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