net.i2p.router.util

Class PriBlockingQueue<E extends PQEntry>

java.lang.Object

java.util.AbstractCollection<E>

java.util.AbstractQueue<E>

java.util.concurrent.PriorityBlockingQueue<E>

net.i2p.router.util.PriBlockingQueue<E>

Type Parameters:

E - type of elements held in this queue, extending PQEntry

All Implemented Interfaces:

Serializable, Iterable<E>, Collection<E>, BlockingQueue<E>, Queue<E>

Direct Known Subclasses:

CoDelPriorityBlockingQueue

public class PriBlockingQueue<E extends PQEntry>
extends PriorityBlockingQueue<E>

Priority blocking queue with bounded capacity and FIFO ordering within priority levels.

Extends PriorityBlockingQueue to provide bounded capacity with FIFO ordering for elements sharing the same priority. Entries extend PQEntry to include sequence numbers for insertion ordering.

Applies sequence timestamps on insertion to ensure FIFO behavior within same priority level while maintaining priority-based ordering. Capacity is controlled by configuration properties to prevent unbounded growth and enable backpressure management.

Thread-safe implementation suitable for concurrent producer-consumer scenarios with comprehensive statistics tracking and performance monitoring.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected I2PAppContext	_context
protected Log	_log
protected String	_name
protected static int	DEFAULT_BACKLOG_SIZE Default backlog and max size depending on system speed.
protected static int	DEFAULT_MAX_SIZE
static String	PROP_BACKLOG_SIZE
static String	PROP_MAX_SIZE Configuration property keys for max size and backlog thresholds.
protected static long[]	RATES Time windows for rate statistics in milliseconds.

Constructor Summary

Constructors

Constructor and Description
PriBlockingQueue(I2PAppContext ctx, String name, int initialCapacity) Constructs a new priority blocking queue with the given initial capacity.

Method Summary

Modifier and Type	Method and Description
boolean	isBacklogged() Checks if the queue size is above the backlog threshold, indicating potential congestion or overload.
boolean	offer(E o) Inserts the specified element into this queue if it is not full, applying sequence timestamp to ensure FIFO ordering within priority.
protected void	timestamp(E o) Assigns a unique sequence number to the element to maintain FIFO ordering among elements of the same priority.

Methods inherited from class java.util.concurrent.PriorityBlockingQueue

add, clear, comparator, contains, drainTo, drainTo, iterator, offer, peek, poll, poll, put, remainingCapacity, remove, size, spliterator, take, toArray, toArray, toString

Methods inherited from class java.util.AbstractQueue

addAll, element, remove

Methods inherited from class java.util.AbstractCollection

containsAll, isEmpty, removeAll, retainAll

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Queue

element, remove

Methods inherited from interface java.util.Collection

addAll, containsAll, equals, hashCode, isEmpty, parallelStream, removeAll, removeIf, retainAll, stream

Methods inherited from interface java.lang.Iterable

forEach

Field Detail

_context

protected final transient I2PAppContext _context

_log

protected final transient Log _log

_name

protected final String _name

DEFAULT_BACKLOG_SIZE

protected static final int DEFAULT_BACKLOG_SIZE

Default backlog and max size depending on system speed.

DEFAULT_MAX_SIZE

protected static final int DEFAULT_MAX_SIZE

PROP_BACKLOG_SIZE

public static final String PROP_BACKLOG_SIZE

See Also:

Constant Field Values

PROP_MAX_SIZE

public static final String PROP_MAX_SIZE

Configuration property keys for max size and backlog thresholds.

See Also:

Constant Field Values

RATES

protected static final long[] RATES

Time windows for rate statistics in milliseconds.

Constructor Detail

PriBlockingQueue

public PriBlockingQueue(I2PAppContext ctx,
                        String name,
                        int initialCapacity)

Constructs a new priority blocking queue with the given initial capacity. The queue is bounded by a configurable max size read once at construction.

Parameters:

ctx - the I2P application context

name - a name for this queue instance (used in stats)

initialCapacity - the initial capacity for the priority queue

Method Detail

isBacklogged

public boolean isBacklogged()

Checks if the queue size is above the backlog threshold, indicating potential congestion or overload.

Returns:

true if queue size is above backlog size threshold, false otherwise

offer

public boolean offer(E o)

Inserts the specified element into this queue if it is not full, applying sequence timestamp to ensure FIFO ordering within priority. Returns false if the queue has reached its maximum size.

Specified by:

offer in interface BlockingQueue<E extends PQEntry>

Specified by:

offer in interface Queue<E extends PQEntry>

Overrides:

offer in class PriorityBlockingQueue<E extends PQEntry>

Parameters:

o - the element to add

Returns:

true if successfully added, false if queue is full

timestamp

protected void timestamp(E o)

Assigns a unique sequence number to the element to maintain FIFO ordering among elements of the same priority.

Parameters:

o - the element to timestamp