1 /* 2 * Copyright (c) 2022, Red Hat, Inc. All rights reserved. 3 * Copyright Amazon.com Inc. or its affiliates. All Rights Reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #ifndef SHARE_RUNTIME_LOCKSTACK_HPP 27 #define SHARE_RUNTIME_LOCKSTACK_HPP 28 29 #include "oops/oopsHierarchy.hpp" 30 #include "utilities/globalDefinitions.hpp" 31 #include "utilities/sizes.hpp" 32 33 class Thread; 34 class OopClosure; 35 36 class LockStack { 37 friend class VMStructs; 38 private: 39 static const int CAPACITY = 8; 40 41 // TODO: It would be very useful if JavaThread::lock_stack_offset() and friends were constexpr, 42 // but this is currently not the case because we're using offset_of() which is non-constexpr, 43 // GCC would warn about non-standard-layout types if we were using offsetof() (which *is* constexpr). 44 static const int lock_stack_offset; 45 static const int lock_stack_top_offset; 46 static const int lock_stack_base_offset; 47 48 // The offset of the next element, in bytes, relative to the JavaThread structure. 49 // We do this instead of a simple index into the array because this allows for 50 // efficient addressing in generated code. 51 uint32_t _top; 52 oop _base[CAPACITY]; 53 54 // Get the owning thread of this lock-stack. 55 inline JavaThread* get_thread() const; 56 57 // Tests if the calling thread is the thread that owns this lock-stack. 58 bool is_owning_thread() const; 59 60 // Verifies consistency of the lock-stack. 61 void verify(const char* msg) const PRODUCT_RETURN; 62 63 // Given an offset (in bytes) calculate the index into the lock-stack. 64 static inline int to_index(uint32_t offset); 65 66 public: 67 static ByteSize top_offset() { return byte_offset_of(LockStack, _top); } 68 static ByteSize base_offset() { return byte_offset_of(LockStack, _base); } 69 70 LockStack(JavaThread* jt); 71 72 // The boundary indicies of the lock-stack. 73 static uint32_t start_offset(); 74 static uint32_t end_offset(); 75 76 // Return true if we have room to push onto this lock-stack, false otherwise. 77 inline bool can_push() const; 78 79 // Pushes an oop on this lock-stack. 80 inline void push(oop o); 81 82 // Pops an oop from this lock-stack. 83 inline oop pop(); 84 85 // Removes an oop from an arbitrary location of this lock-stack. 86 inline void remove(oop o); 87 88 // Tests whether the oop is on this lock-stack. 89 inline bool contains(oop o) const; 90 91 // GC support 92 inline void oops_do(OopClosure* cl); 93 94 }; 95 96 #endif // SHARE_RUNTIME_LOCKSTACK_HPP