ciBaseObject.hpp revision 3602:da91efe96a93
1/* 2 * Copyright (c) 2011, 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_CI_CIBASEOBJECT_HPP 26#define SHARE_VM_CI_CIBASEOBJECT_HPP 27 28#include "ci/ciClassList.hpp" 29#include "memory/allocation.hpp" 30#include "runtime/handles.hpp" 31#include "runtime/jniHandles.hpp" 32 33// ciBaseObject 34// 35// This class represents an oop in the HotSpot virtual machine. 36// Its subclasses are structured in a hierarchy which mirrors 37// an aggregate of the VM's oop and klass hierarchies (see 38// oopHierarchy.hpp). Each instance of ciBaseObject holds a handle 39// to a corresponding oop on the VM side and provides routines 40// for accessing the information in its oop. By using the ciBaseObject 41// hierarchy for accessing oops in the VM, the compiler ensures 42// that it is safe with respect to garbage collection; that is, 43// GC and compilation can proceed independently without 44// interference. 45// 46// Within the VM, the oop and klass hierarchies are separate. 47// The compiler interface does not preserve this separation -- 48// the distinction between `Klass*' and `Klass' are not 49// reflected in the interface and instead the Klass hierarchy 50// is directly modeled as the subclasses of ciKlass. 51class ciBaseObject : public ResourceObj { 52 CI_PACKAGE_ACCESS 53 friend class ciEnv; 54 55protected: 56 uint _ident; 57 58 enum { FLAG_BITS = 1 }; 59 enum { 60 SCAVENGABLE_FLAG = 1 61 }; 62protected: 63 ciBaseObject(): _ident(0) {} 64 65 virtual const char* type_string() { return "ciBaseObject"; } 66 67 void set_ident(uint id); 68 69public: 70 // A number unique to this object. 71 uint ident(); 72 73 // What kind of ciBaseObject is this? 74 virtual bool is_symbol() const { return false; } 75 virtual bool is_object() const { return false; } 76 virtual bool is_metadata() const { return false; } 77 78 ciSymbol* as_symbol() { 79 assert(is_symbol(), "must be"); 80 return (ciSymbol*)this; 81 } 82 ciObject* as_object() { 83 assert(is_object(), "must be"); 84 return (ciObject*)this; 85 } 86 ciMetadata* as_metadata() { 87 assert(is_metadata(), "must be"); 88 return (ciMetadata*)this; 89 } 90}; 91#endif // SHARE_VM_CI_CIBASEOBJECT_HPP 92