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Posted to commits@commons.apache.org by mt...@apache.org on 2009/08/19 09:41:21 UTC
svn commit: r805689 -
/commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java
Author: mturk
Date: Wed Aug 19 07:41:21 2009
New Revision: 805689
URL: http://svn.apache.org/viewvc?rev=805689&view=rev
Log:
Add SharedMemory prototype class
Added:
commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java (with props)
Added: commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java
URL: http://svn.apache.org/viewvc/commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java?rev=805689&view=auto
==============================================================================
--- commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java (added)
+++ commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java Wed Aug 19 07:41:21 2009
@@ -0,0 +1,194 @@
+/* Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.commons.runtime;
+
+import java.io.IOException;
+import org.apache.commons.runtime.io.File;
+import org.apache.commons.runtime.exception.OperatingSystemException;
+import org.apache.commons.runtime.exception.UnsupportedOperatingSystemException;
+
+/**
+ * SharedMemory class.
+ * <p>
+ * <b>Warning:</b><br/>Using this class improperly may crash the running JVM.
+ * </p>
+ *
+ * @since Runtime 1.0
+ */
+public final class SharedMemory
+{
+
+ /*
+ * Reference to the OS shared memory descriptor
+ */
+ private Descriptor shm;
+
+ private SharedMemory()
+ {
+ // No Instance
+ }
+
+ /**
+ * Create and make accessable anonymous shared memory segment.
+ * <p>
+ * A note about Anonymous vs. Named shared memory segments:<br />
+ * Not all plaforms support anonymous shared memory segments, but in
+ * some cases it is prefered over other types of shared memory
+ * implementations. If such a system is not available,
+ * {@code UnsupportedOperatingSystemException} is thrown.
+ * </p>
+ * <p>
+ * A note about allocation sizes:<br />
+ * On some platforms it is necessary to store some metainformation
+ * about the segment within the actual segment. In order to supply
+ * the caller with the requested size it may be necessary for the
+ * implementation to request a slightly greater segment length
+ * from the subsystem. In all cases, the {@code get()}
+ * function will return the first usable byte of memory.
+ * </p>
+ * @param reqsize The desired size of the segment.
+ * @param name The file to use for shared memory on platforms that
+ * require it.
+ */
+ public static SharedMemory create(long size)
+ {
+ return null;
+ }
+
+ /**
+ * Create and make accessable a shared memory segment.
+ * <p>
+ * A note about Anonymous vs. Named shared memory segments:<br />
+ * Not all plaforms support anonymous shared memory segments, but in
+ * some cases it is prefered over other types of shared memory
+ * implementations. If such a system is not available,
+ * {@code UnsupportedOperatingSystemException} is thrown.
+ * </p>
+ * <p>
+ * A note about allocation sizes:<br />
+ * On some platforms it is necessary to store some metainformation
+ * about the segment within the actual segment. In order to supply
+ * the caller with the requested size it may be necessary for the
+ * implementation to request a slightly greater segment length
+ * from the subsystem. In all cases, the {@code get()}
+ * function will return the first usable byte of memory.
+ * </p>
+ * @param reqsize The desired size of the segment.
+ * @param file The abstract file path to use for shared memory on platforms
+ * that require it.
+ */
+ public static SharedMemory create(File file, long size)
+ {
+ return null;
+ }
+
+ /**
+ * Attach to a shared memory segment that was created
+ * by another process.
+ * @param file The abstract file path that was used to create a
+ * shared memory block.
+ */
+ public static SharedMemory attach(File file)
+ {
+ return null;
+ }
+
+ /**
+ * Remove shared memory segment associated with a {@code file}.
+ * <p>
+ * This function is only supported on platforms which support
+ * name-based shared memory segments.
+ * </p>
+ * @param file The abstract file path associated with shared memory
+ * segment which needs to be removed.
+ */
+ public static boolean remove(File file)
+ {
+ return true;
+ }
+
+ /**
+ * Detach the shared memory segment from the system.
+ * <p>
+ * Detaching shared memory will remove reference to the shared
+ * memory.
+ * </p>
+ * <p><b>Warning:</b><br/>
+ * Any usage of the memory pointed by this shared memory
+ * segment after this call will probably crash the running JVM.
+ * </p>
+ */
+ public void detach()
+ {
+ }
+
+ /**
+ * Close and remove the shared memory segment from the system.
+ * <p>
+ * Closing shared memory will remove reference to the shared
+ * memory segment and remove it from the system. Actual removal
+ * will happen when the last {@code SharedMemory} object referencing
+ * the shared memory segment is closed or detached.
+ * </p>
+ * <p><b>Warning:</b><br/>
+ * Any usage of the memory pointed by this shared memory
+ * segment after this call will probably crash the running JVM.
+ * </p>
+ */
+ public void close()
+ {
+ }
+
+ /**
+ * Retrieve the length of a shared memory segment in bytes.
+ */
+ public long size()
+ {
+ return 0;
+ }
+
+ /**
+ * Retrieve new {@code Pointer} base address of the shared memory segment.
+ * <p>
+ * <b>Warning:</b><br/>This address is only usable within the callers address
+ * space, since this API does not guarantee that other attaching
+ * processes will maintain the same address mapping.
+ * </p>
+ * @return Memory pointer.
+ */
+ public Pointer get()
+ {
+ return null;
+ }
+
+ /**
+ * Retrieve new @code Pointer}address of the shared memory segment.
+ * <p>
+ * <b>Warning:</b><br/>This address is only usable within the callers address
+ * space, since this API does not guarantee that other attaching
+ * processes will maintain the same address mapping.
+ * </p>
+ * @param offset Offset in bytes from the begining of the shared memory.
+ * @param size Size to map.
+ * @return Memory pointer.
+ */
+ public Pointer get(long offset, long size)
+ {
+ return null;
+ }
+
+}
+
Propchange: commons/sandbox/runtime/trunk/src/main/java/org/apache/commons/runtime/SharedMemory.java
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