1 /*
2 * Copyright (c) 1998, 2010, 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.
22 *
23 */
24
25 #ifndef SHARE_VM_COMPILER_OOPMAP_HPP
26 #define SHARE_VM_COMPILER_OOPMAP_HPP
27
28 #include "code/compressedStream.hpp"
29 #include "code/vmreg.hpp"
30 #include "memory/allocation.hpp"
31 #include "utilities/growableArray.hpp"
32
33 // Interface for generating the frame map for compiled code. A frame map
34 // describes for a specific pc whether each register and frame stack slot is:
35 // Oop - A GC root for current frame
36 // Value - Live non-oop, non-float value: int, either half of double
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 DerivedPointerEntry;
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 = 5,
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 { // must fit in type_bits
69 unused_value =0, // powers of 2, for masking OopMapStream
70 oop_value = 1,
71 value_value = 2,
72 narrowoop_value = 4,
73 callee_saved_value = 8,
74 derived_oop_value= 16 };
75
76 // Constructors
77 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
78 OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg,t); }
79 OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg,t); set_content_reg(reg2); }
80 OopMapValue (CompressedReadStream* stream) { read_from(stream); }
81
82 // Archiving
83 void write_on(CompressedWriteStream* stream) {
84 stream->write_int(value());
85 if(is_callee_saved() || is_derived_oop()) {
86 stream->write_int(content_reg()->value());
87 }
88 }
89
90 void read_from(CompressedReadStream* stream) {
91 set_value(stream->read_int());
92 if(is_callee_saved() || is_derived_oop()) {
93 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));
94 }
95 }
96
97 // Querying
98 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
99 bool is_value() { return mask_bits(value(), type_mask_in_place) == value_value; }
100 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
101 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
102 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }
103
104 void set_oop() { set_value((value() & register_mask_in_place) | oop_value); }
105 void set_value() { set_value((value() & register_mask_in_place) | value_value); }
106 void set_narrowoop() { set_value((value() & register_mask_in_place) | narrowoop_value); }
107 void set_callee_saved() { set_value((value() & register_mask_in_place) | callee_saved_value); }
108 void set_derived_oop() { set_value((value() & register_mask_in_place) | derived_oop_value); }
109
110 VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }
111 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }
112
113 static bool legal_vm_reg_name(VMReg p) {
114 return (p->value() == (p->value() & register_mask));
115 }
116
117 void set_reg_type(VMReg p, oop_types t) {
118 set_value((p->value() << register_shift) | t);
119 assert(reg() == p, "sanity check" );
120 assert(type() == t, "sanity check" );
121 }
122
123
124 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
125 void set_content_reg(VMReg r) { _content_reg = r->value(); }
126
127 // Physical location queries
128 bool is_register_loc() { return reg()->is_reg(); }
129 bool is_stack_loc() { return reg()->is_stack(); }
130
131 // Returns offset from sp.
132 int stack_offset() {
133 assert(is_stack_loc(), "must be stack location");
134 return reg()->reg2stack();
135 }
136
137 void print_on(outputStream* st) const;
138 void print() const { print_on(tty); }
139 };
140
141
142 class OopMap: public ResourceObj {
143 friend class OopMapStream;
144 friend class VMStructs;
145 private:
146 int _pc_offset; // offset in the code that this OopMap corresponds to
147 int _omv_count; // number of OopMapValues in the stream
148 CompressedWriteStream* _write_stream;
149
150 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
151
152 // Accessors
153 int omv_count() const { return _omv_count; }
154 void set_omv_count(int value) { _omv_count = value; }
155 void increment_count() { _omv_count++; }
156 CompressedWriteStream* write_stream() const { return _write_stream; }
157 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
158
159 private:
160 enum DeepCopyToken { _deep_copy_token };
161 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
162
163 public:
164 OopMap(int frame_size, int arg_count);
165
166 // pc-offset handling
167 int offset() const { return _pc_offset; }
168 void set_offset(int o) { _pc_offset = o; }
169 int count() const { return _omv_count; }
170 int data_size() const { return write_stream()->position(); }
171 address data() const { return write_stream()->buffer(); }
172
173 // Check to avoid double insertion
174 debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; })
175
176 // Construction
177 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
178 // slots to hold 4-byte values like ints and floats in the LP64 build.
