org.agrona.concurrent.UnsafeBuffer

All Implemented Interfaces:: Comparable<DirectBuffer>, AtomicBuffer, DirectBuffer, MutableDirectBuffer

public class UnsafeBuffer extends AbstractMutableDirectBuffer implements AtomicBuffer

Supports regular, byte ordered, and atomic (memory ordered) access to an underlying buffer. The buffer can be a byte[], one of the various ByteBuffer implementations, or an off Java heap memory address.

ByteOrder of a wrapped buffer is not applied to the UnsafeBuffer. UnsafeBuffers are effectively stateless and can be used concurrently, the wrapping methods are an exception. To control ByteOrder use the appropriate method with the ByteOrder overload.

Note: This class has a natural ordering that is inconsistent with equals. Types may be different but equal on buffer contents.

Note: The wrap methods on this class are not thread safe. Concurrent access should only happen after a successful wrap.

Field Summary

Fields

Modifier and Type

Field

Description

static final int

ALIGNMENT

Buffer alignment in bytes to ensure atomic word accesses.

static final String

DISABLE_BOUNDS_CHECKS_PROP_NAME

Should bounds-checks operations be done or not.

static final boolean

SHOULD_BOUNDS_CHECK

Should bounds-checks operations be done or not.

Fields inherited from class org.agrona.AbstractMutableDirectBuffer
addressOffset, byteArray, capacity

Fields inherited from interface org.agrona.concurrent.AtomicBuffer
STRICT_ALIGNMENT_CHECKS, STRICT_ALIGNMENT_CHECKS_PROP_NAME

Fields inherited from interface org.agrona.DirectBuffer
DISABLE_ARRAY_CONTENT_PRINTOUT_PROP_NAME, STR_HEADER_LEN
Constructor Summary

Constructors

Constructor

Description

UnsafeBuffer()

Empty constructor for a reusable wrapper buffer.

UnsafeBuffer(byte[] buffer)

Attach a view to a byte[] for providing direct access.

UnsafeBuffer(byte[] buffer, int offset, int length)

Attach a view to a byte[] for providing direct access.

UnsafeBuffer(long address, int length)

Attach a view to an off-heap memory region by address.

UnsafeBuffer(ByteBuffer buffer)

Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct.

UnsafeBuffer(ByteBuffer buffer, int offset, int length)

Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct.

UnsafeBuffer(DirectBuffer buffer)

Attach a view to an existing DirectBuffer.

UnsafeBuffer(DirectBuffer buffer, int offset, int length)

Attach a view to an existing DirectBuffer.
Method Summary

Modifier and Type

Method

Description

int

addIntOpaque(int index, int increment)

Adds a value to a given index with opaque semantics.

int

addIntOrdered(int index, int increment)

Atomically add a value to a given index with ordered store semantics.

int

addIntRelease(int index, int increment)

Atomically add a value to a given index with release semantics.

long

addLongOpaque(int index, long increment)

Adds a value to a given index with opaque semantics.

long

addLongOrdered(int index, long increment)

Atomically adds a value to a given index with ordered store semantics.

long

addLongRelease(int index, long increment)

Atomically adds a value to a given index with ordered store semantics.

ByteBuffer

byteBuffer()

Get the underlying ByteBuffer if one exists.

int

compareAndExchangeInt(int index, int expectedValue, int updateValue)

Atomic compare and exchange of a int given an expected value.

long

compareAndExchangeLong(int index, long expectedValue, long updateValue)

Atomic compare and exchange of a long given an expected value.

boolean

compareAndSetInt(int index, int expectedValue, int updateValue)

Atomic compare and set of an int given an expected value.

boolean

compareAndSetLong(int index, long expectedValue, long updateValue)

Atomic compare and set of a long given an expected value.

protected final void

ensureCapacity(int index, int length)

A hook to ensure the underlying buffer has enough capacity for writing data into the buffer.

int

getAndAddInt(int index, int delta)

Atomically add a delta to a value at a location returning the previous contents.

long

getAndAddLong(int index, long delta)

Atomically add a delta to a value at a location returning the previous contents.

int

getAndSetInt(int index, int value)

Atomically exchange a value at a location returning the previous contents.

long

getAndSetLong(int index, long value)

Atomically exchange a value at a location returning the previous contents.

byte

getByteVolatile(int index)

Atomically get the value at a given index with volatile semantics.

char

getCharVolatile(int index)

Atomically get the value at a given index with volatile semantics.

int

getIntAcquire(int index)

Atomically get the value at a given index with acquire semantics.

int

getIntOpaque(int index)

Atomically get a value to a given index with opaque semantics.

int

getIntVolatile(int index)

Atomically get the value at a given index with volatile semantics.

long

getLongAcquire(int index)

Atomically get the value at a given index with acquire semantics.

long

getLongOpaque(int index)

Atomically get a value to a given index with opaque semantics.

long

getLongVolatile(int index)

Atomically get the value at a given index with volatile semantics.

short

getShortVolatile(int index)

Atomically get the value at a given index with volatile semantics.

boolean

isExpandable()

Is this buffer expandable to accommodate putting data into it beyond the current capacity?

void

putByteVolatile(int index, byte value)

Atomically put a value to a given index with volatile semantics.

void

putCharVolatile(int index, char value)

Atomically put a value to a given index with volatile semantics.

void

putIntOpaque(int index, int value)

Atomically put a value to a given index with opaque semantics.

void

putIntOrdered(int index, int value)

Atomically put a value to a given index with ordered semantics.

void

putIntRelease(int index, int value)

Atomically put a value to a given index with release semantics.

void

putIntVolatile(int index, int value)

Atomically put a value to a given index with volatile semantics.

void

putLongOpaque(int index, long value)

Atomically put a value to a given index with opaque semantics.

void

putLongOrdered(int index, long value)

Atomically put a value to a given index with ordered store semantics.

void

putLongRelease(int index, long value)

Atomically put a value to a given index with release semantics.

void

putLongVolatile(int index, long value)

Atomically put a value to a given index with volatile semantics.

void

putShortVolatile(int index, short value)

Atomically put a value to a given index with volatile semantics.

String

toString()

void

verifyAlignment()

Verify that the underlying buffer is correctly aligned to prevent word tearing, other ordering issues and the JVM crashes.

void

wrap(byte[] buffer)

Attach a view to a byte[] for providing direct access.

void

wrap(byte[] buffer, int offset, int length)

Attach a view to a byte[] for providing direct access.

void

wrap(long address, int length)

Attach a view to an off-heap memory region by address.

void

wrap(ByteBuffer buffer)

Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct.

void

wrap(ByteBuffer buffer, int offset, int length)

Attach a view to a ByteBuffer for providing direct access.

void

wrap(DirectBuffer buffer)

Attach a view to an existing DirectBuffer.

void

wrap(DirectBuffer buffer, int offset, int length)

Attach a view to a DirectBuffer for providing direct access.

int

wrapAdjustment()

Get the adjustment in indices between an index in this buffer and the wrapped object.

Methods inherited from class org.agrona.AbstractMutableDirectBuffer
addressOffset, boundsCheck, boundsCheck0, byteArray, capacity, checkLimit, compareTo, equals, getByte, getBytes, getBytes, getBytes, getBytes, getBytes, getChar, getChar, getDouble, getDouble, getFloat, getFloat, getInt, getInt, getLong, getLong, getShort, getShort, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringUtf8, getStringUtf8, getStringUtf8, getStringWithoutLengthAscii, getStringWithoutLengthAscii, getStringWithoutLengthUtf8, hashCode, parseIntAscii, parseLongAscii, parseNaturalIntAscii, parseNaturalLongAscii, putByte, putBytes, putBytes, putBytes, putBytes, putBytes, putChar, putChar, putDouble, putDouble, putFloat, putFloat, putInt, putInt, putIntAscii, putLong, putLong, putLongAscii, putNaturalIntAscii, putNaturalIntAsciiFromEnd, putNaturalLongAscii, putNaturalPaddedIntAscii, putShort, putShort, putStringAscii, putStringAscii, putStringAscii, putStringAscii, putStringUtf8, putStringUtf8, putStringUtf8, putStringUtf8, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthUtf8, setMemory

