Patent Publication Number: US-10318359-B2

Title: Techniques to remotely access object events

Description:
CROSS-REFERENCE OF RELATED APPLICATIONS 
     This application is a continuation of, claims the benefit of, and priority to U.S. patent application Ser. No. 13/898,423, filed May 20, 2013, which is a continuation of U.S. patent application Ser. No. 12/858,748, filed on Aug. 18, 2010 and issued as U.S. Pat. No. 8,464,281; the subject matter of both of the above are hereby incorporated by reference in their entireties. 
    
    
     BACKGROUND 
     Object-oriented programming (OOP) is a programming paradigm that uses objects to design software programs. An object may comprise a discrete set of data structures with a defined set of data fields, methods (functions or procedures), properties and events. Each object is capable of receiving messages, processing data, and sending messages to other objects. In other words, each object can be viewed as an independent “machine” with a distinct role or responsibility. As such, a software program may represent a collection of interacting objects. 
     Objects for a software program may be executed in a same process or different processes. A process is an instance of a software program that is being executed. Depending on an operating system, a process may be implemented as one or more threads of execution that execute instructions from the software program concurrently. In some cases, objects for a software program may be executed by different threads of a single process, or by different processes, on a single device. In other cases, objects for a software program may be executed by different processes on different devices, such as in a distributed computing environment. 
     Objects executed in different processes, or in some cases different threads of a single process, typically utilize some form of inter-process communication (IPC) to exchange data between the different processes. IPC techniques may include operations related to message passing, synchronization, shared memory, and remote procedure calls (RPC). Different IPC techniques may be used based on such factors as bandwidth and latency of communication between processes or threads of a process, and a type of data being communicated. 
     A class of IPC techniques may include RPC techniques. RPC techniques may be used to implement a programming concept referred to as “remoting.” Remoting techniques may be used when different objects are implemented by different processes on different devices. Remoting allows a local object executing by a process on one device to access a remote object executing by another process on a different device. For instance, OOP and remoting techniques may be used as a programming model for web applications, such as Rich Internet Applications (RIAs). RIAs are a rapidly growing segment of the software industry. RIAs are web applications that have many of the characteristics of desktop applications, typically delivered either by way of a site-specific browser, via a browser plug-in, or independently via sandboxes or virtual machines. Users generally need to install a software framework using a computer operating system before launching an RIA. The software framework typically retrieves, updates, verifies and executes a given RIA. 
     Web applications such as RIAs utilize various types of remoting techniques. For instance, an RIA may implement objects in a browser as part of a user interface for a web service or web application executing objects on a server. A local object executed by the browser may remotely access certain features of a remote object executed by the web service or web application, such as passing data to the remote object for processing by a method of the remote object. However, conventional remoting techniques are typically limited as to which features of remote objects are accessible, and further, how to access features of remote objects in an efficient manner. It is with respect to these and other considerations that the present improvements are needed. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter. 
     Various embodiments are generally directed to techniques to remotely access object events. Some embodiments are particularly directed to enhanced IPC techniques to remotely access events native to a remote object by other objects executing on separate threads or processes. In one embodiment, object events for a remote object may be accessed without any modifications to the remote object, thereby allowing software programs to utilize legacy objects as originally programmed. 
     In one embodiment, for example, an apparatus such as a computing device may comprise a processor and a memory communicatively coupled to the processor. The memory may be operative to store a remote event bridge having a surrogate object that when executed by the processor is operative to allow an observer object for a first process to subscribe to an event of a subject object for a second process using the surrogate object. In this manner, the remote event bridge and the surrogate object operates as an interface between subject objects and observer objects without any modifications to either class of objects. Other embodiments are described and claimed. 
     These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that both the foregoing general description and the following detailed description are explanatory only and are not restrictive of aspects as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an embodiment of an inter-process communication system. 
         FIG. 2  illustrates an embodiment of a logic flow for an IPC system. 
         FIG. 3  illustrates an embodiment of a first operating environment. 
         FIG. 4  illustrates an embodiment of a second operating environment. 
         FIG. 5  illustrates an embodiment of a third operating environment. 
         FIG. 6  illustrates an embodiment of a fourth operating environment. 
         FIG. 7  illustrates an embodiment of a computing architecture. 
         FIG. 8  illustrates an embodiment of a communications architecture. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments are generally directed to techniques to remotely access object events. Some embodiments are particularly directed to enhanced IPC techniques to remotely access events native to a remote object by other objects executing on separate threads or processes. In one embodiment, object events for a remote object may be accessed without any modifications to the remote object, thereby allowing software programs to utilize legacy objects as originally programmed. 
     In various embodiments, enhanced IPC techniques may be implemented to allow one object to subscribe and communicate with another object. An object may generally comprise any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. In one embodiment, an object may comprise objects suitable for an OOP programming architecture, and in this context, may refer to a particular instance of a class. 
     In one embodiment, enhanced IPC techniques may be implemented to allow an observer object to remotely access object events for a subject object. An observer object may generally refer to any object subscribing to any features of another object, such as an object event of another object. A subject object may generally refer to any object granting a subscription to any features of the object, such as an object event of the object. In some cases, the subject object may also publish event notifications when an event occurs (or “fires”). A subject object may sometimes be referred to herein as a “remote object” or a “remoted object” since a subject object is remotely accessed by an observer object. Although certain embodiments may be described with reference to observer objects and subject objects, it may be appreciated that the enhanced IPC techniques may be implemented for any objects suitable for a given software program, software platform, software framework, or software architecture. The embodiments are not limited in this context. 
     In various embodiments, an observer object and a subject object may be executing on separate threads, processes and/or devices. In one embodiment, for example, each of the observer object and the subject object may be executing on different threads of a single process. In one embodiment, for example, each of the observer object and the subject object may be executing on different processes within a single electronic device. In one embodiment, for example, each of the observer object and the subject object may be executing on different processes, with each process implemented by different electronic devices. 
     Various embodiments implement various enhanced IPC techniques through a remote event bridge. A remote event bridge may refer to a software component designed to operate as an interface between observer objects and subject objects. A remote event bridge allows an observer object to access various object events for a subject object. In one embodiment, a remote event bridge may be implemented as a centralized software component within a process for an observer object or a subject object. In one embodiment, a remote event bridge may be implemented as a distributed software component with portions within each process for an observer object and a subject object. 
     Enhanced IPC techniques implemented by a remote event bridge provide several advantages over conventional IPC techniques. For instance, conventional IPC techniques may implement a client-server technique referred to as “push technology.” Push technology is a communication model where a request for a given transaction is initiated by a publisher, such as a server computer (referred to sometimes as “server push”). Push technology may be contrasted with “pull technology” where a request is initiated by a subscriber, such as a client computer. However, push technology such as server push is typically uni-directional. By way of contrast, enhanced IPC techniques are bi-directional. Server push also requires server side configuration, whereas enhanced IPC techniques may work with any public events on any remote object. Further, server push requires a prearranged set of messages known to both sides. Enhanced IPC techniques may be used to remotely access subject objects without any proprietary messaging. In addition, server push is typically controlled by the server. Enhanced IPC techniques allow any observer objects to anonymously subscribe or unsubscribe to subject objects at runtime using a remote event bridge. Still further, server push generally calls a pre-designated method in a web application such as an RIA. Enhanced IPC techniques allow a RIA to dynamically specify at runtime a method to handle an object event. These and other advantages may be realized in OOP programming models utilizing a remote event bridge implementing one or more enhanced IPC techniques. 
       FIG. 1  illustrates a block diagram for an IPC system  100  designed to implement various enhanced IPC techniques for observer objects to access native object events for subject objects utilizing a remote event bridge. The IPC system  100  may be implemented as part of a computing system or communications system, examples of which are described in more detail with reference to respective  FIGS. 7, 8 . Although the IPC system  100  as shown in  FIG. 1  has a limited number of elements in a certain topology, it may be appreciated that the IPC system  100  may include more or less elements in alternate topologies as desired for a given implementation. 
     In various embodiments, the IPC system  100  may comprise or implement multiple components or modules. As used herein the terms “component” and “module” are intended to refer to computer-related entities, comprising either hardware, a combination of hardware and software, software, or software in execution. For example, a component and/or module can be implemented as a process running on a processor, a hard disk drive, multiple storage drives (of optical and/or magnetic storage medium), an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a server and the server can be a component and/or module. One or more components and/or modules can reside within a process and/or thread of execution, and a component and/or module can be localized on one computer and/or distributed between two or more computers as desired for a given implementation. The embodiments are not limited in this context. 
     In various embodiments, the IPC system  100  may be implemented by one or more electronic devices each having computing and/or communications capabilities. Example computing devices may include without limitation a mobile device, a personal digital assistant, a mobile computing device, a smart phone, a cellular telephone, a handset, a one-way pager, a two-way pager, a messaging device, a computer, a personal computer (PC), a desktop computer, a laptop computer, a notebook computer, a handheld computer, a tablet computer, a server, a server array or server farm, a web server, a network server, an Internet server, a work station, a mini-computer, a mainframe computer, a supercomputer, a network appliance, a web appliance, multiprocessor systems, processor-based systems, or any combination thereof. The embodiments are not limited in this context. 
     In various embodiments, components and/or modules of the IPC system  100 , and any electronic devices implementing some or all of the components and/or modules of the IPC system  100 , may be communicatively coupled via various types of communications media as indicated by various lines or arrows. The devices, components and/or modules may coordinate operations between each other. The coordination may involve the uni-directional or bi-directional exchange of information. For instance, the devices, components and/or modules may communicate information in the form of signals communicated over the communications media. The information can be implemented as signals allocated to various signal lines. In such allocations, each message is a signal. Further embodiments, however, may alternatively employ data messages. Such data messages may be sent across various connections. Exemplary connections within a device include parallel interfaces, serial interfaces, and bus interfaces. Exemplary connections between devices may comprise network connections over a wired or wireless communications network. 
     In various embodiments, the IPC system  100  may be implemented as part of a distributed system. A distributed system typically comprises multiple autonomous computers that communicate through a computer network. The computers interact with each other in order to achieve a common goal, such as solving computational problems. For example, a computational problem may be divided into many tasks, each of which is solved by one computer. A computer program that runs in a distributed system is called a distributed program, and distributed programming is the process of writing such programs. Examples of a distributed system may include without limitation a client-server architecture, a 3-tier architecture, an N-tier architecture, a tightly-coupled or clustered architecture, a peer-to-peer architecture, a master-slave architecture, a shared database architecture, and other types of distributed systems. It is worthy to note that although some embodiments may utilize a distributed system when describing various enhanced IPC techniques, it may be appreciated that the enhanced IPC techniques may be implemented by a single computing device as well. The embodiments are not limited in this context. 
