
72 // "source": These are the addresses of objects created in step [1] above. They are the actual
73 // InstanceKlass*, Method*, etc, of the Java classes that are loaded for executing
74 // Java bytecodes in the JVM process that's dumping the CDS archive.
75 //
76 // It may be necessary to contiue Java execution after ArchiveBuilder is finished.
77 // Therefore, we don't modify any of the "source" objects.
78 //
79 // "buffered": The "source" objects that are deemed archivable are copied into a temporary buffer.
80 // Objects in the buffer are modified in steps [2, 3, 4] (e.g., unshareable info is
81 // removed, pointers are relocated, etc) to prepare them to be loaded at runtime.
82 //
83 // "requested": These are the addreses where the "buffered" objects should be loaded at runtime.
84 // When the "buffered" objects are written into the archive file, their addresses
85 // are adjusted in step [5] such that the lowest of these objects would be mapped
86 // at SharedBaseAddress.
87 //
88 // Translation between "source" and "buffered" addresses is done with two hashtables:
89 // _src_obj_table : "source" -> "buffered"
90 // _buffered_to_src_table : "buffered" -> "source"
91 //
92 // Translation between "buffered" and "requested" addresses is done with a simple shift:
93 // buffered_address + _buffer_to_requested_delta == requested_address
94 //
95 class ArchiveBuilder : public StackObj {
96 protected:
97 DumpRegion* _current_dump_region;
98 address _buffer_bottom; // for writing the contents of rw/ro regions
99 address _last_verified_top;
100 int _num_dump_regions_used;
101 size_t _other_region_used_bytes;
102
103 // These are the addresses where we will request the static and dynamic archives to be
104 // mapped at run time. If the request fails (due to ASLR), we will map the archives at
105 // os-selected addresses.
106 address _requested_static_archive_bottom; // This is determined solely by the value of
107 // SharedBaseAddress during -Xshare:dump.
108 address _requested_static_archive_top;
109 address _requested_dynamic_archive_bottom; // Used only during dynamic dump. It's placed
110 // immediately above _requested_static_archive_top.
111 address _requested_dynamic_archive_top;
112
113 // (Used only during dynamic dump) where the static archive is actually mapped. This
114 // may be different than _requested_static_archive_{bottom,top} due to ASLR
115 address _mapped_static_archive_bottom;
116 address _mapped_static_archive_top;
117
118 intx _buffer_to_requested_delta;
119
120 DumpRegion* current_dump_region() const { return _current_dump_region; }
121
122 public:
123 enum FollowMode {
124 make_a_copy, point_to_it, set_to_null
125 };
126
127 private:
128 class SourceObjInfo {
129 uintx _ptrmap_start; // The bit-offset of the start of this object (inclusive)
130 uintx _ptrmap_end; // The bit-offset of the end of this object (exclusive)
131 bool _read_only;
132 bool _has_embedded_pointer;
133 FollowMode _follow_mode;
134 int _size_in_bytes;
135 int _id; // Each object has a unique serial ID, starting from zero. The ID is assigned
136 // when the object is added into _source_objs.
137 MetaspaceObj::Type _msotype;
138 address _source_addr; // The source object to be copied.
139 address _buffered_addr; // The copy of this object insider the buffer.
140 public:
141 SourceObjInfo(MetaspaceClosure::Ref* ref, bool read_only, FollowMode follow_mode) :
142 _ptrmap_start(0), _ptrmap_end(0), _read_only(read_only), _has_embedded_pointer(false), _follow_mode(follow_mode),
143 _size_in_bytes(ref->size() * BytesPerWord), _id(0), _msotype(ref->msotype()),
144 _source_addr(ref->obj()) {
145 if (follow_mode == point_to_it) {
146 _buffered_addr = ref->obj();
147 } else {
148 _buffered_addr = nullptr;
149 }
150 }
151
152 // This constructor is only used for regenerated objects (created by LambdaFormInvokers, etc).
153 // src = address of a Method or InstanceKlass that has been regenerated.
154 // renegerated_obj_info = info for the regenerated version of src.
