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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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 "oops/array.hpp"
33 #include "oops/klass.hpp"
34 #include "runtime/os.hpp"
35 #include "utilities/bitMap.hpp"
36 #include "utilities/growableArray.hpp"
37 #include "utilities/resizeableResourceHash.hpp"
38 #include "utilities/resourceHash.hpp"
39
40 class ArchiveHeapInfo;
41 class CHeapBitMap;
42 class FileMapInfo;
43 class Klass;
44 class MemRegion;
45 class Symbol;
46
47 // The minimum alignment for non-Klass objects inside the CDS archive. Klass objects need
48 // to follow CompressedKlassPointers::klass_alignment_in_bytes().
49 constexpr size_t SharedSpaceObjectAlignment = Metaspace::min_allocation_alignment_bytes;
50
51 // Overview of CDS archive creation (for both static and dynamic dump):
52 //
53 // [1] Load all classes (static dump: from the classlist, dynamic dump: as part of app execution)
54 // [2] Allocate "output buffer"
55 // [3] Copy contents of the 2 "core" regions (rw/ro) into the output buffer.
56 // - allocate the cpp vtables in rw (static dump only)
57 // - memcpy the MetaspaceObjs into rw/ro:
58 // dump_rw_region();
59 // dump_ro_region();
60 // - fix all the pointers in the MetaspaceObjs to point to the copies
61 // relocate_metaspaceobj_embedded_pointers()
62 // [4] Copy symbol table, dictionary, etc, into the ro region
63 // [5] Relocate all the pointers in rw/ro, so that the archive can be mapped to
64 // the "requested" location without runtime relocation. See relocate_to_requested()
65 //
66 // "source" vs "buffered" vs "requested"
67 //
68 // The ArchiveBuilder deals with three types of addresses.
69 //
70 // "source": These are the addresses of objects created in step [1] above. They are the actual
71 // InstanceKlass*, Method*, etc, of the Java classes that are loaded for executing
72 // Java bytecodes in the JVM process that's dumping the CDS archive.
73 //
74 // It may be necessary to contiue Java execution after ArchiveBuilder is finished.
75 // Therefore, we don't modify any of the "source" objects.
76 //
77 // "buffered": The "source" objects that are deemed archivable are copied into a temporary buffer.
78 // Objects in the buffer are modified in steps [2, 3, 4] (e.g., unshareable info is
79 // removed, pointers are relocated, etc) to prepare them to be loaded at runtime.
80 //
81 // "requested": These are the addreses where the "buffered" objects should be loaded at runtime.
82 // When the "buffered" objects are written into the archive file, their addresses
83 // are adjusted in step [5] such that the lowest of these objects would be mapped
84 // at SharedBaseAddress.
85 //
86 // Translation between "source" and "buffered" addresses is done with two hashtables:
87 // _src_obj_table : "source" -> "buffered"
88 // _buffered_to_src_table : "buffered" -> "source"
89 //
90 // Translation between "buffered" and "requested" addresses is done with a simple shift:
91 // buffered_address + _buffer_to_requested_delta == requested_address
92 //
93 class ArchiveBuilder : public StackObj {
94 protected:
95 DumpRegion* _current_dump_space;
96 address _buffer_bottom; // for writing the contents of rw/ro regions
97 address _last_verified_top;
98 int _num_dump_regions_used;
99 size_t _other_region_used_bytes;
100
101 // These are the addresses where we will request the static and dynamic archives to be
102 // mapped at run time. If the request fails (due to ASLR), we will map the archives at
103 // os-selected addresses.
104 address _requested_static_archive_bottom; // This is determined solely by the value of
105 // SharedBaseAddress during -Xshare:dump.
106 address _requested_static_archive_top;
107 address _requested_dynamic_archive_bottom; // Used only during dynamic dump. It's placed
108 // immediately above _requested_static_archive_top.
109 address _requested_dynamic_archive_top;
110
111 // (Used only during dynamic dump) where the static archive is actually mapped. This
112 // may be different than _requested_static_archive_{bottom,top} due to ASLR
113 address _mapped_static_archive_bottom;
114 address _mapped_static_archive_top;
115
116 intx _buffer_to_requested_delta;
117
118 DumpRegion* current_dump_space() const { return _current_dump_space; }
119
120 public:
121 enum FollowMode {
122 make_a_copy, point_to_it, set_to_null
123 };
124
125 private:
126 class SourceObjInfo {
127 uintx _ptrmap_start; // The bit-offset of the start of this object (inclusive)
128 uintx _ptrmap_end; // The bit-offset of the end of this object (exclusive)
129 bool _read_only;
130 FollowMode _follow_mode;
131 int _size_in_bytes;
132 MetaspaceObj::Type _msotype;
133 address _source_addr; // The source object to be copied.
