Behavioral pattern: Difference between revisions

Revision as of 13:05, 21 February 2024

Latest revision as of 20:17, 8 June 2025

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: Designed to act as a default value of an object

<dl>

<dt>[[Observer pattern]]</dt>

<dd>Defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. The variant '''weak reference pattern''' decouples an observer from an observable to avoid memory leaks in environments without automatic weak references.<ref>{{cite web |last=Nakashian |first=Ashod |date=2004-04-11 |title=Weak Reference Pattern |url=http://c2.com/ |url-status=bot: unknown |archive-url=https://web.archive.org/web/20110303085751/http://c2.com/ |archive-date=2011-03-03 |access-date=2012-05-21 |publisher=c2.com}}</ref></dd></dl>

<dd>a.k.a. Publish/Subscribe or Event Listener. Objects register to observe an event that may be raised by another object

<dl>

<dt>Weak reference pattern</dt>

<dd>De-couple an observer from an observable<ref>{{cite web

|first = Ashod

|last = Nakashian

|url = http://c2.com/

|title = Weak Reference Pattern

|date = 2004-04-11

|publisher = c2.com

|archive-url = https://web.archive.org/web/20110303085751/http://c2.com/

|archive-date = 2011-03-03

|access-date = 2012-05-21

|url-status = bot: unknown

}}</ref>

</dd>

</dl>

</dd>

</dl>

;[[Protocol stack]]

: Communications are handled by multiple layers, which form an encapsulation hierarchy<ref>{{cite web

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|url-status = bot: unknown

}}</ref>

;[[Publish–subscribe pattern]]<dd>A messaging pattern where senders (publishers) and receivers (subscribers) are decoupled via message topics and brokers. Commonly used in distributed systems, this pattern supports asynchronous, many-to-many communication.</dd>

;[[Scheduled-task pattern]]

: A task is scheduled to be performed at a particular interval or clock time (used in [[real-time computing]])