155 SourceObjInfo(address src, SourceObjInfo* renegerated_obj_info) :
156 _ptrmap_start(0), _ptrmap_end(0), _read_only(false),
157 _follow_mode(renegerated_obj_info->_follow_mode),
158 _size_in_bytes(0), _msotype(renegerated_obj_info->_msotype),
159 _source_addr(src), _buffered_addr(renegerated_obj_info->_buffered_addr) {}
160
161 bool should_copy() const { return _follow_mode == make_a_copy; }
162 void set_buffered_addr(address addr) {
163 assert(should_copy(), "must be");
164 assert(_buffered_addr == nullptr, "cannot be copied twice");
165 assert(addr != nullptr, "must be a valid copy");
166 _buffered_addr = addr;
167 }
168 void set_ptrmap_start(uintx v) { _ptrmap_start = v; }
169 void set_ptrmap_end(uintx v) { _ptrmap_end = v; }
170 uintx ptrmap_start() const { return _ptrmap_start; } // inclusive
171 uintx ptrmap_end() const { return _ptrmap_end; } // exclusive
172 bool read_only() const { return _read_only; }
173 bool has_embedded_pointer() const { return _has_embedded_pointer; }
174 void set_has_embedded_pointer() { _has_embedded_pointer = true; }
175 int size_in_bytes() const { return _size_in_bytes; }
176 int id() const { return _id; }
177 void set_id(int i) { _id = i; }
178 address source_addr() const { return _source_addr; }
179 address buffered_addr() const {
180 if (_follow_mode != set_to_null) {
181 assert(_buffered_addr != nullptr, "must be initialized");
182 }
183 return _buffered_addr;
184 }
185 MetaspaceObj::Type msotype() const { return _msotype; }
186 };
187
188 class SourceObjList {
189 uintx _total_bytes;
190 GrowableArray<SourceObjInfo*>* _objs; // Source objects to be archived
191 CHeapBitMap _ptrmap; // Marks the addresses of the pointer fields
192 // in the source objects
193 public:
194 SourceObjList();
195 ~SourceObjList();
196
197 GrowableArray<SourceObjInfo*>* objs() const { return _objs; }
198
199 void append(SourceObjInfo* src_info);
200 void remember_embedded_pointer(SourceObjInfo* pointing_obj, MetaspaceClosure::Ref* ref);
201 void relocate(int i, ArchiveBuilder* builder);
202
203 // convenience accessor
204 SourceObjInfo* at(int i) const { return objs()->at(i); }
205 };
206
207 class CDSMapLogger;
208
209 static const int INITIAL_TABLE_SIZE = 15889;
210 static const int MAX_TABLE_SIZE = 1000000;
211
212 ReservedSpace _shared_rs;
213 VirtualSpace _shared_vs;
214
215 DumpRegion _rw_region;
216 DumpRegion _ro_region;
217
218 // Combined bitmap to track pointers in both RW and RO regions. This is updated
219 // as objects are copied into RW and RO.
220 CHeapBitMap _ptrmap;
221
222 // _ptrmap is split into these two bitmaps which are written into the archive.
223 CHeapBitMap _rw_ptrmap; // marks pointers in the RW region
224 CHeapBitMap _ro_ptrmap; // marks pointers in the RO region
225
226 SourceObjList _rw_src_objs; // objs to put in rw region
227 SourceObjList _ro_src_objs; // objs to put in ro region
228 ResizeableResourceHashtable<address, SourceObjInfo, AnyObj::C_HEAP, mtClassShared> _src_obj_table;
229 ResizeableResourceHashtable<address, address, AnyObj::C_HEAP, mtClassShared> _buffered_to_src_table;
230 GrowableArray<Klass*>* _klasses;
231 GrowableArray<Symbol*>* _symbols;
232 unsigned int _entropy_seed;
233
234 // statistics
235 DumpAllocStats _alloc_stats;
236 size_t _total_heap_region_size;
237
238 void print_region_stats(FileMapInfo *map_info, ArchiveHeapInfo* heap_info);
239 void print_bitmap_region_stats(size_t size, size_t total_size);
240 void print_heap_region_stats(ArchiveHeapInfo* heap_info, size_t total_size);
241
242 // For global access.
243 static ArchiveBuilder* _current;
244
245 public:
246 // Use this when you allocate space outside of ArchiveBuilder::dump_{rw,ro}_region.
247 // These are usually for misc tables that are allocated in the RO space.
248 class OtherROAllocMark {
249 char* _oldtop;
250 public:
251 OtherROAllocMark() {
252 _oldtop = _current->_ro_region.top();
253 }
254 ~OtherROAllocMark();
255 };
256
257 private:
258 FollowMode get_follow_mode(MetaspaceClosure::Ref *ref);
259
260 void iterate_sorted_roots(MetaspaceClosure* it);
261 void sort_klasses();
262 static int compare_symbols_by_address(Symbol** a, Symbol** b);
263 static int compare_klass_by_name(Klass** a, Klass** b);
264
265 void make_shallow_copies(DumpRegion *dump_region, const SourceObjList* src_objs);
266 void make_shallow_copy(DumpRegion *dump_region, SourceObjInfo* src_info);
267
268 void relocate_embedded_pointers(SourceObjList* src_objs);
269
270 bool is_excluded(Klass* k);
271 void clean_up_src_obj_table();
272
273 protected:
274 virtual void iterate_roots(MetaspaceClosure* it) = 0;
275
276 // Conservative estimate for number of bytes needed for:
277 size_t _estimated_metaspaceobj_bytes; // all archived MetaspaceObj's.
