深入jvm虚拟机--第一篇 void TemplateInterpreterGenerator::generate_and_dispatch(Template* t, TosState tos_out) 函数
今天第一次使用虚拟姐打断点,断点设置在了void TemplateInterpreterGenerator::generate_and_dispatch(Template* t, TosState tos_out) 了
在TemplateInterpreterGenerator.cpp中,这个函数之前看书就不太懂,现在debug时候就能分析的比较清楚了,这个函数的介绍在解密jvm的528页中有具体介绍
void TemplateInterpreterGenerator::generate_and_dispatch(Template* t, TosState tos_out) { if (PrintBytecodeHistogram) histogram_bytecode(t); #ifndef PRODUCT // debugging code if (CountBytecodes || TraceBytecodes || StopInterpreterAt > 0) count_bytecode(); if (PrintBytecodePairHistogram) histogram_bytecode_pair(t); if (TraceBytecodes) trace_bytecode(t); if (StopInterpreterAt > 0) stop_interpreter_at(); __ verify_FPU(1, t->tos_in()); #endif // !PRODUCT int step = 0; if (!t->does_dispatch()) { step = t->is_wide() ? Bytecodes::wide_length_for(t->bytecode()) : Bytecodes::length_for(t->bytecode()); if (tos_out == ilgl) tos_out = t->tos_out(); // compute bytecode size assert(step > 0, "just checkin'"); // setup stuff for dispatching next bytecode if (ProfileInterpreter && VerifyDataPointer && MethodData::bytecode_has_profile(t->bytecode())) { __ verify_method_data_pointer(); } __ dispatch_prolog(tos_out, step); } // generate template t->generate(_masm); // advance if (t->does_dispatch()) { #ifdef ASSERT // make sure execution doesn't go beyond this point if code is broken __ should_not_reach_here(); #endif // ASSERT } else { // dispatch to next bytecode __ dispatch_epilog(tos_out, step); } }
先看这个入参函数Template
这个是一个对象,在哪里定义的呢?得往上边查看
void TemplateInterpreterGenerator::set_entry_points(Bytecodes::Code code) { CodeletMark cm(_masm, Bytecodes::name(code), code); // initialize entry points assert(_unimplemented_bytecode != NULL, "should have been generated before"); assert(_illegal_bytecode_sequence != NULL, "should have been generated before"); address bep = _illegal_bytecode_sequence; address zep = _illegal_bytecode_sequence; address cep = _illegal_bytecode_sequence; address sep = _illegal_bytecode_sequence; address aep = _illegal_bytecode_sequence; address iep = _illegal_bytecode_sequence; address lep = _illegal_bytecode_sequence; address fep = _illegal_bytecode_sequence; address dep = _illegal_bytecode_sequence; address vep = _unimplemented_bytecode; address wep = _unimplemented_bytecode; // code for short & wide version of bytecode if (Bytecodes::is_defined(code)) { Template* t = TemplateTable::template_for(code); assert(t->is_valid(), "just checking"); set_short_entry_points(t, bep, cep, sep, aep, iep, lep, fep, dep, vep); } if (Bytecodes::wide_is_defined(code)) { Template* t = TemplateTable::template_for_wide(code); assert(t->is_valid(), "just checking"); set_wide_entry_point(t, wep); } // set entry points EntryPoint entry(bep, zep, cep, sep, aep, iep, lep, fep, dep, vep); Interpreter::_normal_table.set_entry(code, entry); Interpreter::_wentry_point[code] = wep; }
是通过: Template* t = TemplateTable::template_for(code); 得到的; TemplateTable的定义
需要知道的是这个是个 静态类,理解是类似于java,能在全局通过类:成员,类:方法来调用(引用)
class TemplateTable: AllStatic { public: enum Operation { add, sub, mul, div, rem, _and, _or, _xor, shl, shr, ushr }; enum Condition { equal, not_equal, less, less_equal, greater, greater_equal }; enum CacheByte { f1_byte = 1, f2_byte = 2, f1_oop = 0x11 }; // byte_no codes private: static bool _is_initialized; // true if TemplateTable has been initialized static Template _template_table [Bytecodes::number_of_codes]; static Template _template_table_wide[Bytecodes::number_of_codes]; static Template* _desc; // the current template to be generated static Bytecodes::Code bytecode() { return _desc->bytecode(); } static BarrierSet* _bs; // Cache the barrier set. public: //%note templates_1 static InterpreterMacroAssembler* _masm; // the assembler used when generating templates private: // special registers static inline Address at_bcp(int offset); // helpers static void unimplemented_bc(); static void patch_bytecode(Bytecodes::Code bc, Register bc_reg, Register temp_reg, bool load_bc_into_bc_reg = true, int byte_no = -1); // C calls static void call_VM(Register oop_result, address entry_point); static void call_VM(Register oop_result, address entry_point, Register arg_1); static void call_VM(Register oop_result, address entry_point, Register arg_1, Register arg_2); static void call_VM(Register oop_result, address entry_point, Register arg_1, Register arg_2, Register arg_3); // these overloadings are not presently used on SPARC: static void call_VM(Register oop_result, Register last_java_sp, address entry_point); static void call_VM(Register oop_result, Register last_java_sp, address entry_point, Register arg_1); static void call_VM(Register oop_result, Register last_java_sp, address entry_point, Register arg_1, Register arg_2); static void call_VM(Register oop_result, Register last_java_sp, address entry_point, Register arg_1, Register arg_2, Register arg_3); // bytecodes static void nop(); static void aconst_null(); static void iconst(int value); static void lconst(int value); static void fconst(int value); static void dconst(int value); static void bipush(); static void sipush(); static void ldc(bool wide); static void ldc2_w(); static void fast_aldc(bool wide); static void locals_index(Register reg, int offset = 1); static void iload(); static void fast_iload(); static void fast_iload2(); static void fast_icaload(); static void lload(); static void fload(); static void dload(); static void aload(); static void locals_index_wide(Register reg); static void wide_iload(); static void wide_lload(); static void wide_fload(); static void wide_dload(); static void wide_aload(); static void iaload(); static void laload(); static void faload(); static void daload(); static void aaload(); static void baload(); static void caload(); static void saload(); static void iload(int n); static void lload(int n); static void fload(int n); static void dload(int n); static void aload(int n); static void aload_0(); static void istore(); static void lstore(); static void fstore(); static void dstore(); static void astore(); };
那么试着摸索 能看到 _template_table,这个是一个数组,一共有239个,对应了239个字节码指令
static Template* template_for (Bytecodes::Code code) { Bytecodes::check (code); return &_template_table [code]; }
此时code值为01则返回对应的为_nop的指令,意思就是t=一个_nop字节码的信息,还接着看
step = t->is_wide() ? Bytecodes::wide_length_for(t->bytecode()) : Bytecodes::length_for(t->bytecode());
此为generate_and_dispatch函数中的,分析 t->bytecode(),值==01
//share/vm/interpreter/templateTable.cpp文件中
Bytecodes::Code Template::bytecode() const { int i = this - TemplateTable::_template_table; if (i < 0 || i >= Bytecodes::number_of_codes)
i = this - TemplateTable::_template_table_wide; return Bytecodes::cast(i); }
那么看_template_table,还是上面已经介绍的那个,接着分析
Bytecodes::wide_length_for(01)
这里的用法就是静态方法调用,查看Bytecodes类
class Bytecodes: AllStatic { public: enum Code { _illegal = -1, // Java bytecodes _nop = 0, // 0x00 _aconst_null = 1, // 0x01 _iconst_m1 = 2, // 0x02 _iconst_0 = 3, // 0x03 _iconst_1 = 4, // 0x04 _iconst_2 = 5, // 0x05 _iconst_3 = 6, // 0x06 _iconst_4 = 7, // 0x07 _iconst_5 = 8, // 0x08 _lconst_0 = 9, // 0x09 _lconst_1 = 10, // 0x0a _fconst_0 = 11, // 0x0b _fconst_1 = 12, // 0x0c _fconst_2 = 13, // 0x0d _dconst_0 = 14, // 0x0e _dconst_1 = 15, // 0x0f _bipush = 16, // 0x10 _sipush = 17, // 0x11 _ldc = 18, // 0x12 _ldc_w = 19, // 0x13 _ldc2_w = 20, // 0x14 _iload = 21, // 0x15 _lload = 22, // 0x16 _fload = 23, // 0x17 _dload = 24, // 0x18 _aload = 25, // 0x19 _iload_0 = 26, // 0x1a _iload_1 = 27, // 0x1b _iload_2 = 28, // 0x1c _iload_3 = 29, // 0x1d _lload_0 = 30, // 0x1e _lload_1 = 31, // 0x1f _lload_2 = 32, // 0x20 _lload_3 = 33, // 0x21 _fload_0 = 34, // 0x22 number_of_codes }; // Flag bits derived from format strings, can_trap, can_rewrite, etc.: enum Flags { // semantic flags: _bc_can_trap = 1<<0, // bytecode execution can trap or block _bc_can_rewrite = 1<<1, // bytecode execution has an alternate form // format bits (determined only by the format string): _fmt_has_c = 1<<2, // constant, such as sipush "bcc" _fmt_has_j = 1<<3, // constant pool cache index, such as getfield "bjj" _fmt_has_k = 1<<4, // constant pool index, such as ldc "bk" _fmt_has_i = 1<<5, // local index, such as iload _fmt_has_o = 1<<6, // offset, such as ifeq _fmt_has_nbo = 1<<7, // contains native-order field(s) _fmt_has_u2 = 1<<8, // contains double-byte field(s) _fmt_has_u4 = 1<<9, // contains quad-byte field _fmt_not_variable = 1<<10, // not of variable length (simple or wide) _fmt_not_simple = 1<<11, // either wide or variable length _all_fmt_bits = (_fmt_not_simple*2 - _fmt_has_c), // Example derived format syndromes: _fmt_b = _fmt_not_variable, _fmt_bc = _fmt_b | _fmt_has_c, _fmt_bi = _fmt_b | _fmt_has_i, _fmt_bkk = _fmt_b | _fmt_has_k | _fmt_has_u2, _fmt_bJJ = _fmt_b | _fmt_has_j | _fmt_has_u2 | _fmt_has_nbo, _fmt_bo2 = _fmt_b | _fmt_has_o | _fmt_has_u2, _fmt_bo4 = _fmt_b | _fmt_has_o | _fmt_has_u4 }; private: static bool _is_initialized; static const char* _name [number_of_codes]; static BasicType _result_type [number_of_codes]; static s_char _depth [number_of_codes]; static u_char _lengths [number_of_codes]; static Code _java_code [number_of_codes]; static jchar _flags [(1<<BitsPerByte)*2]; // all second page for wide formats static void def(Code code, const char* name, const char* format, const char* wide_format, BasicType result_type, int depth, bool can_trap); static void def(Code code, const char* name, const char* format, const char* wide_format, BasicType result_type, int depth, bool can_trap, Code java_code); static void pd_initialize(); // platform specific initialization static Code pd_base_code_for(Code code); // platform specific base_code_for implementation // Verify that bcp points into method #ifdef ASSERT static bool check_method(const methodOopDesc* method, address bcp); #endif static bool check_must_rewrite(Bytecodes::Code bc); public: // Conversion static void check (Code code) { assert(is_defined(code), "illegal code"); } static void wide_check (Code code) { assert(wide_is_defined(code), "illegal code"); } static Code cast (int code) { return (Code)code; } static Code code_at(const methodOopDesc* method, address bcp) { assert(method == NULL || check_method(method, bcp), "bcp must point into method"); Code code = cast(*bcp); assert(code != _breakpoint || method != NULL, "need methodOop to decode breakpoint"); return (code != _breakpoint) ? code : non_breakpoint_code_at(method, bcp); } static Code java_code_at(const methodOopDesc* method, address bcp) { return java_code(code_at(method, bcp)); } // Fetch a bytecode or a breakpoint: static Code code_or_bp_at(address bcp) { return (Code)cast(*bcp); } static Code code_at(methodOop method, int bci); static bool is_active_breakpoint_at(address bcp) { return (Code)*bcp == _breakpoint; } // find a bytecode, behind a breakpoint if necessary: static Code non_breakpoint_code_at(const methodOopDesc* method, address bcp); // Bytecode attributes static bool is_defined (int code) { return 0 <= code && code < number_of_codes && flags(code, false) != 0; } static bool