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 friend class SCCReader;
158 private:
159 int _pc_offset; // offset in the code that this OopMap corresponds to
160 int _omv_count; // number of OopMapValues in the stream
161 int _num_oops; // number of oops
162 int _index; // index in OopMapSet
163 bool _has_derived_oops;
164 CompressedWriteStream* _write_stream;
165
166 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
167
168 // Accessors
169 int omv_count() const { return _omv_count; }
170 void set_omv_count(int value) { _omv_count = value; }
171 void increment_count() { _omv_count++; }
172 void increment_num_oops() { _num_oops++; }
173 void set_has_derived_oops(bool value) { _has_derived_oops = value; }
174 CompressedWriteStream* write_stream() const { return _write_stream; }
175 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
176
177 enum DeepCopyToken { _deep_copy_token };
178 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
179
180 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
181
182 public:
183 OopMap(int frame_size, int arg_count);
184 OopMap(int data_size);
185
186 // pc-offset handling
187 int offset() const { return _pc_offset; }
188 void set_offset(int o) { _pc_offset = o; }
189 int count() const { return _omv_count; }
190 int data_size() const { return write_stream()->position(); }
191 address data() const { return write_stream()->buffer(); }
192 int num_oops() const { return _num_oops; }
193 bool has_derived_oops() const { return _has_derived_oops; }
194 int index() const { return _index; }
195
196 // Construction
197 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
198 // slots to hold 4-byte values like ints and floats in the LP64 build.
199 void set_oop ( VMReg local);
200 void set_narrowoop(VMReg local);
201 void set_callee_saved( VMReg local, VMReg caller_machine_register );
202 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
203
204 int heap_size() const;
205 void copy_data_to(address addr) const;
206 void copy_and_sort_data_to(address addr) const;
207 OopMap* deep_copy();
208
209 bool legal_vm_reg_name(VMReg local) {
210 return OopMapValue::legal_vm_reg_name(local);
211 }
212
213 // Printing
214 void print_on(outputStream* st) const;
215 void print() const;
216 bool equals(const OopMap* other) const;
217 };
218
219 class OopMapSet : public ResourceObj {
220 friend class VMStructs;
221 friend class SCCReader;
222 private:
223 GrowableArray<OopMap*> _list;
224
225 int add(OopMap* value) { return _list.append(value); }
226
227 public:
228 OopMapSet();
229 OopMapSet(int size);
230
231 // returns the number of OopMaps in this OopMapSet
232 int size() const { return _list.length(); }
233 // returns the OopMap at a given index
234 OopMap* at(int index) const { return _list.at(index); }
235
236 // Collect OopMaps.
237 int add_gc_map(int pc, OopMap* map);
238
239 // Methods oops_do() and all_do() filter out nullptr oops and
240 // oop == CompressedOops::base() before passing oops
241 // to closures.