278 size_t _estimated_hashtable_bytes; // symbol table and dictionaries
279
280 static const int _total_dump_regions = 2;
281
282 size_t estimate_archive_size();
283
284 void start_dump_region(DumpRegion* next);
285 void verify_estimate_size(size_t estimate, const char* which);
286
287 public:
288 address reserve_buffer();
289
290 address buffer_bottom() const { return _buffer_bottom; }
291 address buffer_top() const { return (address)current_dump_region()->top(); }
292 address requested_static_archive_bottom() const { return _requested_static_archive_bottom; }
293 address mapped_static_archive_bottom() const { return _mapped_static_archive_bottom; }
294 intx buffer_to_requested_delta() const { return _buffer_to_requested_delta; }
295
296 bool is_in_buffer_space(address p) const {
297 return (buffer_bottom() != nullptr && buffer_bottom() <= p && p < buffer_top());
298 }
299
300 template <typename T> bool is_in_requested_static_archive(T p) const {
301 return _requested_static_archive_bottom <= (address)p && (address)p < _requested_static_archive_top;
302 }
303
304 template <typename T> bool is_in_mapped_static_archive(T p) const {
305 return _mapped_static_archive_bottom <= (address)p && (address)p < _mapped_static_archive_top;
306 }
307
308 template <typename T> bool is_in_buffer_space(T obj) const {
309 return is_in_buffer_space(address(obj));
310 }
311
312 template <typename T> T to_requested(T obj) const {
313 assert(is_in_buffer_space(obj), "must be");
314 return (T)(address(obj) + _buffer_to_requested_delta);
315 }
316
317 static intx get_buffer_to_requested_delta() {
318 return current()->buffer_to_requested_delta();
319 }
320
321 inline static u4 to_offset_u4(uintx offset) {
322 guarantee(offset <= MAX_SHARED_DELTA, "must be 32-bit offset " INTPTR_FORMAT, offset);
323 return (u4)offset;
324 }
325
326 public:
327 static const uintx MAX_SHARED_DELTA = ArchiveUtils::MAX_SHARED_DELTA;;
328
329 // The address p points to an object inside the output buffer. When the archive is mapped
330 // at the requested address, what's the offset of this object from _requested_static_archive_bottom?
331 uintx buffer_to_offset(address p) const;
332
333 // Same as buffer_to_offset, except that the address p points to either (a) an object
334 // inside the output buffer, or (b), an object in the currently mapped static archive.
335 uintx any_to_offset(address p) const;
336
337 // The reverse of buffer_to_offset()
338 address offset_to_buffered_address(u4 offset) const;
339
340 template <typename T>
341 u4 buffer_to_offset_u4(T p) const {
342 uintx offset = buffer_to_offset((address)p);
343 return to_offset_u4(offset);
344 }
345
346 template <typename T>
347 u4 any_to_offset_u4(T p) const {
348 assert(p != nullptr, "must not be null");
349 uintx offset = any_to_offset((address)p);
350 return to_offset_u4(offset);
351 }
352
353 template <typename T>
354 u4 any_or_null_to_offset_u4(T p) const {
355 if (p == nullptr) {
356 return 0;
357 } else {
358 return any_to_offset_u4<T>(p);
359 }
360 }
361
362 template <typename T>
363 T offset_to_buffered(u4 offset) const {
364 return (T)offset_to_buffered_address(offset);
365 }
366
367 public:
368 ArchiveBuilder();
369 ~ArchiveBuilder();
370
371 int entropy();
372 void gather_klasses_and_symbols();
373 void gather_source_objs();
374 bool gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool read_only);
375 bool gather_one_source_obj(MetaspaceClosure::Ref* ref, bool read_only);
376 void remember_embedded_pointer_in_enclosing_obj(MetaspaceClosure::Ref* ref);
377 static void serialize_dynamic_archivable_items(SerializeClosure* soc);
378
379 DumpRegion* rw_region() { return &_rw_region; }
380 DumpRegion* ro_region() { return &_ro_region; }
381
382 static char* rw_region_alloc(size_t num_bytes) {
383 return current()->rw_region()->allocate(num_bytes);
384 }
385 static char* ro_region_alloc(size_t num_bytes) {
386 return current()->ro_region()->allocate(num_bytes);
387 }
388
389 template <typename T>
390 static Array<T>* new_ro_array(int length) {
391 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
392 Array<T>* array = (Array<T>*)ro_region_alloc(byte_size);
393 array->initialize(length);
394 return array;
395 }
396
397 template <typename T>
398 static Array<T>* new_rw_array(int length) {
399 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
400 Array<T>* array = (Array<T>*)rw_region_alloc(byte_size);
401 array->initialize(length);
402 return array;
403 }
404
405 template <typename T>
406 static size_t ro_array_bytesize(int length) {