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Comparable
compareTo

Methods inherited from interface org.agrona.DirectBuffer
addressOffset, boundsCheck, byteArray, capacity, checkLimit, getByte, getBytes, getBytes, getBytes, getBytes, getBytes, getChar, getChar, getDouble, getDouble, getFloat, getFloat, getInt, getInt, getLong, getLong, getShort, getShort, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringAscii, getStringUtf8, getStringUtf8, getStringUtf8, getStringWithoutLengthAscii, getStringWithoutLengthAscii, getStringWithoutLengthUtf8, parseIntAscii, parseLongAscii, parseNaturalIntAscii, parseNaturalLongAscii

Methods inherited from interface org.agrona.MutableDirectBuffer
putByte, putBytes, putBytes, putBytes, putBytes, putBytes, putChar, putChar, putDouble, putDouble, putFloat, putFloat, putInt, putInt, putIntAscii, putLong, putLong, putLongAscii, putNaturalIntAscii, putNaturalIntAsciiFromEnd, putNaturalLongAscii, putNaturalPaddedIntAscii, putShort, putShort, putStringAscii, putStringAscii, putStringAscii, putStringAscii, putStringUtf8, putStringUtf8, putStringUtf8, putStringUtf8, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthAscii, putStringWithoutLengthUtf8, setMemory

Field Details
- ALIGNMENT
  
  public static final int ALIGNMENT
  
  Buffer alignment in bytes to ensure atomic word accesses.
  See Also:
  
  AtomicBuffer.ALIGNMENT
  
  Constant Field Values
- DISABLE_BOUNDS_CHECKS_PROP_NAME
  
  public static final String DISABLE_BOUNDS_CHECKS_PROP_NAME
  
  Should bounds-checks operations be done or not. Controlled by the DirectBuffer.DISABLE_BOUNDS_CHECKS_PROP_NAME system property.
  See Also:
  
  DirectBuffer.DISABLE_BOUNDS_CHECKS_PROP_NAME
  
  Constant Field Values
- SHOULD_BOUNDS_CHECK
  
  public static final boolean SHOULD_BOUNDS_CHECK
  
  Should bounds-checks operations be done or not. Controlled by the DirectBuffer.DISABLE_BOUNDS_CHECKS_PROP_NAME system property.
  See Also:
  
  DirectBuffer.DISABLE_BOUNDS_CHECKS_PROP_NAME
Constructor Details
- UnsafeBuffer
  
  public UnsafeBuffer()
  
  Empty constructor for a reusable wrapper buffer.
- UnsafeBuffer
  
  public UnsafeBuffer(byte[] buffer)
  
  Attach a view to a byte[] for providing direct access.
  Parameters:
  
  buffer - to which the view is attached.
  
  See Also:
  
  wrap(byte[])
- UnsafeBuffer
  
  public UnsafeBuffer(byte[] buffer, int offset, int length)
  
  Attach a view to a byte[] for providing direct access.
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes within the buffer to begin.
  
  length - in bytes of the buffer included in the view.
  
  See Also:
  
  wrap(byte[], int, int)
- UnsafeBuffer
  
  public UnsafeBuffer(ByteBuffer buffer)
  
  Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct.
  
  Parameters:
  
  buffer - to which the view is attached.
- UnsafeBuffer
  
  public UnsafeBuffer(ByteBuffer buffer, int offset, int length)
  
  Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct.
  
