1 /* 2 * Copyright (c) 1998, 2018, 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 #include "utilities/macros.hpp" 30 #include "oops/klass.hpp" 31 #include "oops/method.hpp" 32 33 // A CompiledICHolder* is a helper object for the inline cache implementation. 34 // It holds: 35 // (1) (method+klass pair) when converting from compiled to an interpreted call 36 // (2) (klass+klass pair) when calling itable stub from megamorphic compiled call 37 // 38 // These are always allocated in the C heap and are freed during a 39 // safepoint by the ICBuffer logic. It's unsafe to free them earlier 40 // since they might be in use. 41 // 42 43 44 class CompiledICHolder : public CHeapObj<mtCompiler> { 45 friend class VMStructs; 46 private: 47 static volatile int _live_count; // allocated 48 static volatile int _live_not_claimed_count; // allocated but not yet in use so not 49 // reachable by iterating over nmethods 50 51 Metadata* _holder_metadata; 52 Klass* _holder_klass; // to avoid name conflict with oopDesc::_klass 53 CompiledICHolder* _next; 54 bool is_metadata_method; 55 56 public: 57 // Constructor 58 CompiledICHolder(Metadata* metadata, Klass* klass, bool is_method = true); 59 ~CompiledICHolder() NOT_DEBUG_RETURN; 60 61 static int live_count() { return _live_count; } 62 static int live_not_claimed_count() { return _live_not_claimed_count; } 63 64 // accessors 65 Klass* holder_klass() const { return _holder_klass; } 66 Metadata* holder_metadata() const { return _holder_metadata; } 67 68 void set_holder_metadata(Metadata* m) { _holder_metadata = m; } 69 void set_holder_klass(Klass* k) { _holder_klass = k; } 70 71 static int holder_metadata_offset() { return offset_of(CompiledICHolder, _holder_metadata); } 72 static int holder_klass_offset() { return offset_of(CompiledICHolder, _holder_klass); } 73 74 CompiledICHolder* next() { return _next; } 75 void set_next(CompiledICHolder* n) { _next = n; } 76 77 inline bool is_loader_alive(BoolObjectClosure* is_alive) { 78 if (is_metadata_method) { 79 if (!((Method*)_holder_metadata)->method_holder()->is_loader_alive(is_alive)) { 80 return false; 81 } 82 } else { 83 if (!((Klass*)_holder_metadata)->is_loader_alive(is_alive)) { 84 return false; 85 } 86 } 87 if (!_holder_klass->is_loader_alive(is_alive)) { 88 return false; 89 } 90 return true; 91 } 92 93 // Verify 94 void verify_on(outputStream* st); 95 96 // Printing 97 void print_on(outputStream* st) const; 98 void print_value_on(outputStream* st) const; 99 100 const char* internal_name() const { return "{compiledICHolder}"; } 101 102 void claim() NOT_DEBUG_RETURN; 103 }; 104 105 #endif // SHARE_VM_OOPS_COMPILEDICHOLDEROOP_HPP