| /* VMMemoryMXBeanImpl.java - VM impl. of a memory bean |
| Copyright (C) 2006, 2010 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.java.lang.management; |
| |
| import java.lang.management.ManagementFactory; |
| import java.lang.management.MemoryPoolMXBean; |
| import java.lang.management.MemoryType; |
| import java.lang.management.MemoryUsage; |
| |
| import java.util.Iterator; |
| import java.util.List; |
| |
| /** |
| * Provides access to information about the memory |
| * management of the current invocation of the virtual |
| * machine. Instances of this bean are obtained by calling |
| * {@link ManagementFactory#getMemoryMXBean()}. |
| * |
| * @author Andrew John Hughes (gnu_andrew@member.fsf.org) |
| * @since 1.5 |
| */ |
| final class VMMemoryMXBeanImpl |
| { |
| |
| private VMMemoryMXBeanImpl() {} // Prohibits instantiation. |
| |
| /** |
| * Returns an instance of {@link java.lang.management.MemoryUsage} |
| * with appropriate initial, used, committed and maximum values |
| * for the heap. By default, this uses the methods of |
| * {@link java.lang.Runtime} to provide some of the values. |
| * |
| * @return an {@link java.lang.management.MemoryUsage} instance |
| * for the heap. |
| */ |
| static MemoryUsage getHeapMemoryUsage() |
| { |
| return getUsage(MemoryType.HEAP); |
| } |
| |
| /** |
| * Returns an instance of {@link java.lang.management.MemoryUsage} |
| * with appropriate initial, used, committed and maximum values |
| * for non-heap memory. |
| * |
| * @return an {@link java.lang.management.MemoryUsage} instance |
| * for non-heap memory. |
| */ |
| static MemoryUsage getNonHeapMemoryUsage() |
| { |
| return getUsage(MemoryType.NON_HEAP); |
| } |
| |
| /** |
| * Returns the number of objects ready to be garbage collected. |
| * |
| * @return the number of finalizable objects. |
| */ |
| static native int getObjectPendingFinalizationCount(); |
| |
| /** |
| * Returns true if the virtual machine will emit additional |
| * information when memory is allocated and deallocated. The |
| * format of the output is left up to the virtual machine. |
| * |
| * @return true if verbose memory usage output is on. |
| */ |
| static native boolean isVerbose(); |
| |
| /** |
| * Turns on or off the emission of additional information |
| * when memory is allocated and deallocated. The format of the |
| * output is left up to the virtual machine. This method |
| * may be called by multiple threads concurrently, but there |
| * is only one global setting of verbosity that is affected. |
| * |
| * @param verbose the new setting for verbose memory usage |
| * output. |
| */ |
| static native void setVerbose(boolean verbose); |
| |
| /** |
| * Totals the memory usage from all the pools that match |
| * the given type. |
| * |
| * @param type the type of memory pools to accumulate |
| * (heap or non-heap). |
| * @return the memory usage overall. |
| */ |
| private static MemoryUsage getUsage(MemoryType type) { |
| long init = 0, committed = 0, used = 0, max = 0; |
| Iterator pools = |
| ManagementFactory.getMemoryPoolMXBeans().iterator(); |
| while (pools.hasNext()) |
| { |
| MemoryPoolMXBean pool = (MemoryPoolMXBean) pools.next(); |
| if (pool.getType() == type) |
| { |
| MemoryUsage usage = pool.getUsage(); |
| if (init != -1) |
| { |
| long poolInit = usage.getInit(); |
| if (poolInit == -1) |
| init = -1; |
| else |
| init += poolInit; |
| } |
| committed += usage.getCommitted(); |
| used += usage.getUsed(); |
| if (max != -1) |
| { |
| long poolMax = usage.getMax(); |
| if (poolMax == -1) |
| max = -1; |
| else |
| max += poolMax; |
| } |
| } |
| } |
| return new MemoryUsage(init, used, committed, max); |
| } |
| |
| } |