1 /*
2 * Copyright (c) 2003, 2013, 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_OOPS_CONSTMETHODOOP_HPP
26 #define SHARE_VM_OOPS_CONSTMETHODOOP_HPP
27
28 #include "oops/oop.hpp"
29
30 // An ConstMethod* represents portions of a Java method which
31 // do not vary.
32 //
33 // Memory layout (each line represents a word). Note that most
34 // applications load thousands of methods, so keeping the size of this
35 // structure small has a big impact on footprint.
36 //
37 // |------------------------------------------------------|
38 // | header |
39 // | klass |
40 // |------------------------------------------------------|
41 // | fingerprint 1 |
42 // | fingerprint 2 |
43 // | constants (oop) |
44 // | stackmap_data (oop) |
45 // | constMethod_size |
46 // | interp_kind | flags | code_size |
47 // | name index | signature index |
48 // | method_idnum | max_stack |
49 // | max_locals | size_of_parameters |
50 // |------------------------------------------------------|
51 // | |
52 // | byte codes |
53 // | |
54 // |------------------------------------------------------|
55 // | compressed linenumber table |
56 // | (see class CompressedLineNumberReadStream) |
57 // | (note that length is unknown until decompressed) |
58 // | (access flags bit tells whether table is present) |
59 // | (indexed from start of ConstMethod*) |
60 // | (elements not necessarily sorted!) |
61 // |------------------------------------------------------|
62 // | localvariable table elements + length (length last) |
63 // | (length is u2, elements are 6-tuples of u2) |
64 // | (see class LocalVariableTableElement) |
65 // | (access flags bit tells whether table is present) |
66 // | (indexed from end of ConstMethod*) |
67 // |------------------------------------------------------|
68 // | exception table + length (length last) |
69 // | (length is u2, elements are 4-tuples of u2) |
70 // | (see class ExceptionTableElement) |
71 // | (access flags bit tells whether table is present) |
72 // | (indexed from end of ConstMethod*) |
73 // |------------------------------------------------------|
74 // | checked exceptions elements + length (length last) |
75 // | (length is u2, elements are u2) |
76 // | (see class CheckedExceptionElement) |
77 // | (access flags bit tells whether table is present) |
78 // | (indexed from end of ConstMethod*) |
79 // |------------------------------------------------------|
80 // | method parameters elements + length (length last) |
81 // | (length is u2, elements are u2, u4 structures) |
82 // | (see class MethodParametersElement) |
83 // | (access flags bit tells whether table is present) |
84 // | (indexed from end of ConstMethod*) |
85 // |------------------------------------------------------|
86 // | generic signature index (u2) |
87 // | (indexed from start of constMethodOop) |
88 // |------------------------------------------------------|
89 //
90 // IMPORTANT: If anything gets added here, there need to be changes to
91 // ensure that ServicabilityAgent doesn't get broken as a result!
92
93
94 // Utitily class decribing elements in checked exceptions table inlined in Method*.
95 class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC {
96 public:
97 u2 class_cp_index;
98 };
99
100
101 // Utitily class decribing elements in local variable table inlined in Method*.
102 class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC {
103 public:
104 u2 start_bci;
105 u2 length;
106 u2 name_cp_index;
107 u2 descriptor_cp_index;
108 u2 signature_cp_index;
109 u2 slot;
110 };
111
112 // Utitily class describing elements in exception table
113 class ExceptionTableElement VALUE_OBJ_CLASS_SPEC {
114 public:
115 u2 start_pc;
116 u2 end_pc;
117 u2 handler_pc;
118 u2 catch_type_index;
119 };
120
121 // Utility class describing elements in method parameters
122 class MethodParametersElement VALUE_OBJ_CLASS_SPEC {
123 public:
124 u2 name_cp_index;
125 // This has to happen, otherwise it will cause SIGBUS from a
126 // misaligned u4 on some architectures (ie SPARC)
127 // because MethodParametersElements are only aligned mod 2
128 // within the ConstMethod container u2 flags_hi;
129 u2 flags_hi;
130 u2 flags_lo;
131 };
132
133 class KlassSizeStats;
134
135 class ConstMethod : public MetaspaceObj {
136 friend class VMStructs;
137
138 public:
139 typedef enum { NORMAL, OVERPASS } MethodType;
140
141 private:
142 enum {
143 _has_linenumber_table = 1,
144 _has_checked_exceptions = 2,
145 _has_localvariable_table = 4,
146 _has_exception_table = 8,
147 _has_generic_signature = 16,
148 _has_method_parameters = 32,
149 _is_overpass = 64
150 };
151
152 // Bit vector of signature
153 // Callers interpret 0=not initialized yet and
154 // -1=too many args to fix, must parse the slow way.
