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/*
* Copyright (c) 2003, 2019, 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_SERVICES_MEMORYUSAGE_HPP
#define SHARE_SERVICES_MEMORYUSAGE_HPP
#include "utilities/globalDefinitions.hpp"
// A memory usage contains the following attributes about memory usage:
// initSize - represents the initial amount of memory (in bytes) that
// the Java virtual machine requests from the operating system
// for memory management. The Java virtual machine may request
// additional memory from the operating system later when appropriate.
// Its value may be undefined.
// used - represents the amount of memory currently used (in bytes).
// committed - represents the amount of memory (in bytes) that is
// guaranteed to be available for use by the Java virtual machine.
// The amount of committed memory may change over time (increase
// or decrease). It is guaranteed to be greater than or equal
// to initSize.
// maxSize - represents the maximum amount of memory (in bytes)
// that can be used for memory management. The maximum amount of
// memory for memory management could be less than the amount of
// committed memory. Its value may be undefined.
class MemoryUsage {
private:
size_t _initSize;
size_t _used;
size_t _committed;
size_t _maxSize;
public:
// Constructors
MemoryUsage(size_t i, size_t u, size_t c, size_t m) :
_initSize(i), _used(u), _committed(c), _maxSize(m) {};
MemoryUsage() :
_initSize(0), _used(0), _committed(0), _maxSize(0) {};
size_t init_size() const { return _initSize; }
size_t used() const { return _used; }
size_t committed() const { return _committed; }
size_t max_size() const { return _maxSize; }
static size_t undefined_size() { return (size_t) -1; }
inline static jlong convert_to_jlong(size_t val) {
// In the 64-bit vm, a size_t can overflow a jlong (which is signed).
jlong ret;
if (val == undefined_size()) {
ret = -1L;
} else {
NOT_LP64(ret = val;)
LP64_ONLY(ret = MIN2(val, (size_t)max_jlong);)
}
return ret;
}
jlong init_size_as_jlong() const { return convert_to_jlong(_initSize); }
jlong used_as_jlong() const { return convert_to_jlong(_used); }
jlong committed_as_jlong() const { return convert_to_jlong(_committed); }
jlong max_size_as_jlong() const { return convert_to_jlong(_maxSize); }
};
#endif // SHARE_SERVICES_MEMORYUSAGE_HPP
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