org.apache.ignite.internal.processors.cache.persistence.pagemem

Class PagePool

java.lang.Object

org.apache.ignite.internal.processors.cache.persistence.pagemem.PagePool

public class PagePool
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
protected long	freePageListPtr Pointer to the address of the free page list.
protected int	idx Segment index.
protected long	lastAllocatedIdxPtr
protected long	pagesBase Pages base.
protected AtomicInteger	pagesCntr Pool pages counter.
protected DirectMemoryRegion	region Direct memory region.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	PagePool(int idx, DirectMemoryRegion region, int sysPageSize, OffheapReadWriteLock rwLock)

Method Summary

Modifier and Type	Method and Description
long	borrowOrAllocateFreePage(int tag) Allocates a new free page.
int	pages()
int	releaseFreePage(long relPtr)
int	size()

Methods inherited from class java.lang.Object

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

Field Detail

idx

protected final int idx

Segment index.

region

protected final DirectMemoryRegion region

Direct memory region.

pagesCntr

protected final AtomicInteger pagesCntr

Pool pages counter.

lastAllocatedIdxPtr

protected long lastAllocatedIdxPtr

freePageListPtr

protected long freePageListPtr

Pointer to the address of the free page list.

pagesBase

protected long pagesBase

Pages base.

Constructor Detail

PagePool

protected PagePool(int idx,
                   DirectMemoryRegion region,
                   int sysPageSize,
                   OffheapReadWriteLock rwLock)

Parameters:

idx - Index.

region - Region

Method Detail

borrowOrAllocateFreePage

public long borrowOrAllocateFreePage(int tag)
                              throws GridOffHeapOutOfMemoryException

Allocates a new free page.

Parameters:

tag - Tag to initialize page RW lock.

Returns:

Relative pointer to the allocated page.

Throws:

GridOffHeapOutOfMemoryException - If failed to allocate new free page.

releaseFreePage

public int releaseFreePage(long relPtr)

Parameters:

relPtr - Relative pointer to free.

Returns:

Resulting number of pages in pool if pages counter is enabled, 0 otherwise.

pages

public int pages()

Returns:

Max number of pages in the pool.

size

public int size()

Returns:

Number of pages in the list.