155 // The real initial value is special to account for nonatomicity of 64 bit
156 // loads and stores. This value may updated and read without a lock by
157 // multiple threads, so is volatile.
158 volatile uint64_t _fingerprint;
159
160 ConstantPool* _constants; // Constant pool
161
162 // Raw stackmap data for the method
163 Array<u1>* _stackmap_data;
164
165 int _constMethod_size;
166 jbyte _interpreter_kind;
167 jbyte _flags;
168
169 // Size of Java bytecodes allocated immediately after Method*.
170 u2 _code_size;
171 u2 _name_index; // Method name (index in constant pool)
172 u2 _signature_index; // Method signature (index in constant pool)
173 u2 _method_idnum; // unique identification number for the method within the class
174 // initially corresponds to the index into the methods array.
175 // but this may change with redefinition
176 u2 _max_stack; // Maximum number of entries on the expression stack
177 u2 _max_locals; // Number of local variables used by this method
178 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words
179
180 // Constructor
181 ConstMethod(int byte_code_size,
182 int compressed_line_number_size,
183 int localvariable_table_length,
184 int exception_table_length,
185 int checked_exceptions_length,
186 int method_parameters_length,
187 u2 generic_signature_index,
188 MethodType is_overpass,
189 int size);
190 public:
191
192 static ConstMethod* allocate(ClassLoaderData* loader_data,
193 int byte_code_size,
194 int compressed_line_number_size,
195 int localvariable_table_length,
196 int exception_table_length,
197 int checked_exceptions_length,
198 int method_parameters_length,
199 u2 generic_signature_index,
200 MethodType mt,
201 TRAPS);
202
203 bool is_constMethod() const { return true; }
204
205 // Inlined tables
206 void set_inlined_tables_length(u2 generic_signature_index,
207 int checked_exceptions_len,
208 int compressed_line_number_size,
209 int localvariable_table_len,
210 int exception_table_len,
211 int method_parameters_length);
212
213 bool has_generic_signature() const
214 { return (_flags & _has_generic_signature) != 0; }
215
216 bool has_linenumber_table() const
217 { return (_flags & _has_linenumber_table) != 0; }
218
219 bool has_checked_exceptions() const
220 { return (_flags & _has_checked_exceptions) != 0; }
221
222 bool has_localvariable_table() const
223 { return (_flags & _has_localvariable_table) != 0; }
224
225 bool has_exception_handler() const
226 { return (_flags & _has_exception_table) != 0; }
227
228 bool has_method_parameters() const
229 { return (_flags & _has_method_parameters) != 0; }
230
231 MethodType method_type() const {
232 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
233 }
234
235 void set_method_type(MethodType mt) {
236 if (mt == NORMAL) {
237 _flags &= ~(_is_overpass);
238 } else {
239 _flags |= _is_overpass;
240 }
241 }
242
243
244 void set_interpreter_kind(int kind) { _interpreter_kind = kind; }
245 int interpreter_kind(void) const { return _interpreter_kind; }
246
247 // constant pool
248 ConstantPool* constants() const { return _constants; }
249 void set_constants(ConstantPool* c) { _constants = c; }
250
251 Method* method() const;
252
253 // stackmap table data
254 Array<u1>* stackmap_data() const { return _stackmap_data; }
255 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
256 bool has_stackmap_table() const { return _stackmap_data != NULL; }
257
258 void init_fingerprint() {
259 const uint64_t initval = CONST64(0x8000000000000000);
260 _fingerprint = initval;
261 }
262
263 uint64_t fingerprint() const {
264 // Since reads aren't atomic for 64 bits, if any of the high or low order
265 // word is the initial value, return 0. See init_fingerprint for initval.
266 uint high_fp = (uint)(_fingerprint >> 32);
267 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
268 return 0L;
269 } else {
270 return _fingerprint;
271 }
272 }
273
274 uint64_t set_fingerprint(uint64_t new_fingerprint) {
275 #ifdef ASSERT
276 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
277 uint64_t oldfp = fingerprint();
278 #endif // ASSERT
279 _fingerprint = new_fingerprint;
280 assert(oldfp == 0L || new_fingerprint == oldfp,
281 "fingerprint cannot change");
282 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
283 "fingerprint should call init to set initial value");
284 return new_fingerprint;
285 }
286
287 // name
288 int name_index() const { return _name_index; }
289 void set_name_index(int index) { _name_index = index; }
290
291 // signature
292 int signature_index() const { return _signature_index; }
293 void set_signature_index(int index) { _signature_index = index; }
294
295 // generics support
296 int generic_signature_index() const {
297 if (has_generic_signature()) {
298 return *generic_signature_index_addr();
299 } else {
300 return 0;
301 }
302 }
303 void set_generic_signature_index(u2 index) {
304 assert(has_generic_signature(), "");
305 u2* addr = generic_signature_index_addr();
306 *addr = index;
307 }
308
309 // Sizing
310 static int header_size() {
311 return sizeof(ConstMethod)/HeapWordSize;
312 }
313
314 // Size needed
315 static int size(int code_size, int compressed_line_number_size,
316 int local_variable_table_length,
317 int exception_table_length,
318 int checked_exceptions_length,
319 int method_parameters_length,
320 u2 generic_signature_index);
321
322 int size() const { return _constMethod_size;}
323 void set_constMethod_size(int size) { _constMethod_size = size; }
324 #if INCLUDE_SERVICES
325 void collect_statistics(KlassSizeStats *sz) const;
326 #endif
327
328 // code size
329 int code_size() const { return _code_size; }
330 void set_code_size(int size) {
331 assert(max_method_code_size < (1 << 16),
332 "u2 is too small to hold method code size in general");
333 assert(0 <= size && size <= max_method_code_size, "invalid code size");
334 _code_size = size;
335 }
336
337 // linenumber table - note that length is unknown until decompression,
338 // see class CompressedLineNumberReadStream.
339 u_char* compressed_linenumber_table() const; // not preserved by gc
340 u2* generic_signature_index_addr() const;
341 u2* checked_exceptions_length_addr() const;
342 u2* localvariable_table_length_addr() const;
343 u2* exception_table_length_addr() const;
344 u2* method_parameters_length_addr() const;
345
346 // checked exceptions
347 int checked_exceptions_length() const;
348 CheckedExceptionElement* checked_exceptions_start() const;
349
350 // localvariable table
351 int localvariable_table_length() const;
352 LocalVariableTableElement* localvariable_table_start() const;
353
354 // exception table
355 int exception_table_length() const;
356 ExceptionTableElement* exception_table_start() const;
357
358 // method parameters table
359 int method_parameters_length() const;
360 MethodParametersElement* method_parameters_start() const;
361
362 // byte codes
363 void set_code(address code) {
364 if (code_size() > 0) {
365 memcpy(code_base(), code, code_size());
366 }
367 }
368 address code_base() const { return (address) (this+1); }
369 address code_end() const { return code_base() + code_size(); }
370 bool contains(address bcp) const { return code_base() <= bcp
371 && bcp < code_end(); }
372 // Offset to bytecodes
373 static ByteSize codes_offset()
374 { return in_ByteSize(sizeof(ConstMethod)); }
375
376 static ByteSize constants_offset()
377 { return byte_offset_of(ConstMethod, _constants); }
378
379 static ByteSize max_stack_offset()
380 { return byte_offset_of(ConstMethod, _max_stack); }
381 static ByteSize size_of_locals_offset()
382 { return byte_offset_of(ConstMethod, _max_locals); }
383 static ByteSize size_of_parameters_offset()
384 { return byte_offset_of(ConstMethod, _size_of_parameters); }
385
386
387 // Unique id for the method
388 static const u2 MAX_IDNUM;
389 static const u2 UNSET_IDNUM;
390 u2 method_idnum() const { return _method_idnum; }
391 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
392
393 // max stack
394 int max_stack() const { return _max_stack; }
395 void set_max_stack(int size) { _max_stack = size; }
396
397 // max locals
398 int max_locals() const { return _max_locals; }
399 void set_max_locals(int size) { _max_locals = size; }
400
401 // size of parameters
402 int size_of_parameters() const { return _size_of_parameters; }
403 void set_size_of_parameters(int size) { _size_of_parameters = size; }
404
405 // Deallocation for RedefineClasses
406 void deallocate_contents(ClassLoaderData* loader_data);
407 bool is_klass() const { return false; }
408 DEBUG_ONLY(bool on_stack() { return false; })
409
410 private:
411 // Since the size of the compressed line number table is unknown, the
412 // offsets of the other variable sized sections are computed backwards
413 // from the end of the ConstMethod*.
414
415 // First byte after ConstMethod*
416 address constMethod_end() const
417 { return (address)((oop*)this + _constMethod_size); }
418
419 // Last short in ConstMethod*
420 u2* last_u2_element() const
421 { return (u2*)constMethod_end() - 1; }
422
423 public:
424 // Printing
425 void print_on (outputStream* st) const;
426 void print_value_on(outputStream* st) const;
427
428 const char* internal_name() const { return "{constMethod}"; }
429
430 // Verify
431 void verify_on(outputStream* st);
432 };
433
434 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP