public class PooledMemoryManager extends Object implements MemoryManager<Buffer>, WrapperAware
MemoryManager implementation based on a series of shared memory pools.
Each pool contains multiple buffers of the fixed length specific for this pool.
There are several tuning options for this MemoryManager implementation.
Buffers will be allocatedDEFAULT_BASE_BUFFER_SIZE)DEFAULT_NUMBER_OF_POOLS)DEFAULT_GROWTH_FACTOR), which means the first buffer pool will contains buffer of size 4 KiB, the seconds one buffer of size 16KiB, the third one buffer of size 64KiBRuntime.getRuntime().availableProcessors()DEFAULT_HEAP_USAGE_PERCENTAGE)DEFAULT_PREALLOCATED_BUFFERS_PERCENTAGE)Buffers will be allocatedHeapMemoryManager or
ByteBufferManager is that this implementation doesn't use ThreadLocal pools
and as such, doesn't suffer from the memory fragmentation/reallocation cycle that can impact the ThreadLocal versions.| Modifier and Type | Field and Description |
|---|---|
static int |
DEFAULT_BASE_BUFFER_SIZE |
static int |
DEFAULT_GROWTH_FACTOR |
static float |
DEFAULT_HEAP_USAGE_PERCENTAGE |
static int |
DEFAULT_NUMBER_OF_POOLS |
static float |
DEFAULT_PREALLOCATED_BUFFERS_PERCENTAGE |
protected DefaultMonitoringConfig<MemoryProbe> |
monitoringConfig
Basic monitoring support.
|
DEFAULT_MEMORY_MANAGER| Constructor and Description |
|---|
PooledMemoryManager()
Creates a new
PooledMemoryManager using the following defaults:
4 KiB base buffer size
3 pools
2 growth factor, which means 1st pool will contain buffers of size 4KiB, the 2nd - 16KiB, the 3rd - 64KiB
Number of pool slices based on Runtime.getRuntime().availableProcessors()
The initial allocation will use 10% of the heap
The percentage of buffers to be preallocated during MemoryManager initialization
|
PooledMemoryManager(boolean isDirect)
Creates a new
PooledMemoryManager using the specified parameters for configuration. |
PooledMemoryManager(int baseBufferSize,
int numberOfPools,
int growthFactor,
int numberOfPoolSlices,
float percentOfHeap,
float percentPreallocated,
boolean isDirect)
Creates a new
PooledMemoryManager using the specified parameters for configuration. |
| Modifier and Type | Method and Description |
|---|---|
Buffer |
allocate(int size)
For this implementation, this method simply calls through to
allocateAtLeast(int); |
Buffer |
allocateAtLeast(int size)
Allocates a buffer of at least the size requested.
|
protected Object |
createJmxManagementObject() |
MonitoringConfig<MemoryProbe> |
getMonitoringConfig()
Return the object associated
MonitoringConfig. |
Buffer |
reallocate(Buffer oldBuffer,
int newSize)
Reallocates an existing buffer to at least the specified size.