407 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
408 return align_up(byte_size, SharedSpaceObjectAlignment);
409 }
410
411 char* ro_strdup(const char* s);
412
413 static int compare_src_objs(SourceObjInfo** a, SourceObjInfo** b);
414 void sort_metadata_objs();
415 void dump_rw_metadata();
416 void dump_ro_metadata();
417 void relocate_metaspaceobj_embedded_pointers();
418 void record_regenerated_object(address orig_src_obj, address regen_src_obj);
419 void make_klasses_shareable();
420 void relocate_to_requested();
421 void write_archive(FileMapInfo* mapinfo, ArchiveHeapInfo* heap_info);
422 void write_region(FileMapInfo* mapinfo, int region_idx, DumpRegion* dump_region,
423 bool read_only, bool allow_exec);
424
425 void write_pointer_in_buffer(address* ptr_location, address src_addr);
426 template <typename T> void write_pointer_in_buffer(T* ptr_location, T src_addr) {
427 write_pointer_in_buffer((address*)ptr_location, (address)src_addr);
428 }
429
430 void mark_and_relocate_to_buffered_addr(address* ptr_location);
431 template <typename T> void mark_and_relocate_to_buffered_addr(T ptr_location) {
432 mark_and_relocate_to_buffered_addr((address*)ptr_location);
433 }
434
435 bool has_been_buffered(address src_addr) const;
436 template <typename T> bool has_been_buffered(T src_addr) const {
437 return has_been_buffered((address)src_addr);
438 }
439
440 address get_buffered_addr(address src_addr) const;
441 template <typename T> T get_buffered_addr(T src_addr) const {
442 return (T)get_buffered_addr((address)src_addr);
443 }
444
445 address get_source_addr(address buffered_addr) const;
446 template <typename T> T get_source_addr(T buffered_addr) const {
447 return (T)get_source_addr((address)buffered_addr);
448 }
449
450 // All klasses and symbols that will be copied into the archive
451 GrowableArray<Klass*>* klasses() const { return _klasses; }
452 GrowableArray<Symbol*>* symbols() const { return _symbols; }
453
454 static bool is_active() {
455 return (_current != nullptr);
456 }
457
458 static ArchiveBuilder* current() {
459 assert(_current != nullptr, "ArchiveBuilder must be active");
460 return _current;
461 }
462
463 static DumpAllocStats* alloc_stats() {
464 return &(current()->_alloc_stats);
465 }
466
467 static CompactHashtableStats* symbol_stats() {
468 return alloc_stats()->symbol_stats();
469 }
470
471 static CompactHashtableStats* string_stats() {
472 return alloc_stats()->string_stats();
473 }
474
475 narrowKlass get_requested_narrow_klass(Klass* k);
476
477 static Klass* get_buffered_klass(Klass* src_klass) {
478 Klass* klass = (Klass*)current()->get_buffered_addr((address)src_klass);
479 assert(klass != nullptr && klass->is_klass(), "must be");
480 return klass;
481 }
482
483 static Symbol* get_buffered_symbol(Symbol* src_symbol) {
484 return (Symbol*)current()->get_buffered_addr((address)src_symbol);
485 }
486
487 void print_stats();
488 void report_out_of_space(const char* name, size_t needed_bytes);
489
490 #ifdef _LP64
491 // The CDS archive contains pre-computed narrow Klass IDs. It carries them in the headers of
492 // archived heap objects. With +UseCompactObjectHeaders, it also carries them in prototypes
493 // in Klass.
494 // When generating the archive, these narrow Klass IDs are computed using the following scheme:
495 // 1) The future encoding base is assumed to point to the first address of the generated mapping.
496 // That means that at runtime, the narrow Klass encoding must be set up with base pointing to
497 // the start address of the mapped CDS metadata archive (wherever that may be). This precludes
498 // zero-based encoding.
499 // 2) The shift must be large enough to result in an encoding range that covers the future assumed
500 // runtime Klass range. That future Klass range will contain both the CDS metadata archive and
501 // the future runtime class space. Since we do not know the size of the future class space, we
502 // need to chose an encoding base/shift combination that will result in a "large enough" size.
503 // The details depend on whether we use compact object headers or legacy object headers.
504 // In Legacy Mode, a narrow Klass ID is 32 bit. This gives us an encoding range size of 4G even
505 // with shift = 0, which is all we need. Therefore, we use a shift=0 for pre-calculating the
506 // narrow Klass IDs.
507 // TinyClassPointer Mode:
508 // We use the highest possible shift value to maximize the encoding range size.
509 static int precomputed_narrow_klass_shift();
510 #endif // _LP64
511
512 };
513
514 #endif // SHARE_CDS_ARCHIVEBUILDER_HPP