Mega Code Archive
0405 Concurrent Collections
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The java.util.concurrent package has several interfaces and classes that are concurrency-oriented extensions to the Collections Framework.
BlockingDeque is a subinterface of BlockingQueue and java.util.Deque. BlockingDeque supports blocking operations. The LinkedBlockingDeque class implements BlockingDeque.
BlockingQueue is a subinterface of java.util.Queue that supports blocking operations. ArrayBlockingQueue, DelayQueue, LinkedBlockingDeque, LinkedBlockingQueue, LinkedTransferQueue, PriorityBlockingQueue, and SynchronousQueue classes implements BlockingQueue.
TransferQueue is a subinterface of BlockingQueue and describes a blocking queue in which producers may wait for consumers to receive elements. The LinkedTransferQueue class implements this interface.
ConcurrentMap is a subinterface of java.util.Map that declares additional atomic putIfAbsent(), remove(), and replace() methods. The ConcurrentHashMap class and the ConcurrentSkipListMap class implement this interface.
ConcurrentNavigableMap is a subinterface of ConcurrentMap and java.util.NavigableMap. The ConcurrentSkipListMap class implements this interface.
ConcurrentLinkedDeque is an unbounded concurrent deque based on linked nodes. ConcurrentLinkedQueue is an unbounded thread-safe FIFO implementation of the Queue interface.
ConcurrentSkipListSet is a scalable concurrent NavigableSet implementation.
CopyOnWriteArrayList is a thread-safe java.util.ArrayList. CopyOnWriteArraySet is a java.util.Set implementation that uses an internal CopyOnWriteArrayList instance for all its operations.
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
public class Main {
public static void main(String[] args) {
final BlockingQueue<Character> bq = new ArrayBlockingQueue<Character>(26);
final ExecutorService executor = Executors.newFixedThreadPool(2);
Runnable producer;
producer = new Runnable() {
public void run() {
for (char ch = 'A'; ch <= 'F'; ch++) {
try {
bq.put(ch);
System.out.println("putting:"+ch);
} catch (InterruptedException ie) {
assert false;
}
}
}
};
executor.execute(producer);
Runnable consumer;
consumer = new Runnable() {
public void run() {
char ch = '\0';
do {
try {
ch = bq.take();
System.out.println("getting:"+ch);
} catch (InterruptedException ie) {
}
} while (ch != 'F');
executor.shutdownNow();
}
};
executor.execute(consumer);
}
}
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