|
void |
release(Buffer buffer)
Release
Buffer. |
boolean |
willAllocateDirect(int size)
Return true if next
MemoryManager.allocate(int) or MemoryManager.allocateAtLeast(int) call,
made in the current thread for the given memory size, going to return a Buffer based
on direct ByteBuffer, or false otherwise. |
Buffer |
wrap(byte[] data)
Returns
Buffer, which wraps the byte array. |
Buffer |
wrap(byte[] data,
int offset,
int length)
Returns
Buffer, which wraps the part of byte array with
specific offset and length. |
Buffer |
wrap(ByteBuffer byteBuffer)
Returns
Buffer, which wraps the ByteBuffer. |
Buffer |
wrap(String s)
|
Buffer |
wrap(String s,
Charset charset)
|
public static final int DEFAULT_BASE_BUFFER_SIZE
public static final int DEFAULT_NUMBER_OF_POOLS
public static final int DEFAULT_GROWTH_FACTOR
public static final float DEFAULT_HEAP_USAGE_PERCENTAGE
public static final float DEFAULT_PREALLOCATED_BUFFERS_PERCENTAGE
protected final DefaultMonitoringConfig<MemoryProbe> monitoringConfig
createJmxManagementObject() method
to plug into the Grizzly 2.0 JMX framework.public PooledMemoryManager()
PooledMemoryManager using the following defaults:
Runtime.getRuntime().availableProcessors()public PooledMemoryManager(boolean isDirect)
PooledMemoryManager using the specified parameters for configuration.isDirect - flag, indicating whether direct or heap based Buffers will be allocatedpublic PooledMemoryManager(int baseBufferSize,
int numberOfPools,
int growthFactor,
int numberOfPoolSlices,
float percentOfHeap,
float percentPreallocated,
boolean isDirect)
PooledMemoryManager using the specified parameters for configuration.baseBufferSize - the base size of the buffer for the 1st pool, every next pool n will have buffer size equal to bufferSize(n-1) * 2^growthFactornumberOfPools - the number of pools, responsible for allocation of buffers of a pool-specific sizegrowthFactor - the buffer size growth factor, that defines 2^x multiplier, used to calculate buffer size for next allocated poolnumberOfPoolSlices - the number of pool slices that every pool will stripe allocation requests acrosspercentOfHeap - percentage of the heap that will be used when populating the poolspercentPreallocated - percentage of buffers to be preallocated during MemoryManager initializationisDirect - flag, indicating whether direct or heap based Buffers will be allocatedpublic Buffer allocate(int size)
allocateAtLeast(int);allocate in interface MemoryManager<Buffer>size - Buffer size to be allocated.Buffer.public Buffer allocateAtLeast(int size)
allocateAtLeast in interface MemoryManager<Buffer>size - the min Buffer size to be allocated.public Buffer reallocate(Buffer oldBuffer, int newSize)
reallocate in interface MemoryManager<Buffer>oldBuffer - old Buffer to be reallocated.newSize - new Buffer required size.public void release(Buffer buffer)
Buffer.
Implementation may ignore releasing and let JVM Garbage collector to take
care about the Buffer, or return Buffer to pool, in case
of more complex MemoryManager implementation.release in interface MemoryManager<Buffer>buffer - Buffer to be released.public boolean willAllocateDirect(int size)
MemoryManager.allocate(int) or MemoryManager.allocateAtLeast(int) call,
made in the current thread for the given memory size, going to return a Buffer based
on direct ByteBuffer, or false otherwise.willAllocateDirect in interface MemoryManager<Buffer>public MonitoringConfig<MemoryProbe> getMonitoringConfig()
MonitoringConfig.getMonitoringConfig in interface MonitoringAware<MemoryProbe>MonitoringConfig.public Buffer wrap(byte[] data)
WrapperAwareBuffer, which wraps the byte array.wrap in interface WrapperAwaredata - byte array to wrapBuffer wrapper on top of passed byte array.public Buffer wrap(byte[] data, int offset, int length)
WrapperAwareBuffer, which wraps the part of byte array with
specific offset and length.wrap in interface WrapperAwaredata - byte array to wrapoffset - byte buffer offsetlength - byte buffer lengthBuffer wrapper on top of passed byte array.public Buffer wrap(String s)
WrapperAwarewrap in interface WrapperAwares - StringBuffer wrapper on top of passed String.public Buffer wrap(String s, Charset charset)
WrapperAwarepublic Buffer wrap(ByteBuffer byteBuffer)
WrapperAwareBuffer, which wraps the ByteBuffer.wrap in interface WrapperAwarebyteBuffer - ByteBuffer to wrapBuffer wrapper on top of passed ByteBuffer.protected Object createJmxManagementObject()
Copyright © 2014 Oracle Corporation. All Rights Reserved.