interpreter.hpp revision 1668:3e8fbc61cee8 
1/*
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24
25// This file contains the platform-independent parts
26// of the interpreter and the interpreter generator.
27
28//------------------------------------------------------------------------------------------------------------------------
29// An InterpreterCodelet is a piece of interpreter code. All
30// interpreter code is generated into little codelets which
31// contain extra information for debugging and printing purposes.
32
33class InterpreterCodelet: public Stub {
34  friend class VMStructs;
35 private:
36  int         _size;                             // the size in bytes
37  const char* _description;                      // a description of the codelet, for debugging & printing
38  Bytecodes::Code _bytecode;                     // associated bytecode if any
39
40 public:
41  // Initialization/finalization
42  void    initialize(int size)                   { _size = size; }
43  void    finalize()                             { ShouldNotCallThis(); }
44
45  // General info/converters
46  int     size() const                           { return _size; }
47  static  int code_size_to_size(int code_size)   { return round_to(sizeof(InterpreterCodelet), CodeEntryAlignment) + code_size; }
48
49  // Code info
50  address code_begin() const                     { return (address)this + round_to(sizeof(InterpreterCodelet), CodeEntryAlignment); }
51  address code_end() const                       { return (address)this + size(); }
52
53  // Debugging
54  void    verify();
55  void    print_on(outputStream* st) const;
56  void    print() const { print_on(tty); }
57
58  // Interpreter-specific initialization
59  void    initialize(const char* description, Bytecodes::Code bytecode);
60
61  // Interpreter-specific attributes
62  int         code_size() const                  { return code_end() - code_begin(); }
63  const char* description() const                { return _description; }
64  Bytecodes::Code bytecode() const               { return _bytecode; }
65};
66
67// Define a prototype interface
68DEF_STUB_INTERFACE(InterpreterCodelet);
69
70
71//------------------------------------------------------------------------------------------------------------------------
72// A CodeletMark serves as an automatic creator/initializer for Codelets
73// (As a subclass of ResourceMark it automatically GC's the allocated
74// code buffer and assemblers).
75
76class CodeletMark: ResourceMark {
77 private:
78  InterpreterCodelet*         _clet;
79  InterpreterMacroAssembler** _masm;
80  CodeBuffer                  _cb;
81
82  int codelet_size() {
83    // Request the whole code buffer (minus a little for alignment).
84    // The commit call below trims it back for each codelet.
85    int codelet_size = AbstractInterpreter::code()->available_space() - 2*K;
86
87    // Guarantee there's a little bit of code space left.
88    guarantee (codelet_size > 0 && (size_t)codelet_size >  2*K,
89               "not enough space for interpreter generation");
90
91    return codelet_size;
92  }
93
94 public:
95  CodeletMark(
96    InterpreterMacroAssembler*& masm,
97    const char* description,
98    Bytecodes::Code bytecode = Bytecodes::_illegal):
99    _clet((InterpreterCodelet*)AbstractInterpreter::code()->request(codelet_size())),
100    _cb(_clet->code_begin(), _clet->code_size())
101
102  { // request all space (add some slack for Codelet data)
103    assert (_clet != NULL, "we checked not enough space already");
104
105    // initialize Codelet attributes
106    _clet->initialize(description, bytecode);
107    // create assembler for code generation
108    masm  = new InterpreterMacroAssembler(&_cb);
109    _masm = &masm;
110  }
111
112  ~CodeletMark() {
113    // align so printing shows nop's instead of random code at the end (Codelets are aligned)
114    (*_masm)->align(wordSize);
115    // make sure all code is in code buffer
116    (*_masm)->flush();
117
118
119    // commit Codelet
120    AbstractInterpreter::code()->commit((*_masm)->code()->pure_insts_size());
121    // make sure nobody can use _masm outside a CodeletMark lifespan
122    *_masm = NULL;
123  }
124};
125
126// Wrapper classes to produce Interpreter/InterpreterGenerator from either
127// the c++ interpreter or the template interpreter.
128
129class Interpreter: public CC_INTERP_ONLY(CppInterpreter) NOT_CC_INTERP(TemplateInterpreter) {
130
131  public:
132  // Debugging/printing
133  static InterpreterCodelet* codelet_containing(address pc)     { return (InterpreterCodelet*)_code->stub_containing(pc); }
134#include "incls/_interpreter_pd.hpp.incl"
135};
136