1 /*
   2  * Copyright (c) 2016, 2019, 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 "jfr/recorder/stringpool/jfrStringPoolBuffer.hpp"
  27 #include "runtime/atomic.hpp"
  28 #include "runtime/orderAccess.inline.hpp"
  29 #include "runtime/thread.inline.hpp"
  30 
  31 JfrStringPoolBuffer::JfrStringPoolBuffer() : JfrBuffer(), _string_count_pos(0), _string_count_top(0) {}
  32 
  33 void JfrStringPoolBuffer::reinitialize() {
  34   concurrent_top();
  35   set_pos((start()));
  36   set_string_pos(0);
  37   set_string_top(0);
  38   set_concurrent_top(start());
  39 }
  40 
  41 uint64_t JfrStringPoolBuffer::string_pos() const {
  42   return OrderAccess::load_acquire(&_string_count_pos);
  43 }
  44 
  45 uint64_t JfrStringPoolBuffer::string_top() const {
  46   return OrderAccess::load_acquire(&_string_count_top);
  47 }
  48 
  49 uint64_t JfrStringPoolBuffer::string_count() const {
  50   return string_pos() - string_top();
  51 }
  52 
  53 void JfrStringPoolBuffer::set_string_pos(uint64_t value) {
  54   Atomic::store(value, &_string_count_pos);
  55 }
  56 
  57 void JfrStringPoolBuffer::increment(uint64_t value) {
  58   Atomic::add(value, &_string_count_pos);
  59 }
  60 
  61 void JfrStringPoolBuffer::set_string_top(uint64_t value) {
  62   Atomic::store(value, &_string_count_top);
  63 }