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes within the buffer to begin.
  
  length - in bytes of the buffer included in the view.
- UnsafeBuffer
  
  public UnsafeBuffer(DirectBuffer buffer)
  
  Attach a view to an existing DirectBuffer.
  
  Parameters:
  
  buffer - to which the view is attached.
- UnsafeBuffer
  
  public UnsafeBuffer(DirectBuffer buffer, int offset, int length)
  
  Attach a view to an existing DirectBuffer.
  
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes within the buffer to begin.
  
  length - in bytes of the buffer included in the view.
- UnsafeBuffer
  
  public UnsafeBuffer(long address, int length)
  
  Attach a view to an off-heap memory region by address. This is useful for interacting with native libraries.
  
  Parameters:
  
  address - where the memory begins off-heap.
  
  length - of the buffer from the given address.
Method Details
- wrap
  
  public void wrap(byte[] buffer)
  
  Attach a view to a byte[] for providing direct access.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
- wrap
  
  public void wrap(byte[] buffer, int offset, int length)
  
  Attach a view to a byte[] for providing direct access.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes at which the view begins.
  
  length - in bytes of the buffer included in the view.
- wrap
  
  public void wrap(ByteBuffer buffer)
  
  Attach a view to a ByteBuffer for providing direct access, the ByteBuffer can be heap based or direct. The ByteBuffer.order() is not relevant for accessing the wrapped buffer.
  When using this method to wrap the view of the ByteBuffer the entire ByteBuffer gets wrapped between index 0 and capacity. If you want to just wrap the ByteBuffer between the position and the limit then you should use the DirectBuffer.wrap(ByteBuffer, int, int) method, eg:
  directBuffer.wrap(byteBuffer, byteBuffer.position(), byteBuffer.remaining());
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
- wrap
  
  public void wrap(ByteBuffer buffer, int offset, int length)
  
  Attach a view to a ByteBuffer for providing direct access.
  The ByteBuffer.order() is not relevant for accessing the wrapped buffer.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes at which the view begins.
  
  length - in bytes of the buffer included in the view.
- wrap
  
  public void wrap(DirectBuffer buffer)
  
  Attach a view to an existing DirectBuffer.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
- wrap
  
  public void wrap(DirectBuffer buffer, int offset, int length)
  
  Attach a view to a DirectBuffer for providing direct access.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  buffer - to which the view is attached.
  
  offset - in bytes at which the view begins.
  
  length - in bytes of the buffer included in the view.
- wrap
  
  public void wrap(long address, int length)
  
  Attach a view to an off-heap memory region by address.
  
  Specified by:
  
  wrap in interface DirectBuffer
  
  Parameters:
  
  address - where the memory begins off-heap.
  
  length - of the buffer from the given address.
- byteBuffer
  
  public ByteBuffer byteBuffer()
  
  Get the underlying ByteBuffer if one exists.
  NB: there may not be a one-to-one mapping between indices on this buffer and the underlying byte[], see DirectBuffer.wrapAdjustment().
  
  Specified by:
  
  byteBuffer in interface DirectBuffer
  
  Returns:
  
  the underlying ByteBuffer if one exists.
- wrapAdjustment
  
  public int wrapAdjustment()
  
  Get the adjustment in indices between an index in this buffer and the wrapped object. The wrapped object might be a ByteBuffer or a byte[].
  You only need to use this adjustment if you plan to perform operations on the underlying byte array or byte buffer that rely on their indices.
  Specified by:
  
  wrapAdjustment in interface DirectBuffer
  
  Returns:
  
  the adjustment in indices between an index in this buffer and the wrapped object.
  
  See Also:
  
  DirectBuffer.byteArray()
  
  DirectBuffer.byteBuffer()
- isExpandable
  
  public boolean isExpandable()
  
  Is this buffer expandable to accommodate putting data into it beyond the current capacity?
  
  Specified by:
  
  isExpandable in interface MutableDirectBuffer
  
  Returns:
  
  true is the underlying storage can expand otherwise false.
- verifyAlignment
  
  public void verifyAlignment()
  Verify that the underlying buffer is correctly aligned to prevent word tearing, other ordering issues and the JVM crashes. In particular this method verifies that the starting offset of the underlying buffer is properly aligned. However, the actual atomic call must ensure that the index is properly aligned, i.e. it must be aligned to the size of the operand. For example a call to any of the following methods AtomicBuffer.putIntRelease(int, int), AtomicBuffer.putIntVolatile(int, int), AtomicBuffer.addIntRelease(int, int) (int, int)}, AtomicBuffer.getIntVolatile(int), AtomicBuffer.getAndAddInt(int, int) or AtomicBuffer.getAndSetInt(int, int), must have the index aligned by four bytes (e.g. 0, 4, 8, 12, 60 etc.).
  Users are encouraged to call this method after constructing the AtomicBuffer instance in order to ensure that the underlying buffer supports atomic access to long values.
  Agrona provides an agent (org.agrona.agent.BufferAlignmentAgent) that checks the alignment of indexes for all operations at runtime. The agent throws an exception if the unaligned access is detected.
  Note: on some platforms unaligned atomic access can lead to the JVM crashes, e.g.:
  # Java VM: OpenJDK 64-Bit Server VM (25.352-b08 mixed mode bsd-aarch64 compressed oops) # # siginfo: si_signo: 10 (SIGBUS), si_code: 1 (BUS_ADRALN)
  Specified by:
  
  verifyAlignment in interface AtomicBuffer
  
  See Also:
  
  AtomicBuffer.ALIGNMENT
- getLongVolatile
  
  public long getLongVolatile(int index)
  
  Atomically get the value at a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getLongVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putLongVolatile
  
  public void putLongVolatile(int index, long value)
  
  Atomically put a value to a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  putLongVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getLongAcquire
  
  public long getLongAcquire(int index)
  
  Atomically get the value at a given index with acquire semantics.
  
  Specified by:
  
  getLongAcquire in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putLongOrdered
  
  public void putLongOrdered(int index, long value)
  
  Atomically put a value to a given index with ordered store semantics.
  Instead of using this method, use AtomicBuffer.putLongRelease(int, long) instead. They are identical and the putLongRelease is the preferred version.
  
  Specified by:
  
  putLongOrdered in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- putLongRelease
  
  public void putLongRelease(int index, long value)
  
  Atomically put a value to a given index with release semantics.
  
  Specified by:
  
  putLongRelease in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- addLongOrdered
  
  public long addLongOrdered(int index, long increment)
  
  Atomically adds a value to a given index with ordered store semantics. Use a negative increment to decrement.
  The load has no ordering semantics. The store has release semantics.
  Instead of using this method, use AtomicBuffer.addLongRelease(int, long) instead. They are identical but the addLongRelease is the preferred version.
  
  Specified by:
  
  addLongOrdered in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- addLongRelease
  
  public long addLongRelease(int index, long increment)
  
  Atomically adds a value to a given index with ordered store semantics. Use a negative increment to decrement.
  The load has no ordering semantics. The store has release semantics.
  
  Specified by:
  
  addLongRelease in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- putLongOpaque
  
  public void putLongOpaque(int index, long value)
  
  Atomically put a value to a given index with opaque semantics.
  
  Specified by:
  
  putLongOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getLongOpaque
  
  public long getLongOpaque(int index)
  
  Atomically get a value to a given index with opaque semantics.
  
  Specified by:
  
  getLongOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  Returns:
  
  the value for at a given index.
- addLongOpaque
  
  public long addLongOpaque(int index, long increment)
  
  Adds a value to a given index with opaque semantics. The read and write will be atomic, but the combination is not atomic. So don't use this method concurrently because you can run into lost updates due to a race-condition.
  
