/*

 * Copyright (c) 2005, 2015, 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 "gc/shared/collectedHeap.hpp"

#include "gc/shared/gcLocker.inline.hpp"

#include "memory/universe.hpp"

#include "oops/oop.inline.hpp"

#include "runtime/thread.hpp"

#include "runtime/unhandledOops.hpp"

#include "utilities/globalDefinitions.hpp"

#ifdef CHECK_UNHANDLED_OOPS

const int free_list_size = 256;

UnhandledOops::UnhandledOops(Thread* thread) {

  _thread = thread;

  _oop_list = new (ResourceObj::C_HEAP, mtInternal)

                    GrowableArray<UnhandledOopEntry>(free_list_size, true);

  _level = 0;

}

UnhandledOops::~UnhandledOops() {

  delete _oop_list;

}

void UnhandledOops::dump_oops(UnhandledOops *list) {

  for (int k = 0; k < list->_oop_list->length(); k++) {

    UnhandledOopEntry entry = list->_oop_list->at(k);

    tty->print(" " INTPTR_FORMAT, p2i(entry._oop_ptr));

  }

  tty->cr();

}

// For debugging unhandled oop detector _in the debugger_

// You don't want to turn it on in compiled code here.

static bool unhandled_oop_print=0;

void UnhandledOops::register_unhandled_oop(oop* op, address pc) {

  if (!_thread->is_in_stack((address)op))

    return;

  _level ++;

  if (unhandled_oop_print) {

    for (int i=0; i<_level; i++) tty->print(" ");

    tty->print_cr("r " INTPTR_FORMAT, p2i(op));

  }

  UnhandledOopEntry entry(op, pc);

  _oop_list->push(entry);

}

bool match_oop_entry(void *op, UnhandledOopEntry e) {

  return (e.oop_ptr() == op);

}

// Mark unhandled oop as okay for GC - the containing struct has an oops_do and

// for some reason the oop has to be on the stack.

// May not be called for the current thread, as in the case of

// VM_GetOrSetLocal in jvmti.

void UnhandledOops::allow_unhandled_oop(oop* op) {

  assert (CheckUnhandledOops, "should only be called with checking option");

  int i = _oop_list->find_from_end(op, match_oop_entry);

  assert(i!=-1, "safe for gc oop not in unhandled_oop_list");

  UnhandledOopEntry entry = _oop_list->at(i);

  assert(!entry._ok_for_gc, "duplicate entry");

  entry._ok_for_gc = true;

  _oop_list->at_put(i, entry);

}

// Called by the oop destructor to remove unhandled oop from the thread's

// oop list.  All oops given are assumed to be on the list.  If not,

// there's a bug in the unhandled oop detector.

void UnhandledOops::unregister_unhandled_oop(oop* op) {

  if (!_thread->is_in_stack((address)op)) return;

  _level --;

  if (unhandled_oop_print) {

    for (int i=0; i<_level; i++) tty->print(" ");

    tty->print_cr("u " INTPTR_FORMAT, p2i(op));

  }

  int i = _oop_list->find_from_end(op, match_oop_entry);

  assert(i!=-1, "oop not in unhandled_oop_list");

  _oop_list->remove_at(i);

}

void UnhandledOops::clear_unhandled_oops() {

  assert (CheckUnhandledOops, "should only be called with checking option");

  for (int k = 0; k < _oop_list->length(); k++) {

    UnhandledOopEntry entry = _oop_list->at(k);

    // If an entry is on the unhandled oop list but isn't on the stack

    // anymore, it must not have gotten unregistered properly and it's a bug

    // in the unhandled oop generator.

    if(!_thread->is_in_stack((address)entry._oop_ptr)) {

      tty->print_cr("oop_ptr is " INTPTR_FORMAT, p2i(entry._oop_ptr));

      tty->print_cr("thread is " INTPTR_FORMAT " from pc " INTPTR_FORMAT,

                     p2i(_thread), p2i(entry._pc));

      assert(false, "heap is corrupted by the unhandled oop detector");

    }

    // Set unhandled oops to a pattern that will crash distinctively

    if (!entry._ok_for_gc) *(intptr_t*)(entry._oop_ptr) = BAD_OOP_ADDR;

  }

}

#endif // CHECK_UNHANDLED_OOPS