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.
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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;
147 int _omv_count;
148 int _omv_data_size;
149 unsigned char* _omv_data;
150 CompressedWriteStream* _write_stream;
151
152 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
153
154 // Accessors
155 unsigned char* omv_data() const { return _omv_data; }
156 void set_omv_data(unsigned char* value) { _omv_data = value; }
157 int omv_data_size() const { return _omv_data_size; }
158 void set_omv_data_size(int value) { _omv_data_size = value; }
159 int omv_count() const { return _omv_count; }
160 void set_omv_count(int value) { _omv_count = value; }
161 void increment_count() { _omv_count++; }
162 CompressedWriteStream* write_stream() const { return _write_stream; }
163 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
164
165 private:
166 enum DeepCopyToken { _deep_copy_token };
167 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
168
169 public:
170 OopMap(int frame_size, int arg_count);
171
172 // pc-offset handling
173 int offset() const { return _pc_offset; }
174 void set_offset(int o) { _pc_offset = o; }
175
176 // Check to avoid double insertion
177 debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; })
178
179 // Construction
180 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
181 // slots to hold 4-byte values like ints and floats in the LP64 build.
182 void set_oop ( VMReg local);
183 void set_value( VMReg local);
184 void set_narrowoop(VMReg local);
185 void set_dead ( VMReg local);
186 void set_callee_saved( VMReg local, VMReg caller_machine_register );
187 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
188 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
189
190 int heap_size() const;
191 void copy_to(address addr);
192 OopMap* deep_copy();
193
194 bool has_derived_pointer() const PRODUCT_RETURN0;
195
196 bool legal_vm_reg_name(VMReg local) {
197 return OopMapValue::legal_vm_reg_name(local);
198 }
199
200 // Printing
201 void print_on(outputStream* st) const;
202 void print() const { print_on(tty); }
203 };
204
205
206 class OopMapSet : public ResourceObj {
207 friend class VMStructs;
208 private:
209 int _om_count;
210 int _om_size;
211 OopMap** _om_data;
212
213 int om_count() const { return _om_count; }
214 void set_om_count(int value) { _om_count = value; }
215 void increment_count() { _om_count++; }
216 int om_size() const { return _om_size; }
217 void set_om_size(int value) { _om_size = value; }
218 OopMap** om_data() const { return _om_data; }
219 void set_om_data(OopMap** value) { _om_data = value; }
220 void grow_om_data();
221 void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; }
222
223 public:
224 OopMapSet();
225
226 // returns the number of OopMaps in this OopMapSet
227 int size() const { return _om_count; }
228 // returns the OopMap at a given index
229 OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; }
230
231 // Collect OopMaps.
232 void add_gc_map(int pc, OopMap* map);
233
234 // Returns the only oop map. Used for reconstructing
235 // Adapter frames during deoptimization
236 OopMap* singular_oop_map();
237
238 // returns OopMap in that is anchored to the pc
239 OopMap* find_map_at_offset(int pc_offset) const;
240
241 int heap_size() const;
242 void copy_to(address addr);
243
244 // Methods oops_do() and all_do() filter out NULL oops and
245 // oop == Universe::narrow_oop_base() before passing oops
246 // to closures.
247
248 // Iterates through frame for a compiled method
249 static void oops_do (const frame* fr,
250 const RegisterMap* reg_map, OopClosure* f);
251 static void update_register_map(const frame* fr, RegisterMap *reg_map);
252
253 // Iterates through frame for a compiled method for dead ones and values, too
254 static void all_do(const frame* fr, const RegisterMap* reg_map,
255 OopClosure* oop_fn,
256 void derived_oop_fn(oop* base, oop* derived),
257 OopClosure* value_fn);
258
259 // Printing
260 void print_on(outputStream* st) const;
261 void print() const { print_on(tty); }
262 };
263
264
265 class OopMapStream : public StackObj {
266 private:
267 CompressedReadStream* _stream;
268 int _mask;
269 int _size;
270 int _position;
271 bool _valid_omv;
272 OopMapValue _omv;
273 void find_next();
274
275 public:
276 OopMapStream(OopMap* oop_map);
277 OopMapStream(OopMap* oop_map, int oop_types_mask);
278 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
279 void next() { find_next(); }
280 OopMapValue current() { return _omv; }
281 };
282
283
284 // Derived pointer support. This table keeps track of all derived points on a
285 // stack. It is cleared before each scavenge/GC. During the traversal of all
286 // oops, it is filled in with references to all locations that contains a
287 // derived oop (assumed to be very few). When the GC is complete, the derived
288 // pointers are updated based on their base pointers new value and an offset.
289 #ifdef COMPILER2
290 class DerivedPointerTable : public AllStatic {
291 friend class VMStructs;
292 private:
293 static GrowableArray<DerivedPointerEntry*>* _list;
294 static bool _active; // do not record pointers for verify pass etc.
295 public:
296 static void clear(); // Called before scavenge/GC
297 static void add(oop *derived, oop *base); // Called during scavenge/GC
298 static void update_pointers(); // Called after scavenge/GC
299 static bool is_empty() { return _list == NULL || _list->is_empty(); }
300 static bool is_active() { return _active; }
301 static void set_active(bool value) { _active = value; }
302 };
303
304 // A utility class to temporarily "deactivate" the DerivedPointerTable.
305 // (Note: clients are responsible for any MT-safety issues)
306 class DerivedPointerTableDeactivate: public StackObj {
307 private:
308 bool _active;
309 public:
310 DerivedPointerTableDeactivate() {
311 _active = DerivedPointerTable::is_active();
312 if (_active) {
313 DerivedPointerTable::set_active(false);
314 }
315 }
316
317 ~DerivedPointerTableDeactivate() {
318 assert(!DerivedPointerTable::is_active(),
319 "Inconsistency: not MT-safe");
320 if (_active) {
321 DerivedPointerTable::set_active(true);
322 }
323 }
324 };
325 #endif // COMPILER2
326
327 #endif // SHARE_VM_COMPILER_OOPMAP_HPP