1 /* 2 * Copyright (c) 1998, 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP 26 #define SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP 27 28 inline intptr_t ObjectMonitor::is_entered(TRAPS) const { 29 if (THREAD == _owner || THREAD->is_lock_owned((address) _owner)) { 30 return 1; 31 } 32 return 0; 33 } 34 35 inline markOop ObjectMonitor::header() const { 36 return _header; 37 } 38 39 inline volatile markOop* ObjectMonitor::header_addr() { 40 assert((intptr_t)this == (intptr_t)&_header, "sync code expects this"); 41 return &_header; 42 } 43 44 inline void ObjectMonitor::set_header(markOop hdr) { 45 _header = hdr; 46 } 47 48 inline jint ObjectMonitor::waiters() const { 49 return _waiters; 50 } 51 52 // Returns NULL if DEFLATER_MARKER is observed. 53 inline void* ObjectMonitor::owner() const { 54 void* owner = _owner; 55 return owner != DEFLATER_MARKER ? owner : NULL; 56 } 57 58 inline void ObjectMonitor::clear() { 59 assert(_header != NULL, "must be non-NULL"); 60 assert(_owner == NULL, "must be NULL: owner=" INTPTR_FORMAT, p2i(_owner)); 61 assert(_ref_count == 0, "must be 0: ref_count=%d", _ref_count); 62 63 _header = NULL; 64 65 clear_using_JT(); 66 } 67 68 inline void ObjectMonitor::clear_using_JT() { 69 // Unlike other *_using_JT() functions, we cannot assert 70 // AsyncDeflateIdleMonitors or Thread::current()->is_Java_thread() 71 // because clear() calls this function for the rest of its checks. 72 73 if (AsyncDeflateIdleMonitors) { 74 // Async deflation protocol uses the header, owner and ref_count 75 // fields. While the ObjectMonitor being deflated is on the global free 76 // list, we leave those three fields alone; owner == DEFLATER_MARKER 77 // and ref_count < 0 will force any racing threads to retry. The 78 // header field is used by install_displaced_markword_in_object() 79 // in the last part of the deflation protocol so we cannot check 80 // its value here. 81 guarantee(_owner == NULL || _owner == DEFLATER_MARKER, 82 "must be NULL or DEFLATER_MARKER: owner=" INTPTR_FORMAT, 83 p2i(_owner)); 84 guarantee(_ref_count <= 0, "must be <= 0: ref_count=%d", _ref_count); 85 } 86 assert(_contentions == 0, "must be 0: contentions=%d", _contentions); 87 assert(_waiters == 0, "must be 0: waiters=%d", _waiters); 88 assert(_recursions == 0, "must be 0: recursions=" INTPTR_FORMAT, _recursions); 89 assert(_object != NULL, "must be non-NULL"); 90 91 set_allocation_state(Free); 92 _object = NULL; 93 } 94 95 inline void* ObjectMonitor::object() const { 96 return _object; 97 } 98 99 inline void* ObjectMonitor::object_addr() { 100 return (void *)(&_object); 101 } 102 103 inline void ObjectMonitor::set_object(void* obj) { 104 _object = obj; 105 } 106 107 inline bool ObjectMonitor::check(TRAPS) { 108 if (THREAD != _owner) { 109 if (THREAD->is_lock_owned((address) _owner)) { 110 _owner = THREAD; // regain ownership of inflated monitor 111 assert (_recursions == 0, "invariant") ; 112 } else { 113 check_slow(THREAD); 114 return false; 115 } 116 } 117 return true; 118 } 119 120 // return number of threads contending for this monitor 121 inline jint ObjectMonitor::contentions() const { 122 return _contentions; 123 } 124 125 // Do NOT set _contentions = 0. There is a race such that _contentions could 126 // be set while inflating prior to setting _owner 127 // Just use Atomic::inc/dec and assert 0 when monitor put on free list 128 inline void ObjectMonitor::set_owner(void* owner) { 129 _owner = owner; 130 _recursions = 0; 131 } 132 133 inline void ObjectMonitor::set_allocation_state(ObjectMonitor::AllocationState s) { 134 _allocation_state = s; 135 } 136 137 inline ObjectMonitor::AllocationState ObjectMonitor::allocation_state() const { 138 return _allocation_state; 139 } 140 141 inline bool ObjectMonitor::is_free() const { 142 return _allocation_state == Free; 143 } 144 145 inline bool ObjectMonitor::is_active() const { 146 return !is_free(); 147 } 148 149 inline bool ObjectMonitor::is_old() const { 150 return _allocation_state == Old; 151 } 152 153 inline bool ObjectMonitor::is_new() const { 154 return _allocation_state == New; 155 } 156 157 inline void ObjectMonitor::dec_ref_count() { 158 // The decrement only needs to be MO_ACQ_REL since the reference 159 // counter is volatile. 160 Atomic::dec(&_ref_count); 161 // Can be negative as part of async deflation protocol. 162 guarantee(AsyncDeflateIdleMonitors || _ref_count >= 0, 163 "sanity check: ref_count=%d", _ref_count); 164 } 165 166 inline void ObjectMonitor::inc_ref_count() { 167 // The increment needs to be MO_SEQ_CST so that the reference 168 // counter update is seen as soon as possible in a race with the 169 // async deflation protocol. 170 Atomic::inc(&_ref_count); 171 // Can be negative as part of async deflation protocol. 172 guarantee(AsyncDeflateIdleMonitors || _ref_count > 0, 173 "sanity check: ref_count=%d", _ref_count); 174 } 175 176 inline jint ObjectMonitor::ref_count() const { 177 return OrderAccess::load_acquire(&_ref_count); 178 } 179 180 #endif // SHARE_RUNTIME_OBJECTMONITOR_INLINE_HPP