Package org.apache.nemo.runtime.executor.data

Class MemoryPoolAssigner

java.lang.Object

org.apache.nemo.runtime.executor.data.MemoryPoolAssigner

@ThreadSafe
public final class MemoryPoolAssigner
extends java.lang.Object

The MemoryPoolAssigner assigns the memory that Nemo uses for writing data blocks from the MemoryPoolAssigner.MemoryPool. Memory is represented in chunks of equal size. Consumers of off-heap memory acquire the memory by requesting a number of MemoryChunk they need. MemoryPoolAssigner currently supports allocation of off-heap memory only. MemoryChunks are allocated on-demand, but if the total allocated memory exceeds the maxOffheapMb, MemoryAllocationException is thrown and the job fails. TODO #397: Separation of JVM heap region and off-heap memory region

Constructor Summary

Constructors

Constructor	Description
MemoryPoolAssigner(int memory, double maxOffheapRatio, int chunkSizeKb)

Method Summary

Modifier and Type	Method	Description
MemoryChunk	allocateChunk()	Returns a single MemoryChunk from MemoryPoolAssigner.MemoryPool.
int	getChunkSize()	Returns the chunk size of the memory pool.
void	returnChunksToPool(java.lang.Iterable<MemoryChunk> target)	Returns all the MemoryChunks in the given List of MemoryChunks.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MemoryPoolAssigner

@Inject
public MemoryPoolAssigner(int memory,
                          double maxOffheapRatio,
                          int chunkSizeKb)

Method Detail

allocateChunk

public MemoryChunk allocateChunk()
                          throws MemoryAllocationException

Returns a single MemoryChunk from MemoryPoolAssigner.MemoryPool.

Returns:

a MemoryChunk

Throws:

MemoryAllocationException - if fails to allocate MemoryChunk.

returnChunksToPool

public void returnChunksToPool(java.lang.Iterable<MemoryChunk> target)

Returns all the MemoryChunks in the given List of MemoryChunks.

Parameters:

target - the list of MemoryChunks to be returned to the memory pool.

getChunkSize

public int getChunkSize()

Returns the chunk size of the memory pool.

Returns:

the chunk size in bytes.