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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.
 *
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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::count() const {
  return _count;
}

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(_count == 0, "Fatal logic error in ObjectMonitor count!");
  assert(_owner == NULL, "Fatal logic error in ObjectMonitor owner!");

  clear_using_JT();
}

inline void ObjectMonitor::clear_using_JT() {
  // When clearing using a JavaThread, we leave _owner == DEFLATER_MARKER
  // and _count < 0 to force any racing threads to retry. 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.

  assert(_header != NULL, "Fatal logic error in ObjectMonitor header!");
  assert(_waiters == 0, "Fatal logic error in ObjectMonitor waiters!");
  assert(_recursions == 0, "Fatal logic error in ObjectMonitor recursions!");
  assert(_object != NULL, "Fatal logic error in ObjectMonitor object!");
  // 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);
  _header = NULL;
  _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 _count;
}

// Do NOT set _count = 0. There is a race such that _count 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 needs to be MO_ACQ_REL. At the moment, the Atomic::dec
  // backend on PPC does not yet conform to these requirements. Therefore
  // the decrement is simulated with an Atomic::sub(1, &addr). Without
  // this MO_ACQ_REL Atomic::dec simulation, AsyncDeflateIdleMonitors is
  // not safe.
  Atomic::sub((jint)1, &_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. At the moment, the Atomic::inc
  // backend on PPC does not yet conform to these requirements. Therefore
  // the increment is simulated with a load phi; cas phi + 1; loop.
  // Without this MO_SEQ_CST Atomic::inc simulation, AsyncDeflateIdleMonitors
  // is not safe.
  for (;;) {
    jint sample = OrderAccess::load_acquire(&_ref_count);
    guarantee(sample >= 0, "sanity check: sample=%d", (int)sample);
    if (Atomic::cmpxchg(sample + 1, &_ref_count, sample) == sample) {
      // Incremented _ref_count without interference.
      return;
    }
    // Implied else: Saw interference so loop and try again.
  }
}

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

#endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP