1 /*
2 * Copyright (c) 2003, 2012, 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 u2 flags;
126 };
127
128
129 class ConstMethod : public MetaspaceObj {
130 friend class VMStructs;
131
132 public:
133 typedef enum { NORMAL, OVERPASS } MethodType;
134
135 private:
136 enum {
137 _has_linenumber_table = 1,
138 _has_checked_exceptions = 2,
139 _has_localvariable_table = 4,
140 _has_exception_table = 8,
141 _has_generic_signature = 16,
142 _has_method_parameters = 32,
143 _is_overpass = 64
144 };
145
146 // Bit vector of signature
147 // Callers interpret 0=not initialized yet and
148 // -1=too many args to fix, must parse the slow way.
149 // The real initial value is special to account for nonatomicity of 64 bit
150 // loads and stores. This value may updated and read without a lock by
151 // multiple threads, so is volatile.
152 volatile uint64_t _fingerprint;
153
154 ConstantPool* _constants; // Constant pool
155
156 // Raw stackmap data for the method
157 Array<u1>* _stackmap_data;
158
159 int _constMethod_size;
160 jbyte _interpreter_kind;
161 jbyte _flags;
162
163 // Size of Java bytecodes allocated immediately after Method*.
164 u2 _code_size;
165 u2 _name_index; // Method name (index in constant pool)
166 u2 _signature_index; // Method signature (index in constant pool)
167 u2 _method_idnum; // unique identification number for the method within the class
168 // initially corresponds to the index into the methods array.
169 // but this may change with redefinition
170 u2 _max_stack; // Maximum number of entries on the expression stack
171 u2 _max_locals; // Number of local variables used by this method
172 u2 _size_of_parameters; // size of the parameter block (receiver + arguments) in words
173
174 // Constructor
175 ConstMethod(int byte_code_size,
176 int compressed_line_number_size,
177 int localvariable_table_length,
178 int exception_table_length,
179 int checked_exceptions_length,
180 int method_parameters_length,
181 u2 generic_signature_index,
182 MethodType is_overpass,
183 int size);
184 public:
185
186 static ConstMethod* allocate(ClassLoaderData* loader_data,
187 int byte_code_size,
188 int compressed_line_number_size,
189 int localvariable_table_length,
190 int exception_table_length,
191 int checked_exceptions_length,
192 int method_parameters_length,
193 u2 generic_signature_index,
194 MethodType mt,
195 TRAPS);
196
197 bool is_constMethod() const { return true; }
198
199 // Inlined tables
200 void set_inlined_tables_length(u2 generic_signature_index,
201 int checked_exceptions_len,
202 int compressed_line_number_size,
203 int localvariable_table_len,
204 int exception_table_len,
205 int method_parameters_length);
206
207 bool has_generic_signature() const
208 { return (_flags & _has_generic_signature) != 0; }
209
210 bool has_linenumber_table() const
211 { return (_flags & _has_linenumber_table) != 0; }
212
213 bool has_checked_exceptions() const
214 { return (_flags & _has_checked_exceptions) != 0; }
215
216 bool has_localvariable_table() const
217 { return (_flags & _has_localvariable_table) != 0; }
218
219 bool has_exception_handler() const
220 { return (_flags & _has_exception_table) != 0; }
221
222 bool has_method_parameters() const
223 { return (_flags & _has_method_parameters) != 0; }
224
225 MethodType method_type() const {
226 return ((_flags & _is_overpass) == 0) ? NORMAL : OVERPASS;
227 }
228
229 void set_method_type(MethodType mt) {
230 if (mt == NORMAL) {
231 _flags &= ~(_is_overpass);
232 } else {
233 _flags |= _is_overpass;
234 }
235 }
236
237
238 void set_interpreter_kind(int kind) { _interpreter_kind = kind; }
239 int interpreter_kind(void) const { return _interpreter_kind; }
240
241 // constant pool
242 ConstantPool* constants() const { return _constants; }
243 void set_constants(ConstantPool* c) { _constants = c; }
244
245 Method* method() const;
246
247 // stackmap table data
248 Array<u1>* stackmap_data() const { return _stackmap_data; }
249 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; }
250 bool has_stackmap_table() const { return _stackmap_data != NULL; }
251
252 void init_fingerprint() {
253 const uint64_t initval = CONST64(0x8000000000000000);
254 _fingerprint = initval;
255 }
256
257 uint64_t fingerprint() const {
258 // Since reads aren't atomic for 64 bits, if any of the high or low order
259 // word is the initial value, return 0. See init_fingerprint for initval.
260 uint high_fp = (uint)(_fingerprint >> 32);
261 if ((int) _fingerprint == 0 || high_fp == 0x80000000) {
262 return 0L;
263 } else {
264 return _fingerprint;
265 }
266 }
267
268 uint64_t set_fingerprint(uint64_t new_fingerprint) {
269 #ifdef ASSERT
270 // Assert only valid if complete/valid 64 bit _fingerprint value is read.
271 uint64_t oldfp = fingerprint();
272 #endif // ASSERT
273 _fingerprint = new_fingerprint;
274 assert(oldfp == 0L || new_fingerprint == oldfp,
275 "fingerprint cannot change");
276 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0,
277 "fingerprint should call init to set initial value");
278 return new_fingerprint;
279 }
280
281 // name
282 int name_index() const { return _name_index; }
283 void set_name_index(int index) { _name_index = index; }
284
285 // signature
286 int signature_index() const { return _signature_index; }
287 void set_signature_index(int index) { _signature_index = index; }
288
289 // generics support
290 int generic_signature_index() const {
291 if (has_generic_signature()) {
292 return *generic_signature_index_addr();
293 } else {
294 return 0;
295 }
296 }
297 void set_generic_signature_index(u2 index) {
298 assert(has_generic_signature(), "");
299 u2* addr = generic_signature_index_addr();
300 *addr = index;
301 }
302
303 // Sizing
304 static int header_size() {
305 return sizeof(ConstMethod)/HeapWordSize;
306 }
307
308 // Size needed
309 static int size(int code_size, int compressed_line_number_size,
310 int local_variable_table_length,
311 int exception_table_length,
312 int checked_exceptions_length,
313 int method_parameters_length,
314 u2 generic_signature_index);
315
316 int size() const { return _constMethod_size;}
317 void set_constMethod_size(int size) { _constMethod_size = size; }
318
319 // code size
320 int code_size() const { return _code_size; }
321 void set_code_size(int size) {
322 assert(max_method_code_size < (1 << 16),
323 "u2 is too small to hold method code size in general");
324 assert(0 <= size && size <= max_method_code_size, "invalid code size");
325 _code_size = size;
326 }
327
328 // linenumber table - note that length is unknown until decompression,
329 // see class CompressedLineNumberReadStream.
330 u_char* compressed_linenumber_table() const; // not preserved by gc
331 u2* generic_signature_index_addr() const;
332 u2* checked_exceptions_length_addr() const;
333 u2* localvariable_table_length_addr() const;
334 u2* exception_table_length_addr() const;
335 u2* method_parameters_length_addr() const;
336
337 // checked exceptions
338 int checked_exceptions_length() const;
339 CheckedExceptionElement* checked_exceptions_start() const;
340
341 // localvariable table
342 int localvariable_table_length() const;
343 LocalVariableTableElement* localvariable_table_start() const;
344
345 // exception table
346 int exception_table_length() const;
347 ExceptionTableElement* exception_table_start() const;
348
349 // method parameters table
350 int method_parameters_length() const;
351 MethodParametersElement* method_parameters_start() const;
352
353 // byte codes
354 void set_code(address code) {
355 if (code_size() > 0) {
356 memcpy(code_base(), code, code_size());
357 }
358 }
359 address code_base() const { return (address) (this+1); }
360 address code_end() const { return code_base() + code_size(); }
361 bool contains(address bcp) const { return code_base() <= bcp
362 && bcp < code_end(); }
363 // Offset to bytecodes
364 static ByteSize codes_offset()
365 { return in_ByteSize(sizeof(ConstMethod)); }
366
367 static ByteSize constants_offset()
368 { return byte_offset_of(ConstMethod, _constants); }
369
370 static ByteSize max_stack_offset()
371 { return byte_offset_of(ConstMethod, _max_stack); }
372 static ByteSize size_of_locals_offset()
373 { return byte_offset_of(ConstMethod, _max_locals); }
374 static ByteSize size_of_parameters_offset()
375 { return byte_offset_of(ConstMethod, _size_of_parameters); }
376
377
378 // Unique id for the method
379 static const u2 MAX_IDNUM;
380 static const u2 UNSET_IDNUM;
381 u2 method_idnum() const { return _method_idnum; }
382 void set_method_idnum(u2 idnum) { _method_idnum = idnum; }
383
384 // max stack
385 int max_stack() const { return _max_stack; }
386 void set_max_stack(int size) { _max_stack = size; }
387
388 // max locals
389 int max_locals() const { return _max_locals; }
390 void set_max_locals(int size) { _max_locals = size; }
391
392 // size of parameters
393 int size_of_parameters() const { return _size_of_parameters; }
394 void set_size_of_parameters(int size) { _size_of_parameters = size; }
395
396 // Deallocation for RedefineClasses
397 void deallocate_contents(ClassLoaderData* loader_data);
398 bool is_klass() const { return false; }
399 DEBUG_ONLY(bool on_stack() { return false; })
400
401 private:
402 // Since the size of the compressed line number table is unknown, the
403 // offsets of the other variable sized sections are computed backwards
404 // from the end of the ConstMethod*.
405
406 // First byte after ConstMethod*
407 address constMethod_end() const
408 { return (address)((oop*)this + _constMethod_size); }
409
410 // Last short in ConstMethod*
411 u2* last_u2_element() const
412 { return (u2*)constMethod_end() - 1; }
413
414 public:
415 // Printing
416 void print_on (outputStream* st) const;
417 void print_value_on(outputStream* st) const;
418
419 const char* internal_name() const { return "{constMethod}"; }
420
421 // Verify
422 void verify_on(outputStream* st);
423 };
424
425 #endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP