1 /* 2 * Copyright (c) 2022, Red Hat, Inc. All rights reserved. 3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. 4 * Copyright (c) 2024, Oracle and/or its affiliates. All rights reserved. 5 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 6 * 7 * This code is free software; you can redistribute it and/or modify it 8 * under the terms of the GNU General Public License version 2 only, as 9 * published by the Free Software Foundation. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 * 25 */ 26 27 #include "precompiled.hpp" 28 #include "memory/allocation.hpp" 29 #include "oops/markWord.hpp" 30 #include "oops/oop.inline.hpp" 31 #include "runtime/globals.hpp" 32 #include "runtime/lockStack.inline.hpp" 33 #include "runtime/objectMonitor.inline.hpp" 34 #include "runtime/safepoint.hpp" 35 #include "runtime/stackWatermark.hpp" 36 #include "runtime/stackWatermarkSet.inline.hpp" 37 #include "runtime/thread.hpp" 38 #include "utilities/copy.hpp" 39 #include "utilities/debug.hpp" 40 #include "utilities/globalDefinitions.hpp" 41 #include "utilities/growableArray.hpp" 42 #include "utilities/ostream.hpp" 43 44 #include <type_traits> 45 46 const int LockStack::lock_stack_offset = in_bytes(JavaThread::lock_stack_offset()); 47 const int LockStack::lock_stack_top_offset = in_bytes(JavaThread::lock_stack_top_offset()); 48 const int LockStack::lock_stack_base_offset = in_bytes(JavaThread::lock_stack_base_offset()); 49 50 LockStack::LockStack(JavaThread* jt) : 51 _top(lock_stack_base_offset), _base() { 52 // Make sure the layout of the object is compatible with the emitted code's assumptions. 53 STATIC_ASSERT(sizeof(_bad_oop_sentinel) == oopSize); 54 STATIC_ASSERT(sizeof(_base[0]) == oopSize); 55 STATIC_ASSERT(std::is_standard_layout<LockStack>::value); 56 STATIC_ASSERT(offsetof(LockStack, _bad_oop_sentinel) == offsetof(LockStack, _base) - oopSize); 57 #ifdef ASSERT 58 for (int i = 0; i < CAPACITY; i++) { 59 _base[i] = nullptr; 60 } 61 #endif 62 } 63 64 uint32_t LockStack::start_offset() { 65 int offset = lock_stack_base_offset; 66 assert(offset > 0, "must be positive offset"); 67 return static_cast<uint32_t>(offset); 68 } 69 70 uint32_t LockStack::end_offset() { 71 int offset = lock_stack_base_offset + CAPACITY * oopSize; 72 assert(offset > 0, "must be positive offset"); 73 return static_cast<uint32_t>(offset); 74 } 75 76 #ifndef PRODUCT 77 void LockStack::verify(const char* msg) const { 78 assert(LockingMode == LM_LIGHTWEIGHT, "never use lock-stack when light weight locking is disabled"); 79 assert((_top <= end_offset()), "lockstack overflow: _top %d end_offset %d", _top, end_offset()); 80 assert((_top >= start_offset()), "lockstack underflow: _top %d start_offset %d", _top, start_offset()); 81 if (SafepointSynchronize::is_at_safepoint() || (Thread::current()->is_Java_thread() && is_owning_thread())) { 82 int top = to_index(_top); 83 for (int i = 0; i < top; i++) { 84 assert(_base[i] != nullptr, "no zapped before top"); 85 if (VM_Version::supports_recursive_lightweight_locking()) { 86 oop o = _base[i]; 87 for (; i < top - 1; i++) { 88 // Consecutive entries may be the same 89 if (_base[i + 1] != o) { 90 break; 91 } 92 } 93 } 94 95 for (int j = i + 1; j < top; j++) { 96 assert(_base[i] != _base[j], "entries must be unique: %s", msg); 97 } 98 } 99 for (int i = top; i < CAPACITY; i++) { 100 assert(_base[i] == nullptr, "only zapped entries after top: i: %d, top: %d, entry: " PTR_FORMAT, i, top, p2i(_base[i])); 101 } 102 } 103 } 104 #endif 105 106 void LockStack::print_on(outputStream* st) { 107 for (int i = to_index(_top); (--i) >= 0;) { 108 st->print("LockStack[%d]: ", i); 109 oop o = _base[i]; 110 if (oopDesc::is_oop(o)) { 111 o->print_on(st); 112 } else { 113 st->print_cr("not an oop: " PTR_FORMAT, p2i(o)); 114 } 115 } 116 } --- EOF ---