  Specified by:
  
  addLongOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- compareAndSetLong
  
  public boolean compareAndSetLong(int index, long expectedValue, long updateValue)
  
  Atomic compare and set of a long given an expected value.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  compareAndSetLong in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  expectedValue - at to be compared.
  
  updateValue - to be exchanged.
  
  Returns:
  
  set successful or not.
- compareAndExchangeLong
  
  public long compareAndExchangeLong(int index, long expectedValue, long updateValue)
  
  Atomic compare and exchange of a long given an expected value.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  compareAndExchangeLong in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  expectedValue - at to be compared.
  
  updateValue - to be exchanged.
  
  Returns:
  
  the old value no matter if the expected value was found.
- getAndSetLong
  
  public long getAndSetLong(int index, long value)
  
  Atomically exchange a value at a location returning the previous contents.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getAndSetLong in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
  
  Returns:
  
  previous value at the index.
- getAndAddLong
  
  public long getAndAddLong(int index, long delta)
  
  Atomically add a delta to a value at a location returning the previous contents. To decrement a negative delta can be provided.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getAndAddLong in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  delta - to be added to the value at the index.
  
  Returns:
  
  previous value.
- getIntVolatile
  
  public int getIntVolatile(int index)
  
  Atomically get the value at a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getIntVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putIntVolatile
  
  public void putIntVolatile(int index, int value)
  
  Atomically put a value to a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  putIntVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getIntAcquire
  
  public int getIntAcquire(int index)
  
  Atomically get the value at a given index with acquire semantics.
  
  Specified by:
  
  getIntAcquire in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putIntOrdered
  
  public void putIntOrdered(int index, int value)
  
  Atomically put a value to a given index with ordered semantics.
  Instead of using this method, use AtomicBuffer.putIntRelease(int, int) instead. They are identical but the putIntRelease is the preferred version.
  
  Specified by:
  
  putIntOrdered in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- putIntRelease
  
  public void putIntRelease(int index, int value)
  
  Atomically put a value to a given index with release semantics.
  
  Specified by:
  
  putIntRelease in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- addIntOrdered
  
  public int addIntOrdered(int index, int increment)
  
  Atomically add a value to a given index with ordered store semantics. Use a negative increment to decrement.
  The load has no ordering semantics. The store has release semantics.
  Instead of using this method, use AtomicBuffer.addIntRelease(int, int) instead. They are identical but the addIntRelease is the preferred version.
  
  Specified by:
  
  addIntOrdered in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- addIntRelease
  
  public int addIntRelease(int index, int increment)
  
  Atomically add a value to a given index with release semantics. Use a negative increment to decrement.
  The load has no ordering semantics. The store has release semantics.
  
  Specified by:
  
  addIntRelease in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- putIntOpaque
  
  public void putIntOpaque(int index, int value)
  
  Atomically put a value to a given index with opaque semantics.
  
  Specified by:
  
  putIntOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getIntOpaque
  
  public int getIntOpaque(int index)
  
  Atomically get a value to a given index with opaque semantics.
  
  Specified by:
  
  getIntOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  Returns:
  
  the value for at a given index.
- addIntOpaque
  
  public int addIntOpaque(int index, int increment)
  
  Adds a value to a given index with opaque semantics. The read and write will be atomic, but the combination is not atomic. So don't use this method concurrently because you can run into lost updates due to a race-condition.
  
  Specified by:
  
  addIntOpaque in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  increment - by which the value at the index will be adjusted.
  
  Returns:
  
  the previous value at the index.
- compareAndSetInt
  
  public boolean compareAndSetInt(int index, int expectedValue, int updateValue)
  
  Atomic compare and set of an int given an expected value.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  compareAndSetInt in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  expectedValue - at to be compared.
  
  updateValue - to be exchanged.
  
