src/share/vm/classfile/metadataOnStackMark.cpp

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

author
aoqi
date
Tue, 08 Aug 2017 15:57:29 +0800
changeset 6876
710a3c8b516e
parent 6122
0b9ea9a72436
parent 0
f90c822e73f8
child 7535
7ae4e26cb1e0
permissions
-rw-r--r--

merge

     1 /*
     2  * Copyright (c) 2013, 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 #include "precompiled.hpp"
    26 #include "classfile/metadataOnStackMark.hpp"
    27 #include "code/codeCache.hpp"
    28 #include "compiler/compileBroker.hpp"
    29 #include "oops/metadata.hpp"
    30 #include "prims/jvmtiImpl.hpp"
    31 #include "runtime/synchronizer.hpp"
    32 #include "runtime/thread.hpp"
    33 #include "services/threadService.hpp"
    34 #include "utilities/growableArray.hpp"
    37 // Keep track of marked on-stack metadata so it can be cleared.
    38 GrowableArray<Metadata*>* _marked_objects = NULL;
    39 NOT_PRODUCT(bool MetadataOnStackMark::_is_active = false;)
    41 // Walk metadata on the stack and mark it so that redefinition doesn't delete
    42 // it.  Class unloading also walks the previous versions and might try to
    43 // delete it, so this class is used by class unloading also.
    44 MetadataOnStackMark::MetadataOnStackMark() {
    45   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
    46   NOT_PRODUCT(_is_active = true;)
    47   if (_marked_objects == NULL) {
    48     _marked_objects = new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(1000, true);
    49   }
    50   Threads::metadata_do(Metadata::mark_on_stack);
    51   CodeCache::alive_nmethods_do(nmethod::mark_on_stack);
    52   CompileBroker::mark_on_stack();
    53   JvmtiCurrentBreakpoints::metadata_do(Metadata::mark_on_stack);
    54   ThreadService::metadata_do(Metadata::mark_on_stack);
    55 }
    57 MetadataOnStackMark::~MetadataOnStackMark() {
    58   assert(SafepointSynchronize::is_at_safepoint(), "sanity check");
    59   // Unmark everything that was marked.   Can't do the same walk because
    60   // redefine classes messes up the code cache so the set of methods
    61   // might not be the same.
    62   for (int i = 0; i< _marked_objects->length(); i++) {
    63     _marked_objects->at(i)->set_on_stack(false);
    64   }
    65   _marked_objects->clear();   // reuse growable array for next time.
    66   NOT_PRODUCT(_is_active = false;)
    67 }
    69 // Record which objects are marked so we can unmark the same objects.
    70 void MetadataOnStackMark::record(Metadata* m) {
    71   assert(_is_active, "metadata on stack marking is active");
    72   _marked_objects->push(m);
    73 }

mercurial