1 /*
2 * Copyright (c) 1998, 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
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_COMPILER_OOPMAP_HPP
26 #define SHARE_COMPILER_OOPMAP_HPP
27
28 #include "code/compressedStream.hpp"
29 #include "code/vmreg.hpp"
30 #include "memory/allocation.hpp"
31 #include "memory/iterator.hpp"
32 #include "oops/oopsHierarchy.hpp"
33 #include "utilities/checkedCast.hpp"
34 #include "utilities/growableArray.hpp"
35
36 // Interface for generating the frame map for compiled code. A frame map
37 // describes for a specific pc whether each register and frame stack slot is:
38 // Oop - A GC root for current frame
39 // Dead - Dead; can be Zapped for debugging
40 // CalleeXX - Callee saved; also describes which caller register is saved
41 // DerivedXX - A derived oop; original oop is described.
42 //
43 // OopMapValue describes a single OopMap entry
44
45 enum class DerivedPointerIterationMode;
46 class frame;
47 class RegisterMap;
48 class OopClosure;
49 class CodeBlob;
50 class ImmutableOopMap;
51
52 enum class derived_base : intptr_t {};
53 enum class derived_pointer : intptr_t {};
54
55 class OopMapValue: public StackObj {
56 friend class VMStructs;
57 private:
58 unsigned short _value;
59 unsigned short value() const { return _value; }
60 void set_value(unsigned short value) { _value = value; }
61 short _content_reg;
62
63 public:
64 // Constants
65 enum { type_bits = 2,
66 register_bits = BitsPerShort - type_bits };
67
68 enum { type_shift = 0,
69 register_shift = type_bits };
70
71 enum { type_mask = right_n_bits(type_bits),
72 type_mask_in_place = type_mask << type_shift,
73 register_mask = right_n_bits(register_bits),
74 register_mask_in_place = register_mask << register_shift };
75
76 enum oop_types {
77 oop_value,
78 narrowoop_value,
79 callee_saved_value,
80 derived_oop_value,
81 unused_value = -1 // Only used as a sentinel value
82 };
83
84 // Constructors
85 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
86 OopMapValue (VMReg reg, oop_types t, VMReg reg2) {
87 set_reg_type(reg, t);
88 set_content_reg(reg2);
89 }
90
91 private:
92 void set_reg_type(VMReg p, oop_types t) {
93 set_value(checked_cast<unsigned short>((p->value() << register_shift) | t));
94 assert(reg() == p, "sanity check" );
95 assert(type() == t, "sanity check" );
96 }
97
98 void set_content_reg(VMReg r) {
99 if (is_callee_saved()) {
100 // This can never be a stack location, so we don't need to transform it.
101 assert(r->is_reg(), "Trying to callee save a stack location");
102 } else if (is_derived_oop()) {
103 assert (r->is_valid(), "must have a valid VMReg");
104 } else {
105 assert (!r->is_valid(), "valid VMReg not allowed");
106 }
107 _content_reg = checked_cast<short>(r->value());
108 }
109
110 public:
111 // Archiving
112 void write_on(CompressedWriteStream* stream) {
113 stream->write_int(value());
114 if(is_callee_saved() || is_derived_oop()) {
115 stream->write_int(checked_cast<int>(content_reg()->value()));
116 }
117 }
118
119 void read_from(CompressedReadStream* stream) {
120 set_value(checked_cast<unsigned short>(stream->read_int()));
121 if (is_callee_saved() || is_derived_oop()) {
122 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));
123 }
124 }
125
126 // Querying
127 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
128 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
129 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
130 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }
131
132 VMReg reg() const { return VMRegImpl::as_VMReg(checked_cast<int>(mask_bits(value(), register_mask_in_place) >> register_shift)); }
133 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }
134
135 static bool legal_vm_reg_name(VMReg p) {
136 return (p->value() == (p->value() & register_mask));
137 }
138
139 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
140
141 // Returns offset from sp.
142 int stack_offset() {
143 assert(reg()->is_stack(), "must be stack location");
144 return reg()->reg2stack();
145 }
146
147 void print_on(outputStream* st) const;
148 void print() const;
149 };
150
151
152 class OopMap: public ResourceObj {
153 friend class OopMapStream;
154 friend class VMStructs;
155 friend class OopMapSet;
156 friend class OopMapSort;
157 private:
158 int _pc_offset; // offset in the code that this OopMap corresponds to
159 int _omv_count; // number of OopMapValues in the stream
160 int _num_oops; // number of oops
161 int _index; // index in OopMapSet
162 bool _has_derived_oops;
163 CompressedWriteStream* _write_stream;
164
165 DEBUG_ONLY( OopMapValue::oop_types* _locs_used; int _locs_length;)
166
167 // Accessors
168 int omv_count() const { return _omv_count; }
169 void set_omv_count(int value) { _omv_count = value; }
170 void increment_count() { _omv_count++; }
171 void increment_num_oops() { _num_oops++; }
172 void set_has_derived_oops(bool value) { _has_derived_oops = value; }
173 CompressedWriteStream* write_stream() const { return _write_stream; }
174 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
175
176 enum DeepCopyToken { _deep_copy_token };
177 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
178
179 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
180
181 public:
182 OopMap(int frame_size, int arg_count);
183
184 // pc-offset handling
185 int offset() const { return _pc_offset; }
186 void set_offset(int o) { _pc_offset = o; }
187 int count() const { return _omv_count; }
188 int data_size() const { return write_stream()->position(); }
189 address data() const { return write_stream()->buffer(); }
190 int num_oops() const { return _num_oops; }
191 bool has_derived_oops() const { return _has_derived_oops; }
192 int index() const { return _index; }
193
194 // Construction
195 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
196 // slots to hold 4-byte values like ints and floats in the LP64 build.
197 void set_oop ( VMReg local);
198 void set_narrowoop(VMReg local);
199 void set_callee_saved( VMReg local, VMReg caller_machine_register );
200 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
201
202 int heap_size() const;
203 void copy_data_to(address addr) const;
204 void copy_and_sort_data_to(address addr) const;
205 OopMap* deep_copy();
206
207 bool legal_vm_reg_name(VMReg local) {
208 return OopMapValue::legal_vm_reg_name(local);
209 }
210
211 // Printing
212 void print_on(outputStream* st) const;
213 void print() const;
214 bool equals(const OopMap* other) const;
215 };
216
217 class OopMapSet : public ResourceObj {
218 friend class VMStructs;
219 private:
220 GrowableArray<OopMap*> _list;
221
222 int add(OopMap* value) { return _list.append(value); }
223
224 public:
225 OopMapSet();
226
227 // returns the number of OopMaps in this OopMapSet
228 int size() const { return _list.length(); }
229 // returns the OopMap at a given index
230 OopMap* at(int index) const { return _list.at(index); }
231
232 // Collect OopMaps.
233 int add_gc_map(int pc, OopMap* map);
234
235 // Methods oops_do() and all_do() filter out nullptr oops and
236 // oop == CompressedOops::base() before passing oops
237 // to closures.
238
239 static const ImmutableOopMap* find_map(const CodeBlob* cb, address pc);
240 static const ImmutableOopMap* find_map(const frame *fr);
241
242 // Iterates through frame for a compiled method
243 static void oops_do (const frame* fr,
244 const RegisterMap* reg_map,
245 OopClosure* f,
246 DerivedOopClosure* df);
247 static void oops_do (const frame* fr,
248 const RegisterMap* reg_map,
249 OopClosure* f,
250 DerivedPointerIterationMode mode);
251 static void update_register_map(const frame* fr, RegisterMap *reg_map);
252
253 #ifndef PRODUCT
254 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map);
255 #endif
256
257 // Printing
258 void print_on(outputStream* st) const;
259 void print() const;
260 };
261
262 class ImmutableOopMapBuilder;
263
264 class OopMapClosure : public Closure {
265 public:
266 virtual bool handle_type(OopMapValue::oop_types type) { return true; }
267 virtual void do_value(VMReg reg, OopMapValue::oop_types type) = 0;
268 };
269
270 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
271 class OopMapDo;
272
273 class ImmutableOopMap {
274 friend class OopMapStream;
275 friend class VMStructs;
276 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
277 friend class OopMapDo;
278 #ifdef ASSERT
279 friend class ImmutableOopMapBuilder;
280 #endif
281 private:
282 int _count; // contains the number of entries in this OopMap
283 int _num_oops;
284 bool _has_derived_oops;
285
286 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
287 public:
288 ImmutableOopMap(const OopMap* oopmap);
289
290 int count() const { return _count; }
291 int num_oops() const { return _num_oops; }
292 bool has_derived_oops() const { return _has_derived_oops; }
293 bool has_any(OopMapValue::oop_types type) const;
294
295 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds or in aot code generation
296
297 void oops_do(const frame* fr, const RegisterMap* reg_map, OopClosure* f, DerivedOopClosure* df) const;
298 void oops_do(const frame* fr, const RegisterMap* reg_map, OopClosure* f, DerivedPointerIterationMode derived_mode) const;
299 void all_type_do(const frame *fr, OopMapValue::oop_types type, OopMapClosure* fn) const;
300 void all_type_do(const frame *fr, OopMapClosure* fn) const;
301 void update_register_map(const frame* fr, RegisterMap *reg_map) const;
302
303 // Printing
304 void print_on(outputStream* st) const;
305 void print() const;
306 };
307
308 class ImmutableOopMapSet;
309 class ImmutableOopMap;
310 class OopMapSet;
311
312 class ImmutableOopMapPair {
313 friend class VMStructs;
314 private:
315 int _pc_offset; // program counter offset from the beginning of the method
316 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
317 public:
318 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
319 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
320 }
321 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
322
323 int pc_offset() const { return _pc_offset; }
324 int oopmap_offset() const { return _oopmap_offset; }
325 };
326
327 class ImmutableOopMapSet {
328 friend class VMStructs;
329 private:
330 int _count; // nr of ImmutableOopMapPairs in the Set
331 int _size; // nr of bytes including ImmutableOopMapSet itself
332
333 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
334
335 public:
336 void operator delete(void* p);
337
338 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
339 ~ImmutableOopMapSet() = default;
340
341 ImmutableOopMap* oopmap_at_offset(int offset) const {
342 assert(offset >= 0 && offset < _size, "must be within boundaries");
343 address addr = data() + offset;
344 return (ImmutableOopMap*) addr;
345 }
346
347 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
348
349 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
350
351 int find_slot_for_offset(int pc_offset) const;
352 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
353 const ImmutableOopMap* find_map_at_slot(int slot, int pc_offset) const;
354
355 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
356
357 int count() const { return _count; }
358 int nr_of_bytes() const { return _size; }
359
360 void print_on(outputStream* st) const;
361 void print() const;
362 };
363
364 class OopMapStream : public StackObj {
365 private:
366 CompressedReadStream _stream;
367 int _size;
368 int _position;
369 bool _valid_omv;
370 OopMapValue _omv;
371 void find_next();
372
373 public:
374 OopMapStream(const OopMap* oop_map);