134 address _buffered_addr; // The copy of this object insider the buffer.
135 public:
136 SourceObjInfo(MetaspaceClosure::Ref* ref, bool read_only, FollowMode follow_mode) :
137 _ptrmap_start(0), _ptrmap_end(0), _read_only(read_only), _follow_mode(follow_mode),
138 _size_in_bytes(ref->size() * BytesPerWord), _msotype(ref->msotype()),
139 _source_addr(ref->obj()) {
140 if (follow_mode == point_to_it) {
141 _buffered_addr = ref->obj();
142 } else {
143 _buffered_addr = nullptr;
144 }
145 }
146
147 // This constructor is only used for regenerated objects (created by LambdaFormInvokers, etc).
148 // src = address of a Method or InstanceKlass that has been regenerated.
149 // renegerated_obj_info = info for the regenerated version of src.
150 SourceObjInfo(address src, SourceObjInfo* renegerated_obj_info) :
151 _ptrmap_start(0), _ptrmap_end(0), _read_only(false),
152 _follow_mode(renegerated_obj_info->_follow_mode),
153 _size_in_bytes(0), _msotype(renegerated_obj_info->_msotype),
154 _source_addr(src), _buffered_addr(renegerated_obj_info->_buffered_addr) {}
155
156 bool should_copy() const { return _follow_mode == make_a_copy; }
157 void set_buffered_addr(address addr) {
158 assert(should_copy(), "must be");
159 assert(_buffered_addr == nullptr, "cannot be copied twice");
160 assert(addr != nullptr, "must be a valid copy");
161 _buffered_addr = addr;
162 }
163 void set_ptrmap_start(uintx v) { _ptrmap_start = v; }
164 void set_ptrmap_end(uintx v) { _ptrmap_end = v; }
165 uintx ptrmap_start() const { return _ptrmap_start; } // inclusive
166 uintx ptrmap_end() const { return _ptrmap_end; } // exclusive
167 bool read_only() const { return _read_only; }
168 int size_in_bytes() const { return _size_in_bytes; }
169 address source_addr() const { return _source_addr; }
170 address buffered_addr() const {
171 if (_follow_mode != set_to_null) {
172 assert(_buffered_addr != nullptr, "must be initialized");
173 }
174 return _buffered_addr;
175 }
176 MetaspaceObj::Type msotype() const { return _msotype; }
177 };
178
179 class SourceObjList {
180 uintx _total_bytes;
181 GrowableArray<SourceObjInfo*>* _objs; // Source objects to be archived
182 CHeapBitMap _ptrmap; // Marks the addresses of the pointer fields
183 // in the source objects
184 public:
185 SourceObjList();
186 ~SourceObjList();
187
188 GrowableArray<SourceObjInfo*>* objs() const { return _objs; }
189
190 void append(SourceObjInfo* src_info);
191 void remember_embedded_pointer(SourceObjInfo* pointing_obj, MetaspaceClosure::Ref* ref);
192 void relocate(int i, ArchiveBuilder* builder);
193
194 // convenience accessor
195 SourceObjInfo* at(int i) const { return objs()->at(i); }
196 };
197
198 class CDSMapLogger;
199
200 static const int INITIAL_TABLE_SIZE = 15889;
201 static const int MAX_TABLE_SIZE = 1000000;
202
203 ReservedSpace _shared_rs;
204 VirtualSpace _shared_vs;
205
206 DumpRegion _rw_region;
207 DumpRegion _ro_region;
208
209 // Combined bitmap to track pointers in both RW and RO regions. This is updated
210 // as objects are copied into RW and RO.
211 CHeapBitMap _ptrmap;
212
213 // _ptrmap is split into these two bitmaps which are written into the archive.
214 CHeapBitMap _rw_ptrmap; // marks pointers in the RW region
215 CHeapBitMap _ro_ptrmap; // marks pointers in the RO region
216
217 SourceObjList _rw_src_objs; // objs to put in rw region
218 SourceObjList _ro_src_objs; // objs to put in ro region
219 ResizeableResourceHashtable<address, SourceObjInfo, AnyObj::C_HEAP, mtClassShared> _src_obj_table;
220 ResizeableResourceHashtable<address, address, AnyObj::C_HEAP, mtClassShared> _buffered_to_src_table;
221 GrowableArray<Klass*>* _klasses;
222 GrowableArray<Symbol*>* _symbols;
223
224 // statistics
225 DumpAllocStats _alloc_stats;
226 size_t _total_heap_region_size;
227
228 void print_region_stats(FileMapInfo *map_info, ArchiveHeapInfo* heap_info);
229 void print_bitmap_region_stats(size_t size, size_t total_size);
230 void print_heap_region_stats(ArchiveHeapInfo* heap_info, size_t total_size);
231
232 // For global access.
