1 /*
2 * Copyright (c) 1998, 2019, 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 "oops/oopsHierarchy.hpp"
32 #include "utilities/growableArray.hpp"
33
34 // Interface for generating the frame map for compiled code. A frame map
35 // describes for a specific pc whether each register and frame stack slot is:
36 // Oop - A GC root for current frame
37 // Dead - Dead; can be Zapped for debugging
38 // CalleeXX - Callee saved; also describes which caller register is saved
39 // DerivedXX - A derived oop; original oop is described.
40 //
41 // OopMapValue describes a single OopMap entry
42
43 class frame;
44 class RegisterMap;
45 class OopClosure;
46
47 class OopMapValue: public StackObj {
48 friend class VMStructs;
49 private:
50 short _value;
51 int value() const { return _value; }
52 void set_value(int value) { _value = value; }
53 short _content_reg;
54
55 public:
56 // Constants
57 enum { type_bits = 2,
58 register_bits = BitsPerShort - type_bits };
59
60 enum { type_shift = 0,
61 register_shift = type_bits };
62
63 enum { type_mask = right_n_bits(type_bits),
64 type_mask_in_place = type_mask << type_shift,
65 register_mask = right_n_bits(register_bits),
66 register_mask_in_place = register_mask << register_shift };
67
68 enum oop_types {
69 oop_value,
70 narrowoop_value,
71 callee_saved_value,
72 derived_oop_value,
73 unused_value = -1 // Only used as a sentinel value
74 };
75
76 // Constructors
77 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
78 OopMapValue (VMReg reg, oop_types t, VMReg reg2) {
79 set_reg_type(reg, t);
80 set_content_reg(reg2);
81 }
82
83 private:
84 void set_reg_type(VMReg p, oop_types t) {
85 set_value((p->value() << register_shift) | t);
86 assert(reg() == p, "sanity check" );
87 assert(type() == t, "sanity check" );
88 }
89
90 void set_content_reg(VMReg r) {
91 if (is_callee_saved()) {
92 // This can never be a stack location, so we don't need to transform it.
93 assert(r->is_reg(), "Trying to callee save a stack location");
94 } else if (is_derived_oop()) {
95 assert (r->is_valid(), "must have a valid VMReg");
96 } else {
97 assert (!r->is_valid(), "valid VMReg not allowed");
98 }
99 _content_reg = r->value();
100 }
101
102 public:
103 // Archiving
104 void write_on(CompressedWriteStream* stream) {
105 stream->write_int(value());
106 if(is_callee_saved() || is_derived_oop()) {
107 stream->write_int(content_reg()->value());
108 }
109 }
110
111 void read_from(CompressedReadStream* stream) {
112 set_value(stream->read_int());
113 if (is_callee_saved() || is_derived_oop()) {
114 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));
115 }
116 }
117
118 // Querying
119 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
120 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
121 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
122 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }
123
124 VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }
125 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }
126
127 static bool legal_vm_reg_name(VMReg p) {
128 return (p->value() == (p->value() & register_mask));
129 }
130
131 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
132
133 // Returns offset from sp.
134 int stack_offset() {
135 assert(reg()->is_stack(), "must be stack location");
136 return reg()->reg2stack();
137 }
138
139 void print_on(outputStream* st) const;
140 void print() const;
141 };
142
143
144 class OopMap: public ResourceObj {
145 friend class OopMapStream;
146 friend class VMStructs;
147 private:
148 int _pc_offset; // offset in the code that this OopMap corresponds to
149 int _omv_count; // number of OopMapValues in the stream
150 CompressedWriteStream* _write_stream;
151
152 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
153
154 // Accessors
155 int omv_count() const { return _omv_count; }
156 void set_omv_count(int value) { _omv_count = value; }
157 void increment_count() { _omv_count++; }
158 CompressedWriteStream* write_stream() const { return _write_stream; }
159 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
160
161 private:
162 enum DeepCopyToken { _deep_copy_token };
163 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
164
165 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
166
167 public:
168 OopMap(int frame_size, int arg_count);
169
170 // pc-offset handling
171 int offset() const { return _pc_offset; }
172 void set_offset(int o) { _pc_offset = o; }
173 int count() const { return _omv_count; }
174 int data_size() const { return write_stream()->position(); }
175 address data() const { return write_stream()->buffer(); }
176
177 // Construction
178 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
179 // slots to hold 4-byte values like ints and floats in the LP64 build.
