drill-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From julienledem <...@git.apache.org>
Subject [GitHub] drill pull request: DRILL-4134: Allocator updates
Date Tue, 01 Dec 2015 18:11:37 GMT
Github user julienledem commented on a diff in the pull request:

    https://github.com/apache/drill/pull/283#discussion_r46315028
  
    --- Diff: exec/memory/base/src/main/java/org/apache/drill/exec/memory/AllocatorManager.java
---
    @@ -0,0 +1,386 @@
    +/**
    + * 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.drill.exec.memory;
    +
    +import static org.apache.drill.exec.memory.BaseAllocator.indent;
    +import io.netty.buffer.DrillBuf;
    +import io.netty.buffer.PooledByteBufAllocatorL;
    +import io.netty.buffer.UnsafeDirectLittleEndian;
    +
    +import java.util.IdentityHashMap;
    +import java.util.concurrent.atomic.AtomicInteger;
    +import java.util.concurrent.atomic.AtomicLong;
    +import java.util.concurrent.locks.Lock;
    +import java.util.concurrent.locks.ReadWriteLock;
    +import java.util.concurrent.locks.ReentrantReadWriteLock;
    +
    +import org.apache.drill.common.HistoricalLog;
    +import org.apache.drill.exec.memory.BaseAllocator.Verbosity;
    +import org.apache.drill.exec.metrics.DrillMetrics;
    +import org.apache.drill.exec.ops.BufferManager;
    +
    +import com.carrotsearch.hppc.LongObjectOpenHashMap;
    +import com.google.common.base.Preconditions;
    +
    +/**
    + * Manages the relationship between one or more allocators and a particular UDLE. Ensures
that one allocator owns the
    + * memory that multiple allocators may be referencing. Manages a BufferLedger between
each of its associated allocators.
    + * This class is also responsible for managing when memory is allocated and returned
to the Netty-based
    + * PooledByteBufAllocatorL.
    + *
    + * The only reason that this isn't package private is we're forced to put DrillBuf in
Netty's package which need access
    + * to these objects or methods.
    + *
    + * Threading: AllocatorManager manages thread-safety internally. Operations within the
context of a single BufferLedger
    + * are lockless in nature and can be leveraged by multiple threads. Operations that cross
the context of two ledgers
    + * will acquire a lock on the AllocatorManager instance. Important note, there is one
AllocatorManager per
    + * UnsafeDirectLittleEndian buffer allocation. As such, there will be thousands of these
in a typical query. The
    + * contention of acquiring a lock on AllocatorManager should be very low.
    + *
    + */
    +public class AllocatorManager {
    +  // private static final org.slf4j.Logger logger = org.slf4j.LoggerFactory.getLogger(AllocatorManager.class);
    +
    +  private static final AtomicLong LEDGER_ID_GENERATOR = new AtomicLong(0);
    +  static final PooledByteBufAllocatorL INNER_ALLOCATOR = new PooledByteBufAllocatorL(DrillMetrics.getInstance());
    +
    +  private final RootAllocator root;
    +  private volatile BufferLedger owningLedger;
    +  private final int size;
    +  private final UnsafeDirectLittleEndian underlying;
    +  private final ReadWriteLock lock = new ReentrantReadWriteLock();
    +  private final LongObjectOpenHashMap<BufferLedger> map = new LongObjectOpenHashMap<>();
    +  private final AutoCloseableLock readLock = new AutoCloseableLock(lock.readLock());
    +  private final AutoCloseableLock writeLock = new AutoCloseableLock(lock.writeLock());
    +  private final IdentityHashMap<DrillBuf, Object> buffers =
    +      BaseAllocator.DEBUG ? new IdentityHashMap<DrillBuf, Object>() : null;
    +
    +  AllocatorManager(BaseAllocator accountingAllocator, int size) {
    +    Preconditions.checkNotNull(accountingAllocator);
    +    this.root = accountingAllocator.root;
    +    this.underlying = INNER_ALLOCATOR.allocate(size);
    +    this.owningLedger = associate(accountingAllocator);
    +    this.size = underlying.capacity();
    +  }
    +
    +  /**
    +   * Associate the existing underlying buffer with a new allocator.
    +   *
    +   * @param allocator
    +   *          The target allocator to associate this buffer with.
    +   * @return The Ledger (new or existing) that associates the underlying buffer to this
new ledger.
    +   */
    +  public BufferLedger associate(BaseAllocator allocator) {
    +    if (root != allocator.root) {
    +      throw new IllegalStateException(
    +          "A buffer can only be associated between two allocators that share the same
root.");
    --- End diff --
    
    maybe add both allocators info to help with debugging


---
If your project is set up for it, you can reply to this email and have your
reply appear on GitHub as well. If your project does not have this feature
enabled and wishes so, or if the feature is enabled but not working, please
contact infrastructure at infrastructure@apache.org or file a JIRA ticket
with INFRA.
---

Mime
View raw message