org.apache.flink.runtime.memory.OpaqueMemoryResource Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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,
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* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.memory;
import org.apache.flink.util.function.ThrowingRunnable;
import java.util.concurrent.atomic.AtomicBoolean;
import static org.apache.flink.util.Preconditions.checkArgument;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* An opaque memory resource, meaning a memory resource not understood by Flink or the JVM.
* An example for this is a native resource, like RocksDB's block cache memory pool.
*
* The resource must be closed after it is not used any more.
*/
public final class OpaqueMemoryResource implements AutoCloseable {
private final T resourceHandle;
private final long size;
private final ThrowingRunnable disposer;
private final AtomicBoolean closed = new AtomicBoolean();
public OpaqueMemoryResource(T resourceHandle, long size, ThrowingRunnable disposer) {
checkArgument(size >= 0, "size must be >= 0");
this.resourceHandle = checkNotNull(resourceHandle, "resourceHandle");
this.disposer = checkNotNull(disposer, "disposer");
this.size = size;
}
/**
* Gets the handle to the resource.
*/
public T getResourceHandle() {
return resourceHandle;
}
/**
* Gets the size, in bytes.
*/
public long getSize() {
return size;
}
/**
* Releases this resource.
* This method is idempotent.
*/
@Override
public void close() throws Exception {
if (closed.compareAndSet(false, true)) {
disposer.run();
}
}
@Override
public String toString() {
return "OpaqueMemoryResource (" + size + " bytes) @ " + resourceHandle + (closed.get() ? " (disposed)" : "");
}
}