jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp

Thu, 12 Oct 2017 21:27:07 +0800

author: aoqi
date: Thu, 12 Oct 2017 21:27:07 +0800
changeset 7535: 7ae4e26cb1e0
parent 6969: 02e61cf08ab3
parent 6876: 710a3c8b516e
permissions: -rw-r--r--

merge

 /*
  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP
 #define SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP
 #include "memory/iterator.hpp"
 #include "oops/oopsHierarchy.hpp"
 #include "runtime/os.hpp"
 #include "utilities/debug.hpp"
 // A BufferingOops closure tries to separate out the cost of finding roots
 // from the cost of applying closures to them.  It maintains an array of
 // ref-containing locations.  Until the array is full, applying the closure
 // to an oop* merely records that location in the array.  Since this
 // closure app cost is small, an elapsed timer can approximately attribute
 // all of this cost to the cost of finding the roots.  When the array fills
 // up, the wrapped closure is applied to all elements, keeping track of
 // this elapsed time of this process, and leaving the array empty.
 // The caller must be sure to call "done" to process any unprocessed
 // buffered entriess.
 class BufferingOopClosure: public OopClosure {
   friend class TestBufferingOopClosure;
 protected:
   static const size_t BufferLength = 1024;
   // We need to know if the buffered addresses contain oops or narrowOops.
   // We can't tag the addresses the way StarTask does, because we need to
   // be able to handle unaligned addresses coming from oops embedded in code.
   //
   // The addresses for the full-sized oops are filled in from the bottom,
   // while the addresses for the narrowOops are filled in from the top.
   OopOrNarrowOopStar  _buffer[BufferLength];
   OopOrNarrowOopStar* _oop_top;
   OopOrNarrowOopStar* _narrowOop_bottom;
   OopClosure* _oc;
   double      _closure_app_seconds;
   bool is_buffer_empty() {
     return _oop_top == _buffer && _narrowOop_bottom == (_buffer + BufferLength - 1);
   }
   bool is_buffer_full() {
     return _narrowOop_bottom < _oop_top;
   }
   // Process addresses containing full-sized oops.
   void process_oops() {
     for (OopOrNarrowOopStar* curr = _buffer; curr < _oop_top; ++curr) {
       _oc->do_oop((oop*)(*curr));
     }
     _oop_top = _buffer;
   }
   // Process addresses containing narrow oops.
   void process_narrowOops() {
     for (OopOrNarrowOopStar* curr = _buffer + BufferLength - 1; curr > _narrowOop_bottom; --curr) {
       _oc->do_oop((narrowOop*)(*curr));
     }
     _narrowOop_bottom = _buffer + BufferLength - 1;
   }
   // Apply the closure to all oops and clear the buffer.
   // Accumulate the time it took.
   void process_buffer() {
     double start = os::elapsedTime();
     process_oops();
     process_narrowOops();
     _closure_app_seconds += (os::elapsedTime() - start);
   }
   void process_buffer_if_full() {
     if (is_buffer_full()) {
       process_buffer();
     }
   }
   void add_narrowOop(narrowOop* p) {
     assert(!is_buffer_full(), "Buffer should not be full");
     *_narrowOop_bottom = (OopOrNarrowOopStar)p;
     _narrowOop_bottom--;
   }
   void add_oop(oop* p) {
     assert(!is_buffer_full(), "Buffer should not be full");
     *_oop_top = (OopOrNarrowOopStar)p;
     _oop_top++;
   }
 public:
   virtual void do_oop(narrowOop* p) {
     process_buffer_if_full();
     add_narrowOop(p);
   }
   virtual void do_oop(oop* p)       {
     process_buffer_if_full();
     add_oop(p);
   }
   void done() {
     if (!is_buffer_empty()) {
       process_buffer();
     }
   }
   double closure_app_seconds() {
     return _closure_app_seconds;
   }
   BufferingOopClosure(OopClosure *oc) :
     _oc(oc),
     _oop_top(_buffer),
     _narrowOop_bottom(_buffer + BufferLength - 1),
     _closure_app_seconds(0.0) { }
 };
 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_BUFFERINGOOPCLOSURE_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp@7ae4e26cb1e0 (annotated)

src/share/vm/gc_implementation/g1/bufferingOopClosure.hpp