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Diffstat (limited to 'libjava/classpath/vm/reference/gnu/java/lang/management/VMMemoryMXBeanImpl.java')
-rw-r--r-- | libjava/classpath/vm/reference/gnu/java/lang/management/VMMemoryMXBeanImpl.java | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/libjava/classpath/vm/reference/gnu/java/lang/management/VMMemoryMXBeanImpl.java b/libjava/classpath/vm/reference/gnu/java/lang/management/VMMemoryMXBeanImpl.java new file mode 100644 index 000000000..7f69bdfb7 --- /dev/null +++ b/libjava/classpath/vm/reference/gnu/java/lang/management/VMMemoryMXBeanImpl.java @@ -0,0 +1,156 @@ +/* VMMemoryMXBeanImpl.java - VM impl. of a memory bean + Copyright (C) 2006 Free Software Foundation + +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 +{ + + /** + * 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); + } + +} |