Java.util.concurrent Queues: Difference between revisions
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<tt>java.util.concurrent.BlockingQueue<E></tt> is a <tt>java.util.Queue</tt> that has operations that wait for the queue to become non-empty when retrieving an element, and wait for space to become available in the queue when storing an element. When configured with a fixed size (example <tt>[[#ArrayBlockingQueue|ArrayBlockingQueue]]</tt>), it can be used as a memory sprawl control mechanisms, providing memory-safe separation between threads. | <tt>java.util.concurrent.BlockingQueue<E></tt> is a <tt>java.util.Queue</tt> that has operations that wait for the queue to become non-empty when retrieving an element, and wait for space to become available in the queue when storing an element. When configured with a fixed size (example <tt>[[#ArrayBlockingQueue|ArrayBlockingQueue]]</tt>), it can be used as a memory sprawl control mechanisms, providing memory-safe separation between threads. | ||
'''Insertion Operations''': | |||
* put() blocks if the queue is full. | * put() blocks if the queue is full. | ||
* add() throws exception if the queue is full. | * add() throws exception if the queue is full. | ||
* offer() attempts to insert and immediately returns <tt>true</tt> if the insertion was successful or <tt>false</tt> if no space is available. offer() has an overloaded version that times out. | * offer() attempts to insert and immediately returns <tt>true</tt> if the insertion was successful or <tt>false</tt> if no space is available. offer() has an overloaded version that times out. | ||
'''Removal Operations''': | |||
* take() blocks if the queue is empty. | * take() blocks if the queue is empty. | ||
* remove() throws exception if the queue is empty. | * remove() throws exception if the queue is empty. | ||
* poll() attempts to remove the head of the queue and returns null if the queue is empty. poll() has an overloaded version that times out. | * poll() attempts to remove the head of the queue and returns null if the queue is empty. poll() has an overloaded version that times out. | ||
'''Inspection Operations''': | |||
* peek() retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. | * peek() retrieves, but does not remove, the head of this queue, or returns null if this queue is empty. | ||
* element() retrieves, but does not remove, the head of this queue, and throws exception if the queue is empty. | * element() retrieves, but does not remove, the head of this queue, and throws exception if the queue is empty. | ||
Revision as of 17:28, 23 March 2018
Internal
Overview
Blocking Queue
java.util.concurrent.BlockingQueue<E> is a java.util.Queue that has operations that wait for the queue to become non-empty when retrieving an element, and wait for space to become available in the queue when storing an element. When configured with a fixed size (example ArrayBlockingQueue), it can be used as a memory sprawl control mechanisms, providing memory-safe separation between threads.
Insertion Operations:
- put() blocks if the queue is full.
- add() throws exception if the queue is full.
- offer() attempts to insert and immediately returns true if the insertion was successful or false if no space is available. offer() has an overloaded version that times out.
Removal Operations:
- take() blocks if the queue is empty.
- remove() throws exception if the queue is empty.
- poll() attempts to remove the head of the queue and returns null if the queue is empty. poll() has an overloaded version that times out.
Inspection Operations:
- peek() retrieves, but does not remove, the head of this queue, or returns null if this queue is empty.
- element() retrieves, but does not remove, the head of this queue, and throws exception if the queue is empty.
It has the following implementations: