StorageMemoryPool¶

StorageMemoryPool is a MemoryPool.

Creating Instance¶

StorageMemoryPool takes the following to be created:

• Lock Object
• MemoryMode (ON_HEAP or OFF_HEAP)

StorageMemoryPool is created when:

• MemoryManager is created (and initializes on-heap and off-heap storage memory pools)

MemoryStore¶

StorageMemoryPool is given a MemoryStore when MemoryManager is requested to associate one with the on- and off-heap storage memory pools.

StorageMemoryPool uses the MemoryStore (to evict blocks) when requested to:

• Acquire Memory
• Free Space to Shrink Pool

Size of Memory Used¶

StorageMemoryPool keeps track of the size of the memory acquired.

The size descreases when StorageMemoryPool is requested to releaseMemory or releaseAllMemory.

memoryUsed is part of the MemoryPool abstraction.

Acquiring Memory¶

acquireMemory(
  blockId: BlockId,
  numBytes: Long): Boolean
acquireMemory(
  blockId: BlockId,
  numBytesToAcquire: Long,
  numBytesToFree: Long): Boolean

acquireMemory...FIXME

acquireMemory is used when:

• UnifiedMemoryManager is requested to acquire storage memory

Freeing Space to Shrink Pool¶

freeSpaceToShrinkPool(
  spaceToFree: Long): Long

freeSpaceToShrinkPool...FIXME

freeSpaceToShrinkPool is used when:

• UnifiedMemoryManager is requested to acquire execution memory