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
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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).
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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,
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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
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// Dead - Dead; can be Zapped for debugging
37// CalleeXX - Callee saved; also describes which caller register is saved
38// DerivedXX - A derived oop; original oop is described.
39//
40// OopMapValue describes a single OopMap entry
41
42class frame;
43class RegisterMap;
44class OopClosure;
45
46class OopMapValue: public StackObj {
47 friend class VMStructs;
48private:
49 short _value;
50 int value() const { return _value; }
51 void set_value(int value) { _value = value; }
52 short _content_reg;
53
54public:
55 // Constants
56 enum { type_bits = 4,
57 register_bits = BitsPerShort - type_bits };
58
59 enum { type_shift = 0,
60 register_shift = type_bits };
61
62 enum { type_mask = right_n_bits(type_bits),
63 type_mask_in_place = type_mask << type_shift,
64 register_mask = right_n_bits(register_bits),
65 register_mask_in_place = register_mask << register_shift };
66
67 enum oop_types { // must fit in type_bits
68 unused_value =0, // powers of 2, for masking OopMapStream
69 oop_value = 1,
70 narrowoop_value = 2,
71 callee_saved_value = 4,
72 derived_oop_value= 8 };
73
74 // Constructors
75 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
76 OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg, t); set_content_reg(VMRegImpl::Bad()); }
77 OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg, t); set_content_reg(reg2); }
78 OopMapValue (CompressedReadStream* stream) { read_from(stream); }
79
80 // Archiving
81 void write_on(CompressedWriteStream* stream) {
82 stream->write_int(value());
83 if(is_callee_saved() || is_derived_oop()) {
84 stream->write_int(content_reg()->value());
85 }
86 }
87
88 void read_from(CompressedReadStream* stream) {
89 set_value(stream->read_int());
90 if (is_callee_saved() || is_derived_oop()) {
91 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));
92 }
93 }
94
95 // Querying
96 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
97 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
98 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
99 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }
100
101 void set_oop() { set_value((value() & register_mask_in_place) | oop_value); }
102 void set_narrowoop() { set_value((value() & register_mask_in_place) | narrowoop_value); }
103 void set_callee_saved() { set_value((value() & register_mask_in_place) | callee_saved_value); }
104 void set_derived_oop() { set_value((value() & register_mask_in_place) | derived_oop_value); }
105
106 VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }
107 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }
108
109 static bool legal_vm_reg_name(VMReg p) {
110 return (p->value() == (p->value() & register_mask));
111 }
112
113 void set_reg_type(VMReg p, oop_types t) {
114 set_value((p->value() << register_shift) | t);
115 assert(reg() == p, "sanity check" );
116 assert(type() == t, "sanity check" );
117 }
118
119
120 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
121 void set_content_reg(VMReg r) { _content_reg = r->value(); }
122
123 // Physical location queries
124 bool is_register_loc() { return reg()->is_reg(); }
125 bool is_stack_loc() { return reg()->is_stack(); }
126
127 // Returns offset from sp.
128 int stack_offset() {
129 assert(is_stack_loc(), "must be stack location");
130 return reg()->reg2stack();
131 }
132
133 void print_on(outputStream* st) const;
134 void print() const;
135};
136
137
138class OopMap: public ResourceObj {
139 friend class OopMapStream;
140 friend class VMStructs;
141 private:
142 int _pc_offset; // offset in the code that this OopMap corresponds to
143 int _omv_count; // number of OopMapValues in the stream
144 CompressedWriteStream* _write_stream;
145
146 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
147
148 // Accessors
149 int omv_count() const { return _omv_count; }
150 void set_omv_count(int value) { _omv_count = value; }
151 void increment_count() { _omv_count++; }
152 CompressedWriteStream* write_stream() const { return _write_stream; }
153 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
154
155 private:
156 enum DeepCopyToken { _deep_copy_token };
157 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
158
159 public:
160 OopMap(int frame_size, int arg_count);
161
162 // pc-offset handling
163 int offset() const { return _pc_offset; }
164 void set_offset(int o) { _pc_offset = o; }
165 int count() const { return _omv_count; }
166 int data_size() const { return write_stream()->position(); }
167 address data() const { return write_stream()->buffer(); }
168
169 // Check to avoid double insertion
170 debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; })
171
172 // Construction
173 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
174 // slots to hold 4-byte values like ints and floats in the LP64 build.
