1 /*
   2  * Copyright (c) 2007, 2016, 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.marlin;
  27 
  28 import static com.sun.marlin.MarlinConst.LOG_UNSAFE_MALLOC;
  29 import jdk.internal.misc.Unsafe;
  30 
  31 /**
  32  *
  33  * @author bourgesl
  34  */
  35 public final class OffHeapArray  {
  36 
  37     // unsafe reference
  38     public static final Unsafe UNSAFE;
  39     // size of int / float
  40     static final int SIZE_INT;
  41 
  42     static {
  43         UNSAFE   = Unsafe.getUnsafe();
  44         SIZE_INT = Unsafe.ARRAY_INT_INDEX_SCALE;
  45     }
  46 
  47     /* members */
  48     public long address;
  49     long length;
  50     int  used;
  51 
  52     public OffHeapArray(final Object parent, final long len) {
  53         // note: may throw OOME:
  54         this.address = UNSAFE.allocateMemory(len);
  55         this.length  = len;
  56         this.used    = 0;
  57         if (LOG_UNSAFE_MALLOC) {
  58             MarlinUtils.logInfo(System.currentTimeMillis()
  59                                 + ": OffHeapArray.allocateMemory =   "
  60                                 + len + " to addr = " + this.address);
  61         }
  62 
  63         // Register a cleaning function to ensure freeing off-heap memory:
  64         MarlinUtils.getCleaner().register(parent, () -> this.free());
  65     }
  66 
  67     /*
  68      * As realloc may change the address, updating address is MANDATORY
  69      * @param len new array length
  70      * @throws OutOfMemoryError if the allocation is refused by the system
  71      */
  72     void resize(final long len) {
  73         // note: may throw OOME:
  74         this.address = UNSAFE.reallocateMemory(address, len);
  75         this.length  = len;
  76         if (LOG_UNSAFE_MALLOC) {
  77             MarlinUtils.logInfo(System.currentTimeMillis()
  78                                 + ": OffHeapArray.reallocateMemory = "
  79                                 + len + " to addr = " + this.address);
  80         }
  81     }
  82 
  83     void free() {
  84         UNSAFE.freeMemory(this.address);
  85         if (LOG_UNSAFE_MALLOC) {
  86             MarlinUtils.logInfo(System.currentTimeMillis()
  87                                 + ": OffHeapArray.freeMemory =       "
  88                                 + this.length
  89                                 + " at addr = " + this.address);
  90         }
  91     }
  92 
  93     void fill(final byte val) {
  94         UNSAFE.setMemory(this.address, this.length, val);
  95     }
  96 }