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 class OopClosure;
47
48 class OopMapValue: public StackObj {
49 friend class VMStructs;
50 private:
51 short _value;
52 int value() const { return _value; }
53 void set_value(int value) { _value = value; }
54 short _content_reg;
55
56 public:
57 // Constants
58 enum { type_bits = 5,
59 register_bits = BitsPerShort - type_bits };
60
61 enum { type_shift = 0,
62 register_shift = type_bits };
63
64 enum { type_mask = right_n_bits(type_bits),
65 type_mask_in_place = type_mask << type_shift,
66 register_mask = right_n_bits(register_bits),
67 register_mask_in_place = register_mask << register_shift };
68
69 enum oop_types { // must fit in type_bits
70 unused_value =0, // powers of 2, for masking OopMapStream
71 oop_value = 1,
72 value_value = 2,
73 narrowoop_value = 4,
74 callee_saved_value = 8,
75 derived_oop_value= 16 };
76
77 // Constructors
78 OopMapValue () { set_value(0); set_content_reg(VMRegImpl::Bad()); }
79 OopMapValue (VMReg reg, oop_types t) { set_reg_type(reg, t); set_content_reg(VMRegImpl::Bad()); }
80 OopMapValue (VMReg reg, oop_types t, VMReg reg2) { set_reg_type(reg, t); set_content_reg(reg2); }
81 OopMapValue (CompressedReadStream* stream) { read_from(stream); }
82
83 // Archiving
84 void write_on(CompressedWriteStream* stream) {
85 stream->write_int(value());
86 if(is_callee_saved() || is_derived_oop()) {
87 stream->write_int(content_reg()->value());
88 }
89 }
90
91 void read_from(CompressedReadStream* stream) {
92 set_value(stream->read_int());
93 if (is_callee_saved() || is_derived_oop()) {
94 set_content_reg(VMRegImpl::as_VMReg(stream->read_int(), true));
95 }
96 }
97
98 // Querying
99 bool is_oop() { return mask_bits(value(), type_mask_in_place) == oop_value; }
100 bool is_value() { return mask_bits(value(), type_mask_in_place) == value_value; }
101 bool is_narrowoop() { return mask_bits(value(), type_mask_in_place) == narrowoop_value; }
102 bool is_callee_saved() { return mask_bits(value(), type_mask_in_place) == callee_saved_value; }
103 bool is_derived_oop() { return mask_bits(value(), type_mask_in_place) == derived_oop_value; }
104
105 void set_oop() { set_value((value() & register_mask_in_place) | oop_value); }
106 void set_value() { set_value((value() & register_mask_in_place) | value_value); }
107 void set_narrowoop() { set_value((value() & register_mask_in_place) | narrowoop_value); }
108 void set_callee_saved() { set_value((value() & register_mask_in_place) | callee_saved_value); }
109 void set_derived_oop() { set_value((value() & register_mask_in_place) | derived_oop_value); }
110
111 VMReg reg() const { return VMRegImpl::as_VMReg(mask_bits(value(), register_mask_in_place) >> register_shift); }
112 oop_types type() const { return (oop_types)mask_bits(value(), type_mask_in_place); }
113
114 static bool legal_vm_reg_name(VMReg p) {
115 return (p->value() == (p->value() & register_mask));
116 }
117
118 void set_reg_type(VMReg p, oop_types t) {
119 set_value((p->value() << register_shift) | t);
120 assert(reg() == p, "sanity check" );
121 assert(type() == t, "sanity check" );
122 }
123
124
125 VMReg content_reg() const { return VMRegImpl::as_VMReg(_content_reg, true); }
126 void set_content_reg(VMReg r) { _content_reg = r->value(); }
127
128 // Physical location queries
129 bool is_register_loc() { return reg()->is_reg(); }
130 bool is_stack_loc() { return reg()->is_stack(); }
131
132 // Returns offset from sp.
133 int stack_offset() {
134 assert(is_stack_loc(), "must be stack location");
135 return reg()->reg2stack();
136 }
137
138 void print_on(outputStream* st) const;
139 void print() const { print_on(tty); }
140 };
141
142
143 class OopMap: public ResourceObj {
144 friend class OopMapStream;
145 friend class VMStructs;
146 private:
147 int _pc_offset;
148 int _omv_count;
149 int _omv_data_size;
150 unsigned char* _omv_data;
151 CompressedWriteStream* _write_stream;
152
153 debug_only( OopMapValue::oop_types* _locs_used; int _locs_length;)
154
155 // Accessors
156 unsigned char* omv_data() const { return _omv_data; }
157 void set_omv_data(unsigned char* value) { _omv_data = value; }
158 int omv_data_size() const { return _omv_data_size; }
159 void set_omv_data_size(int value) { _omv_data_size = value; }
160 int omv_count() const { return _omv_count; }
161 void set_omv_count(int value) { _omv_count = value; }
162 void increment_count() { _omv_count++; }
163 CompressedWriteStream* write_stream() const { return _write_stream; }
164 void set_write_stream(CompressedWriteStream* value) { _write_stream = value; }
165
166 private:
167 enum DeepCopyToken { _deep_copy_token };
168 OopMap(DeepCopyToken, OopMap* source); // used only by deep_copy
169
170 public:
171 OopMap(int frame_size, int arg_count);
172
173 // pc-offset handling
174 int offset() const { return _pc_offset; }
175 void set_offset(int o) { _pc_offset = o; }
176
177 // Check to avoid double insertion
178 debug_only(OopMapValue::oop_types locs_used( int indx ) { return _locs_used[indx]; })
179
180 // Construction
181 // frame_size units are stack-slots (4 bytes) NOT intptr_t; we can name odd
182 // slots to hold 4-byte values like ints and floats in the LP64 build.