175 void set_oop ( VMReg local);
176 void set_value( VMReg local);
177 void set_narrowoop(VMReg local);
178 void set_dead ( VMReg local);
179 void set_callee_saved( VMReg local, VMReg caller_machine_register );
180 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
181 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
182
183 int heap_size() const;
184 void copy_data_to(address addr) const;
185 OopMap* deep_copy();
186
187 bool has_derived_pointer() const PRODUCT_RETURN0;
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
200class OopMapSet : public ResourceObj {
201 friend class VMStructs;
202 private:
203 int _om_count;
204 int _om_size;
205 OopMap** _om_data;
206
207 int om_count() const { return _om_count; }
208 void set_om_count(int value) { _om_count = value; }
209 void increment_count() { _om_count++; }
210 int om_size() const { return _om_size; }
211 void set_om_size(int value) { _om_size = value; }
212 OopMap** om_data() const { return _om_data; }
213 void set_om_data(OopMap** value) { _om_data = value; }
214 void grow_om_data();
215 void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; }
216
217 public:
218 OopMapSet();
219
220 // returns the number of OopMaps in this OopMapSet
221 int size() const { return _om_count; }
222 // returns the OopMap at a given index
223 OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; }
224
225 // Collect OopMaps.
226 void add_gc_map(int pc, OopMap* map);
227
228 // Returns the only oop map. Used for reconstructing
229 // Adapter frames during deoptimization
230 OopMap* singular_oop_map();
231
232 // returns OopMap in that is anchored to the pc
233 OopMap* find_map_at_offset(int pc_offset) const;
234
235 int heap_size() const;
236
237 // Methods oops_do() and all_do() filter out NULL oops and
238 // oop == CompressedOops::base() before passing oops
239 // to closures.
240
241 // Iterates through frame for a compiled method
242 static void oops_do (const frame* fr,
243 const RegisterMap* reg_map, OopClosure* f);
244 static void update_register_map(const frame* fr, RegisterMap *reg_map);
245
246 // Iterates through frame for a compiled method for dead ones and values, too
247 static void all_do(const frame* fr, const RegisterMap* reg_map,
248 OopClosure* oop_fn,
249 void derived_oop_fn(oop* base, oop* derived),
250 OopClosure* value_fn);
251
252 // Printing
253 void print_on(outputStream* st) const;
254 void print() const;
255};
256
257class ImmutableOopMapBuilder;
258
259class ImmutableOopMap {
260 friend class OopMapStream;
261 friend class VMStructs;
262#ifdef ASSERT
263 friend class ImmutableOopMapBuilder;
264#endif
265private:
266 int _count; // contains the number of entries in this OopMap
267
268 address data_addr() const { return (address) this + sizeof(ImmutableOopMap); }
269public:
270 ImmutableOopMap(const OopMap* oopmap);
271
272 bool has_derived_pointer() const PRODUCT_RETURN0;
273 int count() const { return _count; }
274#ifdef ASSERT
275 int nr_of_bytes() const; // this is an expensive operation, only used in debug builds
276#endif
277
278 // Printing
279 void print_on(outputStream* st) const;
280 void print() const;
281};
282
283class ImmutableOopMapSet;
284class ImmutableOopMap;
285class OopMapSet;
286
287class ImmutableOopMapPair {
288 friend class VMStructs;
289private:
290 int _pc_offset; // program counter offset from the beginning of the method
291 int _oopmap_offset; // offset in the data in the ImmutableOopMapSet where the ImmutableOopMap is located
292public:
293 ImmutableOopMapPair(int pc_offset, int oopmap_offset) : _pc_offset(pc_offset), _oopmap_offset(oopmap_offset) {
294 assert(pc_offset >= 0 && oopmap_offset >= 0, "check");
295 }
296 const ImmutableOopMap* get_from(const ImmutableOopMapSet* set) const;
297
298 int pc_offset() const { return _pc_offset; }
299 int oopmap_offset() const { return _oopmap_offset; }
300};
301
302class ImmutableOopMapSet {
303 friend class VMStructs;
304private:
305 int _count; // nr of ImmutableOopMapPairs in the Set
306 int _size; // nr of bytes including ImmutableOopMapSet itself
307
308 address data() const { return (address) this + sizeof(*this) + sizeof(ImmutableOopMapPair) * _count; }
309
310public:
311 ImmutableOopMapSet(const OopMapSet* oopmap_set, int size) : _count(oopmap_set->size()), _size(size) {}
312
313 ImmutableOopMap* oopmap_at_offset(int offset) const {
314 assert(offset >= 0 && offset < _size, "must be within boundaries");
315 address addr = data() + offset;
316 return (ImmutableOopMap*) addr;
317 }
318
319 ImmutableOopMapPair* get_pairs() const { return (ImmutableOopMapPair*) ((address) this + sizeof(*this)); }