179 void set_oop ( VMReg local);
180 void set_value( VMReg local);
181 void set_narrowoop(VMReg local);
182 void set_dead ( VMReg local);
183 void set_callee_saved( VMReg local, VMReg caller_machine_register );
184 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
185 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
186
187 int heap_size() const;
188 void copy_data_to(address addr) const;
189 OopMap* deep_copy();
190
191 bool has_derived_pointer() const PRODUCT_RETURN0;
192
193 bool legal_vm_reg_name(VMReg local) {
194 return OopMapValue::legal_vm_reg_name(local);
195 }
196
197 // Printing
198 void print_on(outputStream* st) const;
199 void print() const { print_on(tty); }
200 bool equals(const OopMap* other) const;
201 };
202
203
204 class OopMapSet : public ResourceObj {
205 friend class VMStructs;
206 private:
207 int _om_count;
208 int _om_size;
209 OopMap** _om_data;
210
211 int om_count() const { return _om_count; }
212 void set_om_count(int value) { _om_count = value; }
213 void increment_count() { _om_count++; }
214 int om_size() const { return _om_size; }
215 void set_om_size(int value) { _om_size = value; }
216 OopMap** om_data() const { return _om_data; }
217 void set_om_data(OopMap** value) { _om_data = value; }
218 void grow_om_data();
219 void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; }
220
221 public:
222 OopMapSet();
223
224 // returns the number of OopMaps in this OopMapSet
225 int size() const { return _om_count; }
226 // returns the OopMap at a given index
227 OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; }
228
229 // Collect OopMaps.
230 void add_gc_map(int pc, OopMap* map);
231
232 // Returns the only oop map. Used for reconstructing
233 // Adapter frames during deoptimization
234 OopMap* singular_oop_map();
235
236 // returns OopMap in that is anchored to the pc
237 OopMap* find_map_at_offset(int pc_offset) const;
238
239 int heap_size() const;
240
241 // Methods oops_do() and all_do() filter out NULL oops and
242 // oop == Universe::narrow_oop_base() before passing oops
243 // to closures.
244
245 // Iterates through frame for a compiled method
246 static void oops_do (const frame* fr,
247 const RegisterMap* reg_map, OopClosure* f);
248 static void update_register_map(const frame* fr, RegisterMap *reg_map);
249
250 // Iterates through frame for a compiled method for dead ones and values, too
251 static void all_do(const frame* fr, const RegisterMap* reg_map,
252 OopClosure* oop_fn,
253 void derived_oop_fn(oop* base, oop* derived),
254 OopClosure* value_fn);
255
256 // Printing
257 void print_on(outputStream* st) const;
258 void print() const { print_on(tty); }
259 };
260
261 class ImmutableOopMapBuilder;
262
263 class ImmutableOopMap {
264 friend class OopMapStream;
265 friend class VMStructs;
266 #ifdef ASSERT
267 friend class ImmutableOopMapBuilder;
268 #endif
269 private:
270 int _count; // contains the number of entries in this OopMap
271
272 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
273 public:
274 ImmutableOopMap(const OopMap* oopmap);
275
276 bool has_derived_pointer() const PRODUCT_RETURN0;
277 int count() const { return _count; }
278 #ifdef ASSERT
279 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
280 #endif
281
282 // Printing
283 void print_on(outputStream* st) const;
284 void print() const { print_on(tty); }
285 };
286
287 class ImmutableOopMapSet;
288 class ImmutableOopMap;
289 class OopMapSet;
290
291 class ImmutableOopMapPair {
292 friend class VMStructs;
293 private:
294 int _pc_offset; // program counter offset from the beginning of the method
295 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
296 public:
297 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
298 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
299 }
300 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
301
302 int pc_offset() const { return _pc_offset; }
303 int oopmap_offset() const { return _oopmap_offset; }
304 };
305
306 class ImmutableOopMapSet {
307 friend class VMStructs;
308 private:
309 int _count; // nr of ImmutableOopMapPairs in the Set
310 int _size; // nr of bytes including ImmutableOopMapSet itself
311
312 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
313
314 public:
315 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
316
317 ImmutableOopMap* oopmap_at_offset(int offset) const {
318 assert(offset >= 0 && offset < _size, "must be within boundaries");
319 address addr = data() + offset;
320 return (ImmutableOopMap*) addr;
321 }
322