180 void set_oop ( VMReg local);
181 void set_narrowoop(VMReg local);
182 void set_callee_saved( VMReg local, VMReg caller_machine_register );
183 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
184
185 int heap_size() const;
186 void copy_data_to(address addr) const;
187 OopMap* deep_copy();
188
189 bool legal_vm_reg_name(VMReg local) {
190 return OopMapValue::legal_vm_reg_name(local);
191 }
192
193 // Printing
194 void print_on(outputStream* st) const;
195 void print() const;
196 bool equals(const OopMap* other) const;
197 };
198
199
200 class OopMapSet : public ResourceObj {
201 friend class VMStructs;
202 friend class OopClosureWalker;
203 private:
204 GrowableArray<OopMap*> _list;
205
206 void add(OopMap* value) { _list.append(value); }
207
208 static void stack_oop_do(oop *p, OopClosure* oop_fn,
209 GrowableArray<oop> *stack_oops,
210 intptr_t *stack_base, intptr_t *stack_top);
211
212 public:
213 OopMapSet();
214
215 // returns the number of OopMaps in this OopMapSet
216 int size() const { return _list.length(); }
217 // returns the OopMap at a given index
218 OopMap* at(int index) const { return _list.at(index); }
219
220 // Collect OopMaps.
221 void add_gc_map(int pc, OopMap* map);
222
223 // Methods oops_do() and all_do() filter out NULL oops and
224 // oop == CompressedOops::base() before passing oops
225 // to closures.
226
227 // Iterates through frame for a compiled method
228 static void oops_do (const frame* fr,
229 const RegisterMap* reg_map, OopClosure* f);
230 static void update_register_map(const frame* fr, RegisterMap *reg_map);
231
232 // Iterates through frame for a compiled method for dead ones and values, too
233 static void all_do(const frame* fr, const RegisterMap* reg_map,
234 OopClosure* oop_fn,
235 void derived_oop_fn(oop* base, oop* derived),
236 OopClosure* value_fn);
237
238 // Printing
239 void print_on(outputStream* st) const;
240 void print() const;
241 };
242
243 class ImmutableOopMapBuilder;
244
245 class ImmutableOopMap {
246 friend class OopMapStream;
247 friend class VMStructs;
248 #ifdef ASSERT
249 friend class ImmutableOopMapBuilder;
250 #endif
251 private:
252 int _count; // contains the number of entries in this OopMap
253
254 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
255 public:
256 ImmutableOopMap(const OopMap* oopmap);
257
258 int count() const { return _count; }
259 #ifdef ASSERT
260 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
261 #endif
262
263 // Printing
264 void print_on(outputStream* st) const;
265 void print() const;
266 };
267
268 class ImmutableOopMapSet;
269 class ImmutableOopMap;
270 class OopMapSet;
271
272 class ImmutableOopMapPair {
273 friend class VMStructs;
274 private:
275 int _pc_offset; // program counter offset from the beginning of the method
276 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
277 public:
278 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
279 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
280 }
281 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
282
283 int pc_offset() const { return _pc_offset; }
284 int oopmap_offset() const { return _oopmap_offset; }
285 };
286
287 class ImmutableOopMapSet {
288 friend class VMStructs;
289 private:
290 int _count; // nr of ImmutableOopMapPairs in the Set
291 int _size; // nr of bytes including ImmutableOopMapSet itself
292
293 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
294
295 public:
296 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
297
298 ImmutableOopMap* oopmap_at_offset(int offset) const {
299 assert(offset >= 0 && offset < _size, "must be within boundaries");
300 address addr = data() + offset;
301 return (ImmutableOopMap*) addr;
302 }
303
304 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
305
306 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
307
308 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
309
310 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
311
312 int count() const { return _count; }