233 static ArchiveBuilder* _current;
234
235 public:
236 // Use this when you allocate space outside of ArchiveBuilder::dump_{rw,ro}_region.
237 // These are usually for misc tables that are allocated in the RO space.
238 class OtherROAllocMark {
239 char* _oldtop;
240 public:
241 OtherROAllocMark() {
242 _oldtop = _current->_ro_region.top();
243 }
244 ~OtherROAllocMark();
245 };
246
247 private:
248 FollowMode get_follow_mode(MetaspaceClosure::Ref *ref);
249
250 void iterate_sorted_roots(MetaspaceClosure* it);
251 void sort_klasses();
252 static int compare_symbols_by_address(Symbol** a, Symbol** b);
253 static int compare_klass_by_name(Klass** a, Klass** b);
254
255 void make_shallow_copies(DumpRegion *dump_region, const SourceObjList* src_objs);
256 void make_shallow_copy(DumpRegion *dump_region, SourceObjInfo* src_info);
257
258 void relocate_embedded_pointers(SourceObjList* src_objs);
259
260 bool is_excluded(Klass* k);
261 void clean_up_src_obj_table();
262
263 protected:
264 virtual void iterate_roots(MetaspaceClosure* it) = 0;
265
266 // Conservative estimate for number of bytes needed for:
267 size_t _estimated_metaspaceobj_bytes; // all archived MetaspaceObj's.
268 size_t _estimated_hashtable_bytes; // symbol table and dictionaries
269
270 static const int _total_dump_regions = 2;
271
272 size_t estimate_archive_size();
273
274 void start_dump_space(DumpRegion* next);
275 void verify_estimate_size(size_t estimate, const char* which);
276
277 public:
278 address reserve_buffer();
279
280 address buffer_bottom() const { return _buffer_bottom; }
281 address buffer_top() const { return (address)current_dump_space()->top(); }
282 address requested_static_archive_bottom() const { return _requested_static_archive_bottom; }
283 address mapped_static_archive_bottom() const { return _mapped_static_archive_bottom; }
284 intx buffer_to_requested_delta() const { return _buffer_to_requested_delta; }
285
286 bool is_in_buffer_space(address p) const {
287 return (buffer_bottom() <= p && p < buffer_top());
288 }
289
290 template <typename T> bool is_in_requested_static_archive(T p) const {
291 return _requested_static_archive_bottom <= (address)p && (address)p < _requested_static_archive_top;
292 }
293
294 template <typename T> bool is_in_mapped_static_archive(T p) const {
295 return _mapped_static_archive_bottom <= (address)p && (address)p < _mapped_static_archive_top;
296 }
297
298 template <typename T> bool is_in_buffer_space(T obj) const {
299 return is_in_buffer_space(address(obj));
300 }
301
302 template <typename T> T to_requested(T obj) const {
303 assert(is_in_buffer_space(obj), "must be");
304 return (T)(address(obj) + _buffer_to_requested_delta);
305 }
306
307 static intx get_buffer_to_requested_delta() {
308 return current()->buffer_to_requested_delta();
309 }
310
311 inline static u4 to_offset_u4(uintx offset) {
312 guarantee(offset <= MAX_SHARED_DELTA, "must be 32-bit offset " INTPTR_FORMAT, offset);
313 return (u4)offset;
314 }
315
316 public:
317 static const uintx MAX_SHARED_DELTA = 0x7FFFFFFF;
318
319 // The address p points to an object inside the output buffer. When the archive is mapped
320 // at the requested address, what's the offset of this object from _requested_static_archive_bottom?
321 uintx buffer_to_offset(address p) const;
322
323 // Same as buffer_to_offset, except that the address p points to either (a) an object
324 // inside the output buffer, or (b), an object in the currently mapped static archive.
