danepitkin commented on code in PR #38016: URL: https://github.com/apache/arrow/pull/38016#discussion_r1346148466
########## java/memory/memory-ffm/src/main/java/org/apache/arrow/memory/FfmAllocationManager.java: ########## @@ -0,0 +1,77 @@ +/* + * 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.arrow.memory; + +import java.lang.foreign.Arena; +import java.lang.foreign.MemorySegment; + +/** + * Allocation manager based on java.lang.foreign API. + */ +public final class FfmAllocationManager extends AllocationManager { + + private static final ArrowBuf EMPTY = new ArrowBuf(ReferenceManager.NO_OP, + null, + 0, + MemorySegment.NULL.address() + ); + + public static final AllocationManager.Factory FACTORY = new Factory() { + @Override + public AllocationManager create(BufferAllocator accountingAllocator, long size) { + return new FfmAllocationManager(accountingAllocator, size); + } + + @Override + public ArrowBuf empty() { + return EMPTY; + } + }; + + private final Arena arena; + + private final MemorySegment allocatedMemorySegment; + + private final long allocatedSize; + + private final long allocatedAddress; + + FfmAllocationManager(BufferAllocator accountingAllocator, long requestedSize) { + super(accountingAllocator); + arena = Arena.ofShared(); Review Comment: An `Arena` controls the lifecycle of native (off-heap) memory segments. The `Shared` Arena has a bounded lifetime, is explicitly closeable, and is accessible by multiple threads.[1] [1]https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/foreign/Arena.html -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
