/**
* 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.hadoop.hive.llap.cache;
import com.google.common.annotations.VisibleForTesting;
import java.util.concurrent.atomic.AtomicLong;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hive.conf.HiveConf;
import org.apache.hadoop.hive.conf.HiveConf.ConfVars;
import org.apache.hadoop.hive.llap.io.api.impl.LlapIoImpl;
import org.apache.hadoop.hive.llap.metrics.LlapDaemonCacheMetrics;
/**
* Implementation of memory manager for low level cache. Note that memory is released during
* reserve most of the time, by calling the evictor to evict some memory. releaseMemory is
* called rarely.
*/
public class LowLevelCacheMemoryManager implements MemoryManager {
private final AtomicLong usedMemory;
private final LowLevelCachePolicy evictor;
private final LlapDaemonCacheMetrics metrics;
private long maxSize;
public LowLevelCacheMemoryManager(
long maxSize, LowLevelCachePolicy evictor, LlapDaemonCacheMetrics metrics) {
this.maxSize = maxSize;
this.evictor = evictor;
this.usedMemory = new AtomicLong(0);
this.metrics = metrics;
if (LlapIoImpl.LOG.isInfoEnabled()) {
LlapIoImpl.LOG.info("Memory manager initialized with max size {} and" +
" {} ability to evict blocks", maxSize, ((evictor == null) ? "no " : ""));
}
}
@Override
public void reserveMemory(final long memoryToReserve) {
boolean result = reserveMemory(memoryToReserve, true);
if (result) return;
// Can only happen if there's no evictor, or if thread is interrupted.
throw new RuntimeException("Cannot reserve memory"
+ (Thread.currentThread().isInterrupted() ? "; thread interrupted" : ""));
}
@VisibleForTesting
public boolean reserveMemory(final long memoryToReserve, boolean waitForEviction) {
// TODO: if this cannot evict enough, it will spin infinitely. Terminate at some point?
int badCallCount = 0;
int nextLog = 4;
long evictedTotalMetric = 0, reservedTotalMetric = 0, remainingToReserve = memoryToReserve;
boolean result = true;
while (remainingToReserve > 0) {
long usedMem = usedMemory.get(), newUsedMem = usedMem + remainingToReserve;
if (newUsedMem <= maxSize) {
if (usedMemory.compareAndSet(usedMem, newUsedMem)) {
reservedTotalMetric += remainingToReserve;
break;
}
continue;
}
if (evictor == null) return false;
// TODO: for one-block case, we could move notification for the last block out of the loop.
long evicted = evictor.evictSomeBlocks(remainingToReserve);
if (evicted == 0) {
if (!waitForEviction) {
result = false;
break;
}
++badCallCount;
if (badCallCount == nextLog) {
LlapIoImpl.LOG.warn("Cannot evict blocks for " + badCallCount + " calls; cache full?");
nextLog <<= 1;
try {
Thread.sleep(Math.min(1000, nextLog));
} catch (InterruptedException e) {
Thread.currentThread().interrupt();
result = false;
break;
}
}
continue;
}
evictedTotalMetric += evicted;
badCallCount = 0;
// Adjust the memory - we have to account for what we have just evicted.
while (true) {
long availableToReserveAfterEvict = maxSize - usedMem + evicted;
long reservedAfterEvict = Math.min(remainingToReserve, availableToReserveAfterEvict);
if (usedMemory.compareAndSet(usedMem, usedMem - evicted + reservedAfterEvict)) {
remainingToReserve -= reservedAfterEvict;
reservedTotalMetric += reservedAfterEvict;
break;
}
usedMem = usedMemory.get();
}
}
if (!result) {
releaseMemory(reservedTotalMetric);
reservedTotalMetric = 0;
}
metrics.incrCacheCapacityUsed(reservedTotalMetric - evictedTotalMetric);
return result;
}
@Override
public long forceReservedMemory(int allocationSize, int count) {
if (evictor == null) return 0;
return evictor.tryEvictContiguousData(allocationSize, count);
}
@Override
public void releaseMemory(final long memoryToRelease) {
long oldV;
do {
oldV = usedMemory.get();
assert oldV >= memoryToRelease;
} while (!usedMemory.compareAndSet(oldV, oldV - memoryToRelease));
metrics.incrCacheCapacityUsed(-memoryToRelease);
}
@Override
public String debugDumpForOom() {
if (evictor == null) return null;
return "\ncache state\n" + evictor.debugDumpForOom();
}
@Override
public void debugDumpShort(StringBuilder sb) {
if (evictor == null) return;
evictor.debugDumpShort(sb);
}
@Override
public void updateMaxSize(long maxSize) {
this.maxSize = maxSize;
}
}