view src/share/vm/runtime/rframe.cpp @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children 3e8fbc61cee8
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/*
 * Copyright (c) 1997, 2007, 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 "incls/_precompiled.incl"

#include "incls/_rframe.cpp.incl"

static RFrame*const  noCaller    = (RFrame*) 0x1;               // no caller (i.e., initial frame)
static RFrame*const  noCallerYet = (RFrame*) 0x0;               // caller not yet computed

RFrame::RFrame(frame fr, JavaThread* thread, RFrame*const callee) :
  _fr(fr), _thread(thread), _callee(callee), _num(callee ? callee->num() + 1 : 0) {
  _caller = (RFrame*)noCallerYet;
  _invocations = 0;
  _distance = 0;
}

void RFrame::set_distance(int d) {
  assert(is_compiled() || d >= 0, "should be positive");
  _distance = d;
}

InterpretedRFrame::InterpretedRFrame(frame fr, JavaThread* thread, RFrame*const callee)
: RFrame(fr, thread, callee) {
  RegisterMap map(thread, false);
  _vf     = javaVFrame::cast(vframe::new_vframe(&_fr, &map, thread));
  _method = methodHandle(thread, _vf->method());
  assert(   _vf->is_interpreted_frame(), "must be interpreted");
  init();
}

InterpretedRFrame::InterpretedRFrame(frame fr, JavaThread* thread, methodHandle m)
: RFrame(fr, thread, NULL) {
  RegisterMap map(thread, false);
  _vf     = javaVFrame::cast(vframe::new_vframe(&_fr, &map, thread));
  _method = m;

  assert(   _vf->is_interpreted_frame(),  "must be interpreted");
  init();
}

CompiledRFrame::CompiledRFrame(frame fr, JavaThread* thread, RFrame*const  callee)
: RFrame(fr, thread, callee) {
  init();
}

CompiledRFrame::CompiledRFrame(frame fr, JavaThread* thread)
: RFrame(fr, thread, NULL) {
  init();
}

DeoptimizedRFrame::DeoptimizedRFrame(frame fr, JavaThread* thread, RFrame*const  callee)
: InterpretedRFrame(fr, thread, callee) {}

RFrame* RFrame::new_RFrame(frame fr, JavaThread* thread, RFrame*const  callee) {
  RFrame* rf;
  int dist = callee ? callee->distance() : -1;
  if (fr.is_interpreted_frame()) {
    rf = new InterpretedRFrame(fr, thread, callee);
    dist++;
  } else if (fr.is_compiled_frame()) {
    // Even deopted frames look compiled because the deopt
    // is invisible until it happens.
    rf = new CompiledRFrame(fr, thread, callee);
  } else {
    assert(false, "Unhandled frame type");
  }
  rf->set_distance(dist);
  rf->init();
  return rf;
}

RFrame* RFrame::caller() {
  if (_caller != noCallerYet) return (_caller == noCaller) ? NULL : _caller;    // already computed caller

  // caller not yet computed; do it now
  if (_fr.is_first_java_frame()) {
    _caller = (RFrame*)noCaller;
    return NULL;
  }

  RegisterMap map(_thread, false);
  frame sender = _fr.real_sender(&map);
  if (sender.is_java_frame()) {
    _caller = new_RFrame(sender, thread(), this);
    return _caller;
  }

  // Real caller is not java related
  _caller = (RFrame*)noCaller;
  return NULL;
}

int InterpretedRFrame::cost() const {
  return _method->code_size();    // fix this
  //return _method->estimated_inline_cost(_receiverKlass);
}

int CompiledRFrame::cost() const {
  nmethod* nm = top_method()->code();
  if (nm != NULL) {
    return nm->code_size();
  } else {
    return top_method()->code_size();
  }
}

void CompiledRFrame::init() {
  RegisterMap map(thread(), false);
  vframe* vf = vframe::new_vframe(&_fr, &map, thread());
  assert(vf->is_compiled_frame(), "must be compiled");
  _nm = compiledVFrame::cast(vf)->code();
  vf = vf->top();
  _vf = javaVFrame::cast(vf);
  _method = methodHandle(thread(), CodeCache::find_nmethod(_fr.pc())->method());
  assert(_method(), "should have found a method");
#ifndef PRODUCT
  _invocations = _method->compiled_invocation_count();
#endif
}

void InterpretedRFrame::init() {
  _invocations = _method->invocation_count() + _method->backedge_count();
}

void RFrame::print(const char* kind) {
#ifndef PRODUCT
#ifdef COMPILER2
  int cnt = top_method()->interpreter_invocation_count();
#else
  int cnt = top_method()->invocation_count();
#endif
  tty->print("%3d %s ", _num, is_interpreted() ? "I" : "C");
  top_method()->print_short_name(tty);
  tty->print_cr(": inv=%5d(%d) cst=%4d", _invocations, cnt, cost());
#endif
}

void CompiledRFrame::print() {
  RFrame::print("comp");
}

void InterpretedRFrame::print() {
  RFrame::print("int.");
}

void DeoptimizedRFrame::print() {
  RFrame::print("deopt.");
}