183 void set_oop ( VMReg local);
184 void set_value( VMReg local);
185 void set_narrowoop(VMReg local);
186 void set_dead ( VMReg local);
187 void set_callee_saved( VMReg local, VMReg caller_machine_register );
188 void set_derived_oop ( VMReg local, VMReg derived_from_local_register );
189 void set_xxx(VMReg reg, OopMapValue::oop_types x, VMReg optional);
190
191 int heap_size() const;
192 void copy_to(address addr);
193 OopMap* deep_copy();
194
195 bool has_derived_pointer() const PRODUCT_RETURN0;
196
197 bool legal_vm_reg_name(VMReg local) {
198 return OopMapValue::legal_vm_reg_name(local);
199 }
200
201 // Printing
202 void print_on(outputStream* st) const;
203 void print() const { print_on(tty); }
204 };
205
206
207 class OopMapSet : public ResourceObj {
208 friend class VMStructs;
209 private:
210 int _om_count;
211 int _om_size;
212 OopMap** _om_data;
213
214 int om_count() const { return _om_count; }
215 void set_om_count(int value) { _om_count = value; }
216 void increment_count() { _om_count++; }
217 int om_size() const { return _om_size; }
218 void set_om_size(int value) { _om_size = value; }
219 OopMap** om_data() const { return _om_data; }
220 void set_om_data(OopMap** value) { _om_data = value; }
221 void grow_om_data();
222 void set(int index,OopMap* value) { assert((index == 0) || ((index > 0) && (index < om_size())),"bad index"); _om_data[index] = value; }
223
224 public:
225 OopMapSet();
226
227 // returns the number of OopMaps in this OopMapSet
228 int size() const { return _om_count; }
229 // returns the OopMap at a given index
230 OopMap* at(int index) const { assert((index >= 0) && (index <= om_count()),"bad index"); return _om_data[index]; }
231
232 // Collect OopMaps.
233 void add_gc_map(int pc, OopMap* map);
234
235 // Returns the only oop map. Used for reconstructing
236 // Adapter frames during deoptimization
237 OopMap* singular_oop_map();
238
239 // returns OopMap in that is anchored to the pc
240 OopMap* find_map_at_offset(int pc_offset) const;
241
242 int heap_size() const;
243 void copy_to(address addr);
244
245 // Methods oops_do() and all_do() filter out NULL oops and
246 // oop == Universe::narrow_oop_base() before passing oops
247 // to closures.
248
249 // Iterates through frame for a compiled method
250 static void oops_do (const frame* fr,
251 const RegisterMap* reg_map, OopClosure* f);
252 static void update_register_map(const frame* fr, RegisterMap *reg_map);
253
254 // Iterates through frame for a compiled method for dead ones and values, too
255 static void all_do(const frame* fr, const RegisterMap* reg_map,
256 OopClosure* oop_fn,
257 void derived_oop_fn(oop* base, oop* derived),
258 OopClosure* value_fn);
259
260 // Printing
261 void print_on(outputStream* st) const;
262 void print() const { print_on(tty); }
263 };
264
265
266 class OopMapStream : public StackObj {
267 private:
268 CompressedReadStream* _stream;
269 int _mask;
270 int _size;
271 int _position;
272 bool _valid_omv;
273 OopMapValue _omv;
274 void find_next();
275
276 public:
277 OopMapStream(OopMap* oop_map);
278 OopMapStream(OopMap* oop_map, int oop_types_mask);
279 bool is_done() { if(!_valid_omv) { find_next(); } return !_valid_omv; }
280 void next() { find_next(); }
281 OopMapValue current() { return _omv; }
282 };
283
284
285 // Derived pointer support. This table keeps track of all derived points on a
286 // stack. It is cleared before each scavenge/GC. During the traversal of all
287 // oops, it is filled in with references to all locations that contains a
288 // derived oop (assumed to be very few). When the GC is complete, the derived
289 // pointers are updated based on their base pointers new value and an offset.
290 #ifdef COMPILER2
291 class DerivedPointerTable : public AllStatic {
292 friend class VMStructs;
293 private:
294 static GrowableArray<DerivedPointerEntry*>* _list;
295 static bool _active; // do not record pointers for verify pass etc.
296 public:
297 static void clear(); // Called before scavenge/GC
298 static void add(oop *derived, oop *base); // Called during scavenge/GC
299 static void update_pointers(); // Called after scavenge/GC
300 static bool is_empty() { return _list == NULL || _list->is_empty(); }
301 static bool is_active() { return _active; }
302 static void set_active(bool value) { _active = value; }
303 };
304
305 // A utility class to temporarily "deactivate" the DerivedPointerTable.
306 // (Note: clients are responsible for any MT-safety issues)
307 class DerivedPointerTableDeactivate: public StackObj {
308 private:
309 bool _active;
310 public:
311 DerivedPointerTableDeactivate() {
312 _active = DerivedPointerTable::is_active();
313 if (_active) {
314 DerivedPointerTable::set_active(false);
315 }
316 }
317
318 ~DerivedPointerTableDeactivate() {
319 assert(!DerivedPointerTable::is_active(),
320 "Inconsistency: not MT-safe");
321 if (_active) {
322 DerivedPointerTable::set_active(true);
323 }
324 }
325 };
326 #endif // COMPILER2
327
328 #endif // SHARE_VM_COMPILER_OOPMAP_HPP