325 uintx any_to_offset(address p) const;
326
327 template <typename T>
328 u4 buffer_to_offset_u4(T p) const {
329 uintx offset = buffer_to_offset((address)p);
330 return to_offset_u4(offset);
331 }
332
333 template <typename T>
334 u4 any_to_offset_u4(T p) const {
335 uintx offset = any_to_offset((address)p);
336 return to_offset_u4(offset);
337 }
338
339 static void assert_is_vm_thread() PRODUCT_RETURN;
340
341 public:
342 ArchiveBuilder();
343 ~ArchiveBuilder();
344
345 void gather_klasses_and_symbols();
346 void gather_source_objs();
347 bool gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool read_only);
348 bool gather_one_source_obj(MetaspaceClosure::Ref* ref, bool read_only);
349 void remember_embedded_pointer_in_enclosing_obj(MetaspaceClosure::Ref* ref);
350 static void serialize_dynamic_archivable_items(SerializeClosure* soc);
351
352 DumpRegion* rw_region() { return &_rw_region; }
353 DumpRegion* ro_region() { return &_ro_region; }
354
355 static char* rw_region_alloc(size_t num_bytes) {
356 return current()->rw_region()->allocate(num_bytes);
357 }
358 static char* ro_region_alloc(size_t num_bytes) {
359 return current()->ro_region()->allocate(num_bytes);
360 }
361
362 template <typename T>
363 static Array<T>* new_ro_array(int length) {
364 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
365 Array<T>* array = (Array<T>*)ro_region_alloc(byte_size);
366 array->initialize(length);
367 return array;
368 }
369
370 template <typename T>
371 static Array<T>* new_rw_array(int length) {
372 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
373 Array<T>* array = (Array<T>*)rw_region_alloc(byte_size);
374 array->initialize(length);
375 return array;
376 }
377
378 template <typename T>
379 static size_t ro_array_bytesize(int length) {
380 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
381 return align_up(byte_size, SharedSpaceObjectAlignment);
382 }
383
384 char* ro_strdup(const char* s);
385
386 void dump_rw_metadata();
387 void dump_ro_metadata();
388 void relocate_metaspaceobj_embedded_pointers();
389 void record_regenerated_object(address orig_src_obj, address regen_src_obj);
390 void make_klasses_shareable();
391 void relocate_to_requested();
392 void write_archive(FileMapInfo* mapinfo, ArchiveHeapInfo* heap_info);
393 void write_region(FileMapInfo* mapinfo, int region_idx, DumpRegion* dump_region,
394 bool read_only, bool allow_exec);
395
396 void write_pointer_in_buffer(address* ptr_location, address src_addr);
397 template <typename T> void write_pointer_in_buffer(T* ptr_location, T src_addr) {
398 write_pointer_in_buffer((address*)ptr_location, (address)src_addr);
399 }
400
401 address get_buffered_addr(address src_addr) const;
402 template <typename T> T get_buffered_addr(T src_addr) const {
403 return (T)get_buffered_addr((address)src_addr);
404 }
405
406 address get_source_addr(address buffered_addr) const;
407 template <typename T> T get_source_addr(T buffered_addr) const {
408 return (T)get_source_addr((address)buffered_addr);
409 }
410
411 // All klasses and symbols that will be copied into the archive
412 GrowableArray<Klass*>* klasses() const { return _klasses; }
413 GrowableArray<Symbol*>* symbols() const { return _symbols; }
414
415 static bool is_active() {
416 return (_current != nullptr);
417 }
418
419 static ArchiveBuilder* current() {
420 assert_is_vm_thread();
421 assert(_current != nullptr, "ArchiveBuilder must be active");
422 return _current;
423 }
424
425 static DumpAllocStats* alloc_stats() {
426 return &(current()->_alloc_stats);
427 }
428
429 static CompactHashtableStats* symbol_stats() {
430 return alloc_stats()->symbol_stats();
431 }
432
433 static CompactHashtableStats* string_stats() {
434 return alloc_stats()->string_stats();
435 }
436
437 narrowKlass get_requested_narrow_klass(Klass* k);
438
439 static Klass* get_buffered_klass(Klass* src_klass) {
440 Klass* klass = (Klass*)current()->get_buffered_addr((address)src_klass);
441 assert(klass != nullptr && klass->is_klass(), "must be");
442 return klass;
443 }
444
445 static Symbol* get_buffered_symbol(Symbol* src_symbol) {
446 return (Symbol*)current()->get_buffered_addr((address)src_symbol);
447 }
448
449 void print_stats();
450 void report_out_of_space(const char* name, size_t needed_bytes);
451
452 #ifdef _LP64
453 // Archived heap object headers (and soon, with Lilliput, markword prototypes) carry pre-computed
454 // narrow Klass ids calculated with the following scheme:
455 // 1) the encoding base must be the mapping start address.
456 // 2) shift must be large enough to result in an encoding range that covers the runtime Klass range.
457 // That Klass range is defined by CDS archive size and runtime class space size. Luckily, the maximum
458 // size can be predicted: archive size is assumed to be <1G, class space size capped at 3G, and at
459 // runtime we put both regions adjacent to each other. Therefore, runtime Klass range size < 4G.
460 // The value of this precomputed shift depends on the class pointer mode at dump time.
461 // Legacy Mode:
462 // Since nKlass itself is 32 bit, our encoding range len is 4G, and since we set the base directly
463 // at mapping start, these 4G are enough. Therefore, we don't need to shift at all (shift=0).
464 // TinyClassPointer Mode:
465 // To cover the 4G, we need the highest possible shift value. That may change in the future, if
466 // we decide to correct the pre-calculated narrow Klass IDs at load time.
467 static int precomputed_narrow_klass_shift();
468 #endif // _LP64
469
470 };
471
472 #endif // SHARE_CDS_ARCHIVEBUILDER_HPP