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 private:
203 GrowableArray<OopMap*> _list;
204
205 void add(OopMap* value) { _list.append(value); }
206
207 public:
208 OopMapSet();
209
210 // returns the number of OopMaps in this OopMapSet
211 int size() const { return _list.length(); }
212 // returns the OopMap at a given index
213 OopMap* at(int index) const { return _list.at(index); }
214
215 // Collect OopMaps.
216 void add_gc_map(int pc, OopMap* map);
217
218 // Methods oops_do() and all_do() filter out NULL oops and
219 // oop == CompressedOops::base() before passing oops
220 // to closures.
221
222 // Iterates through frame for a compiled method
223 static void oops_do (const frame* fr,
224 const RegisterMap* reg_map, OopClosure* f);
225 static void update_register_map(const frame* fr, RegisterMap *reg_map);
226
227 // Iterates through frame for a compiled method for dead ones and values, too
228 static void all_do(const frame* fr, const RegisterMap* reg_map,
229 OopClosure* oop_fn,
230 void derived_oop_fn(oop* base, oop* derived),
231 OopClosure* value_fn);
232
233 // Printing
234 void print_on(outputStream* st) const;
235 void print() const;
236 };
237
238 class ImmutableOopMapBuilder;
239
240 class ImmutableOopMap {
241 friend class OopMapStream;
242 friend class VMStructs;
243 #ifdef ASSERT
244 friend class ImmutableOopMapBuilder;
245 #endif
246 private:
247 int _count; // contains the number of entries in this OopMap
248
249 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
250 public:
251 ImmutableOopMap(const OopMap* oopmap);
252
253 int count() const { return _count; }
254 #ifdef ASSERT
255 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
256 #endif
257
258 // Printing
259 void print_on(outputStream* st) const;
260 void print() const;
261 };
262
263 class ImmutableOopMapSet;
264 class ImmutableOopMap;
265 class OopMapSet;
266
267 class ImmutableOopMapPair {
268 friend class VMStructs;
269 private:
270 int _pc_offset; // program counter offset from the beginning of the method
271 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
272 public:
273 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
274 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
275 }
276 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
277
278 int pc_offset() const { return _pc_offset; }
279 int oopmap_offset() const { return _oopmap_offset; }
280 };
281
282 class ImmutableOopMapSet {
283 friend class VMStructs;
284 private:
285 int _count; // nr of ImmutableOopMapPairs in the Set
286 int _size; // nr of bytes including ImmutableOopMapSet itself
287
288 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
289
290 public:
291 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
292
293 ImmutableOopMap* oopmap_at_offset(int offset) const {
294 assert(offset >= 0 && offset < _size, "must be within boundaries");
295 address addr = data() + offset;
296 return (ImmutableOopMap*) addr;
297 }
298
299 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
300
301 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
302
303 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
304
305 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
306
307 int count() const { return _count; }
308 int nr_of_bytes() const { return _size; }
309
310 void print_on(outputStream* st) const;
311 void print() const;
312 };
313
314 class OopMapStream : public StackObj {
315 private:
316 CompressedReadStream* _stream;
317 int _size;
318 int _position;
319 bool _valid_omv;
320 OopMapValue _omv;
321 void find_next();
322
323 public:
324 OopMapStream(OopMap* oop_map);
325 OopMapStream(const ImmutableOopMap* oop_map);
326 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
327 void next() { find_next(); }
328 OopMapValue current() { return _omv; }
329 #ifdef ASSERT
330 int stream_position() const { return _stream->position(); }
331 #endif
332 };
333
334 class ImmutableOopMapBuilder {
335 private:
336 class Mapping;
337
338 private:
339 const OopMapSet* _set;
340 const OopMap* _empty;
341 const OopMap* _last;
342 int _empty_offset;
343 int _last_offset;
344 int _offset;
345 int _required;
346 Mapping* _mapping;
347 ImmutableOopMapSet* _new_set;
348
349 /* Used for bookkeeping when building ImmutableOopMaps */
350 class Mapping : public ResourceObj {
351 public:
352 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
353
354 kind_t _kind;
355 int _offset;
356 int _size;
357 const OopMap* _map;
358 const OopMap* _other;
359
360 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(NULL) {}
361
362 void set(kind_t kind, int offset, int size, const OopMap* map = 0, const OopMap* other = 0) {
363 _kind = kind;
364 _offset = offset;
365 _size = size;
366 _map = map;
367 _other = other;
368 }
369 };
370
371 public:
372 ImmutableOopMapBuilder(const OopMapSet* set);
373
374 int heap_size();
375 ImmutableOopMapSet* build();
376 ImmutableOopMapSet* generate_into(address buffer);
377 private:
378 bool is_empty(const OopMap* map) const {
379 return map->count() == 0;
380 }
381
382 bool is_last_duplicate(const OopMap* map) {
383 if (_last != NULL && _last->count() > 0 && _last->equals(map)) {
384 return true;
385 }
386 return false;
387 }
388
389 #ifdef ASSERT
390 void verify(address buffer, int size, const ImmutableOopMapSet* set);
391 #endif
392
393 bool has_empty() const {
394 return _empty_offset != -1;
395 }
396
397 int size_for(const OopMap* map) const;
398 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
399 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
400 void fill(ImmutableOopMapSet* set, int size);
401 };
402
403
404 // Derived pointer support. This table keeps track of all derived points on a
405 // stack. It is cleared before each scavenge/GC. During the traversal of all
406 // oops, it is filled in with references to all locations that contains a
407 // derived oop (assumed to be very few). When the GC is complete, the derived
408 // pointers are updated based on their base pointers new value and an offset.
409 #if COMPILER2_OR_JVMCI
410 class DerivedPointerTable : public AllStatic {
411 friend class VMStructs;
412 private:
413 class Entry;
414 static bool _active; // do not record pointers for verify pass etc.
415
416 public:
417 static void clear(); // Called before scavenge/GC
418 static void add(oop *derived, oop *base); // Called during scavenge/GC
419 static void update_pointers(); // Called after scavenge/GC
420 static bool is_empty();
421 static bool is_active() { return _active; }
422 static void set_active(bool value) { _active = value; }
423 };
424
425 // A utility class to temporarily "deactivate" the DerivedPointerTable.
426 // (Note: clients are responsible for any MT-safety issues)
427 class DerivedPointerTableDeactivate: public StackObj {
428 private:
429 bool _active;
430 public:
431 DerivedPointerTableDeactivate() {
432 _active = DerivedPointerTable::is_active();
433 if (_active) {
434 DerivedPointerTable::set_active(false);
435 }
436 }
437
438 ~DerivedPointerTableDeactivate() {
439 assert(!DerivedPointerTable::is_active(),
440 "Inconsistency: not MT-safe");
441 if (_active) {
442 DerivedPointerTable::set_active(true);
443 }
444 }
445 };
446 #endif // COMPILER2_OR_JVMCI
447
448 #endif // SHARE_COMPILER_OOPMAP_HPP