1 /*

     2  * Copyright (c) 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 #include "precompiled.hpp"

    26 #include "code/compiledMethod.hpp"

    27 #include "code/nmethod.hpp"

    28 #include "gc/shared/gcBehaviours.hpp"

    29 

    30 IsUnloadingBehaviour* IsUnloadingBehaviour::_current = NULL;

    31 

    32 class IsCompiledMethodUnloadingOopClosure: public OopClosure {

    33   BoolObjectClosure *_cl;

    34   bool _is_unloading;

    35 

    36 public:

    37   IsCompiledMethodUnloadingOopClosure(BoolObjectClosure* cl)

    38     : _cl(cl),

    39       _is_unloading(false)

    40   { }

    41 

    42   virtual void do_oop(oop* p) {

    43     if (_is_unloading) {

    44       return;

    45     }

    46     oop obj = *p;

    47     if (obj == NULL) {

    48       return;

    49     }

    50     if (!_cl->do_object_b(obj)) {

    51       _is_unloading = true;

    52     }

    53   }

    54 

    55   virtual void do_oop(narrowOop* p) {

    56     ShouldNotReachHere();

    57   }

    58 

    59   bool is_unloading() const {

    60     return _is_unloading;

    61   }

    62 };

    63 

    64 bool ClosureIsUnloadingBehaviour::is_unloading(CompiledMethod* cm) const {

    65   if (cm->is_nmethod()) {

    66     IsCompiledMethodUnloadingOopClosure cl(_cl);

    67     static_cast<nmethod*>(cm)->oops_do(&cl);

    68     return cl.is_unloading();

    69   } else {

    70     return false;

    71   }

    72 }