wide_is_defined(int code) { return is_defined(code) && flags(code, true) != 0; } static const char* name (Code code) { check(code); return _name [code]; } static BasicType result_type (Code code) { check(code); return _result_type [code]; } static int depth (Code code) { check(code); return _depth [code]; } // Note: Length functions must return <=0 for invalid bytecodes. // Calling check(code) in length functions would throw an unwanted assert. static int length_for (Code code) { /*no check*/ return _lengths [code] & 0xF; } static int wide_length_for(Code code) { /*no check*/ return _lengths [code] >> 4; } static bool can_trap (Code code) { check(code); return has_all_flags(code, _bc_can_trap, false); } static Code java_code (Code code) { check(code); return _java_code [code]; } static bool can_rewrite (Code code) { check(code); return has_all_flags(code, _bc_can_rewrite, false); } static bool must_rewrite(Bytecodes::Code code) { return can_rewrite(code) && check_must_rewrite(code); } static bool native_byte_order(Code code) { check(code); return has_all_flags(code, _fmt_has_nbo, false); } static bool uses_cp_cache (Code code) { check(code); return has_all_flags(code, _fmt_has_j, false); } // if 'end' is provided, it indicates the end of the code buffer which // should not be read past when parsing. static int special_length_at(Bytecodes::Code code, address bcp, address end = NULL); static int special_length_at(methodOop method, address bcp, address end = NULL) { return special_length_at(code_at(method, bcp), bcp, end); } static int raw_special_length_at(address bcp, address end = NULL); static int length_for_code_at(Bytecodes::Code code, address bcp) { int l = length_for(code); return l > 0 ? l : special_length_at(code, bcp); } static int length_at (methodOop method, address bcp) { return length_for_code_at(code_at(method, bcp), bcp); } static int java_length_at (methodOop method, address bcp) { return length_for_code_at(java_code_at(method, bcp), bcp); } static bool is_java_code (Code code) { return 0 <= code && code < number_of_java_codes; } static bool is_aload (Code code) { return (code == _aload || code == _aload_0 || code == _aload_1 || code == _aload_2 || code == _aload_3); } static bool is_astore (Code code) { return (code == _astore || code == _astore_0 || code == _astore_1 || code == _astore_2 || code == _astore_3); } static bool is_zero_const (Code code) { return (code == _aconst_null || code == _iconst_0 || code == _fconst_0 || code == _dconst_0); } static bool is_invoke (Code code) { return (_invokevirtual <= code && code <= _invokedynamic); } static int compute_flags (const char* format, int more_flags = 0); // compute the flags static int flags (int code, bool is_wide) { assert(code == (u_char)code, "must be a byte"); return _flags[code + (is_wide ? (1<<BitsPerByte) : 0)]; } static int format_bits (Code code, bool is_wide) { return flags(code, is_wide) & _all_fmt_bits; } static bool has_all_flags (Code code, int test_flags, bool is_wide) { return (flags(code, is_wide) & test_flags) == test_flags; } // Initialization static void initialize (); }; #endif // SHARE_VM_INTERPRETER_BYTECODES_HPP
那么
static int wide_length_for(Code code) { /*no check*/ return _lengths [code] >> 4; }
这个静态类中的值
那么久能看到了 _lengths[01] 为1,
static int length_for (Code code) { /*no check*/ return _lengths [code] & 0xF; }
_lengths[01]为1 &1111111 还是为1;
今天先分析到这里,明天再续
现在准备执行
// generate template t->generate(_masm);
还是要看Template这个东西,先看类的定义
//"interpreter/interpreterRuntime.hpp" class Template VALUE_OBJ_CLASS_SPEC { private: enum Flags { uses_bcp_bit, // set if template needs the bcp pointing to bytecode does_dispatch_bit, // set if template dispatches on its own calls_vm_bit, // set if template calls the vm wide_bit // set if template belongs to a wide instruction }; typedef void (*generator)(int arg); int _flags; // describes interpreter template properties (bcp unknown) TosState _tos_in; // tos cache state before template execution TosState _tos_out; // tos cache state after template execution generator _gen; // template code generator int _arg; // argument for template code generator void initialize(int flags, TosState tos_in, TosState tos_out, generator gen, int arg); friend class TemplateTable; public: Bytecodes::Code bytecode() const; bool is_valid() const { return _gen != NULL; } bool uses_bcp() const { return (_flags & (1 << uses_bcp_bit )) != 0; } bool does_dispatch() const { return (_flags & (1 << does_dispatch_bit)) != 0; } bool calls_vm() const { return (_flags & (1 << calls_vm_bit )) != 0; } bool is_wide() const { return (_flags & (1 << wide_bit )) != 0; } TosState tos_in() const { return _tos_in; } TosState tos_out() const { return _tos_out; } void generate(InterpreterMacroAssembler* masm); };
//进入函数内部
void Template::generate(InterpreterMacroAssembler* masm) { // parameter passing TemplateTable::_desc = this; TemplateTable::_masm = masm; // code generation _gen(_arg); ///这个函数在 TemplateTable类中 masm->flush(); }
进入_gen(_arg)
//templateTable_x86.cpp void TemplateTable::nop() { transition(vtos, vtos); // nothing to do }
这里正是对应了templateTable
特别注意上边的类的调用: Template::generater ===>调用了 TemplateTable::nop函数
这nop函数啥也没做
void TemplateTable::transition(TosState tos_in, TosState tos_out) { assert(_desc->tos_in() == tos_in , "inconsistent tos_in information"); assert(_desc->tos_out() == tos_out, "inconsistent tos_out information"); }
这样就结束了, t->generate(_masm);生成模板的函数调用,之前看过template是 在哪里 Template TemplateTable::_template_table [Bytecodes::number_of_codes];保存
那么他是怎么创造的呢?
//templateTable.cpp
void TemplateTable::initialize() { if (_is_initialized) return; // Initialize table TraceTime timer("TemplateTable initialization", TraceStartupTime); _bs = Universe::heap()->barrier_set(); // For better readability const char _ = ' '; const int ____ = 0; const int ubcp = 1 << Template::uses_bcp_bit; const int disp = 1 << Template::does_dispatch_bit; const int clvm = 1 << Template::calls_vm_bit; const int iswd = 1 << Template::wide_bit; // interpr. templates // Java spec bytecodes ubcp|disp|clvm|iswd in out generator argument def(Bytecodes::_nop , ____|____|____|____, vtos, vtos, nop , _ ); def(Bytecodes::_aconst_null , ____|____|____|____, vtos, atos, aconst_null , _ ); def(Bytecodes::_iconst_m1 , ____|____|____|____, vtos, itos, iconst , -1 ); def(Bytecodes::_iconst_0 , ____|____|____|____, vtos, itos, iconst , 0 ); def(Bytecodes::_iconst_1 , ____|____|____|____, vtos, itos, iconst , 1 ); def(Bytecodes::_iconst_2 , ____|____|____|____, vtos, itos, iconst , 2 ); def(Bytecodes::_iconst_3 , ____|____|____|____, vtos, itos, iconst , 3 ); def(Bytecodes::_iconst_4 , ____|____|____|____, vtos, itos, iconst , 4 ); def(Bytecodes::_iconst_5 , ____|____|____|____, vtos, itos, iconst , 5 ); def(Bytecodes::_lconst_0 , ____|____|____|____, vtos, ltos, lconst , 0 ); def(Bytecodes::_lconst_1 , ____|____|____|____, vtos, ltos, lconst , 1 ); def(Bytecodes::_fconst_0 , ____|____|____|____, vtos, ftos, fconst , 0 ); def(Bytecodes::_fconst_1 , ____|____|____|____, vtos, ftos, fconst , 1 ); def(Bytecodes::_fconst_2 , ____|____|____|____, vtos, ftos, fconst , 2 ); def(Bytecodes::_dconst_0 , ____|____|____|____, vtos, dtos, dconst , 0 ); def(Bytecodes::_dconst_1 , ____|____|____|____, vtos, dtos, dconst , 1 ); def(Bytecodes::_bipush , ubcp|____|____|____, vtos, itos, bipush , _ ); def(Bytecodes::_sipush , ubcp|____|____|____, vtos, itos, sipush , _ ); def(Bytecodes::_ldc , ubcp|____|clvm|____, vtos, vtos, ldc , false ); def(Bytecodes::_ldc_w , ubcp|____|clvm|____, vtos, vtos, ldc , true ); def(Bytecodes::_ldc2_w , ubcp|____|____|____, vtos, vtos, ldc2_w , _ ); def(Bytecodes::_iload , ubcp|____|clvm|____, vtos, itos, iload , _ ); def(Bytecodes::_lload , ubcp|____|____|____, vtos, ltos, lload , _ ); def(Bytecodes::_fload , ubcp|____|____|____, vtos, ftos, fload , _ ); def(Bytecodes::_dload , ubcp|____|____|____, vtos, dtos, dload , _ ); def(Bytecodes::_aload , ubcp|____|clvm|____, vtos, atos, aload , _ ); def(Bytecodes::_iload_0 , ____|____|____|____, vtos, itos, iload , 0 ); def(Bytecodes::_iload_1 , ____|____|____|____, vtos, itos, iload , 1 ); def(Bytecodes::_iload_2 , ____|____|____|____, vtos, itos, iload , 2 ); def(Bytecodes::_iload_3 , ____|____|____|____, vtos, itos, iload , 3 ); def(Bytecodes::_lload_0 , ____|____|____|____, vtos, ltos, lload , 0 ); def(Bytecodes::_lload_1 , ____|____|____|____, vtos, ltos, lload , 1 ); def(Bytecodes::_lload_2 , ____|____|____|____, vtos, ltos, lload , 2 ); def(Bytecodes::_lload_3 , ____|____|____|____, vtos, ltos, lload , 3 ); def(Bytecodes::_fload_0 , ____|____|____|____, vtos, ftos, fload , 0 ); def(Bytecodes::_fload_1 , ____|____|____|____, vtos, ftos, fload , 1 ); def(Bytecodes::_fload_2 , ____|____|____|____, vtos, ftos, fload , 2 ); def(Bytecodes::_fload_3 , ____|____|____|____, vtos, ftos, fload , 3 ); def(Bytecodes::_dload_0 , ____|____|____|____, vtos, dtos, dload , 0 ); def(Bytecodes::_dload_1 , ____|____|____|____, vtos, dtos, dload , 1 ); def(Bytecodes::_dload_2 , ____|____|____|____, vtos, dtos, dload , 2 ); def(Bytecodes::_dload_3 , ____|____|____|____, vtos, dtos, dload , 3 ); def(Bytecodes::_aload_0 , ubcp|____|clvm|____, vtos, atos, aload_0 , _ ); def(Bytecodes::_aload_1 , ____|____|____|____, vtos, atos, aload , 1 ); def(Bytecodes::_aload_2 , ____|____|____|____, vtos, atos, aload , 2 ); def(Bytecodes::_aload_3 , ____|____|____|____, vtos, atos, aload , 3 ); def(Bytecodes::_iaload , ____|____|____|____, itos, itos, iaload , _ ); def(Bytecodes::_laload , ____|____|____|____, itos, ltos, laload , _ ); def(Bytecodes::_faload , ____|____|____|____, itos, ftos, faload , _ ); def(Bytecodes::_daload , ____|____|____|____, itos, dtos, daload , _ ); def(Bytecodes::_aaload , ____|____|____|____, itos, atos, aaload , _ ); def(Bytecodes::_baload , ____|____|____|____, itos, itos, baload , _ ); def(Bytecodes::_caload , ____|____|____|____, itos, itos, caload , _ ); def(Bytecodes::_saload , ____|____|____|____, itos, itos, saload , _ ); def(Bytecodes::_istore , ubcp|____|clvm|____, itos, vtos, istore , _ ); def(Bytecodes::_lstore , ubcp|____|____|____, ltos, vtos, lstore , _ ); def(Bytecodes::_fstore , ubcp|____|____|____, ftos, vtos, fstore , _ ); def(Bytecodes::_dstore , ubcp|____|____|____, dtos, vtos, dstore , _ ); def(Bytecodes::_astore , ubcp|____|clvm|____, vtos, vtos, astore , _ ); def(Bytecodes::_istore_0 , ____|____|____|____, itos, vtos, istore , 0 ); def(Bytecodes::_istore_1 , ____|____|____|____, itos, vtos, istore , 1 ); def(Bytecodes::_istore_2 , ____|____|____|____, itos, vtos, istore , 2 ); def(Bytecodes::_istore_3 , ____|____|____|____, itos, vtos, istore , 3 ); def(Bytecodes::_lstore_0 , ____|____|____|____, ltos, vtos, lstore , 0 ); def(Bytecodes::_lstore_1 , ____|____|____|____, ltos, vtos, lstore , 1 ); def(Bytecodes::_lstore_2 , ____|____|____|____, ltos, vtos, lstore , 2 ); def(Bytecodes::_lstore_3 , ____|____|____|____, ltos, vtos, lstore , 3 ); def(Bytecodes::_fstore_0 , ____|____|____|____, ftos, vtos, fstore , 0 ); def(Bytecodes::_fstore_1 , ____|____|____|____, ftos, vtos, fstore , 1 ); def(Bytecodes::_fstore_2 , ____|____|____|____, ftos, vtos, fstore , 2 ); def(Bytecodes::_fstore_3 , ____|____|____|____, ftos, vtos, fstore , 3 ); def(Bytecodes::_dstore_0 , ____|____|____|____, dtos, vtos, dstore , 0 ); def(Bytecodes::_dstore_1 , ____|____|____|____, dtos, vtos, dstore , 1 ); def(Bytecodes::_dstore_2 , ____|____|____|____, dtos, vtos, dstore , 2 ); def(Bytecodes::_dstore_3 , ____|____|____|____, dtos, vtos, dstore , 3 ); def(Bytecodes::_astore_0 , ____|____|____|____, vtos, vtos, astore , 0 ); def(Bytecodes::_astore_1 , ____|____|____|____, vtos, vtos, astore , 1 ); def(Bytecodes::_astore_2 , ____|____|____|____, vtos, vtos, astore , 2 ); def(Bytecodes::_astore_3 , ____|____|____|____, vtos, vtos, astore , 3 ); def(Bytecodes::_iastore , ____|____|____|____, itos, vtos, iastore , _ ); def(Bytecodes::_lastore , ____|____|____|____, ltos, vtos, lastore , _ ); def(Bytecodes::_fastore , ____|____|____|____, ftos, vtos, fastore , _ ); def(Bytecodes::_dastore , ____|____|____|____, dtos, vtos, dastore , _ ); def(Bytecodes::_aastore , ____|____|clvm|____, vtos, vtos, aastore , _ ); def(Bytecodes::_bastore , ____|____|____|____, itos, vtos, bastore , _ ); def(Bytecodes::_castore , ____|____|____|____, itos, vtos, castore , _ ); def(Bytecodes::_sastore , ____|____|____|____, itos, vtos, sastore , _ ); def(Bytecodes::_pop , ____|____|____|____, vtos, vtos, pop , _ ); def(Bytecodes::_pop2 , ____|____|____|____, vtos, vtos, pop2 , _ ); def(Bytecodes::_dup , ____|____|____|____, vtos, vtos, dup , _ ); def(Bytecodes::_dup_x1 , ____|____|____|____, vtos, vtos, dup_x1 , _ ); def(Bytecodes::_dup_x2 , ____|____|____|____, vtos, vtos, dup_x2 , _ ); def(Bytecodes::_dup2 , ____|____|____|____, vtos, vtos, dup2 , _ ); def(Bytecodes::_dup2_x1 , ____|____|____|____, vtos, vtos, dup2_x1 , _ ); def(Bytecodes::_dup2_x2 , ____|____|____|____, vtos, vtos, dup2_x2 , _ ); def(Bytecodes::_swap , ____|____|____|____, vtos, vtos, swap , _ ); def(Bytecodes::_iadd , ____|____|____|____, itos, itos, iop2 , add ); def(Bytecodes::_ladd , ____|____|____|____, ltos, ltos, lop2 , add ); def(Bytecodes::_fadd , ____|____|____|____, ftos, ftos, fop2 , add ); def(Bytecodes::_dadd , ____|____|____|____, dtos, dtos, dop2 , add ); def(Bytecodes::_isub , ____|____|____|____, itos, itos, iop2 , sub ); def(Bytecodes::_lsub , ____|____|____|____, ltos, ltos, lop2 , sub ); def(Bytecodes::_fsub , ____|____|____|____, ftos, ftos, fop2 , sub ); def(Bytecodes::_dsub , ____|____|____|____, dtos, dtos, dop2 , sub ); def(Bytecodes::_imul , ____|____|____|____, itos, itos, iop2 , mul ); def(Bytecodes::_lmul , ____|____|____|____, ltos, ltos, lmul , _ ); def(Bytecodes::_fmul , ____|____|____|____, ftos, ftos, fop2 , mul ); def(Bytecodes::_dmul , ____|____|____|____, dtos, dtos, dop2 , mul ); def(Bytecodes::_idiv , ____|____|____|____, itos, itos, idiv , _ ); def(Bytecodes::_ldiv , ____|____|____|____, ltos, ltos, ldiv , _ ); def(Bytecodes::_fdiv , ____|____|____|____, ftos, ftos, fop2 , div ); def(Bytecodes::_ddiv , ____|____|____|____, dtos, dtos, dop2 , div ); def(Bytecodes::_irem , ____|____|____|____, itos, itos, irem , _ ); def(Bytecodes::_lrem , ____|____|____|____, ltos, ltos, lrem , _ ); def(Bytecodes::_frem , ____|____|____|____, ftos, ftos, fop2 , rem ); def(Bytecodes::_drem , ____|____|____|____, dtos, dtos, dop2 , rem ); def(Bytecodes::_ineg , ____|____|____|____, itos, itos, ineg , _ ); def(Bytecodes::_lneg , ____|____|____|____, ltos, ltos, lneg , _ ); def(Bytecodes::_fneg , ____|____|____|____, ftos, ftos, fneg , _ ); def(Bytecodes::_dneg , ____|____|____|____, dtos, dtos, dneg , _ ); def(Bytecodes::_ishl , ____|____|____|____, itos, itos, iop2 , shl ); def(Bytecodes::_lshl , ____|____|____|____, itos, ltos, lshl , _ ); def(Bytecodes::_ishr , ____|____|____|____, itos, itos, iop2 , shr ); def(Bytecodes::_lshr , ____|____|____|____, itos, ltos, lshr , _ ); def(Bytecodes::_iushr , ____|____|____|____, itos, itos, iop2 , ushr ); def(Bytecodes::_lushr , ____|____|____|____, itos, ltos, lushr , _ ); def(Bytecodes::_iand , ____|____|____|____, itos, itos, iop2 , _and ); def(Bytecodes::_land , ____|____|____|____, ltos, ltos, lop2 , _and ); def(Bytecodes::_ior , ____|____|____|____, itos, itos, iop2 , _or ); def(Bytecodes::_lor , ____|____|____|____, ltos, ltos, lop2 , _or ); def(Bytecodes::_ixor , ____|____|____|____, itos, itos, iop2 , _xor ); def(Bytecodes::_lxor , ____|____|____|____, ltos, ltos, lop2 , _xor ); def(Bytecodes::_iinc , ubcp|____|clvm|____, vtos, vtos, iinc , _ ); def(Bytecodes::_i2l , ____|____|____|____, itos, ltos, convert , _ ); def(Bytecodes::_i2f , ____|____|____|____, itos, ftos, convert , _ ); def(Bytecodes::_i2d , ____|____|____|____, itos, dtos, convert , _ ); def(Bytecodes::_l2i , ____|____|____|____, ltos, itos, convert , _ ); def(Bytecodes::_l2f , ____|____|____|____, ltos, ftos, convert , _ ); def(Bytecodes::_l2d , ____|____|____|____, ltos, dtos, convert , _ ); def(Bytecodes::_f2i , ____|____|____|____, ftos, itos, convert , _ ); def(Bytecodes::_f2l , ____|____|____|____, ftos, ltos, convert , _ ); def(Bytecodes::_f2d , ____|____|____|____, ftos, dtos, convert , _ ); def(Bytecodes::_d2i , ____|____|____|____, dtos, itos, convert , _ ); def(Bytecodes::_d2l , ____|____|____|____, dtos, ltos, convert , _ ); def(Bytecodes::_d2f , ____|____|____|____, dtos, ftos, convert , _ ); def(Bytecodes::_i2b , ____|____|____|____, itos, itos, convert , _ ); def(Bytecodes::_i2c , ____|____|____|____, itos, itos, convert , _ ); def(Bytecodes::_i2s , ____|____|____|____, itos, itos, convert , _ ); def(Bytecodes::_lcmp , ____|____|____|____, ltos, itos, lcmp , _ ); def(Bytecodes::_fcmpl , ____|____|____|____, ftos, itos, float_cmp , -1 ); def(Bytecodes::_fcmpg , ____|____|____|____, ftos, itos, float_cmp , 1 ); def(Bytecodes::_dcmpl , ____|____|____|____, dtos, itos, double_cmp , -1 ); def(Bytecodes::_dcmpg , ____|____|____|____, dtos, itos, double_cmp , 1 ); def(Bytecodes::_ifeq , ubcp|____|clvm|____, itos, vtos, if_0cmp , equal ); def(Bytecodes::_ifne , ubcp|____|clvm|____, itos, vtos, if_0cmp , not_equal ); def(Bytecodes::_iflt , ubcp|____|clvm|____, itos, vtos, if_0cmp , less ); def(Bytecodes::_ifge , ubcp|____|clvm|____, itos, vtos, if_0cmp , greater_equal); def(Bytecodes::_ifgt , ubcp|____|clvm|____, itos, vtos, if_0cmp , greater ); def(Bytecodes::_ifle , ubcp|____|clvm|____, itos, vtos, if_0cmp , less_equal ); def(Bytecodes::_if_icmpeq , ubcp|____|clvm|____, itos, vtos, if_icmp , equal ); def(Bytecodes::_if_icmpne , ubcp|____|clvm|____, itos, vtos, if_icmp , not_equal ); def(Bytecodes::_if_icmplt , ubcp|____|clvm|____, itos, vtos, if_icmp , less ); def(Bytecodes::_if_icmpge , ubcp|____|clvm|____, itos, vtos, if_icmp , greater_equal); def(Bytecodes::_if_icmpgt , ubcp|____|clvm|____, itos, vtos, if_icmp , greater ); def(Bytecodes::_if_icmple , ubcp|____|clvm|____, itos, vtos, if_icmp , less_equal ); def(Bytecodes::_if_acmpeq , ubcp|____|clvm|____, atos, vtos, if_acmp , equal ); def(Bytecodes::_if_acmpne , ubcp|____|clvm|____, atos, vtos, if_acmp , not_equal ); def(Bytecodes::_goto , ubcp|disp|clvm|____, vtos, vtos, _goto , _ ); def(Bytecodes::_jsr , ubcp|disp|____|____, vtos, vtos, jsr , _ ); // result is not an oop, so do not transition to atos def(Bytecodes::_ret , ubcp|disp|____|____, vtos, vtos, ret , _ ); def(Bytecodes::_tableswitch , ubcp|disp|____|____, itos, vtos, tableswitch , _ ); def(Bytecodes::_lookupswitch , ubcp|disp|____|____, itos, itos, lookupswitch , _ ); def(Bytecodes::_ireturn , ____|disp|clvm|____, itos, itos, _return , itos ); def(Bytecodes::_lreturn , ____|disp|clvm|____, ltos, ltos, _return , ltos ); def(Bytecodes::_freturn , ____|disp|clvm|____, ftos, ftos, _return , ftos ); def(Bytecodes::_dreturn , ____|disp|clvm|____, dtos, dtos, _return , dtos ); def(Bytecodes::_areturn , ____|disp|clvm|____, atos, atos, _return , atos ); def(Bytecodes::_return , ____|disp|clvm|____, vtos, vtos, _return , vtos ); def(Bytecodes::_getstatic , ubcp|____|clvm|____, vtos, vtos, getstatic , f1_byte ); def(Bytecodes::_putstatic , ubcp|____|clvm|____, vtos, vtos, putstatic , f2_byte ); def(Bytecodes::_getfield , ubcp|____|clvm|____, vtos, vtos, getfield , f1_byte ); def(Bytecodes::_putfield , ubcp|____|clvm|____, vtos, vtos, putfield , f2_byte ); def(Bytecodes::_invokevirtual , ubcp|disp|clvm|____, vtos, vtos, invokevirtual , f2_byte ); def(Bytecodes::_invokespecial , ubcp|disp|clvm|____, vtos, vtos, invokespecial , f1_byte ); def(Bytecodes::_invokestatic , ubcp|disp|clvm|____, vtos, vtos, invokestatic , f1_byte ); def(Bytecodes::_invokeinterface , ubcp|disp|clvm|____, vtos, vtos, invokeinterface , f1_byte ); def(Bytecodes::_invokedynamic , ubcp|disp|clvm|____, vtos, vtos, invokedynamic , f1_oop ); def(Bytecodes::_new , ubcp|____|clvm|____, vtos, atos, _new , _ ); def(Bytecodes::_newarray , ubcp|____|clvm|____, itos, atos, newarray , _ ); def(Bytecodes::_anewarray , ubcp|____|clvm|____, itos, atos, anewarray , _ ); def(Bytecodes::_arraylength , ____|____|____|____, atos, itos, arraylength , _ ); def(Bytecodes::_athrow , ____|disp|____|____, atos, vtos, athrow , _ ); def(Bytecodes::_checkcast , ubcp|____|clvm|____, atos, atos, checkcast , _ ); def(Bytecodes::_instanceof , ubcp|____|clvm|____, atos, itos, instanceof , _ ); def(Bytecodes::_monitorenter , ____|disp|clvm|____, atos, vtos, monitorenter , _ ); def(Bytecodes::_monitorexit , ____|____|clvm|____, atos, vtos, monitorexit , _ ); def(Bytecodes::_wide , ubcp|disp|____|____, vtos, vtos, wide , _ ); def(Bytecodes::_multianewarray , ubcp|____|clvm|____, vtos, atos, multianewarray , _ ); def(Bytecodes::_ifnull , ubcp|____|clvm|____, atos, vtos, if_nullcmp , equal ); def(Bytecodes::_ifnonnull , ubcp|____|clvm|____, atos, vtos, if_nullcmp , not_equal ); def(Bytecodes::_goto_w , ubcp|____|clvm|____, vtos, vtos, goto_w , _ ); def(Bytecodes::_jsr_w , ubcp|____|____|____, vtos, vtos, jsr_w , _ ); // wide Java spec bytecodes def(Bytecodes::_iload , ubcp|____|____|iswd, vtos, itos, wide_iload , _ ); def(Bytecodes::_lload , ubcp|____|____|iswd, vtos, ltos, wide_lload , _ ); def(Bytecodes::_fload , ubcp|____|____|iswd, vtos, ftos, wide_fload , _ ); def(Bytecodes::_dload , ubcp|____|____|iswd, vtos, dtos, wide_dload , _ ); def(Bytecodes::_aload , ubcp|____|____|iswd, vtos, atos, wide_aload , _ ); def(Bytecodes::_istore , ubcp|____|____|iswd, vtos, vtos, wide_istore , _ ); def(Bytecodes::_lstore , ubcp|____|____|iswd, vtos, vtos, wide_lstore , _ ); def(Bytecodes::_fstore , ubcp|____|____|iswd, vtos, vtos, wide_fstore , _ ); def(Bytecodes::_dstore , ubcp|____|____|iswd, vtos, vtos, wide_dstore , _ ); def(Bytecodes::_astore , ubcp|____|____|iswd, vtos, vtos, wide_astore , _ ); def(Bytecodes::_iinc , ubcp|____|____|iswd, vtos, vtos, wide_iinc , _ ); def(Bytecodes::_ret , ubcp|disp|____|iswd, vtos, vtos, wide_ret , _ ); def(Bytecodes::_breakpoint , ubcp|disp|clvm|____, vtos, vtos, _breakpoint , _ ); // JVM bytecodes def(Bytecodes::_fast_agetfield , ubcp|____|____|____, atos, atos, fast_accessfield , atos ); def(Bytecodes::_fast_bgetfield , ubcp|____|____|____, atos, itos, fast_accessfield , itos ); def(Bytecodes::_fast_cgetfield , ubcp|____|____|____, atos, itos, fast_accessfield , itos ); def(Bytecodes::_fast_dgetfield , ubcp|____|____|____, atos, dtos, fast_accessfield , dtos ); def(Bytecodes::_fast_fgetfield , ubcp|____|____|____, atos, ftos, fast_accessfield , ftos ); def(Bytecodes::_fast_igetfield , ubcp|____|____|____, atos, itos, fast_accessfield , itos ); def(Bytecodes::_fast_lgetfield , ubcp|____|____|____, atos, ltos, fast_accessfield , ltos ); def(Bytecodes::_fast_sgetfield , ubcp|____|____|____, atos, itos, fast_accessfield , itos ); def(Bytecodes::_fast_aputfield , ubcp|____|____|____, atos, vtos, fast_storefield , atos ); def(Bytecodes::_fast_bputfield , ubcp|____|____|____, itos, vtos, fast_storefield , itos ); def(Bytecodes::_fast_zputfield , ubcp|____|____|____, itos, vtos, fast_storefield , itos ); def(Bytecodes::_fast_cputfield , ubcp|____|____|____, itos, vtos, fast_storefield , itos ); def(Bytecodes::_fast_dputfield , ubcp|____|____|____, dtos, vtos, fast_storefield , dtos ); def(Bytecodes::_fast_fputfield , ubcp|____|____|____, ftos, vtos, fast_storefield , ftos ); def(Bytecodes::_fast_iputfield , ubcp|____|____|____, itos, vtos, fast_storefield , itos ); def(Bytecodes::_fast_lputfield , ubcp|____|____|____, ltos, vtos, fast_storefield , ltos ); def(Bytecodes::_fast_sputfield , ubcp|____|____|____, itos, vtos, fast_storefield , itos ); def(Bytecodes::_fast_aload_0 , ____|____|____|____, vtos, atos, aload , 0 ); def(Bytecodes::_fast_iaccess_0 , ubcp|____|____|____, vtos, itos, fast_xaccess , itos ); def(Bytecodes::_fast_aaccess_0 , ubcp|____|____|____, vtos, atos, fast_xaccess , atos ); def(Bytecodes::_fast_faccess_0 , ubcp|____|____|____, vtos, ftos, fast_xaccess , ftos ); def(Bytecodes::_fast_iload , ubcp|____|____|____, vtos, itos, fast_iload , _ ); def(Bytecodes::_fast_iload2 , ubcp|____|____|____, vtos, itos, fast_iload2 , _ ); def(Bytecodes::_fast_icaload , ubcp|____|____|____, vtos, itos, fast_icaload , _ ); def(Bytecodes::_fast_invokevfinal , ubcp|disp|clvm|____, vtos, vtos, fast_invokevfinal , f2_byte ); def(Bytecodes::_fast_linearswitch , ubcp|disp|____|____, itos, vtos, fast_linearswitch , _ ); def(Bytecodes::_fast_binaryswitch , ubcp|disp|____|____, itos, vtos, fast_binaryswitch , _ ); def(Bytecodes::_fast_aldc , ubcp|____|clvm|____, vtos, atos, fast_aldc , false ); def(Bytecodes::_fast_aldc_w , ubcp|____|clvm|____, vtos, atos, fast_aldc , true ); def(Bytecodes::_return_register_finalizer , ____|disp|clvm|____, vtos, vtos, _return , vtos ); def(Bytecodes::_shouldnotreachhere , ____|____|____|____, vtos, vtos, shouldnotreachhere , _ ); // platform specific bytecodes pd_initialize(); _is_initialized = true; }
看这个函数:TemplateTable::initialize(),这里为每个字节码指令进行了一次def(....)命令,
def(Bytecodes::_nop , ____|____|____|____, vtos, vtos, nop , _ );
def就是定义的意思,关注这个nop参数,他是一个函数位于templateTable.cpp
void TemplateTable::nop() { transition(vtos, vtos); // nothing to do }
看def函数
void TemplateTable::def(Bytecodes::Code code, int flags, TosState in, TosState out, void (*gen)(int arg), int arg) { // should factor out these constants const int ubcp = 1 << Template::uses_bcp_bit; const int disp = 1 << Template::does_dispatch_bit; const int clvm = 1 << Template::calls_vm_bit; const int iswd = 1 << Template::wide_bit; // determine which table to use bool is_wide = (flags & iswd) != 0; // make sure that wide instructions have a vtos entry point // (since they are executed extremely rarely, it doesn't pay out to have an // extra set of 5 dispatch tables for the wide instructions - for simplicity // they all go with one table) assert(in == vtos || !is_wide, "wide instructions have vtos entry point only"); Template* t = is_wide ? template_for_wide(code) : template_for(code); // setup entry t->initialize(flags, in, out, gen, arg); assert(t->bytecode() == code, "just checkin'"); }
关键点就在 Template* t = is_wide ? template_for_wide(code) : template_for(code);
之前分析过t=? : template_for(code);是在 static Template _template_table [];数组中保存的
那么这句话就是获取一个得到数组中的一个引用,应该这个t不能是null,否则就会空指针异常了,应该在哪里初始化过了,那么接下了
生成具体内容 t->initialize(flags, in, out, gen, arg);
// Implementation of Template void Template::initialize(int flags, TosState tos_in, TosState tos_out, generator gen, int arg) { _flags = flags; _tos_in = tos_in; _tos_out = tos_out; _gen = gen; _arg = arg; }
也没干别的就是把 templateTable中的函数指针,数据等赋值给了 Template对象(模板对象)
接着分析 dispatch_epilog(tos_out, step);
__ dispatch_epilog 其中的开头__ 代表 masm 这在揭秘虚拟机中有解释,
void InterpreterMacroAssembler::dispatch_epilog(TosState state, int step) { dispatch_next(state, step); }
void InterpreterMacroAssembler::dispatch_next(TosState state, int step, bool generate_poll) { // load next bytecode (load before advancing _bcp_register to prevent AGI) load_unsigned_byte(rbx, Address(_bcp_register, step)); // advance _bcp_register increment(_bcp_register, step); dispatch_base(state, Interpreter::dispatch_table(state), true, generate_poll); }
对应的
那么今天就结束了,下次再续
