1 /*
2 * Copyright (c) 2020, 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
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7 * published by the Free Software Foundation.
8 *
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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 struct ArchiveHeapBitmapInfo;
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_space;
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_space() const { return _current_dump_space; }
118
119 public:
120 enum FollowMode {
121 make_a_copy, point_to_it, set_to_null
122 };
123
124 private:
125 class SpecialRefInfo {
126 // We have a "special pointer" of the given _type at _field_offset of _src_obj.
127 // See MetaspaceClosure::push_special().
128 MetaspaceClosure::SpecialRef _type;
129 address _src_obj;
130 size_t _field_offset;
131 DEBUG_ONLY(size_t _src_obj_size_in_bytes;)
132
133 public:
134 SpecialRefInfo() {}
135 SpecialRefInfo(MetaspaceClosure::SpecialRef type, address src_obj, size_t field_offset, size_t src_obj_size_in_bytes)
136 : _type(type), _src_obj(src_obj), _field_offset(field_offset) {
137 DEBUG_ONLY(_src_obj_size_in_bytes = src_obj_size_in_bytes);
138 }
139
140 MetaspaceClosure::SpecialRef type() const { return _type; }
141 address src_obj() const { return _src_obj; }
142 size_t field_offset() const { return _field_offset; }
143
144 DEBUG_ONLY(size_t src_obj_size_in_bytes() const { return _src_obj_size_in_bytes; })
145 };
146
147 class SourceObjInfo {
148 MetaspaceClosure::Ref* _ref; // The object that's copied into the buffer
149 uintx _ptrmap_start; // The bit-offset of the start of this object (inclusive)
150 uintx _ptrmap_end; // The bit-offset of the end of this object (exclusive)
151 bool _read_only;
152 FollowMode _follow_mode;
153 int _size_in_bytes;
154 MetaspaceObj::Type _msotype;
155 address _source_addr; // The value of the source object (_ref->obj()) when this
156 // SourceObjInfo was created. Note that _ref->obj() may change
157 // later if _ref is relocated.
158 address _buffered_addr; // The copy of _ref->obj() insider the buffer.
159 public:
160 SourceObjInfo(MetaspaceClosure::Ref* ref, bool read_only, FollowMode follow_mode) :
161 _ref(ref), _ptrmap_start(0), _ptrmap_end(0), _read_only(read_only), _follow_mode(follow_mode),
162 _size_in_bytes(ref->size() * BytesPerWord), _msotype(ref->msotype()),
163 _source_addr(ref->obj()) {
164 if (follow_mode == point_to_it) {
165 _buffered_addr = ref->obj();
166 } else {
167 _buffered_addr = NULL;
168 }
169 }
170
171 bool should_copy() const { return _follow_mode == make_a_copy; }
172 MetaspaceClosure::Ref* ref() const { return _ref; }
173 void set_buffered_addr(address addr) {
174 assert(should_copy(), "must be");
175 assert(_buffered_addr == NULL, "cannot be copied twice");
176 assert(addr != NULL, "must be a valid copy");
177 _buffered_addr = addr;
178 }
179 void set_ptrmap_start(uintx v) { _ptrmap_start = v; }
180 void set_ptrmap_end(uintx v) { _ptrmap_end = v; }
181 uintx ptrmap_start() const { return _ptrmap_start; } // inclusive
182 uintx ptrmap_end() const { return _ptrmap_end; } // exclusive
183 bool read_only() const { return _read_only; }
184 int size_in_bytes() const { return _size_in_bytes; }
185 address source_addr() const { return _source_addr; }
186 address buffered_addr() const { return _buffered_addr; }
187 MetaspaceObj::Type msotype() const { return _msotype; }
188
189 // convenience accessor
190 address obj() const { return ref()->obj(); }
191 };
192
193 class SourceObjList {
194 uintx _total_bytes;
195 GrowableArray<SourceObjInfo*>* _objs; // Source objects to be archived
196 CHeapBitMap _ptrmap; // Marks the addresses of the pointer fields
197 // in the source objects
198 public:
199 SourceObjList();
200 ~SourceObjList();
201
202 GrowableArray<SourceObjInfo*>* objs() const { return _objs; }
203
204 void append(MetaspaceClosure::Ref* enclosing_ref, SourceObjInfo* src_info);
205 void remember_embedded_pointer(SourceObjInfo* pointing_obj, MetaspaceClosure::Ref* ref);
206 void relocate(int i, ArchiveBuilder* builder);
207
208 // convenience accessor
209 SourceObjInfo* at(int i) const { return objs()->at(i); }
210 };
211
212 class SrcObjTableCleaner {
213 public:
214 bool do_entry(address key, const SourceObjInfo& value) {
215 delete value.ref();
216 return true;
217 }
218 };
219
220 class CDSMapLogger;
221
222 static const int INITIAL_TABLE_SIZE = 15889;
223 static const int MAX_TABLE_SIZE = 1000000;
224
225 ReservedSpace _shared_rs;
226 VirtualSpace _shared_vs;
227
228 DumpRegion _rw_region;
229 DumpRegion _ro_region;
230 CHeapBitMap _ptrmap; // bitmap used by ArchivePtrMarker
231
232 SourceObjList _rw_src_objs; // objs to put in rw region
233 SourceObjList _ro_src_objs; // objs to put in ro region
234 ResizeableResourceHashtable<address, SourceObjInfo, AnyObj::C_HEAP, mtClassShared> _src_obj_table;
235 ResizeableResourceHashtable<address, address, AnyObj::C_HEAP, mtClassShared> _buffered_to_src_table;
236 GrowableArray<Klass*>* _klasses;
237 GrowableArray<Symbol*>* _symbols;
238 GrowableArray<SpecialRefInfo>* _special_refs;
239
240 // statistics
241 DumpAllocStats _alloc_stats;
242 size_t _total_closed_heap_region_size;
243 size_t _total_open_heap_region_size;
244
245 void print_region_stats(FileMapInfo *map_info,
246 GrowableArray<MemRegion>* closed_heap_regions,
247 GrowableArray<MemRegion>* open_heap_regions);
248 void print_bitmap_region_stats(size_t size, size_t total_size);
249 void print_heap_region_stats(GrowableArray<MemRegion>* regions,
250 const char *name, size_t total_size);
251
252 // For global access.
