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+/* 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);
+ }
+
+}