     The IPC system  100  may comprise or implement multiple elements, including one or more processors  102 - a  arranged to execute multiple processes  110 - b . The one or more processors  102 - a  may also be arranged to execute an IPC component  140 . The IPC component  140  may comprise or implement various enhanced IPC techniques utilizing a remote event bridge  130 . The remote event bridge  130  may facilitate communications between the multiple processes  110 - b  allowing any objects executed by one of the multiple processes  110 - b  to subscribe to object events  124 - c  surfaced by any objects executed by another of the multiple processes  110 - b , and vice-versa. 
     It is worthy to note that “a” and “b” and “c” and similar designators as used herein are intended to be variables representing any positive integer. Thus, for example, if an implementation sets a value for a=5, then a complete set of processes  110 - a  may include processes  110 - 1 ,  110 - 2 ,  110 - 3 ,  110 - 4  and  110 - 5 . The embodiments are not limited in this context. 
     In the illustrated embodiment shown in  FIG. 1 , a processor  102 - 1  may execute an observer object  112  as part of a process  110 - 1 . A processor  102 - 2  may execute a subject object  122  as part of a process  110 - 2 . The objects  112 ,  122  may comprise or be implemented as any entity that can be manipulated by the commands of a programming language, such as a value, variable, function, or data structure. In one embodiment, the objects  112 ,  122  may represent objects suitable for an OOP programming architecture, and in this context, may refer to a particular instance of a class. Each of the objects  112 ,  122  may comprise a discrete set of data structures with a defined set of data fields, methods (functions or procedures), properties and/or events, and may be created using any suitable OOP programming language. Although a single observer object  112  and a single subject object  122  are shown in  FIG. 1 , it may be appreciated that any number of observer objects  112  and subject objects  122  may be used for a given implementation, such as any number of objects collectively operating as a web application or web service. Further, although the observer object  112  and the subject object  122  are illustrated as executed by respective processes  110 - 1 ,  110 - 2 , it may be appreciated that the observer object  112  and the subject object  122  may be executed using different threads of a single process  110 - b  (e.g.,  110 - 3 ). The embodiments are not limited in this context. 
     The IPC component  140  may implement the remote event bridge  130  to allow the observer object  112  executed by the process  110 - 1  to subscribe to one or more object events  124 - c  surfaced by the subject object  122  executed by the process  110 - 2 . Each of the object events  124 - c  may comprise a piece of application-level information from an underlying programming framework, such as a graphical user interface (GUI) toolkit, for example. In one embodiment, the object events  124 - c  may comprise any events suitable for event-driven or event-based programming. Event driven systems are typically used when there is some asynchronous external activity that needs to be handled by a program. For example, asynchronous external activity may comprise a user who presses a button on their mouse. The outside activity causes an object event  124 - c  to occur (it fires), some outside hardware and or software will collect data about the object event  124 - c , and when the program signals that it is ready to accept the object event  124 - c , the object event  124 - c  will be dispatched to the program by invoking the appropriate subroutine to deal with the event, referred to as the event handler. An event handler is an asynchronous callback subroutine that handles inputs received in a program. Some exemplary object events  124 - c  may include without limitation key presses, mouse movements, action selections, timer expirations, file reads, messages, user actions, and any other defined events suitable for event-driven or event-based programming. The embodiments are not limited in this context. 
     In one embodiment, the processes  110 - 1 ,  110 - 2  may be executed by a same computing device. For instance, a single computing device may implement a multi-processor system having the processors  102 - 1 ,  102 - 2  arranged to execute the respective processes  110 - 1 ,  110 - 2 . Alternatively, a single computing device may implement a single processor  102 - 3  executing both of the processes  110 - 1 ,  110 - 2 . The embodiments are not limited in this context. 
     In one embodiment, the processes  110 - 1 ,  110 - 2  may be executed by different computing devices. For instance, one computing device may implement the processor  102 - 1  while another computing device implements the processor  102 - 2 . The computing devices implementing the respective processors  102 - 1 ,  102 - 2  may communicate over a network, such as a public network (e.g., Internet) or a private network (e.g., Intranet). The embodiments are not limited in this context. 
     In one embodiment, the processes  110 - 1 ,  110 - 2  and associated objects may be implemented using different programming languages. For instance, the process  110 - 1  may comprise part of a RIA, such as a web application or web service of a service-oriented architecture (SOA) for deployment on a server computing device using various server side technologies, such as a JAVA PLATFORM ENTERPRISE EDITION™ (JAVA EE) programmed in the JAVA™ programming language, made by Oracle® Corporation, C, C++, C#, and so forth. The process  110 - 2  may also comprise part of a RIA, such as a front-end of a SOA for deployment on a web browser of a client computing device using various client side technologies, such as an Adobe Flash platform programmed in an object-oriented programming language such as ACTIONSCRIPT™ and ADOBE® FLEX, made by Adobe Systems Incorporated. It may be appreciated that these programming languages are provided by way of example and not limitation. One or more processes  110 - b  may be implemented using any suitable programming language utilizing an OOP programming model. 
     The IPC component  140  may implement the remote event bridge  130  to allow the observer object  112  executed by the process  110 - 1  to subscribe to the object event  124 - c  surfaced by the subject object  122  executed by the process  110 - 2 . This may be accomplished, for example, using a publish/subscribe model. When the observer object  112  sends a subscription request to subscribe to the object event  124 - c  of the subject object  122 , a bridge manager  136  of the remote event bridge  130  intercepts the subscription request. The bridge manager  136  may be arranged to generate and manage a surrogate object  132  to service the subscription request. The surrogate object  132  may be designed to operate as an interface to communicate data between the observer object  112  and the subject object  122  without changing any of the structures or operations for the observer object  112  or the subject object  122 . In one embodiment, for example, the surrogate object  132  of the remote event bridge  130  may subscribe to the object event  124 - c  of the subject object  122  using a surrogate event handler  134 . The surrogate object  132  may receive an event notification when the surrogate event handler  134  is called, and call an observer event handler  114  of the observer object  112  in response to the event notification. The remote event bridge  130  may be described in more detail with reference to  FIG. 2 . 
     Operations for the above-described embodiments may be further described with reference to one or more logic flows. It may be appreciated that the representative logic flows do not necessarily have to be executed in the order presented, or in any particular order, unless otherwise indicated. Moreover, various activities described with respect to the logic flows can be executed in serial or parallel fashion. The logic flows may be implemented using one or more hardware elements and/or software elements of the described embodiments or alternative elements as desired for a given set of design and performance constraints. For example, the logic flows may be implemented as logic (e.g., computer program instructions) for execution by a logic device (e.g., a general-purpose or specific-purpose computer). 
       FIG. 2  illustrates one embodiment of a logic flow  200 . The logic flow  200  may be representative of some or all of the operations executed by one or more embodiments described herein. For instance, the logic flow  200  may be representative of some or all of the operations executed by the IPC component  140  and/or the remote event bridge  130 . 
     In the illustrated embodiment shown in  FIG. 2 , the logic flow  200  may receive a subscription request from an observer object having an observer event handler, the subscription request to subscribe to an object event of a subject object at block  202 . For example, the bridge manager  136  of the remote event bridge  130  may receive a subscription request from the observer object  112  having the observer event handler  114 . The subscription request may comprise a request to subscribe to the object event  124 - c  of the subject object  122 . 
     The logic flow  200  may create a surrogate object by a remote event bridge, the surrogate object having a surrogate event handler arranged to call the observer event handler at block  204 . For example, the bridge manager  136  of the remote event bridge  130  may intercept the subscription request, and create the surrogate object  132 . The surrogate object  132  may have the surrogate event handler  134  arranged to call the observer event handler  114 . 
     The logic flow  200  may subscribe the surrogate object to the object event of the subject object using the surrogate event handler at block  206 . For example, the bridge manager  136  may subscribe the surrogate object  132  to the object event  124 - c  of the subject object  122  using the surrogate event handler  134  on behalf of the observer object  112 . 
     The logic flow  200  may receive an event notification when the surrogate event handler is called at block  208 . For example, the surrogate object  132  may receive an event notification when the surrogate event handler  134  is called by the subject object  122 . The subject object  122  may call the surrogate event handler  134  when the object event  124 - c  subscribed to by the surrogate object  132  actually occurs (or “fires”). For instance, assume the object event  124 - c  is a mouse-click. When the subject object  122  detects a mouse-click, such as for selecting a GUI element presented by a GUI view, the subject object may call the surrogate event handler  134 . 
     The logic flow  200  may call the observer event handler in response to the event notification at block  210 . For example, the surrogate object  132  may receive the event notification, and the surrogate event handler  134  may call the observer event handler  114  in response to the event notification. In this manner, the observer object  112  may receive the event notification from the subject object  122  via the surrogate object  132 . This may occur transparently without the observer object  112  or the subject object  122  being aware of the remote event bridge  130  or the surrogate object  132 . 
       FIG. 3  illustrates an embodiment of an operating environment  300  suitable for the IPC system  100 . The operating environment  300  illustrates signaling and/or message flow between the various elements of the IPC system  100  to provide enhanced IPC techniques for subscribing to object events  124 - c  of objects executed by heterogeneous processes  110 - b.    
     In the illustrated embodiment shown in  FIG. 3 , the operating environment  300  may be implemented as a client-server architecture comprising a server computing device  302  and a client computing device  304 . Each of the computing devices  302 ,  304  may implement a portion of the IPC system  100  as a distributed system. The server computing device  302  may implement the processor  102 - 1  for executing the process  110 - 1  with the observer object  112 . The server computing device  302  may also implement a remote object proxy  310 . The client computing device  304  may implement the processor  102 - 2  for executing the process  110 - 2  and the remote event bridge  130 . Although the operating environment  300  illustrates the remote event bridge  130  implemented by the processor  102 - 2  of the client computing device  304 , it may be appreciated that the remote event bridge  130  may be implemented by another processor of the client computing device  304 . Further, although the operating environment  300  illustrates the remote event bridge  130  implemented by the processor  102 - 2  of the client computing device  304 , it may be appreciated that the remote event bridge  130  may be implemented by the processor  102 - 1  (or another processor) of the server computing device  302 . 
     The computing devices  302 ,  304  may each have computing resources to process digital information and communications resources to communicate digital information. The computing devices  302 ,  304  may communicate with each over a network  306 . The network  306  may comprise a public network (e.g., the Internet) or a private network (e.g., an intranet). The computing devices  302 ,  304  may communicate with each other using various wired or wireless communications techniques. Computing aspects of the computing devices  302 ,  304  may be described in more detail with reference to  FIG. 7 . Communications aspects for the computing devices  302 ,  304  may be described in more detail with reference to  FIG. 8 . 
