1 /* 2 * Copyright (c) 1998, 2012, 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_VM_OOPS_COMPILEDICHOLDEROOP_HPP 26 #define SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP 27 28 #include "oops/oop.hpp" 29 30 // A CompiledICHolder* is a helper object for the inline cache implementation. 31 // It holds an intermediate value (method+klass pair) used when converting from 32 // compiled to an interpreted call. 33 // 34 // These are always allocated in the C heap and are freed during a 35 // safepoint by the ICBuffer logic. It's unsafe to free them earlier 36 // since they might be in use. 37 // 38 39 40 class CompiledICHolder : public CHeapObj<mtCompiler> { 41 friend class VMStructs; 42 private: 43 static volatile int _live_count; // allocated 44 static volatile int _live_not_claimed_count; // allocated but not yet in use so not 45 // reachable by iterating over nmethods 46 47 Method* _holder_method; 48 Klass* _holder_klass; // to avoid name conflict with oopDesc::_klass 49 CompiledICHolder* _next; 50 51 public: 52 // Constructor 53 CompiledICHolder(Method* method, Klass* klass) 54 : _holder_method(method), _holder_klass(klass) { 55 #ifdef ASSERT 56 Atomic::inc(&_live_count); 57 Atomic::inc(&_live_not_claimed_count); 58 #endif 59 } 60 61 ~CompiledICHolder() { 62 #ifdef ASSERT 63 assert(_live_count > 0, "underflow"); 64 Atomic::dec(&_live_count); 65 #endif 66 } 67 68 static int live_count() { return _live_count; } 69 static int live_not_claimed_count() { return _live_not_claimed_count; } 70 71 // accessors 72 Method* holder_method() const { return _holder_method; } 73 Klass* holder_klass() const { return _holder_klass; } 74 75 void set_holder_method(Method* m) { _holder_method = m; } 76 void set_holder_klass(Klass* k) { _holder_klass = k; } 77 78 // interpreter support (offsets in bytes) 79 static int holder_method_offset() { return offset_of(CompiledICHolder, _holder_method); } 80 static int holder_klass_offset() { return offset_of(CompiledICHolder, _holder_klass); } 81 82 CompiledICHolder* next() { return _next; } 83 void set_next(CompiledICHolder* n) { _next = n; } 84 85 // Verify 86 void verify_on(outputStream* st); 87 88 // Printing 89 void print_on(outputStream* st) const; 90 void print_value_on(outputStream* st) const; 91 92 const char* internal_name() const { return "{compiledICHolder}"; } 93 94 void claim() { 95 #ifdef ASSERT 96 Atomic::dec(&_live_not_claimed_count); 97 #endif 98 } 99 }; 100 101 #endif // SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP