src/share/vm/ci/ciBaseObject.hpp

Tue, 08 Aug 2017 15:57:29 +0800

author
aoqi
date
Tue, 08 Aug 2017 15:57:29 +0800
changeset 6876
710a3c8b516e
parent 0
f90c822e73f8
permissions
-rw-r--r--

merge

     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  */
    25 #ifndef SHARE_VM_CI_CIBASEOBJECT_HPP
    26 #define SHARE_VM_CI_CIBASEOBJECT_HPP
    28 #include "ci/ciClassList.hpp"
    29 #include "memory/allocation.hpp"
    30 #include "runtime/handles.hpp"
    31 #include "runtime/jniHandles.hpp"
    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.
    51 class ciBaseObject : public ResourceObj {
    52   CI_PACKAGE_ACCESS
    53   friend class ciEnv;
    55 protected:
    56   uint     _ident;
    58   enum { FLAG_BITS   = 1 };
    59   enum {
    60          SCAVENGABLE_FLAG = 1
    61        };
    62 protected:
    63   ciBaseObject(): _ident(0) {}
    65   virtual const char* type_string() { return "ciBaseObject"; }
    67   void set_ident(uint id);
    69 public:
    70   // A number unique to this object.
    71   uint ident();
    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; }
    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

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