--- Berin Loritsch <[EMAIL PROTECTED]> wrote:
> I remember reading an article on how to implement an
> efficient ThreadSafe hashmap.
> The problem is that I can't remember where. The
> concept is to reduce the locking
> contention to a "bucket". The implementation they
> had was fairly simple, and
> went something along these lines:
This might be the place.(atleast this where I found:-)
http://www-106.ibm.com/developerworks/java/library/j-threads2.html
>
> LockedBucketMap
> {
> Object[] locks;
> Node[] buckets;
>
> LockedBucketMap()
> {
> this(256);
> }
>
> LockedBucketMap( int numBockets )
> {
> locks = new Object[numBuckets];
> buckets = new Node[numBuckets];
>
> for (int i = 0; i < locks.length; i++)
> {
> locks[i] = new Object();
> }
> }
>
> void put( Object key, Object value )
> {
> int hash = getHash(key);
>
> Node node = null;
>
> synchronized( locks[hash] )
> {
> node = buckets[hash];
> if (node == null)
> {
> buckets[hash] = new Node( key,
> value );
> }
> else
> {
> while (node != null)
> {
> node = node.next;
> }
> node.next = new Node(key, value);
> }
> }
> }
>
> Object get( Object key )
> {
> int hash = getHash(key);
> Node node = null;
> Object value = null;
>
> synchronized( locks[hash] )
> {
> node = buckets[hash];
>
> while (node != null)
> {
> if (node.key.equals(key)) return
> node.value;
> node = node.next;
> }
> }
> return value;
> }
>
> int getHash( Object key )
> {
> return key.hashCode() % buckets.length;
> }
>
> class Node
> {
> Object key;
> Object value;
> Node next;
> }
> }
>
> I don't have time to test it, debug it, or optimize
> it (what about using
> ArrayList and a Node that matches against the key
> object etc. for lookup).
> Could someone take the ball and run with it? We
> desperately need to reduce
> thread contention on the ECM and ContainerManager
> implementations.
>
> --
>
> "They that give up essential liberty to obtain a
> little temporary safety
> deserve neither liberty nor safety."
> - Benjamin Franklin
>
>
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>
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