     The processes  110 - 1 ,  110 - 2  may interoperate to implement a RIA of a SOA. As shown, the observer object  112  may be executed as part of the process  110 - 1  by the processor  102 - 1  on the client computing device  304 . For instance, the process  110 - 1  may comprise some or all of application logic (or business logic) for a RIA residing on the server computing device  302 . The process  110 - 1  may be programmed in accordance with various programming languages, application platforms and application frameworks, including JAVA made by Oracle Corporation, COLDFUSION made by Adobe Systems, .NET made by Microsoft® Corporation, WebORB for .NET, Hypertext Preprocessor (PHP), Ruby, Python, Perl, Lisp, Dylan, Pike, Cluster (CLU), Smalltalk, Eiffel, Ruby on Rails (RoR), among other programming languages. 
     The subject object  122  may be executed as part of the process  110 - 2  by the processor  102 - 2  on the client computing device  304 . For instance, the process  110 - 2  may comprise some or all of a user interface for a RIA implemented by a web browser. Examples of suitable web browsers may include MICROSOFT INTERNET EXPLORER®, GOOGLE® CHROME and APPLE® SAFARI, to name just a few. In one embodiment, the process  110 - 2  may be an RIA programmed using an ADOBE FLEX software development kit (SDK) and C#, among other programming languages. 
     The processes  110 - 1 ,  110 - 2  may communicate with each other over the network  306  utilizing various remoting techniques. For instance, the processes  110 - 1 ,  110 - 2  may communicate using simple object access protocol (SOAP). SOAP is a protocol specification for exchanging structured information to implement web services over a computer network. SOAP relies on extensible markup language (XML) as a message format. SOAP also relies on other application layer protocols, such as remote procedure call (RPC) and hypertext transfer protocol (HTTP), for message negotiation and transmission. SOAP can form a foundation layer of a web services protocol stack, providing a basic messaging framework upon which web services can be built. HTTP is an application layer request-response protocol specification for client-server computing. It may be appreciated that SOAP is merely an example and not a limitation, and any other communications protocols suitable for remoting (e.g., remote invocation or remote method invocation) consistent with the embodiments may be used for a given implementation. For instance, the processes  110 - 1 ,  110 - 2  may utilize an action message format (AMF) to communicate between an ADOBE FLASH application and a remote service over the network  306 . In another example, the processes  110 - 1 ,  110 - 2  may utilize a real time messaging protocol (RTMP) to communicate between the processes  110 - 1 ,  110 - 2 . In yet another example, the processes  110 - 1 ,  110 - 2  may utilize any number of transport protocols, including HTTP, transmission control protocol and internet protocol (TCP/IP), a real-time transport protocol (RTP), a real-time transport control protocol (RTCP), a user datagram protocol (UDP) and other transports to communicate between the processes  110 - 1 ,  110 - 2 . The embodiments are not limited in this context. 
     The server computing device  302  may implement a remote object proxy  310  to facilitate remoting operations. The remote object proxy  310  may operate as a bridge to integrate various message protocols, such as AMF, with a native language for the subject object  122 , such as JAVA or C#. Examples for the remote object proxy  310  may include without limitation Adobe BlazeDS, WebORB, and other server bridges. Additionally or alternatively, the client computing device  304  may implement a remote object proxy  310  for the remote event bridge  130  to interface with the surrogate object  132 . 
     In the illustrated embodiment shown in  FIG. 3 , the observer object  112  may send a subscription request  340  to subscribe to the object event  124 - 1  of the subject object  122  via the remote object proxy  310  as indicated by arrow  322 . The bridge manager  136  of the remote event bridge  130  may receive the subscription request  340  from the observer object  112 . The bridge manager  136  may intercept the subscription request  340 , and create the surrogate object  132 . The surrogate object  132  may have the surrogate event handler  134  arranged to call the observer event handler  114 . The bridge manager  136  may subscribe the surrogate object  132  to the object event  124 - 1  of the subject object  122  using the surrogate event handler  134  on behalf of the observer object  112  as indicated by arrow  324 . 
     Once subscribed, the subject object  122  may call the surrogate event handler  134  when the object event  124 - 1  subscribed to by the surrogate object  132  actually fires, such as detecting a mouse-click for selecting a GUI element presented by a GUI view. The call may operate as an implicit event notification  342  for the surrogate event handler as indicated by arrow  326 . The surrogate object  132  may receive the event notification  342 , and the surrogate event handler  134  may call the observer event handler  114  in response to the event notification  342  as indicated by arrow  328 . In this manner, the observer object  112  may receive the event notification  342  from the subject object  122  via the surrogate object  132 . After the surrogate event handler  134  calls the observer event handler  114 , the surrogate event handler  134  may send a function return  344  to the subject object  122  as indicated by arrow  330 . 
       FIG. 4  illustrates an embodiment of an operating environment  400  suitable for the IPC system  100 . The operating environment  400  may be similar to the operating environment  300  as described with reference to  FIG. 3 . Further, the operating environment  400  illustrates an embodiment where the remote event bridge  130  passes event arguments between the observer object  112  and the subject object  122 . 
     In addition to the observer object  112  transparently receiving the event notification  342  from the subject object  122  via the surrogate object  132 , the remote event bridge  130  may also implement enhanced IPC techniques for passing event arguments between the observer object  112  and the subject object  122 . This may be accomplished, for example, using additional objects for the remote event bridge, such as a reply object  450  and a map object  460 . 
     When the bridge manager  136  of the remote event bridge  130  receives the subscription request  340  from the observer object  112 , the remote event bridge  130  may generate the surrogate object  132 . In addition, the bridge manager may also generate the reply object  450  and the map object  460 . The reply object  450  may have a reply method  452  arranged to pass event arguments between the observer object  112  and the subject object  122 . The map object  460  may have a mapping method  462  arranged to map information for one or more observer event arguments  440  received from the observer object  112  to one or more corresponding subject event arguments  442  of the subject object  122  to form mapped event arguments  446 . The map object  460  may send the mapped event arguments to the subject object  122  as part of the function return  344 . 
     In the illustrated embodiment shown in  FIG. 4 , the observer object  112  may subscribe to the object event  124 - 1  via the remote event bridge  130  using operations and messaging  422 ,  424 ,  426  and  428  corresponding to messaging  322 ,  324 ,  326  and  328  as described with the operating environment  300 . Once subscribed, the subject object  122  may call the surrogate event handler  134  when the object event  124 - 1  subscribed to by the surrogate object  132  actually fires, such as detecting a mouse-click for selecting a GUI element presented by a GUI view. The surrogate object  132  may receive the event notification  342 , and the surrogate event handler  134  may call the observer event handler  114  in response to the event notification  342  as indicated by arrow  428 . 
     In the operating environment  400 , however, rather than send the function return  344  to the subject object  122  after the surrogate event handler  134  calls the observer event handler  114 , the surrogate event handler  134  may block the function return  344  to the subject object after the surrogate event handler  134  is called as indicated by arrow  430 . The surrogate event handler  134  may then call the reply method  452  of the reply object  450 . The reply method  452  may be arranged to pass event arguments between the observer object  112  and the subject object  122 . The reply object  450  may receive the function call for the reply method  452 , and execute the reply method  452  to wait for the arrival of the observer event arguments  440 . 
     Once the observer object  112  receives the event notification  342  through calling of the observer event handler  114 , the observer object  112  or another object executed by the process  110 - 1  may reply to the event notification  342  with information intended for the subject object  122  executed by the process  110 - 2 . For instance, assume the application logic implemented by the server computing device  302  sends a response to the mouse-click of the object event  124 - 1 , such as a request for security credentials for a user. The observer object  112  may generate a reply with one or more observer event arguments  440 , and pass the observer event arguments  440  to the remote event bridge  130  as indicated by arrow  432 . 
     The bridge manager  136  of the remote event bridge  130  may receive a reply from the observer object  112  having the one or more observer event arguments  440 . The reply object  450  may call the mapping method  462  of the map object  460 . The mapping method  462  may map information for one or more observer event arguments  440  received from the observer object  112  to one or more corresponding subject event arguments  442  of the subject object  122  to form one or more mapped event arguments  446 . The mapping method  462  may pass the one or more mapped event arguments  446  to the surrogate object  132 . 
     The surrogate object  132  may receive the one or more mapped event arguments  446 , and unblock the function return  344  to the subject object  122 . The surrogate object  132  may then send the one or more mapped event arguments  446  to the subject object  122  with the function return  344  for the subject object  122  as indicated by arrow  434 . The subject object  122  may receive the one or more mapped event arguments  446  as input parameters and invoke a suitable method associated with the subject object  122  in accordance with the mapped event arguments  446 . 
       FIG. 5  illustrates an embodiment of an operating environment  500  suitable for the IPC system  100 . More particularly,  FIG. 5  illustrates a block diagram of a computing device  502 . The computing device  502  may comprise a centralized system arranged to implement all of the structure and/or operations for the IPC system  100  in a single computing entity. In one embodiment, for example, the computing device  502  may implement the structure and/or operations for the IPC system  100  entirely within a single computing device, rather than in a distributed system implementing the structure and/or operations for the IPC system  100  within the computing devices  302 ,  304  as described with reference to  FIG. 3 . 
     As previously described, in one embodiment the processes  110 - 1 ,  110 - 2  may be executed by a same computing device. In the illustrated embodiment shown in  FIG. 5 , the computing device  502  may comprise a multi-processor system having the processors  102 - 1 ,  102 - 2  arranged to execute the respective processes  110 - 1 ,  110 - 2 . The remote event bridge  130  may be executed by either the processor  102 - 1 ,  102 - 2  as part of the respective processes  110 - 1 ,  110 - 2  as desired for a given implementation. Alternatively, the remote event bridge  130  may be executed by a separate processor (e.g.,  102 - 3 ) and/or process (e.g.,  110 - 3 ) as desired for a given implementation. The embodiments are not limited in this context. 
     Additionally or alternatively, the computing device  502  may implement processes  110 - 1 ,  110 - 2  in separate virtual systems, such as separate “sandboxes” or virtual machines. A sandbox is a security mechanism for separating running programs providing a tightly-controlled set of resources, such as scratch space on disk and memory. Access to other programs, networks, input/output (I/O) devices, and other resources provided by the computing device  502  may be restricted as well. A virtual machine is a software implementation of a machine (e.g., a computer) that executes programs like a physical machine. The embodiments are not limited in this context. 
