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