jdk/src/hotspot/share/runtime/objectMonitor.inline.hpp
Daniel D. Daugherty 62d77dc3fc 8247280: more fencing needed in async deflation for non-TSO machines
Reviewed-by: dholmes, pchilanomate
2020-07-15 16:59:39 -04:00

242 lines
9.3 KiB
C++

/*
* Copyright (c) 1998, 2020, 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
#include "logging/log.hpp"
#include "runtime/atomic.hpp"
inline intptr_t ObjectMonitor::is_entered(TRAPS) const {
if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) {
return 1;
}
return 0;
}
inline markWord ObjectMonitor::header() const {
return Atomic::load(&_header);
}
inline volatile markWord* ObjectMonitor::header_addr() {
assert((intptr_t)this == (intptr_t)&_header, "sync code expects this");
return &_header;
}
inline void ObjectMonitor::set_header(markWord hdr) {
Atomic::store(&_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;
}
// Returns true if owner field == DEFLATER_MARKER and false otherwise.
// This accessor is called when we really need to know if the owner
// field == DEFLATER_MARKER and any non-NULL value won't do the trick.
inline bool ObjectMonitor::owner_is_DEFLATER_MARKER() {
return Atomic::load(&_owner) == DEFLATER_MARKER;
}
// Returns true if 'this' is being async deflated and false otherwise.
inline bool ObjectMonitor::is_being_async_deflated() {
return AsyncDeflateIdleMonitors && contentions() < 0;
}
inline void ObjectMonitor::clear() {
assert(Atomic::load(&_header).value() != 0, "must be non-zero");
assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner));
Atomic::store(&_header, markWord::zero());
clear_common();
}
inline void ObjectMonitor::clear_common() {
if (AsyncDeflateIdleMonitors) {
// Async deflation protocol uses the header, owner and contentions
// fields. While the ObjectMonitor being deflated is on the global
// free list, we leave those three fields alone; contentions < 0
// will force any racing threads to retry. The header field is used
// by install_displaced_markword_in_object() to restore the object's
// header so we cannot check its value here.
guarantee(_owner == NULL || _owner == DEFLATER_MARKER,
"must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT,
p2i(_owner));
}
assert(contentions() <= 0, "must not be positive: contentions=%d", contentions());
assert(_waiters == 0, "must be 0: waiters=%d", _waiters);
assert(_recursions == 0, "must be 0: recursions=" INTX_FORMAT, _recursions);
assert(_object != NULL, "must be non-NULL");
set_allocation_state(Free);
_object = NULL;
}
inline void* ObjectMonitor::object() const {
return _object;
}
inline void* ObjectMonitor::object_addr() {
return (void *)(&_object);
}
inline void ObjectMonitor::set_object(void* obj) {
_object = obj;
}
// Return number of threads contending for this monitor.
inline jint ObjectMonitor::contentions() const {
return Atomic::load(&_contentions);
}
// Add value to the contentions field.
inline void ObjectMonitor::add_to_contentions(jint value) {
Atomic::add(&_contentions, value);
}
// Clear _owner field; current value must match old_value.
inline void ObjectMonitor::release_clear_owner(void* old_value) {
void* prev = Atomic::load(&_owner);
ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
Atomic::release_store(&_owner, (void*)NULL);
log_trace(monitorinflation, owner)("release_clear_owner(): mid="
INTPTR_FORMAT ", old_value=" INTPTR_FORMAT,
p2i(this), p2i(old_value));
}
// Simply set _owner field to new_value; current value must match old_value.
// (Simple means no memory sync needed.)
inline void ObjectMonitor::set_owner_from(void* old_value, void* new_value) {
void* prev = Atomic::load(&_owner);
ADIM_guarantee(prev == old_value, "unexpected prev owner=" INTPTR_FORMAT
", expected=" INTPTR_FORMAT, p2i(prev), p2i(old_value));
Atomic::store(&_owner, new_value);
log_trace(monitorinflation, owner)("set_owner_from(): mid="
INTPTR_FORMAT ", old_value=" INTPTR_FORMAT
", new_value=" INTPTR_FORMAT, p2i(this),
p2i(old_value), p2i(new_value));
}
// Simply set _owner field to new_value; current value must match old_value1 or old_value2.
// (Simple means no memory sync needed.)
inline void ObjectMonitor::set_owner_from(void* old_value1, void* old_value2, void* new_value) {
void* prev = Atomic::load(&_owner);
ADIM_guarantee(prev == old_value1 || prev == old_value2,
"unexpected prev owner=" INTPTR_FORMAT ", expected1="
INTPTR_FORMAT " or expected2=" INTPTR_FORMAT, p2i(prev),
p2i(old_value1), p2i(old_value2));
_owner = new_value;
log_trace(monitorinflation, owner)("set_owner_from(old1=" INTPTR_FORMAT
", old2=" INTPTR_FORMAT "): mid="
INTPTR_FORMAT ", prev=" INTPTR_FORMAT
", new=" INTPTR_FORMAT, p2i(old_value1),
p2i(old_value2), p2i(this), p2i(prev),
p2i(new_value));
}
// Simply set _owner field to self; current value must match basic_lock_p.
inline void ObjectMonitor::set_owner_from_BasicLock(void* basic_lock_p, Thread* self) {
void* prev = Atomic::load(&_owner);
ADIM_guarantee(prev == basic_lock_p, "unexpected prev owner=" INTPTR_FORMAT
", expected=" INTPTR_FORMAT, p2i(prev), p2i(basic_lock_p));
// Non-null owner field to non-null owner field is safe without
// cmpxchg() as long as all readers can tolerate either flavor.
Atomic::store(&_owner, self);
log_trace(monitorinflation, owner)("set_owner_from_BasicLock(): mid="
INTPTR_FORMAT ", basic_lock_p="
INTPTR_FORMAT ", new_value=" INTPTR_FORMAT,
p2i(this), p2i(basic_lock_p), p2i(self));
}
// Try to set _owner field to new_value if the current value matches
// old_value. Otherwise, does not change the _owner field. Returns
// the prior value of the _owner field.
inline void* ObjectMonitor::try_set_owner_from(void* old_value, void* new_value) {
void* prev = Atomic::cmpxchg(&_owner, old_value, new_value);
if (prev == old_value) {
log_trace(monitorinflation, owner)("try_set_owner_from(): mid="
INTPTR_FORMAT ", prev=" INTPTR_FORMAT
", new=" INTPTR_FORMAT, p2i(this),
p2i(prev), p2i(new_value));
}
return prev;
}
inline void ObjectMonitor::release_set_allocation_state(ObjectMonitor::AllocationState s) {
Atomic::release_store(&_allocation_state, s);
}
inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) {
_allocation_state = s;
}
inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const {
return _allocation_state;
}
inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state_acquire() const {
return Atomic::load_acquire(&_allocation_state);
}
inline bool ObjectMonitor::is_free() const {
return _allocation_state == Free;
}
inline bool ObjectMonitor::is_old() const {
return allocation_state_acquire() == Old;
}
inline bool ObjectMonitor::is_new() const {
return _allocation_state == New;
}
// The _next_om field can be concurrently read and modified so we
// use Atomic operations to disable compiler optimizations that
// might try to elide loading and/or storing this field.
inline ObjectMonitor* ObjectMonitor::next_om() const {
return Atomic::load(&_next_om);
}
// Simply set _next_om field to new_value.
inline void ObjectMonitor::set_next_om(ObjectMonitor* new_value) {
Atomic::store(&_next_om, new_value);
}
// Try to set _next_om field to new_value if the current value matches
// old_value. Otherwise, does not change the _next_om field. Returns
// the prior value of the _next_om field.
inline ObjectMonitor* ObjectMonitor::try_set_next_om(ObjectMonitor* old_value, ObjectMonitor* new_value) {
return Atomic::cmpxchg(&_next_om, old_value, new_value);
}
#endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP