view src/share/vm/ci/ciSignature.cpp @ 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 78bbf4d43a14
children
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/*
 * Copyright (c) 1999, 2014, 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.
 *
 */

#include "precompiled.hpp"
#include "ci/ciMethodType.hpp"
#include "ci/ciSignature.hpp"
#include "ci/ciUtilities.hpp"
#include "memory/allocation.inline.hpp"
#include "oops/oop.inline.hpp"
#include "runtime/signature.hpp"

// ciSignature
//
// This class represents the signature of a method.

// ------------------------------------------------------------------
// ciSignature::ciSignature
ciSignature::ciSignature(ciKlass* accessing_klass, constantPoolHandle cpool, ciSymbol* symbol) {
  ASSERT_IN_VM;
  EXCEPTION_CONTEXT;
  _accessing_klass = accessing_klass;
  _symbol = symbol;

  ciEnv* env = CURRENT_ENV;
  Arena* arena = env->arena();
  _types = new (arena) GrowableArray<ciType*>(arena, 8, 0, NULL);

  int size = 0;
  int count = 0;
  ResourceMark rm(THREAD);
  Symbol* sh = symbol->get_symbol();
  SignatureStream ss(sh);
  for (; ; ss.next()) {
    // Process one element of the signature
    ciType* type;
    if (!ss.is_object()) {
      type = ciType::make(ss.type());
    } else {
      Symbol* name = ss.as_symbol(THREAD);
      if (HAS_PENDING_EXCEPTION) {
        type = ss.is_array() ? (ciType*)ciEnv::unloaded_ciobjarrayklass()
          : (ciType*)ciEnv::unloaded_ciinstance_klass();
        env->record_out_of_memory_failure();
        CLEAR_PENDING_EXCEPTION;
      } else {
        ciSymbol* klass_name = env->get_symbol(name);
        type = env->get_klass_by_name_impl(_accessing_klass, cpool, klass_name, false);
      }
    }
    _types->append(type);
    if (ss.at_return_type()) {
      // Done processing the return type; do not add it into the count.
      break;
    }
    size += type->size();
    count++;
  }
  _size = size;
  _count = count;
}

// ------------------------------------------------------------------
// ciSignature::ciSignature
ciSignature::ciSignature(ciKlass* accessing_klass, ciSymbol* symbol, ciMethodType* method_type) :
  _symbol(symbol),
  _accessing_klass(accessing_klass),
  _size( method_type->ptype_slot_count()),
  _count(method_type->ptype_count())
{
  ASSERT_IN_VM;
  EXCEPTION_CONTEXT;
  Arena* arena = CURRENT_ENV->arena();
  _types = new (arena) GrowableArray<ciType*>(arena, _count + 1, 0, NULL);
  for (int i = 0; i < _count; i++) {
    _types->append(method_type->ptype_at(i));
  }
  _types->append(method_type->rtype());
}

// ------------------------------------------------------------------
// ciSignature::return_type
//
// What is the return type of this signature?
ciType* ciSignature::return_type() const {
  return _types->at(_count);
}

// ------------------------------------------------------------------
// ciSignature::type_at
//
// What is the type of the index'th element of this
// signature?
ciType* ciSignature::type_at(int index) const {
  assert(index < _count, "out of bounds");
  // The first _klasses element holds the return klass.
  return _types->at(index);
}

// ------------------------------------------------------------------
// ciSignature::equals
//
// Compare this signature to another one.  Signatures with different
// accessing classes but with signature-types resolved to the same
// types are defined to be equal.
bool ciSignature::equals(ciSignature* that) {
  // Compare signature
  if (!this->as_symbol()->equals(that->as_symbol()))  return false;
  // Compare all types of the arguments
  for (int i = 0; i < _count; i++) {
    if (this->type_at(i) != that->type_at(i))         return false;
  }
  // Compare the return type
  if (this->return_type() != that->return_type())     return false;
  return true;
}

// ------------------------------------------------------------------
// ciSignature::print_signature
void ciSignature::print_signature() {
  _symbol->print_symbol();
}

// ------------------------------------------------------------------
// ciSignature::print
void ciSignature::print() {
  tty->print("<ciSignature symbol=");
  print_signature();
 tty->print(" accessing_klass=");
  _accessing_klass->print();
  tty->print(" address=" INTPTR_FORMAT ">", p2i((address)this));
}