253 static ArchiveBuilder* _current;
254
255 public:
256 // Use this when you allocate space outside of ArchiveBuilder::dump_{rw,ro}_region.
257 // These are usually for misc tables that are allocated in the RO space.
258 class OtherROAllocMark {
259 char* _oldtop;
260 public:
261 OtherROAllocMark() {
262 _oldtop = _current->_ro_region.top();
263 }
264 ~OtherROAllocMark();
265 };
266
267 private:
268 bool is_dumping_full_module_graph();
269 FollowMode get_follow_mode(MetaspaceClosure::Ref *ref);
270
271 void iterate_sorted_roots(MetaspaceClosure* it, bool is_relocating_pointers);
272 void sort_symbols_and_fix_hash();
273 void sort_klasses();
274 static int compare_symbols_by_address(Symbol** a, Symbol** b);
275 static int compare_klass_by_name(Klass** a, Klass** b);
276
277 void make_shallow_copies(DumpRegion *dump_region, const SourceObjList* src_objs);
278 void make_shallow_copy(DumpRegion *dump_region, SourceObjInfo* src_info);
279
280 void update_special_refs();
281 void relocate_embedded_pointers(SourceObjList* src_objs);
282
283 bool is_excluded(Klass* k);
284 void clean_up_src_obj_table();
285
286 protected:
287 virtual void iterate_roots(MetaspaceClosure* it, bool is_relocating_pointers) = 0;
288
289 // Conservative estimate for number of bytes needed for:
290 size_t _estimated_metaspaceobj_bytes; // all archived MetaspaceObj's.
291 size_t _estimated_hashtable_bytes; // symbol table and dictionaries
292
293 static const int _total_dump_regions = 2;
294
295 size_t estimate_archive_size();
296
297 void start_dump_space(DumpRegion* next);
298 void verify_estimate_size(size_t estimate, const char* which);
299
300 public:
301 address reserve_buffer();
302
303 address buffer_bottom() const { return _buffer_bottom; }
304 address buffer_top() const { return (address)current_dump_space()->top(); }
305 address requested_static_archive_bottom() const { return _requested_static_archive_bottom; }
306 address mapped_static_archive_bottom() const { return _mapped_static_archive_bottom; }
307 intx buffer_to_requested_delta() const { return _buffer_to_requested_delta; }
308
309 bool is_in_buffer_space(address p) const {
310 return (buffer_bottom() <= p && p < buffer_top());
311 }
312
313 template <typename T> bool is_in_requested_static_archive(T p) const {
314 return _requested_static_archive_bottom <= (address)p && (address)p < _requested_static_archive_top;
315 }
316
317 template <typename T> bool is_in_mapped_static_archive(T p) const {
318 return _mapped_static_archive_bottom <= (address)p && (address)p < _mapped_static_archive_top;
319 }
320
321 template <typename T> bool is_in_buffer_space(T obj) const {
322 return is_in_buffer_space(address(obj));
323 }
324
325 template <typename T> T to_requested(T obj) const {
326 assert(is_in_buffer_space(obj), "must be");
327 return (T)(address(obj) + _buffer_to_requested_delta);
328 }
329
330 static intx get_buffer_to_requested_delta() {
331 return current()->buffer_to_requested_delta();
332 }
333
334 public:
335 static const uintx MAX_SHARED_DELTA = 0x7FFFFFFF;
336
337 // The address p points to an object inside the output buffer. When the archive is mapped
338 // at the requested address, what's the offset of this object from _requested_static_archive_bottom?
339 uintx buffer_to_offset(address p) const;
340
341 // Same as buffer_to_offset, except that the address p points to either (a) an object
342 // inside the output buffer, or (b), an object in the currently mapped static archive.
343 uintx any_to_offset(address p) const;
344
345 template <typename T>
346 u4 buffer_to_offset_u4(T p) const {
347 uintx offset = buffer_to_offset((address)p);
348 guarantee(offset <= MAX_SHARED_DELTA, "must be 32-bit offset " INTPTR_FORMAT, offset);
349 return (u4)offset;
350 }
351
352 template <typename T>
353 u4 any_to_offset_u4(T p) const {
354 uintx offset = any_to_offset((address)p);
355 guarantee(offset <= MAX_SHARED_DELTA, "must be 32-bit offset " INTPTR_FORMAT, offset);
356 return (u4)offset;
357 }
358
359 static void assert_is_vm_thread() PRODUCT_RETURN;
360
361 public:
362 ArchiveBuilder();
363 ~ArchiveBuilder();
364
365 void gather_klasses_and_symbols();
366 void gather_source_objs();
367 bool gather_klass_and_symbol(MetaspaceClosure::Ref* ref, bool read_only);
368 bool gather_one_source_obj(MetaspaceClosure::Ref* enclosing_ref, MetaspaceClosure::Ref* ref, bool read_only);
369 void add_special_ref(MetaspaceClosure::SpecialRef type, address src_obj, size_t field_offset, size_t src_obj_size_in_bytes) {
370 _special_refs->append(SpecialRefInfo(type, src_obj, field_offset, src_obj_size_in_bytes));
371 }
372 void remember_embedded_pointer_in_copied_obj(MetaspaceClosure::Ref* enclosing_ref, MetaspaceClosure::Ref* ref);
373
374 DumpRegion* rw_region() { return &_rw_region; }
375 DumpRegion* ro_region() { return &_ro_region; }
376
377 static char* rw_region_alloc(size_t num_bytes) {
378 return current()->rw_region()->allocate(num_bytes);
379 }
380 static char* ro_region_alloc(size_t num_bytes) {
381 return current()->ro_region()->allocate(num_bytes);
382 }
383
384 template <typename T>
385 static Array<T>* new_ro_array(int length) {
386 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
387 Array<T>* array = (Array<T>*)ro_region_alloc(byte_size);
388 array->initialize(length);
389 return array;
390 }
391
392 template <typename T>
393 static Array<T>* new_rw_array(int length) {
394 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
395 Array<T>* array = (Array<T>*)rw_region_alloc(byte_size);
396 array->initialize(length);
397 return array;
398 }
399
400 template <typename T>
401 static size_t ro_array_bytesize(int length) {
402 size_t byte_size = Array<T>::byte_sizeof(length, sizeof(T));
403 return align_up(byte_size, SharedSpaceObjectAlignment);
404 }
405
406 void dump_rw_metadata();
407 void dump_ro_metadata();
408 void relocate_metaspaceobj_embedded_pointers();
409 void relocate_roots();
410 void relocate_vm_classes();
411 void make_klasses_shareable();
412 void relocate_to_requested();
413 void write_archive(FileMapInfo* mapinfo,
414 GrowableArray<MemRegion>* closed_heap_regions,
415 GrowableArray<MemRegion>* open_heap_regions,
416 GrowableArray<ArchiveHeapBitmapInfo>* closed_heap_oopmaps,
417 GrowableArray<ArchiveHeapBitmapInfo>* open_heap_oopmaps);
418 void write_region(FileMapInfo* mapinfo, int region_idx, DumpRegion* dump_region,
419 bool read_only, bool allow_exec);
420
421 address get_buffered_addr(address src_addr) const;
422 address get_source_addr(address buffered_addr) const;
423 template <typename T> T get_source_addr(T buffered_addr) const {
424 return (T)get_source_addr((address)buffered_addr);
425 }
426
427 // All klasses and symbols that will be copied into the archive
428 GrowableArray<Klass*>* klasses() const { return _klasses; }
429 GrowableArray<Symbol*>* symbols() const { return _symbols; }
430
431 static bool is_active() {
432 return (_current != NULL);
433 }
434
435 static ArchiveBuilder* current() {
436 assert_is_vm_thread();
437 assert(_current != NULL, "ArchiveBuilder must be active");
438 return _current;
439 }
440
441 static DumpAllocStats* alloc_stats() {
442 return &(current()->_alloc_stats);
443 }
444
445 static CompactHashtableStats* symbol_stats() {
446 return alloc_stats()->symbol_stats();
447 }
448
449 static CompactHashtableStats* string_stats() {
450 return alloc_stats()->string_stats();
451 }
452
453 void relocate_klass_ptr_of_oop(oop o);
454
455 static Klass* get_buffered_klass(Klass* src_klass) {
456 Klass* klass = (Klass*)current()->get_buffered_addr((address)src_klass);
457 assert(klass != NULL && klass->is_klass(), "must be");
458 return klass;
459 }
460
461 static Symbol* get_buffered_symbol(Symbol* src_symbol) {
462 return (Symbol*)current()->get_buffered_addr((address)src_symbol);
463 }
464
465 void print_stats();
466 void report_out_of_space(const char* name, size_t needed_bytes);
467 };
468
469 #endif // SHARE_CDS_ARCHIVEBUILDER_HPP