1 /* 2 * Copyright (c) 2003, 2005, 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 // A memory usage contains the following attributes about memory usage: 26 // initSize - represents the initial amount of memory (in bytes) that 27 // the Java virtual machine requests from the operating system 28 // for memory management. The Java virtual machine may request 29 // additional memory from the operating system later when appropriate. 30 // Its value may be undefined. 31 // used - represents the amount of memory currently used (in bytes). 32 // committed - represents the amount of memory (in bytes) that is 33 // guaranteed to be available for use by the Java virtual machine. 34 // The amount of committed memory may change over time (increase 35 // or decrease). It is guaranteed to be greater than or equal 36 // to initSize. 37 // maxSize - represents the maximum amount of memory (in bytes) 38 // that can be used for memory management. The maximum amount of 39 // memory for memory management could be less than the amount of 40 // committed memory. Its value may be undefined. 41 42 class MemoryUsage VALUE_OBJ_CLASS_SPEC { 43 private: 44 size_t _initSize; 45 size_t _used; 46 size_t _committed; 47 size_t _maxSize; 48 49 public: 50 // Constructors 51 MemoryUsage(size_t i, size_t u, size_t c, size_t m) : 52 _initSize(i), _used(u), _committed(c), _maxSize(m) {}; 53 MemoryUsage() : 54 _initSize(0), _used(0), _committed(0), _maxSize(0) {}; 55 56 size_t init_size() const { return _initSize; } 57 size_t used() const { return _used; } 58 size_t committed() const { return _committed; } 59 size_t max_size() const { return _maxSize; } 60 61 inline static jlong convert_to_jlong(size_t val) { 62 // In the 64-bit vm, a size_t can overflow a jlong (which is signed). 63 jlong ret; 64 if (val == (size_t)-1) { 65 ret = -1L; 66 } else { 67 NOT_LP64(ret = val;) 68 LP64_ONLY(ret = MIN2(val, (size_t)max_jlong);) 69 } 70 return ret; 71 } 72 73 jlong init_size_as_jlong() const { return convert_to_jlong(_initSize); } 74 jlong used_as_jlong() const { return convert_to_jlong(_used); } 75 jlong committed_as_jlong() const { return convert_to_jlong(_committed); } 76 jlong max_size_as_jlong() const { return convert_to_jlong(_maxSize); } 77 };