eu.stratosphere.runtime.io.network.bufferprovider.GlobalBufferPool Maven / Gradle / Ivy
/***********************************************************************************************************************
* Copyright (C) 2010-2014 by the Stratosphere project (http://stratosphere.eu)
*
* Licensed 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 eu.stratosphere.runtime.io.network.bufferprovider;
import java.util.Queue;
import java.util.concurrent.ArrayBlockingQueue;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import eu.stratosphere.core.memory.MemorySegment;
/**
* A global buffer pool for the network stack.
*
* All buffers used by the network stack come from this pool. Requests to this pool are mediated by instances of
* {@link LocalBufferPool}.
*
* The size and number of buffers can be configured via the global system config.
*/
public final class GlobalBufferPool {
private final static Log LOG = LogFactory.getLog(GlobalBufferPool.class);
// -----------------------------------------------------------------------------------------------------------------
/** Total number of buffers */
private final int numBuffers;
/** Size of each buffer (in bytes) */
private final int bufferSize;
/** The available buffers */
private final Queue buffers;
private boolean isDestroyed;
// -----------------------------------------------------------------------------------------------------------------
public GlobalBufferPool(int numBuffers, int bufferSize) {
this.numBuffers = numBuffers;
this.bufferSize = bufferSize;
this.buffers = new ArrayBlockingQueue(this.numBuffers);
for (int i = 0; i < this.numBuffers; i++) {
this.buffers.add(new MemorySegment(new byte[this.bufferSize]));
}
LOG.info(String.format("Initialized global buffer pool with %d buffers (%d bytes each).",
this.numBuffers, this.bufferSize));
}
// -----------------------------------------------------------------------------------------------------------------
/**
* Requests a buffer from the pool.
*
* @return buffer from pool or null, if no buffer available
*/
public MemorySegment requestBuffer() {
return this.buffers.poll();
}
/**
* Returns a buffer to the pool.
*
* @param buffer the buffer to be returned
*/
public void returnBuffer(MemorySegment buffer) {
this.buffers.add(buffer);
}
/**
* Returns the size of buffers (in bytes).
*
* @return size of buffers (in bytes)
*/
public int getBufferSize() {
return this.bufferSize;
}
/**
* Returns the total number of managed buffers.
*
* @return total number of managed buffers
*/
public int numBuffers() {
return this.numBuffers;
}
/**
* Returns the number of currently available buffers.
*
* @return currently available number of buffers
*/
public int numAvailableBuffers() {
return this.buffers.size();
}
public synchronized void destroy() {
if (!this.isDestroyed) {
// mark as shutdown and release memory
this.isDestroyed = true;
for (MemorySegment buffer : this.buffers) {
buffer.free();
}
this.buffers.clear();
}
}
}