313 int nr_of_bytes() const { return _size; }
314
315 void print_on(outputStream* st) const;
316 void print() const;
317 };
318
319 class OopMapStream : public StackObj {
320 private:
321 CompressedReadStream* _stream;
322 int _size;
323 int _position;
324 bool _valid_omv;
325 OopMapValue _omv;
326 void find_next();
327
328 public:
329 OopMapStream(OopMap* oop_map);
330 OopMapStream(const ImmutableOopMap* oop_map);
331 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
332 void next() { find_next(); }
333 OopMapValue current() { return _omv; }
334 #ifdef ASSERT
335 int stream_position() const { return _stream->position(); }
336 #endif
337 };
338
339 class ImmutableOopMapBuilder {
340 private:
341 class Mapping;
342
343 private:
344 const OopMapSet* _set;
345 const OopMap* _empty;
346 const OopMap* _last;
347 int _empty_offset;
348 int _last_offset;
349 int _offset;
350 int _required;
351 Mapping* _mapping;
352 ImmutableOopMapSet* _new_set;
353
354 /* Used for bookkeeping when building ImmutableOopMaps */
355 class Mapping : public ResourceObj {
356 public:
357 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
358
359 kind_t _kind;
360 int _offset;
361 int _size;
362 const OopMap* _map;
363 const OopMap* _other;
364
365 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(NULL) {}
366
367 void set(kind_t kind, int offset, int size, const OopMap* map = 0, const OopMap* other = 0) {
368 _kind = kind;
369 _offset = offset;
370 _size = size;
371 _map = map;
372 _other = other;
373 }
374 };
375
376 public:
377 ImmutableOopMapBuilder(const OopMapSet* set);
378
379 int heap_size();
380 ImmutableOopMapSet* build();
381 ImmutableOopMapSet* generate_into(address buffer);
382 private:
383 bool is_empty(const OopMap* map) const {
384 return map->count() == 0;
385 }
386
387 bool is_last_duplicate(const OopMap* map) {
388 if (_last != NULL && _last->count() > 0 && _last->equals(map)) {
389 return true;
390 }
391 return false;
392 }
393
394 #ifdef ASSERT
395 void verify(address buffer, int size, const ImmutableOopMapSet* set);
396 #endif
397
398 bool has_empty() const {
399 return _empty_offset != -1;
400 }
401
402 int size_for(const OopMap* map) const;
403 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
404 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
405 void fill(ImmutableOopMapSet* set, int size);
406 };
407
408
409 // Derived pointer support. This table keeps track of all derived points on a
410 // stack. It is cleared before each scavenge/GC. During the traversal of all
411 // oops, it is filled in with references to all locations that contains a
412 // derived oop (assumed to be very few). When the GC is complete, the derived
413 // pointers are updated based on their base pointers new value and an offset.
414 #if COMPILER2_OR_JVMCI
415 class DerivedPointerTable : public AllStatic {
416 friend class VMStructs;
417 private:
418 class Entry;
419 static bool _active; // do not record pointers for verify pass etc.
420
421 public:
422 static void clear(); // Called before scavenge/GC
423 static void add(oop *derived, oop *base); // Called during scavenge/GC
424 static void update_pointers(); // Called after scavenge/GC
425 static bool is_empty();
426 static bool is_active() { return _active; }
427 static void set_active(bool value) { _active = value; }
428 };
429
430 // A utility class to temporarily "deactivate" the DerivedPointerTable.
431 // (Note: clients are responsible for any MT-safety issues)
432 class DerivedPointerTableDeactivate: public StackObj {
433 private:
434 bool _active;
435 public:
436 DerivedPointerTableDeactivate() {
437 _active = DerivedPointerTable::is_active();
438 if (_active) {
439 DerivedPointerTable::set_active(false);
440 }
441 }
442
443 ~DerivedPointerTableDeactivate() {
444 assert(!DerivedPointerTable::is_active(),
445 "Inconsistency: not MT-safe");
446 if (_active) {
447 DerivedPointerTable::set_active(true);
448 }
449 }
450 };
451 #endif // COMPILER2_OR_JVMCI
452
453 #endif // SHARE_COMPILER_OOPMAP_HPP