constMethod.hpp revision 3602:da91efe96a93
137463Sbde/* 232213Swosch * Copyright (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved. 319477Sjoerg * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 43077Sache * 53077Sache * This code is free software; you can redistribute it and/or modify it 632213Swosch * under the terms of the GNU General Public License version 2 only, as 73081Sache * published by the Free Software Foundation. 83077Sache * 93077Sache * This code is distributed in the hope that it will be useful, but WITHOUT 103077Sache * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 113077Sache * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 123077Sache * version 2 for more details (a copy is included in the LICENSE file that 1337463Sbde * accompanied this code). 1437463Sbde * 153077Sache * You should have received a copy of the GNU General Public License version 1632213Swosch * 2 along with this work; if not, write to the Free Software Foundation, 1732213Swosch * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 183077Sache * 193077Sache * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 203077Sache * or visit www.oracle.com if you need additional information or have any 213077Sache * questions. 223077Sache * 233077Sache */ 243077Sache 2537463Sbde#ifndef SHARE_VM_OOPS_CONSTMETHODOOP_HPP 2637463Sbde#define SHARE_VM_OOPS_CONSTMETHODOOP_HPP 273077Sache 283077Sache#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 | generic_signature_index | 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 80 81// Utitily class decribing elements in checked exceptions table inlined in Method*. 82class CheckedExceptionElement VALUE_OBJ_CLASS_SPEC { 83 public: 84 u2 class_cp_index; 85}; 86 87 88// Utitily class decribing elements in local variable table inlined in Method*. 89class LocalVariableTableElement VALUE_OBJ_CLASS_SPEC { 90 public: 91 u2 start_bci; 92 u2 length; 93 u2 name_cp_index; 94 u2 descriptor_cp_index; 95 u2 signature_cp_index; 96 u2 slot; 97}; 98 99// Utitily class describing elements in exception table 100class ExceptionTableElement VALUE_OBJ_CLASS_SPEC { 101 public: 102 u2 start_pc; 103 u2 end_pc; 104 u2 handler_pc; 105 u2 catch_type_index; 106}; 107 108 109class ConstMethod : public MetaspaceObj { 110 friend class VMStructs; 111private: 112 enum { 113 _has_linenumber_table = 1, 114 _has_checked_exceptions = 2, 115 _has_localvariable_table = 4, 116 _has_exception_table = 8 117 }; 118 119 // Bit vector of signature 120 // Callers interpret 0=not initialized yet and 121 // -1=too many args to fix, must parse the slow way. 122 // The real initial value is special to account for nonatomicity of 64 bit 123 // loads and stores. This value may updated and read without a lock by 124 // multiple threads, so is volatile. 125 volatile uint64_t _fingerprint; 126 127 ConstantPool* _constants; // Constant pool 128 129 // Raw stackmap data for the method 130 Array<u1>* _stackmap_data; 131 132 int _constMethod_size; 133 jbyte _interpreter_kind; 134 jbyte _flags; 135 136 // Size of Java bytecodes allocated immediately after Method*. 137 u2 _code_size; 138 u2 _name_index; // Method name (index in constant pool) 139 u2 _signature_index; // Method signature (index in constant pool) 140 u2 _method_idnum; // unique identification number for the method within the class 141 // initially corresponds to the index into the methods array. 142 // but this may change with redefinition 143 u2 _generic_signature_index; // Generic signature (index in constant pool, 0 if absent) 144 145 146 // Constructor 147 ConstMethod(int byte_code_size, 148 int compressed_line_number_size, 149 int localvariable_table_length, 150 int exception_table_length, 151 int checked_exceptions_length, 152 int size); 153public: 154 static ConstMethod* allocate(ClassLoaderData* loader_data, 155 int byte_code_size, 156 int compressed_line_number_size, 157 int localvariable_table_length, 158 int exception_table_length, 159 int checked_exceptions_length, 160 TRAPS); 161 162 bool is_constMethod() const { return true; } 163 164 // Inlined tables 165 void set_inlined_tables_length(int checked_exceptions_len, 166 int compressed_line_number_size, 167 int localvariable_table_len, 168 int exception_table_len); 169 170 bool has_linenumber_table() const 171 { return (_flags & _has_linenumber_table) != 0; } 172 173 bool has_checked_exceptions() const 174 { return (_flags & _has_checked_exceptions) != 0; } 175 176 bool has_localvariable_table() const 177 { return (_flags & _has_localvariable_table) != 0; } 178 179 bool has_exception_handler() const 180 { return (_flags & _has_exception_table) != 0; } 181 182 void set_interpreter_kind(int kind) { _interpreter_kind = kind; } 183 int interpreter_kind(void) const { return _interpreter_kind; } 184 185 // constant pool 186 ConstantPool* constants() const { return _constants; } 187 void set_constants(ConstantPool* c) { _constants = c; } 188 189 Method* method() const; 190 191 // stackmap table data 192 Array<u1>* stackmap_data() const { return _stackmap_data; } 193 void set_stackmap_data(Array<u1>* sd) { _stackmap_data = sd; } 194 bool has_stackmap_table() const { return _stackmap_data != NULL; } 195 196 void init_fingerprint() { 197 const uint64_t initval = CONST64(0x8000000000000000); 198 _fingerprint = initval; 199 } 200 201 uint64_t fingerprint() const { 202 // Since reads aren't atomic for 64 bits, if any of the high or low order 203 // word is the initial value, return 0. See init_fingerprint for initval. 