375 OopMapStream(const ImmutableOopMap* oop_map);
376 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
377 void next() { find_next(); }
378 OopMapValue current() { return _omv; }
379 int stream_position() const { return _stream.position(); }
380 };
381
382 class ImmutableOopMapBuilder {
383 private:
384 class Mapping;
385
386 private:
387 const OopMapSet* _set;
388 const OopMap* _empty;
389 const OopMap* _last;
390 int _empty_offset;
391 int _last_offset;
392 int _offset;
393 int _required;
394 Mapping* _mapping;
395 ImmutableOopMapSet* _new_set;
396
397 /* Used for bookkeeping when building ImmutableOopMaps */
398 class Mapping : public ResourceObj {
399 public:
400 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
401
402 kind_t _kind;
403 int _offset;
404 int _size;
405 const OopMap* _map;
406 const OopMap* _other;
407
408 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(nullptr) {}
409
410 void set(kind_t kind, int offset, int size, const OopMap* map, const OopMap* other = nullptr) {
411 _kind = kind;
412 _offset = offset;
413 _size = size;
414 _map = map;
415 _other = other;
416 }
417 };
418
419 public:
420 ImmutableOopMapBuilder(const OopMapSet* set);
421
422 int heap_size();
423 ImmutableOopMapSet* build();
424 ImmutableOopMapSet* generate_into(address buffer);
425 private:
426 bool is_empty(const OopMap* map) const {
427 return map->count() == 0;
428 }
429
430 bool is_last_duplicate(const OopMap* map) {
431 if (_last != nullptr && _last->count() > 0 && _last->equals(map)) {
432 return true;
433 }
434 return false;
435 }
436
437 #ifdef ASSERT
438 void verify(address buffer, int size, const ImmutableOopMapSet* set);
439 #endif
440
441 bool has_empty() const {
442 return _empty_offset != -1;
443 }
444
445 int size_for(const OopMap* map) const;
446 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
447 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
448 void fill(ImmutableOopMapSet* set, int size);
449 };
450
451 class SkipNullValue {
452 public:
453 static inline bool should_skip(void* val);
454 };
455
456 class IncludeAllValues {
457 public:
458 static bool should_skip(void* value) { return false; }
459 };
460
461 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
462 class OopMapDo {
463 private:
464 OopFnT* _oop_fn;
465 DerivedOopFnT* _derived_oop_fn;
466 public:
467 OopMapDo(OopFnT* oop_fn, DerivedOopFnT* derived_oop_fn) : _oop_fn(oop_fn), _derived_oop_fn(derived_oop_fn) {}
468 template <typename RegisterMapT>
469 void oops_do(const frame* fr, const RegisterMapT* reg_map, const ImmutableOopMap* oopmap);
470 private:
471 template <typename RegisterMapT>
472 void iterate_oops_do(const frame *fr, const RegisterMapT *reg_map, const ImmutableOopMap* oopmap);
473 };
474
475 // Derived pointer support. This table keeps track of all derived points on a
476 // stack. It is cleared before each scavenge/GC. During the traversal of all
477 // oops, it is filled in with references to all locations that contains a
478 // derived oop (assumed to be very few). When the GC is complete, the derived
479 // pointers are updated based on their base pointers new value and an offset.
480 #if COMPILER2_OR_JVMCI
481 class DerivedPointerTable : public AllStatic {
482 friend class VMStructs;
483 private:
484 class Entry;
485 static bool _active; // do not record pointers for verify pass etc.
486
487 public:
488 static void clear(); // Called before scavenge/GC
489 static void add(derived_pointer* derived, derived_base* base); // Called during scavenge/GC
490 static void update_pointers(); // Called after scavenge/GC
491 static bool is_empty();
492 static bool is_active() { return _active; }
493 static void set_active(bool value) { _active = value; }
494 };
495
496 // A utility class to temporarily "deactivate" the DerivedPointerTable.
497 // (Note: clients are responsible for any MT-safety issues)
498 class DerivedPointerTableDeactivate: public StackObj {
499 private:
500 bool _active;
501 public:
502 DerivedPointerTableDeactivate() {
503 _active = DerivedPointerTable::is_active();
504 if (_active) {
505 DerivedPointerTable::set_active(false);
506 }
507 }
508
509 ~DerivedPointerTableDeactivate() {
510 assert(!DerivedPointerTable::is_active(),
511 "Inconsistency: not MT-safe");
512 if (_active) {
513 DerivedPointerTable::set_active(true);
514 }
515 }
516 };
517 #endif // COMPILER2_OR_JVMCI
518
519 #endif // SHARE_COMPILER_OOPMAP_HPP