320
321 static ImmutableOopMapSet* build_from(const OopMapSet* oopmap_set);
322
323 const ImmutableOopMap* find_map_at_offset(int pc_offset) const;
324
325 const ImmutableOopMapPair* pair_at(int index) const { assert(index >= 0 && index < _count, "check"); return &get_pairs()[index]; }
326
327 int count() const { return _count; }
328 int nr_of_bytes() const { return _size; }
329
330 void print_on(outputStream* st) const;
331 void print() const;
332};
333
334class OopMapStream : public StackObj {
335 private:
336 CompressedReadStream* _stream;
337 int _mask;
338 int _size;
339 int _position;
340 bool _valid_omv;
341 OopMapValue _omv;
342 void find_next();
343
344 public:
345 OopMapStream(OopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
346 OopMapStream(const ImmutableOopMap* oop_map, int oop_types_mask = OopMapValue::type_mask_in_place);
347 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
348 void next() { find_next(); }
349 OopMapValue current() { return _omv; }
350#ifdef ASSERT
351 int stream_position() const { return _stream->position(); }
352#endif
353};
354
355class ImmutableOopMapBuilder {
356private:
357 class Mapping;
358
359private:
360 const OopMapSet* _set;
361 const OopMap* _empty;
362 const OopMap* _last;
363 int _empty_offset;
364 int _last_offset;
365 int _offset;
366 int _required;
367 Mapping* _mapping;
368 ImmutableOopMapSet* _new_set;
369
370 /* Used for bookkeeping when building ImmutableOopMaps */
371 class Mapping : public ResourceObj {
372 public:
373 enum kind_t { OOPMAP_UNKNOWN = 0, OOPMAP_NEW = 1, OOPMAP_EMPTY = 2, OOPMAP_DUPLICATE = 3 };
374
375 kind_t _kind;
376 int _offset;
377 int _size;
378 const OopMap* _map;
379 const OopMap* _other;
380
381 Mapping() : _kind(OOPMAP_UNKNOWN), _offset(-1), _size(-1), _map(NULL) {}
382
383 void set(kind_t kind, int offset, int size, const OopMap* map = 0, const OopMap* other = 0) {
384 _kind = kind;
385 _offset = offset;
386 _size = size;
387 _map = map;
388 _other = other;
389 }
390 };
391
392public:
393 ImmutableOopMapBuilder(const OopMapSet* set);
394
395 int heap_size();
396 ImmutableOopMapSet* build();
397 ImmutableOopMapSet* generate_into(address buffer);
398private:
399 bool is_empty(const OopMap* map) const {
400 return map->count() == 0;
401 }
402
403 bool is_last_duplicate(const OopMap* map) {
404 if (_last != NULL && _last->count() > 0 && _last->equals(map)) {
405 return true;
406 }
407 return false;
408 }
409
410#ifdef ASSERT
411 void verify(address buffer, int size, const ImmutableOopMapSet* set);
412#endif
413
414 bool has_empty() const {
415 return _empty_offset != -1;
416 }
417
418 int size_for(const OopMap* map) const;
419 void fill_pair(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
420 int fill_map(ImmutableOopMapPair* pair, const OopMap* map, int offset, const ImmutableOopMapSet* set);
421 void fill(ImmutableOopMapSet* set, int size);
422};
423
424
425// Derived pointer support. This table keeps track of all derived points on a
426// stack. It is cleared before each scavenge/GC. During the traversal of all
427// oops, it is filled in with references to all locations that contains a
428// derived oop (assumed to be very few). When the GC is complete, the derived
429// pointers are updated based on their base pointers new value and an offset.
430#if COMPILER2_OR_JVMCI
431class DerivedPointerTable : public AllStatic {
432 friend class VMStructs;
433 private:
434 class Entry;
435 static bool _active; // do not record pointers for verify pass etc.
436
437 public:
438 static void clear(); // Called before scavenge/GC
439 static void add(oop *derived, oop *base); // Called during scavenge/GC
440 static void update_pointers(); // Called after scavenge/GC
441 static bool is_empty();
442 static bool is_active() { return _active; }
443 static void set_active(bool value) { _active = value; }
444};
445
446// A utility class to temporarily "deactivate" the DerivedPointerTable.
447// (Note: clients are responsible for any MT-safety issues)
448class DerivedPointerTableDeactivate: public StackObj {
449 private:
450 bool _active;
451 public:
452 DerivedPointerTableDeactivate() {
453 _active = DerivedPointerTable::is_active();
454 if (_active) {
455 DerivedPointerTable::set_active(false);
456 }
457 }
458
459 ~DerivedPointerTableDeactivate() {
460 assert(!DerivedPointerTable::is_active(),
461 "Inconsistency: not MT-safe");
462 if (_active) {
463 DerivedPointerTable::set_active(true);
464 }
465 }
466};
467#endif // COMPILER2_OR_JVMCI
468
469#endif // SHARE_COMPILER_OOPMAP_HPP
470