204 uint high_fp = (uint)(_fingerprint >> 32); 205 if ((int) _fingerprint == 0 || high_fp == 0x80000000) { 206 return 0L; 207 } else { 208 return _fingerprint; 209 } 210 } 211 212 uint64_t set_fingerprint(uint64_t new_fingerprint) { 213#ifdef ASSERT 214 // Assert only valid if complete/valid 64 bit _fingerprint value is read. 215 uint64_t oldfp = fingerprint(); 216#endif // ASSERT 217 _fingerprint = new_fingerprint; 218 assert(oldfp == 0L || new_fingerprint == oldfp, 219 "fingerprint cannot change"); 220 assert(((new_fingerprint >> 32) != 0x80000000) && (int)new_fingerprint !=0, 221 "fingerprint should call init to set initial value"); 222 return new_fingerprint; 223 } 224 225 // name 226 int name_index() const { return _name_index; } 227 void set_name_index(int index) { _name_index = index; } 228 229 // signature 230 int signature_index() const { return _signature_index; } 231 void set_signature_index(int index) { _signature_index = index; } 232 233 // generics support 234 int generic_signature_index() const { return _generic_signature_index; } 235 void set_generic_signature_index(int index) { _generic_signature_index = index; } 236 237 // Sizing 238 static int header_size() { 239 return sizeof(ConstMethod)/HeapWordSize; 240 } 241 242 // Size needed 243 static int size(int code_size, int compressed_line_number_size, 244 int local_variable_table_length, 245 int exception_table_length, 246 int checked_exceptions_length); 247 248 int size() const { return _constMethod_size;} 249 void set_constMethod_size(int size) { _constMethod_size = size; } 250 251 // code size 252 int code_size() const { return _code_size; } 253 void set_code_size(int size) { 254 assert(max_method_code_size < (1 << 16), 255 "u2 is too small to hold method code size in general"); 256 assert(0 <= size && size <= max_method_code_size, "invalid code size"); 257 _code_size = size; 258 } 259 260 // linenumber table - note that length is unknown until decompression, 261 // see class CompressedLineNumberReadStream. 262 u_char* compressed_linenumber_table() const; // not preserved by gc 263 u2* checked_exceptions_length_addr() const; 264 u2* localvariable_table_length_addr() const; 265 u2* exception_table_length_addr() const; 266 267 // checked exceptions 268 int checked_exceptions_length() const; 269 CheckedExceptionElement* checked_exceptions_start() const; 270 271 // localvariable table 272 int localvariable_table_length() const; 273 LocalVariableTableElement* localvariable_table_start() const; 274 275 // exception table 276 int exception_table_length() const; 277 ExceptionTableElement* exception_table_start() const; 278 279 // byte codes 280 void set_code(address code) { 281 if (code_size() > 0) { 282 memcpy(code_base(), code, code_size()); 283 } 284 } 285 address code_base() const { return (address) (this+1); } 286 address code_end() const { return code_base() + code_size(); } 287 bool contains(address bcp) const { return code_base() <= bcp 288 && bcp < code_end(); } 289 // Offset to bytecodes 290 static ByteSize codes_offset() 291 { return in_ByteSize(sizeof(ConstMethod)); } 292 293 static ByteSize constants_offset() 294 { return byte_offset_of(ConstMethod, _constants); } 295 296 // Unique id for the method 297 static const u2 MAX_IDNUM; 298 static const u2 UNSET_IDNUM; 299 u2 method_idnum() const { return _method_idnum; } 300 void set_method_idnum(u2 idnum) { _method_idnum = idnum; } 301 302 // Deallocation for RedefineClasses 303 void deallocate_contents(ClassLoaderData* loader_data); 304 bool is_klass() const { return false; } 305 DEBUG_ONLY(bool on_stack() { return false; }) 306 307private: 308 // Since the size of the compressed line number table is unknown, the 309 // offsets of the other variable sized sections are computed backwards 310 // from the end of the ConstMethod*. 311 312 // First byte after ConstMethod* 313 address constMethod_end() const 314 { return (address)((oop*)this + _constMethod_size); } 315 316 // Last short in ConstMethod* 317 u2* last_u2_element() const 318 { return (u2*)constMethod_end() - 1; } 319 320 public: 321 // Printing 322 void print_on (outputStream* st) const; 323 void print_value_on(outputStream* st) const; 324 325 const char* internal_name() const { return "{constMethod}"; } 326 327 // Verify 328 void verify_on(outputStream* st); 329}; 330 331#endif // SHARE_VM_OOPS_CONSTMETHODOOP_HPP 332