242
243 static const ImmutableOopMap* find_map(const CodeBlob* cb, address pc);
244 static const ImmutableOopMap* find_map(const frame *fr);
245
246 // Iterates through frame for a compiled method
247 static void oops_do (const frame* fr,
248 const RegisterMap* reg_map,
249 OopClosure* f,
250 DerivedOopClosure* df);
251 static void oops_do (const frame* fr,
252 const RegisterMap* reg_map,
253 OopClosure* f,
254 DerivedPointerIterationMode mode);
255 static void update_register_map(const frame* fr, RegisterMap *reg_map);
256
257 #ifndef PRODUCT
258 static void trace_codeblob_maps(const frame *fr, const RegisterMap *reg_map);
259 #endif
260
261 // Printing
262 void print_on(outputStream* st) const;
263 void print() const;
264 };
265
266 class ImmutableOopMapBuilder;
267
268 class OopMapClosure : public Closure {
269 public:
270 virtual bool handle_type(OopMapValue::oop_types type) { return true; }
271 virtual void do_value(VMReg reg, OopMapValue::oop_types type) = 0;
272 };
273
274 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
275 class OopMapDo;
276
277 class ImmutableOopMap {
278 friend class OopMapStream;
279 friend class VMStructs;
280 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
281 friend class OopMapDo;
282 #ifdef ASSERT
283 friend class ImmutableOopMapBuilder;
284 #endif
285 private:
286 int _count; // contains the number of entries in this OopMap
287 int _num_oops;
288 bool _has_derived_oops;
289
290 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
291 public:
292 ImmutableOopMap(const OopMap* oopmap);
293
294 int count() const { return _count; }
295 int num_oops() const { return _num_oops; }
296 bool has_derived_oops() const { return _has_derived_oops; }
297 bool has_any(OopMapValue::oop_types type) const;
298
299 #ifdef ASSERT
300 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
301 #endif
302
303 void oops_do(const frame* fr, const RegisterMap* reg_map, OopClosure* f, DerivedOopClosure* df) const;
304 void oops_do(const frame* fr, const RegisterMap* reg_map, OopClosure* f, DerivedPointerIterationMode derived_mode) const;
305 void all_type_do(const frame *fr, OopMapValue::oop_types type, OopMapClosure* fn) const;
306 void all_type_do(const frame *fr, OopMapClosure* fn) const;
307 void update_register_map(const frame* fr, RegisterMap *reg_map) const;
308
309 // Printing
310 void print_on(outputStream* st) const;
311 void print() const;
312 };
313
314 class ImmutableOopMapSet;
315 class ImmutableOopMap;
316 class OopMapSet;
317
318 class ImmutableOopMapPair {
319 friend class VMStructs;
320 private:
321 int _pc_offset; // program counter offset from the beginning of the method
322 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
323 public:
324 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
325 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
326 }
327 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
328
329 int pc_offset() const { return _pc_offset; }
330 int oopmap_offset() const { return _oopmap_offset; }
331 };
332
333 class ImmutableOopMapSet {
334 friend class VMStructs;
335 private:
336 int _count; // nr of ImmutableOopMapPairs in the Set
337 int _size; // nr of bytes including ImmutableOopMapSet itself
338
339 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
340
341 public:
342 void operator delete(void* p);
343
344 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
345 ~ImmutableOopMapSet() = default;
346
347 ImmutableOopMap* oopmap_at_offset(int offset) const {
348 assert(offset >= 0 && offset < _size, "must be within boundaries");
349 address addr = data() + offset;
350 return (ImmutableOopMap*) addr;
351 }
352
353 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
354
355 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
356
357 int find_slot_for_offset(int pc_offset) const;
358 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
359 const ImmutableOopMap* find_map_at_slot(int slot, int pc_offset) const;
360
361 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
362
363 int count() const { return _count; }
364 int nr_of_bytes() const { return _size; }
365
366 void print_on(outputStream* st) const;
367 void print() const;
368 };
369
370 class OopMapStream : public StackObj {
371 private:
372 CompressedReadStream _stream;
373 int _size;
374 int _position;
375 bool _valid_omv;
376 OopMapValue _omv;
377 void find_next();
378
379 public:
380 OopMapStream(const OopMap* oop_map);
