view src/share/vm/interpreter/interpreter.hpp @ 20543:e7d0505c8a30

8059758: Footprint regressions with JDK-8038423 Summary: Changes in JDK-8038423 always initialize (zero out) virtual memory used for auxiliary data structures. This causes a footprint regression for G1 in startup benchmarks. This is because they do not touch that memory at all, so the operating system does not actually commit these pages. The fix is to, if the initialization value of the data structures matches the default value of just committed memory (=0), do not do anything. Reviewed-by: jwilhelm, brutisso
author tschatzl
date Fri, 10 Oct 2014 15:51:58 +0200
parents 094cbdffa87d
children 7848fc12602b
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/*
 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#ifndef SHARE_VM_INTERPRETER_INTERPRETER_HPP
#define SHARE_VM_INTERPRETER_INTERPRETER_HPP

#include "code/stubs.hpp"
#include "interpreter/cppInterpreter.hpp"
#include "interpreter/templateInterpreter.hpp"
#ifdef ZERO
#ifdef TARGET_ARCH_zero
# include "entry_zero.hpp"
#endif
#endif

// This file contains the platform-independent parts
// of the interpreter and the interpreter generator.

//------------------------------------------------------------------------------------------------------------------------
// An InterpreterCodelet is a piece of interpreter code. All
// interpreter code is generated into little codelets which
// contain extra information for debugging and printing purposes.

class InterpreterCodelet: public Stub {
  friend class VMStructs;
 private:
  int         _size;                             // the size in bytes
  const char* _description;                      // a description of the codelet, for debugging & printing
  Bytecodes::Code _bytecode;                     // associated bytecode if any
  DEBUG_ONLY(CodeStrings _strings;)              // Comments for annotating assembler output.

 public:
  // Initialization/finalization
  void    initialize(int size,
                     CodeStrings& strings)       { _size = size;
                                                   DEBUG_ONLY(::new(&_strings) CodeStrings();)
                                                   DEBUG_ONLY(_strings.assign(strings);) }
  void    finalize()                             { ShouldNotCallThis(); }

  // General info/converters
  int     size() const                           { return _size; }
  static  int code_size_to_size(int code_size)   { return round_to(sizeof(InterpreterCodelet), CodeEntryAlignment) + code_size; }

  // Code info
  address code_begin() const                     { return (address)this + round_to(sizeof(InterpreterCodelet), CodeEntryAlignment); }
  address code_end() const                       { return (address)this + size(); }

  // Debugging
  void    verify();
  void    print_on(outputStream* st) const;
  void    print() const { print_on(tty); }

  // Interpreter-specific initialization
  void    initialize(const char* description, Bytecodes::Code bytecode);

  // Interpreter-specific attributes
  int         code_size() const                  { return code_end() - code_begin(); }
  const char* description() const                { return _description; }
  Bytecodes::Code bytecode() const               { return _bytecode; }
};

// Define a prototype interface
DEF_STUB_INTERFACE(InterpreterCodelet);


//------------------------------------------------------------------------------------------------------------------------
// A CodeletMark serves as an automatic creator/initializer for Codelets
// (As a subclass of ResourceMark it automatically GC's the allocated
// code buffer and assemblers).

class CodeletMark: ResourceMark {
 private:
  InterpreterCodelet*         _clet;
  InterpreterMacroAssembler** _masm;
  CodeBuffer                  _cb;

  int codelet_size() {
    // Request the whole code buffer (minus a little for alignment).
    // The commit call below trims it back for each codelet.
    int codelet_size = AbstractInterpreter::code()->available_space() - 2*K;

    // Guarantee there's a little bit of code space left.
    guarantee (codelet_size > 0 && (size_t)codelet_size >  2*K,
               "not enough space for interpreter generation");

    return codelet_size;
  }

 public:
  CodeletMark(
    InterpreterMacroAssembler*& masm,
    const char* description,
    Bytecodes::Code bytecode = Bytecodes::_illegal):
    _clet((InterpreterCodelet*)AbstractInterpreter::code()->request(codelet_size())),
    _cb(_clet->code_begin(), _clet->code_size())

  { // request all space (add some slack for Codelet data)
    assert (_clet != NULL, "we checked not enough space already");

    // initialize Codelet attributes
    _clet->initialize(description, bytecode);
    // create assembler for code generation
    masm  = new InterpreterMacroAssembler(&_cb);
    _masm = &masm;
  }

  ~CodeletMark() {
    // align so printing shows nop's instead of random code at the end (Codelets are aligned)
    (*_masm)->align(wordSize);
    // make sure all code is in code buffer
    (*_masm)->flush();


    // commit Codelet
    AbstractInterpreter::code()->commit((*_masm)->code()->pure_insts_size(), (*_masm)->code()->strings());
    // make sure nobody can use _masm outside a CodeletMark lifespan
    *_masm = NULL;
  }
};

// Wrapper classes to produce Interpreter/InterpreterGenerator from either
// the c++ interpreter or the template interpreter.

class Interpreter: public CC_INTERP_ONLY(CppInterpreter) NOT_CC_INTERP(TemplateInterpreter) {

  public:
  // Debugging/printing
  static InterpreterCodelet* codelet_containing(address pc)     { return (InterpreterCodelet*)_code->stub_containing(pc); }
#ifdef TARGET_ARCH_x86
# include "interpreter_x86.hpp"
#endif
#ifdef TARGET_ARCH_sparc
# include "interpreter_sparc.hpp"
#endif
#ifdef TARGET_ARCH_zero
# include "interpreter_zero.hpp"
#endif
#ifdef TARGET_ARCH_arm
# include "interpreter_arm.hpp"
#endif
#ifdef TARGET_ARCH_ppc
# include "interpreter_ppc.hpp"
#endif

};

#endif // SHARE_VM_INTERPRETER_INTERPRETER_HPP