  Returns:
  
  successful or not.
- compareAndExchangeInt
  
  public int compareAndExchangeInt(int index, int expectedValue, int updateValue)
  
  Atomic compare and exchange of a int given an expected value.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  compareAndExchangeInt in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  expectedValue - at to be compared.
  
  updateValue - to be exchanged.
  
  Returns:
  
  the old value no matter if the expected value was found.
- getAndSetInt
  
  public int getAndSetInt(int index, int value)
  
  Atomically exchange a value at a location returning the previous contents.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getAndSetInt in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
  
  Returns:
  
  previous value.
- getAndAddInt
  
  public int getAndAddInt(int index, int delta)
  
  Atomically add a delta to a value at a location returning the previous contents. To decrement a negative delta can be provided.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getAndAddInt in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  delta - to be added to the value at the index.
  
  Returns:
  
  previous value.
- getShortVolatile
  
  public short getShortVolatile(int index)
  
  Atomically get the value at a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getShortVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putShortVolatile
  
  public void putShortVolatile(int index, short value)
  
  Atomically put a value to a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  putShortVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getByteVolatile
  
  public byte getByteVolatile(int index)
  
  Atomically get the value at a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getByteVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putByteVolatile
  
  public void putByteVolatile(int index, byte value)
  
  Atomically put a value to a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  putByteVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- getCharVolatile
  
  public char getCharVolatile(int index)
  
  Atomically get the value at a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  getCharVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes from which to get.
  
  Returns:
  
  the value for at a given index.
- putCharVolatile
  
  public void putCharVolatile(int index, char value)
  
  Atomically put a value to a given index with volatile semantics.
  This call has sequential-consistent semantics.
  
  Specified by:
  
  putCharVolatile in interface AtomicBuffer
  
  Parameters:
  
  index - in bytes for where to put.
  
  value - for at a given index.
- toString
  
  public String toString()
  
  Overrides:
  
  toString in class Object
- ensureCapacity
  
  protected final void ensureCapacity(int index, int length)
  
  Description copied from class: AbstractMutableDirectBuffer
  
  A hook to ensure the underlying buffer has enough capacity for writing data into the buffer.
  
  Specified by:
  
  ensureCapacity in class AbstractMutableDirectBuffer
  
  Parameters:
  
  index - at which write occurs.
  
  length - in bytes.

Class UnsafeBuffer

Field Summary

Fields inherited from class org.agrona.AbstractMutableDirectBuffer

Fields inherited from interface org.agrona.concurrent.AtomicBuffer

Fields inherited from interface org.agrona.DirectBuffer

Constructor Summary

Method Summary

Methods inherited from class org.agrona.AbstractMutableDirectBuffer

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Comparable

Methods inherited from interface org.agrona.DirectBuffer

Methods inherited from interface org.agrona.MutableDirectBuffer

Field Details

ALIGNMENT

DISABLE_BOUNDS_CHECKS_PROP_NAME

SHOULD_BOUNDS_CHECK

Constructor Details

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

UnsafeBuffer

Method Details

wrap

wrap

wrap

wrap

wrap

wrap

wrap

byteBuffer

wrapAdjustment

isExpandable

verifyAlignment

getLongVolatile

putLongVolatile

getLongAcquire

putLongOrdered

putLongRelease

addLongOrdered

addLongRelease

putLongOpaque

getLongOpaque

addLongOpaque

compareAndSetLong

compareAndExchangeLong

getAndSetLong

getAndAddLong

getIntVolatile

putIntVolatile

getIntAcquire

putIntOrdered

putIntRelease

addIntOrdered

addIntRelease

putIntOpaque

getIntOpaque

addIntOpaque

compareAndSetInt

compareAndExchangeInt

getAndSetInt

getAndAddInt

getShortVolatile

putShortVolatile

getByteVolatile

putByteVolatile

getCharVolatile

putCharVolatile

toString

ensureCapacity