| /* |
| * 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.phoenix.memory; |
| |
| import net.jcip.annotations.GuardedBy; |
| import net.jcip.annotations.ThreadSafe; |
| |
| import org.apache.phoenix.exception.SQLExceptionCode; |
| import org.apache.phoenix.exception.SQLExceptionInfo; |
| |
| /** |
| * |
| * Child memory manager that delegates through to global memory manager, |
| * but enforces that at most a threshold percentage is used by this |
| * memory manager. No blocking is done if the threshold is exceeded, |
| * but the standard blocking will be done by the global memory manager. |
| * |
| * |
| * @since 0.1 |
| */ |
| @ThreadSafe |
| public class ChildMemoryManager extends DelegatingMemoryManager { |
| private final Object sync = new Object(); |
| private final int maxPercOfTotal; |
| @GuardedBy("sync") |
| private long allocatedBytes; |
| |
| public ChildMemoryManager(MemoryManager mm, int maxPercOfTotal) { |
| super(mm); |
| if (mm instanceof ChildMemoryManager) { |
| throw new IllegalStateException("ChildMemoryManager cannot delegate to another ChildMemoryManager"); |
| } |
| this.maxPercOfTotal = maxPercOfTotal; |
| if (maxPercOfTotal <= 0 || maxPercOfTotal > 100) { |
| throw new IllegalArgumentException("Max percentage of total memory (" + maxPercOfTotal + "%) must be greater than zero and less than or equal to 100"); |
| } |
| } |
| |
| |
| private long adjustAllocation(long minBytes, long reqBytes) { |
| assert(reqBytes >= minBytes); |
| long availBytes = getAvailableMemory(); |
| // Check if this memory managers percentage of allocated bytes exceeds its allowed maximum |
| if (minBytes > availBytes) { |
| throw new InsufficientMemoryException( |
| new SQLExceptionInfo.Builder(SQLExceptionCode.INSUFFICIENT_MEMORY) |
| .setMessage("Attempt to allocate more memory than the max allowed of " + maxPercOfTotal + "%") |
| .build().buildException()); |
| } |
| // Revise reqBytes down to available memory if necessary |
| return Math.min(reqBytes,availBytes); |
| } |
| |
| @Override |
| public MemoryChunk allocate(long minBytes, long nBytes) { |
| synchronized (sync) { |
| nBytes = adjustAllocation(minBytes, nBytes); |
| final MemoryChunk chunk = super.allocate(minBytes, nBytes); |
| allocatedBytes += chunk.getSize(); |
| // Instantiate delegate chunk to track allocatedBytes correctly |
| return new MemoryChunk() { |
| @Override |
| public void close() { |
| synchronized (sync) { |
| allocatedBytes -= chunk.getSize(); |
| chunk.close(); |
| } |
| } |
| |
| @Override |
| public long getSize() { |
| return chunk.getSize(); |
| } |
| |
| @Override |
| public void resize(long nBytes) { |
| synchronized (sync) { |
| long size = getSize(); |
| long deltaBytes = nBytes - size; |
| if (deltaBytes > 0) { |
| adjustAllocation(deltaBytes,deltaBytes); // Throw if too much memory |
| } |
| chunk.resize(nBytes); |
| allocatedBytes += deltaBytes; |
| } |
| } |
| }; |
| } |
| } |
| |
| @Override |
| public long getAvailableMemory() { |
| synchronized (sync) { |
| long availBytes = getMaxMemory() - allocatedBytes; |
| // Sanity check (should never happen) |
| if (availBytes < 0) { |
| throw new IllegalStateException("Available memory has become negative: " + availBytes + " bytes. Allocated memory: " + allocatedBytes + " bytes."); |
| } |
| return availBytes; |
| } |
| } |
| |
| @Override |
| public long getMaxMemory() { |
| return maxPercOfTotal * super.getMaxMemory() / 100; |
| } |
| } |