Class MallocMT

java.lang.Object

one.nio.mem.Malloc

one.nio.mem.MallocMT

All Implemented Interfaces:

Allocator, MallocMXBean

Direct Known Subclasses:

MallocAnalyzer

public class MallocMT
extends Malloc

Concurrent implementation of Malloc. Divides the whole memory space into several synchronized Malloc-segments to reduce lock contention.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_CONCURRENCY_LEVEL
private Malloc[]	segments
private long	segmentSize

Fields inherited from class Malloc

base, BASE_OFFSET, BIN_COUNT, BIN_SIZE, BIN_SPACE, capacity, CAPACITY_OFFSET, FREE_MASK, HEADER_SIZE, LEFT_OFFSET, MAX_CHUNK, MIN_CHUNK, NEXT_OFFSET, OCCUPIED_MASK, PREV_OFFSET, SIGNATURE_OFFSET, SIGNATURE_V2, SIGNATURE_V3, SIZE_OFFSET

Constructor Summary

Constructors

Constructor	Description
MallocMT(long capacity)
MallocMT(long capacity, int concurrencyLevel)
MallocMT(long base, long capacity)
MallocMT(long base, long capacity, int concurrencyLevel)
MallocMT(MappedFile mmap)
MallocMT(MappedFile mmap, int concurrencyLevel)

Method Summary

Modifier and Type	Method	Description
int	allocatedSize(long address)
void	free(long address)
long	getFreeMemory()
(package private) void	init()
private void	initSegments(int concurrencyLevel)
long	malloc(int size)
Malloc	segment(int index)
private Malloc	segmentByAddress(long address)
Malloc	segmentFor(long n)	Deterministically get one of the segments by some long value
int	segments()
void	verify()	Verify the layout of the heap.

Methods inherited from class Malloc

base, binSize, calloc, chooseBin, getBin, getTotalMemory, getUsedMemory, mallocImpl

Methods inherited from class Object

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

Field Details

DEFAULT_CONCURRENCY_LEVEL

public static final int DEFAULT_CONCURRENCY_LEVEL

See Also:

• Constant Field Values

segments

private Malloc[] segments

segmentSize

private long segmentSize

Constructor Details

MallocMT

public MallocMT(long capacity,
 int concurrencyLevel)

MallocMT

public MallocMT(long capacity)

MallocMT

public MallocMT(long base,
 long capacity,
 int concurrencyLevel)

MallocMT

public MallocMT(long base,
 long capacity)

MallocMT

public MallocMT(MappedFile mmap,
 int concurrencyLevel)

MallocMT

public MallocMT(MappedFile mmap)

Method Details

segments

public int segments()

segment

public Malloc segment(int index)

segmentFor

public Malloc segmentFor(long n)

Deterministically get one of the segments by some long value

Parameters:

n - an index of the segment to return

Returns:

the Malloc instance for the specified segment

getFreeMemory

public long getFreeMemory()

Specified by:

getFreeMemory in interface MallocMXBean

Overrides:

getFreeMemory in class Malloc

malloc

public long malloc(int size)

Specified by:

malloc in interface Allocator

Overrides:

malloc in class Malloc

segmentByAddress

private Malloc segmentByAddress(long address)

free

public void free(long address)

Specified by:

free in interface Allocator

Overrides:

free in class Malloc

allocatedSize

public int allocatedSize(long address)

Overrides:

allocatedSize in class Malloc

verify

public void verify()

Description copied from interface: Allocator

Verify the layout of the heap. Expensive operation, used only for debugging purposes.

Specified by:

verify in interface Allocator

Overrides:

verify in class Malloc

init

void init()

Overrides:

init in class Malloc

initSegments

private void initSegments(int concurrencyLevel)