Taken from Wikipedia, personal adaptations and additions made, shortened to be used as a small reference card, links back to wikipedia kept for details.
See also Software Anti-Patterns.
| Architectural patterns [ Choice: How is the software system (as a whole) organized? ] |
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| Layers | Separation of the system in layers, each layer knowing only of the layer above and under itself. |
| Model-View-Controller | Separation of the view (user interface) from the model (underlying data) and the controller (user interaction) |
| Multitier architecture |
The presentation, the application processing, and the data management are logically separate processes. |
| Pipeline | Chain of processing elements. |
| Implicit invocation | Event broadcasting, the caller doesn't know who is called. |
| Blackboard system | A common knowledge base, is iteratively updated by a diverse subsystems |
| Peer-to-peer | No central server, each peer is supplier and consumer |
| Service-oriented architecture | Loose coupling of services within the system. |
| Naked objects | Objects and their representation are not biased by adapters or proxys. |
| Creational patterns [ Choice: How to create the objects? ] |
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| Abstract factory | Interface for creating families of related or dependent objects without specifying their concrete classes. |
| Factory method | Creating an object, but let subclasses decide which class to instantiate. Factory Method lets a class defer instantiation to subclasses. |
| Builder | Separate the construction of a complex object from its representation. The same construction process can create different representations. |
| Lazy initialization | Tactic of delaying the creation of an object, the calculation of a value, or some other expensive process until the first time it is needed. |
| Object pool | Avoid expensive acquisition and release of resources by recycling objects that are no longer in use. |
| Prototype | Specify the kinds of objects to create using a prototypical instance, and create new objects by copying this prototype. (Cloning) |
| Singleton | Ensure a class has only one instance, and provide a global point of access to it. |
| Multiton | Ensure a class has only named instances, and provide global point of access to them. |
| Resource acquisition is initialization | Ensure that resources are properly released by tying them to the lifespan of suitable objects. |
| Structural patterns [ Choice: What relationship have the objects? ] |
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| Adapter or Wrapper | Convert the interface of a class into another interface clients expect. Adapter lets classes work together that couldn't otherwise because of incompatible interfaces. |
| Bridge | Decouple an abstraction from its implementation so that the two can vary independently. |
| Composite | Compose objects into tree structures to represent part-whole hierarchies. Composite lets clients treat individual objects and compositions of objects uniformly. |
| Decorator | Attach additional responsibilities to an object dynamically keeping the same interface. Decorators provide a flexible alternative to subclassing for extending functionality. |
| Facade | Provide a unified interface to a set of interfaces in a subsystem. Facade defines a higher-level interface that makes the subsystem easier to use. |
| Flyweight | Use sharing to support large numbers of fine-grained objects efficiently. |
| Proxy | Provide a surrogate or placeholder for another object to control access to it. |
| Behavioral patterns [ Choice: How are the objects communicating? ] |
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| Chain of responsibility | Avoid coupling the sender of a request to its receiver by giving more than one object a chance to handle the request. Chain the receiving objects and pass the request along the chain until an object handles it. |
| Command | Encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations. |
| Interpreter | Given a language, define a representation for its grammar along with an interpreter that uses the representation to interpret sentences in the language. |
| Iterator | Provide a way to access the elements of an aggregate object sequentially without exposing its underlying representation. |
| Mediator | Define an object that encapsulates how a set of objects interact. Mediator promotes loose coupling by keeping objects from referring to each other explicitly, and it lets you vary their interaction independently. |
| Restorer | An alternative to the existing Memento pattern. |
| Memento | Without violating encapsulation, capture and externalize an object's internal state so that the object can be restored to this state later. |
| Null Object | Designed to act as a default value of an object, usually to avoid special treatment for null pointers. |
| Observer or Publish/subscribe | Define a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically. |
| Blackboard | Generalized observer, which allows multiple readers and writers. Communicates information system-wide. |
| State | Allow an object to alter its behavior when its internal state changes. The object will appear to change its class. |
| Strategy | Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it. |
| Specification | Recombinable business logic in a boolean fashion |
| Template method | Define the skeleton of an algorithm in an operation, deferring some steps to subclasses. Template Method lets subclasses redefine certain steps of an algorithm without changing the algorithm's structure. |
| Visitor | Represent an operation to be performed on the elements of an object structure. Visitor lets you define a new operation without changing the classes of the elements on which it operates. |
| Concurrency patterns [ Choice: How to synchronize concurrent access to the object? ] |
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| Active Object | Decouples method execution from method invocation that reside in their own thread of control. The goal is to introduce concurrency, by using asynchronous method invocation and a scheduler for handling requests. |
| Binding Properties | Combining multiple observers to force properties in different objects to be synchronized or coordinated in some way. |
| Event-Based Asynchronous | Addresses problems with the Asynchronous Pattern that occur in multithreaded programs. |
| Balking | Executes an action on an object only when the object is in a particular state. |
| Guarded suspension | In concurrent programming, managing operations that require both a lock to be acquired and a precondition to be satisfied before the operation can be executed. |
| Monitor object | Approach to synchronize two or more computer tasks that use a shared resource, usually a hardware device or a set of variables. |
| Scheduler | Explicitly control when threads may execute single-threaded code. |
| Thread pool | A number of threads are created to perform a number of tasks, which are usually organized in a queue. Typically, there are many more tasks than threads. |
| Thread-specific storage | Thread-local storage (TLS) is a computer programming method that uses static or global memory local to a thread. |
| Reactor | Handling service requests delivered concurrently to a service handler by one or more inputs. The service handler then demultiplexes the incoming requests and dispatches them synchronously to the associated request handlers. |
| Lock | One thread puts a "lock" on a resource, preventing other threads from accessing or modifying it. |
| Double checked locking | "double-checked locking optimization". Reduce the overhead of acquiring a lock by first testing the locking criterion (the 'lock hint') in an unsafe manner; only if that succeeds does the actual lock proceed.
In some language/hardware combinations, can be unsafe. It can therefore sometimes be considered an anti-pattern. |
| Read write lock | Allows concurrent read access to an object but requires exclusive access for write operations. |