323 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
324
325 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
326
327 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
328
329 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
330
331 int count() const { return _count; }
332 int nr_of_bytes() const { return _size; }
333
334 void print_on(outputStream* st) const;
335 void print() const { print_on(tty); }
336 };
337
338 class OopMapStream : public StackObj {
339 private:
340 CompressedReadStream* _stream;
341 int _mask;
342 int _size;
343 int _position;
344 bool _valid_omv;
345 OopMapValue _omv;
346 void find_next();
347
348 public:
349 OopMapStream(OopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
350 OopMapStream(const ImmutableOopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
351 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
352 void next() { find_next(); }
353 OopMapValue current() { return _omv; }
354 #ifdef ASSERT
355 int stream_position() const { return _stream->position(); }
356 #endif
357 };
358
359 class ImmutableOopMapBuilder {
360 private:
361 class Mapping;
362
363 private:
364 const OopMapSet* _set;
365 const OopMap* _empty;
366 const OopMap* _last;
367 int _empty_offset;
368 int _last_offset;
369 int _offset;
370 int _required;
371 Mapping* _mapping;
372 ImmutableOopMapSet* _new_set;
373
374 /* Used for bookkeeping when building ImmutableOopMaps */
375 class Mapping : public ResourceObj {
376 public:
377 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
378
379 kind_t _kind;
380 int _offset;
381 int _size;
382 const OopMap* _map;
383 const OopMap* _other;
384
385 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(NULL) {}
386
387 void set(kind_t kind, int offset, int size, const OopMap* map = 0, const OopMap* other = 0) {
388 _kind = kind;
389 _offset = offset;
390 _size = size;
391 _map = map;
392 _other = other;
393 }
394 };
395
396 public:
397 ImmutableOopMapBuilder(const OopMapSet* set);
398
399 int heap_size();
400 ImmutableOopMapSet* build();
401 ImmutableOopMapSet* generate_into(address buffer);
402 private:
403 bool is_empty(const OopMap* map) const {
404 return map->count() == 0;
405 }
406
407 bool is_last_duplicate(const OopMap* map) {
408 if (_last != NULL && _last->count() > 0 && _last->equals(map)) {
409 return true;
410 }
411 return false;
412 }
413
414 #ifdef ASSERT
415 void verify(address buffer, int size, const ImmutableOopMapSet* set);
416 #endif
417
418 bool has_empty() const {
419 return _empty_offset != -1;
420 }
421
422 int size_for(const OopMap* map) const;
423 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
424 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
425 void fill(ImmutableOopMapSet* set, int size);
426 };
427
428
429 // Derived pointer support. This table keeps track of all derived points on a
430 // stack. It is cleared before each scavenge/GC. During the traversal of all
431 // oops, it is filled in with references to all locations that contains a
432 // derived oop (assumed to be very few). When the GC is complete, the derived
433 // pointers are updated based on their base pointers new value and an offset.
434 #if defined(COMPILER2) || INCLUDE_JVMCI
435 class DerivedPointerTable : public AllStatic {
436 friend class VMStructs;
437 private:
438 static GrowableArray<DerivedPointerEntry*>* _list;
439 static bool _active; // do not record pointers for verify pass etc.
440 public:
441 static void clear(); // Called before scavenge/GC
442 static void add(oop *derived, oop *base); // Called during scavenge/GC
443 static void update_pointers(); // Called after scavenge/GC
444 static bool is_empty() { return _list == NULL || _list->is_empty(); }
445 static bool is_active() { return _active; }
446 static void set_active(bool value) { _active = value; }
447 };
448
449 // A utility class to temporarily "deactivate" the DerivedPointerTable.
450 // (Note: clients are responsible for any MT-safety issues)
451 class DerivedPointerTableDeactivate: public StackObj {
452 private:
453 bool _active;
454 public:
455 DerivedPointerTableDeactivate() {
456 _active = DerivedPointerTable::is_active();
457 if (_active) {
458 DerivedPointerTable::set_active(false);
459 }
460 }
461
462 ~DerivedPointerTableDeactivate() {
463 assert(!DerivedPointerTable::is_active(),
464 "Inconsistency: not MT-safe");
465 if (_active) {
466 DerivedPointerTable::set_active(true);
467 }
468 }
469 };
470 #endif // COMPILER2 || JVMCI
471
472 #endif // SHARE_VM_COMPILER_OOPMAP_HPP