381 OopMapStream(const ImmutableOopMap* oop_map);
382 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
383 void next() { find_next(); }
384 OopMapValue current() { return _omv; }
385 #ifdef ASSERT
386 int stream_position() const { return _stream.position(); }
387 #endif
388 };
389
390 class ImmutableOopMapBuilder {
391 private:
392 class Mapping;
393
394 private:
395 const OopMapSet* _set;
396 const OopMap* _empty;
397 const OopMap* _last;
398 int _empty_offset;
399 int _last_offset;
400 int _offset;
401 int _required;
402 Mapping* _mapping;
403 ImmutableOopMapSet* _new_set;
404
405 /* Used for bookkeeping when building ImmutableOopMaps */
406 class Mapping : public ResourceObj {
407 public:
408 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
409
410 kind_t _kind;
411 int _offset;
412 int _size;
413 const OopMap* _map;
414 const OopMap* _other;
415
416 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(nullptr) {}
417
418 void set(kind_t kind, int offset, int size, const OopMap* map, const OopMap* other = nullptr) {
419 _kind = kind;
420 _offset = offset;
421 _size = size;
422 _map = map;
423 _other = other;
424 }
425 };
426
427 public:
428 ImmutableOopMapBuilder(const OopMapSet* set);
429
430 int heap_size();
431 ImmutableOopMapSet* build();
432 ImmutableOopMapSet* generate_into(address buffer);
433 private:
434 bool is_empty(const OopMap* map) const {
435 return map->count() == 0;
436 }
437
438 bool is_last_duplicate(const OopMap* map) {
439 if (_last != nullptr && _last->count() > 0 && _last->equals(map)) {
440 return true;
441 }
442 return false;
443 }
444
445 #ifdef ASSERT
446 void verify(address buffer, int size, const ImmutableOopMapSet* set);
447 #endif
448
449 bool has_empty() const {
450 return _empty_offset != -1;
451 }
452
453 int size_for(const OopMap* map) const;
454 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
455 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
456 void fill(ImmutableOopMapSet* set, int size);
457 };
458
459 class SkipNullValue {
460 public:
461 static inline bool should_skip(void* val);
462 };
463
464 class IncludeAllValues {
465 public:
466 static bool should_skip(void* value) { return false; }
467 };
468
469 template <typename OopFnT, typename DerivedOopFnT, typename ValueFilterT>
470 class OopMapDo {
471 private:
472 OopFnT* _oop_fn;
473 DerivedOopFnT* _derived_oop_fn;
474 public:
475 OopMapDo(OopFnT* oop_fn, DerivedOopFnT* derived_oop_fn) : _oop_fn(oop_fn), _derived_oop_fn(derived_oop_fn) {}
476 template <typename RegisterMapT>
477 void oops_do(const frame* fr, const RegisterMapT* reg_map, const ImmutableOopMap* oopmap);
478 private:
479 template <typename RegisterMapT>
480 void iterate_oops_do(const frame *fr, const RegisterMapT *reg_map, const ImmutableOopMap* oopmap);
481 };
482
483 // Derived pointer support. This table keeps track of all derived points on a
484 // stack. It is cleared before each scavenge/GC. During the traversal of all
485 // oops, it is filled in with references to all locations that contains a
486 // derived oop (assumed to be very few). When the GC is complete, the derived
487 // pointers are updated based on their base pointers new value and an offset.
488 #if COMPILER2_OR_JVMCI
489 class DerivedPointerTable : public AllStatic {
490 friend class VMStructs;
491 private:
492 class Entry;
493 static bool _active; // do not record pointers for verify pass etc.
494
495 public:
496 static void clear(); // Called before scavenge/GC
497 static void add(derived_pointer* derived, derived_base* base); // Called during scavenge/GC
498 static void update_pointers(); // Called after scavenge/GC
499 static bool is_empty();
500 static bool is_active() { return _active; }
501 static void set_active(bool value) { _active = value; }
502 };
503
504 // A utility class to temporarily "deactivate" the DerivedPointerTable.
505 // (Note: clients are responsible for any MT-safety issues)
506 class DerivedPointerTableDeactivate: public StackObj {
507 private:
508 bool _active;
509 public:
510 DerivedPointerTableDeactivate() {
511 _active = DerivedPointerTable::is_active();
512 if (_active) {
513 DerivedPointerTable::set_active(false);
514 }
515 }
516
517 ~DerivedPointerTableDeactivate() {
518 assert(!DerivedPointerTable::is_active(),
519 "Inconsistency: not MT-safe");
520 if (_active) {
521 DerivedPointerTable::set_active(true);
522 }
523 }
524 };
525 #endif // COMPILER2_OR_JVMCI
526
527 #endif // SHARE_COMPILER_OOPMAP_HPP