hotspot/src/share/vm/oops/constMethod.hpp
changeset 13728 882756847a04
parent 13282 9872915dd78d
child 14385 959bbcc16725
equal deleted inserted replaced
13727:caf5eb7dd4a7 13728:882756847a04
       
     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            | 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*.
       
    82 class 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*.
       
    89 class 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
       
   100 class 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 
       
   109 class ConstMethod : public MetaspaceObj {
       
   110   friend class VMStructs;
       
   111 private:
       
   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);
       
   153 public:
       
   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 
       
   307 private:
       
   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