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 * Copyright (c) 1998, 2019, 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
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#ifndef SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP
#define SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP

inline intptr_t ObjectMonitor::is_entered(TRAPS) const {
  if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) {
    return 1;
  }
  return 0;
}

inline markOop ObjectMonitor::header() const {
  return _header;
}

inline volatile markOop* ObjectMonitor::header_addr() {
  assert((intptr_t)this == (intptr_t)&_header, "sync code expects this");
  return &_header;
}

inline void ObjectMonitor::set_header(markOop hdr) {
  _header = hdr;
}

inline jint ObjectMonitor::waiters() const {
  return _waiters;
}

// Returns NULL if DEFLATER_MARKER is observed.
inline void* ObjectMonitor::owner() const {
  void* owner = _owner;
  return owner != DEFLATER_MARKER ? owner : NULL;
}

inline void ObjectMonitor::clear() {
  assert(_header != NULL, "must be non-NULL");
  assert(_contentions == 0, "must be 0: contentions=%d", _contentions);
  assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));

  _header = NULL;

  clear_using_JT();
}

inline void ObjectMonitor::clear_using_JT() {
  // Unlike other *_using_JT() functions, we cannot assert
  // AsyncDeflateIdleMonitors or Thread::current()->is_Java_thread()
  // because clear() calls this function for the rest of its checks.

  if (AsyncDeflateIdleMonitors) {
    // Async deflation protocol uses the _header, _contentions and _owner
    // fields. While the ObjectMonitor being deflated is on the global free
    // list, we leave those three fields alone; _owner == DEFLATER_MARKER
    // and _contentions < 0 will force any racing threads to retry. The
    // _header field is used by install_displaced_markword_in_object()
    // in the last part of the deflation protocol so we cannot check
    // its values here.
    guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
              "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
              p2i(_owner));
    guarantee(_contentions <= 0, "must be <= 0: contentions=%d", _contentions);
  }
  assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
  assert(_recursions == 0, "must be 0: recursions=" INTPTR_FORMAT, _recursions);
  assert(_object != NULL, "must be non-NULL");
  // Do not assert _ref_count == 0 here because a racing thread could
  // increment _ref_count, observe _owner == DEFLATER_MARKER and then
  // decrement _ref_count.

  set_allocation_state(Free);
  _object = NULL;
  // Do not clear _ref_count here because _ref_count is for indicating
  // that the ObjectMonitor* is in use which is orthogonal to whether
  // the ObjectMonitor itself is in use for a locking operation.
}

inline void* ObjectMonitor::object() const {
  return _object;
}

inline void* ObjectMonitor::object_addr() {
  return (void *)(&_object);
}

inline void ObjectMonitor::set_object(void* obj) {
  _object = obj;
}

inline bool ObjectMonitor::check(TRAPS) {
  if (THREAD != _owner) {
    if (THREAD->is_lock_owned((address) _owner)) {
      _owner = THREAD;  // regain ownership of inflated monitor
      assert (_recursions == 0, "invariant") ;
    } else {
      check_slow(THREAD);
      return false;
    }
  }
  return true;
}

// return number of threads contending for this monitor
inline jint ObjectMonitor::contentions() const {
  return _contentions;
}

// Do NOT set _contentions = 0. There is a race such that _contentions could
// be set while inflating prior to setting _owner
// Just use Atomic::inc/dec and assert 0 when monitor put on free list
inline void ObjectMonitor::set_owner(void* owner) {
  _owner = owner;
  _recursions = 0;
}

inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {
  _allocation_state = s;
}

inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const {
  return _allocation_state;
}

inline bool ObjectMonitor::is_free() const {
  return _allocation_state == Free;
}

inline bool ObjectMonitor::is_active() const {
  return !is_free();
}

inline bool ObjectMonitor::is_old() const {
  return _allocation_state == Old;
}

inline bool ObjectMonitor::is_new() const {
  return _allocation_state == New;
}

inline void ObjectMonitor::dec_ref_count() {
  // The decrement only needs to be MO_ACQ_REL since the reference
  // counter is volatile.
  Atomic::dec(&_ref_count);
  guarantee(_ref_count >= 0, "sanity check: ref_count=%d", _ref_count);
}

inline void ObjectMonitor::inc_ref_count() {
  // The increment needs to be MO_SEQ_CST so that the reference
  // counter update is seen as soon as possible in a race with the
  // async deflation protocol.
  Atomic::inc(&_ref_count);
  guarantee(_ref_count > 0, "sanity check: ref_count=%d", _ref_count);
}

inline jint ObjectMonitor::ref_count() const {
  return OrderAccess::load_acquire(&_ref_count);
}

#endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP