src/share/vm/gc_implementation/shared/markSweep.cpp

Mon, 07 Jul 2014 10:12:40 +0200

author
stefank
date
Mon, 07 Jul 2014 10:12:40 +0200
changeset 6992
2c6ef90f030a
parent 6971
7426d8d76305
child 7535
7ae4e26cb1e0
permissions
-rw-r--r--

8049421: G1 Class Unloading after completing a concurrent mark cycle
Reviewed-by: tschatzl, ehelin, brutisso, coleenp, roland, iveresov
Contributed-by: stefan.karlsson@oracle.com, mikael.gerdin@oracle.com

     1 /*
     2  * Copyright (c) 1997, 2014, 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 "compiler/compileBroker.hpp"
    27 #include "gc_implementation/shared/gcTimer.hpp"
    28 #include "gc_implementation/shared/gcTrace.hpp"
    29 #include "gc_implementation/shared/markSweep.inline.hpp"
    30 #include "gc_interface/collectedHeap.inline.hpp"
    31 #include "oops/methodData.hpp"
    32 #include "oops/objArrayKlass.inline.hpp"
    33 #include "oops/oop.inline.hpp"
    35 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
    37 uint                    MarkSweep::_total_invocations = 0;
    39 Stack<oop, mtGC>              MarkSweep::_marking_stack;
    40 Stack<ObjArrayTask, mtGC>     MarkSweep::_objarray_stack;
    42 Stack<oop, mtGC>              MarkSweep::_preserved_oop_stack;
    43 Stack<markOop, mtGC>          MarkSweep::_preserved_mark_stack;
    44 size_t                  MarkSweep::_preserved_count = 0;
    45 size_t                  MarkSweep::_preserved_count_max = 0;
    46 PreservedMark*          MarkSweep::_preserved_marks = NULL;
    47 ReferenceProcessor*     MarkSweep::_ref_processor   = NULL;
    48 STWGCTimer*             MarkSweep::_gc_timer        = NULL;
    49 SerialOldTracer*        MarkSweep::_gc_tracer       = NULL;
    51 MarkSweep::FollowRootClosure  MarkSweep::follow_root_closure;
    53 void MarkSweep::FollowRootClosure::do_oop(oop* p)       { follow_root(p); }
    54 void MarkSweep::FollowRootClosure::do_oop(narrowOop* p) { follow_root(p); }
    56 MarkSweep::MarkAndPushClosure MarkSweep::mark_and_push_closure;
    57 CLDToOopClosure               MarkSweep::follow_cld_closure(&mark_and_push_closure);
    58 CLDToOopClosure               MarkSweep::adjust_cld_closure(&adjust_pointer_closure);
    60 void MarkSweep::MarkAndPushClosure::do_oop(oop* p)       { mark_and_push(p); }
    61 void MarkSweep::MarkAndPushClosure::do_oop(narrowOop* p) { mark_and_push(p); }
    63 void MarkSweep::follow_class_loader(ClassLoaderData* cld) {
    64   MarkSweep::follow_cld_closure.do_cld(cld);
    65 }
    67 void MarkSweep::follow_stack() {
    68   do {
    69     while (!_marking_stack.is_empty()) {
    70       oop obj = _marking_stack.pop();
    71       assert (obj->is_gc_marked(), "p must be marked");
    72       obj->follow_contents();
    73     }
    74     // Process ObjArrays one at a time to avoid marking stack bloat.
    75     if (!_objarray_stack.is_empty()) {
    76       ObjArrayTask task = _objarray_stack.pop();
    77       ObjArrayKlass* k = (ObjArrayKlass*)task.obj()->klass();
    78       k->oop_follow_contents(task.obj(), task.index());
    79     }
    80   } while (!_marking_stack.is_empty() || !_objarray_stack.is_empty());
    81 }
    83 MarkSweep::FollowStackClosure MarkSweep::follow_stack_closure;
    85 void MarkSweep::FollowStackClosure::do_void() { follow_stack(); }
    87 // We preserve the mark which should be replaced at the end and the location
    88 // that it will go.  Note that the object that this markOop belongs to isn't
    89 // currently at that address but it will be after phase4
    90 void MarkSweep::preserve_mark(oop obj, markOop mark) {
    91   // We try to store preserved marks in the to space of the new generation since
    92   // this is storage which should be available.  Most of the time this should be
    93   // sufficient space for the marks we need to preserve but if it isn't we fall
    94   // back to using Stacks to keep track of the overflow.
    95   if (_preserved_count < _preserved_count_max) {
    96     _preserved_marks[_preserved_count++].init(obj, mark);
    97   } else {
    98     _preserved_mark_stack.push(mark);
    99     _preserved_oop_stack.push(obj);
   100   }
   101 }
   103 MarkSweep::AdjustPointerClosure MarkSweep::adjust_pointer_closure;
   105 void MarkSweep::AdjustPointerClosure::do_oop(oop* p)       { adjust_pointer(p); }
   106 void MarkSweep::AdjustPointerClosure::do_oop(narrowOop* p) { adjust_pointer(p); }
   108 void MarkSweep::adjust_marks() {
   109   assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
   110          "inconsistent preserved oop stacks");
   112   // adjust the oops we saved earlier
   113   for (size_t i = 0; i < _preserved_count; i++) {
   114     _preserved_marks[i].adjust_pointer();
   115   }
   117   // deal with the overflow stack
   118   StackIterator<oop, mtGC> iter(_preserved_oop_stack);
   119   while (!iter.is_empty()) {
   120     oop* p = iter.next_addr();
   121     adjust_pointer(p);
   122   }
   123 }
   125 void MarkSweep::restore_marks() {
   126   assert(_preserved_oop_stack.size() == _preserved_mark_stack.size(),
   127          "inconsistent preserved oop stacks");
   128   if (PrintGC && Verbose) {
   129     gclog_or_tty->print_cr("Restoring %d marks",
   130                            _preserved_count + _preserved_oop_stack.size());
   131   }
   133   // restore the marks we saved earlier
   134   for (size_t i = 0; i < _preserved_count; i++) {
   135     _preserved_marks[i].restore();
   136   }
   138   // deal with the overflow
   139   while (!_preserved_oop_stack.is_empty()) {
   140     oop obj       = _preserved_oop_stack.pop();
   141     markOop mark  = _preserved_mark_stack.pop();
   142     obj->set_mark(mark);
   143   }
   144 }
   146 MarkSweep::IsAliveClosure   MarkSweep::is_alive;
   148 bool MarkSweep::IsAliveClosure::do_object_b(oop p) { return p->is_gc_marked(); }
   150 MarkSweep::KeepAliveClosure MarkSweep::keep_alive;
   152 void MarkSweep::KeepAliveClosure::do_oop(oop* p)       { MarkSweep::KeepAliveClosure::do_oop_work(p); }
   153 void MarkSweep::KeepAliveClosure::do_oop(narrowOop* p) { MarkSweep::KeepAliveClosure::do_oop_work(p); }
   155 void marksweep_init() {
   156   MarkSweep::_gc_timer = new (ResourceObj::C_HEAP, mtGC) STWGCTimer();
   157   MarkSweep::_gc_tracer = new (ResourceObj::C_HEAP, mtGC) SerialOldTracer();
   158 }
   160 #ifndef PRODUCT
   162 void MarkSweep::trace(const char* msg) {
   163   if (TraceMarkSweep)
   164     gclog_or_tty->print("%s", msg);
   165 }
   167 #endif

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