com.bigdata.rwstore

Class AllocBlock

java.lang.Object

com.bigdata.rwstore.AllocBlock

public class AllocBlock
extends Object

Bit maps for an allocator. The allocator is a bit map managed as int[]s.

Method Summary

Methods

Modifier and Type	Method and Description
void	abortshadow(RWWriteCacheService cache) Must release allocations made by this allocator.
void	addAddresses(ArrayList addrs, int rootAddr)
boolean	addressInRange(int addr, int size)
int	alloc(int size) The shadow, if non-null defines the context for this request.
void	deshadow() The transient bits will have been added to correctly, we now just need to restore the commit bits from the m_saveCommit, to allow re-allocation of non-committed storage.
boolean	free(int addr, int size)
boolean	freeBit(int bit)
boolean	freeBit(int bit, boolean sessionProtect)
int	getAllocBits()
String	getStats(RWStore.AllocationStats stats)
boolean	hasFree()
void	shadow() Store m_commit bits in m_saveCommit then duplicate transients to m_commit.
String	show()
boolean	verify(int addr, int size)

Methods inherited from class java.lang.Object

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

Method Detail

verify

public boolean verify(int addr,
             int size)

addressInRange

public boolean addressInRange(int addr,
                     int size)

free

public boolean free(int addr,
           int size)

freeBit

public boolean freeBit(int bit)

freeBit

public boolean freeBit(int bit,
              boolean sessionProtect)

alloc

public int alloc(int size)

The shadow, if non-null defines the context for this request. If an existing shadow is registered, then the allocation fails immediately. If no existing shadow is registered, and a new allocation can be made then this AllocBlock is registered with the shadow. Note that when shadows are used, an allocator on a free list may not have allocations available for all contexts, so the assumption that presence on the free list implies availability is not assertable.

hasFree

public boolean hasFree()

getAllocBits

public int getAllocBits()

getStats

public String getStats(RWStore.AllocationStats stats)

addAddresses

public void addAddresses(ArrayList addrs,
                int rootAddr)

shadow

public void shadow()

Store m_commit bits in m_saveCommit then duplicate transients to m_commit. This ensures, that while shadowed, the allocator will not re-use storage that was allocated prior to the shadow creation.

deshadow

public void deshadow()

The transient bits will have been added to correctly, we now just need to restore the commit bits from the m_saveCommit, to allow re-allocation of non-committed storage.

abortshadow

public void abortshadow(RWWriteCacheService cache)

Must release allocations made by this allocator. The commit bits are the old transient bits, so any allocated bits set in live, but not in commit, were set within this context. The m_commit is the m_transients bits at the point of the link of the allocationContext with this allocator, bits set in m_live that are not set in m_commit, were made by this allocator for the aborted context. L 1100 0110 AC 0111 AB 0110 T 1100 1110 1111 1110 C 1100 1100 1110 1100 BUT the shadow abort must not undo transients bits that were deleted from other contexts. This issue is resolved with the deferred free mechanism linked to the ContextAllocation.

show

public String show()