1 /* 2 * Copyright (c) 2003, 2013, 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 #ifndef SHARE_VM_SERVICES_MEMORYUSAGE_HPP 26 #define SHARE_VM_SERVICES_MEMORYUSAGE_HPP 27 28 #include "utilities/globalDefinitions.hpp" 29 30 // A memory usage contains the following attributes about memory usage: 31 // initSize - represents the initial amount of memory (in bytes) that 32 // the Java virtual machine requests from the operating system 33 // for memory management. The Java virtual machine may request 34 // additional memory from the operating system later when appropriate. 35 // Its value may be undefined. 36 // used - represents the amount of memory currently used (in bytes). 37 // committed - represents the amount of memory (in bytes) that is 38 // guaranteed to be available for use by the Java virtual machine. 39 // The amount of committed memory may change over time (increase 40 // or decrease). It is guaranteed to be greater than or equal 41 // to initSize. 42 // maxSize - represents the maximum amount of memory (in bytes) 43 // that can be used for memory management. The maximum amount of 44 // memory for memory management could be less than the amount of 45 // committed memory. Its value may be undefined. 46 47 class MemoryUsage VALUE_OBJ_CLASS_SPEC { 48 private: 49 size_t _initSize; 50 size_t _used; 51 size_t _committed; 52 size_t _maxSize; 53 54 public: 55 // Constructors 56 MemoryUsage(size_t i, size_t u, size_t c, size_t m) : 57 _initSize(i), _used(u), _committed(c), _maxSize(m) {}; 58 MemoryUsage() : 59 _initSize(0), _used(0), _committed(0), _maxSize(0) {}; 60 61 size_t init_size() const { return _initSize; } 62 size_t used() const { return _used; } 63 size_t committed() const { return _committed; } 64 size_t max_size() const { return _maxSize; } 65 66 static size_t undefined_size() { return (size_t) -1; } 67 68 inline static jlong convert_to_jlong(size_t val) { 69 // In the 64-bit vm, a size_t can overflow a jlong (which is signed). 70 jlong ret; 71 if (val == undefined_size()) { 72 ret = -1L; 73 } else { 74 NOT_LP64(ret = val;) 75 LP64_ONLY(ret = MIN2(val, (size_t)max_jlong);) 76 } 77 return ret; 78 } 79 80 jlong init_size_as_jlong() const { return convert_to_jlong(_initSize); } 81 jlong used_as_jlong() const { return convert_to_jlong(_used); } 82 jlong committed_as_jlong() const { return convert_to_jlong(_committed); } 83 jlong max_size_as_jlong() const { return convert_to_jlong(_maxSize); } 84 }; 85 86 #endif // SHARE_VM_SERVICES_MEMORYUSAGE_HPP