       FIG. 6  illustrates an embodiment of an operating environment  600  suitable for the IPC system  100 . More particularly,  FIG. 6  illustrates a block diagram of a computing device  602 . The computing device  602  may comprise a centralized system arranged to implement all of the structure and/or operations for the IPC system  100  in a single computing entity. In one embodiment, for example, the computing device  602  may implement the structure and/or operations for the IPC system  100  entirely within a single computing device, rather than in a distributed system implementing the structure and/or operations for the IPC system  100  within the computing devices  302 ,  304  as described with reference to  FIG. 3 . 
     As previously described, in one embodiment the processes  110 - 1 ,  110 - 2  may be executed by a same computing device on a single processor. In the illustrated embodiment shown in  FIG. 6 , the computing device  602  may implement a single processor  102 - 3  executing both of the processes  110 - 1 ,  110 - 2 . The remote event bridge  130  may be executed by the processor  102 - 3  as part of the process  110 - 1  or process  110 - 2  as desired for a given implementation. Alternatively, the remote event bridge  130  may be executed by a separate processor (e.g.,  102 - 4 ) and/or process (e.g.,  110 - 3 ) as desired for a given implementation. The embodiments are not limited in this context. 
     A more detailed implementation for the remote event bridge  130  may be further described using the following specific example. In general, the remote event bridge  130  may be implemented in any technology which supports object events, object remoting, a strong type system with reflection, a messaging protocol such as RMTP, and a RIA environment for the remote client. A reference implementation of the remote event bridge  130  may be implemented using the programming language C# in a .NET programming environment. Remoting services may be implemented using WebORB to form a bridge between a Flex AMF3 message format and the native programming language C# implemented for the objects  112 ,  122 . The object  122  is part of a software program developed in ADOBE FLEX. The reference implementation of the remote event bridge  130  defines the object events  124 - c  to be in the standard .NET form of:
         public event EventHandler&lt;TEventArgs&gt;EventName
 
It is worthy to note, however, that this implementation could be extended to work with any event signature.
       

     In the reference implementation of the remote event bridge  130 , the remote event bridge  130  utilizes two objects. The first object represents the bridge manager  136  and is called “RemoteEventBridge.” As previously described, the bridge manager  136  is a remotable object to subscribe to an object event  124 - c . The second object represents the surrogate object  132  and is called “RemoteEventSurrogate.” As previously described, the surrogate object  132  is an internal object to manage a subscription. 
     In the reference implementation of the remote event bridge  130 , an object event  124 - c  may be consumed using the following call:
         public void Subscribe(string ObjectName, string EventName, string HandlerName, bool WaitForReply),
 
where ObjectName is a fully qualified name of the object, EventName is a name of the event, HandlerName is a name of an RIA method to be called for handling the event, and WaitForReply is server code to wait for data to be returned in the event argument.
       

     If a remote RIA client wishes to return data via a writable property in the event arguments, as described by the operating environment  400  with reference to  FIG. 4 , the following call may be used:
         public void Reply(string EventName, EventArgs ea)
 
where EventName is a name of the event, and ea are event arguments (derived from the .Net EventArgs class)
       

     The enhanced IPC techniques in general, and the remote event bridge  130  in particular, may have various use scenarios. One particular use scenario is for providing user notification when a remotely executing job is completed. These jobs are typically generated on a mid-tier and sent to a server for execution by a proprietary language processor. Since these jobs could take anywhere from one second to several days to complete, polling is an inefficient technique for determining job completion. The remote event bridge  130  allows the delivery of an OnJobComplete event from a .NET object in the mid-tier to a Flex client running in a Flash/web browser. When the Flex client receives the event a suitable user interface notifies the user while updating the job status. 
     Another usage for the remote event bridge  130  in the same application is informing the user of when certain actions take place. For example, a user could add a comment to a document owned by another user. If Flex client code subscribes to a SystemNotify event in the .NET mid-tier, then a real time notification can be presented to the user, informing them that a comment has been added to their document. 
     Yet another usage for the remote event bridge  130  is returning information. During the course of application logic execution on the mid-tier, a situation can arise in which additional information is required from the user. In a desktop application this is easily handled by an event which in turn is fielded by a user interface component to gather the information from the user and return it to the point of execution where it is required. Such a scenario, however, may be quite difficult to handle in a RIA. The remote event bridge  130  solves this problem not only by allowing the event to be handled in the remote Flex client, but also by its ability to return data to the event from the remote handler. Such functionality is not possible in existing publish-subscribe implementations or server messaging services. 
     Note that each of these examples assumes that standard .NET C# objects are used without modification. While a publish-subscribe technique could be theoretically used in an attempt to handle the second use case, most implementations work at a server level rather than an object level. The remote event bridge  130  offers object level granularity which is not possible with typical publish-subscribe mechanisms. 
     The enhanced IPC techniques and the remote event bridge  130  may be implemented for any software program, and may be particularly useful for RIA programs such as web services and web applications. In one embodiment, the remote event bridge  130  may be implemented for an RIA program referred to as SAS Guided Analysis (SGA), made by SAS® Institute Inc., of Cary, N.C. SGA is a RIA written in Flex which utilizes a highly interactive graphical user interface to expose SAS analytics to users with a novice level statistical background. Since the SAS computational process is essentially batch oriented with a highly variable execution time, it is very desirable to provide the user with a notification when the results are available. Such a mechanism is typically unavailable in existing browser-based applications. 
     SGA addresses this need by using the remote event bridge  130  to subscribe to a JobCompleted event on an ExecutionService object in a .NET mid tier. When a SAS job has completed, the remote event bridge  130  receives the event and remotes it to the SGA Flex client. The interface is updated with results from the job and other related status information. This presents the user with near instant feedback when the SAS job processing has completed resulting in a good interactive user experience. 
     Another feature in SGA which utilizes the remote event bridge  130  is the notification mechanism. There are several occurrences in an SGA system that are of interest to one of more connected users. One example is when a project owned by one user is modified by another user. Another example is when a user connects or disconnects from the SGA system. Each of these notifications is handled by the SGA Flex client which subscribes to a SystemNotify event on a RemoteSession object in the .NET mid tier. Unlike the typical publish-subscribe mechanism where a client application receives all messages of a particular type, the remote event bridge  130  subscribes to an event at an object level rather than a server level. Therefore a user would receive events only on the instance of an object to which they have subscribed. Since there is a RemoteSession object for each connected user, the user would only receive events intended for their particular SGA session. By way of contrast, a typical publish-subscribe mechanism would require client side filtering. However, the remote event bridge  130  delivers events to the intended subscriber independent of all other subscribers. This aspect is a key benefit of the remote event bridge  130 . 
     Another example of enhanced user experience which may be attributed to the remote event bridge  130  is related to the days of terminal based computing. If a user was logged on to a system from a given terminal and wanted to logon from another terminal at different location, the second logon would typically be rejected. The alternatives were to have someone physically present at the first terminal to log the user off or call the system administrator to force a logoff from the first terminal with a privileged system command. The SGA has a much better user experience for this scenario. The mid-tier RemoteSession object has a SessionMoved event which is remoted to the Flex client user interface via the remote event bridge  130 . If a user is working in an SGA session and moves to another computer without logging out, they may simply logon at the new location. The mid-tier code recognizes the user has an active session, connects the new Flex client to the existing session, and sends the event to the original Flex client via the remote event bridge  130 . The original Flex client disables the user interface and issues a message that the session has moved to another computer. It is worthy to note that this is a relatively seamless operation and requires no action from an additional person or an IT support department. The remote event bridge  130  allows an object level subscription to the user&#39;s RemoteSession object which makes this user experience possible. A traditional server level publish-subscribe mechanism is typically unable to provide this functionality. 
     Instant real time notification and event remoting provide a large benefit for the user experience of a RIA. The remote event bridge  130  not only allows delivery of object events to a thin client user interface such as Flex, but such events are delivered to a specific user. This targeted delivery is typically not possible to address in a server-based publish-subscribe mechanism. On the development side there is another large benefit since object events may be remoted without modification or configuration. This allows development of objects which may be transparently targeted for desktop or mid-tier usage. The object event mechanism may be consumed from a remote client without special consideration by using the remote event bridge  130 . This significantly reduces development costs and complexity. Further, any object which is configured for binary object remoting is also eligible for public event subscription via the remote event bridge  130  without additional server configuration. This aspect benefits IT personnel by substantially reducing deployment and configuration requirements of an n-tier application. Other use scenarios and benefits exist for the remote event bridge  130 , and these are merely a few illustrative examples and not meant to be an exhaustive list of use scenarios and benefits. 
     The ability to use a remote object event from a RIA is a very compelling feature which compliments object remoting. By working with an object event without modification, the remote event bridge protects code investment since the object may be used in multiple environments such as a server or a desktop application. Existing technology allows a server push of data to a remote client but does not support the event construct supported by many languages such as C# and JAVA. The remote event bridge  130  allows a RIA such as a Flex client to use an event in the same manner as in-process code without modification or additional server configuration. 
       FIG. 7  illustrates an embodiment of an exemplary computing architecture  700  suitable for implementing various embodiments as previously described. The computing architecture  700  includes various common computing elements, such as one or more processors, co-processors, memory units, chipsets, controllers, peripherals, interfaces, oscillators, timing devices, video cards, audio cards, multimedia input/output (I/O) components, and so forth. The embodiments, however, are not limited to implementation by the computing architecture  700 . 
     As shown in  FIG. 7 , the computing architecture  700  comprises a processing unit  704 , a system memory  706  and a system bus  708 . The processing unit  704  can be any of various commercially available processors. Dual microprocessors and other multi-processor architectures may also be employed as the processing unit  704 . The system bus  708  provides an interface for system components including, but not limited to, the system memory  706  to the processing unit  704 . The system bus  708  can be any of several types of bus structure that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and a local bus using any of a variety of commercially available bus architectures. 
     The system memory  706  may include various types of memory units, such as read-only memory (ROM), random-access memory (RAM), dynamic RAM (DRAM), Double-Data-Rate DRAM (DDRAM), synchronous DRAM (SDRAM), static RAM (SRAM), programmable ROM (PROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, polymer memory such as ferroelectric polymer memory, ovonic memory, phase change or ferroelectric memory, silicon-oxide-nitride-oxide-silicon (SONOS) memory, magnetic or optical cards, or any other type of media suitable for storing information. In the illustrated embodiment shown in  FIG. 7 , the system memory  706  can include non-volatile memory  710  and/or volatile memory  712 . A basic input/output system (BIOS) can be stored in the non-volatile memory  710 . 
     The computer  702  may include various types of computer-readable storage media, including an internal hard disk drive (HDD)  714 - 1 , a magnetic floppy disk drive (FDD)  716  to read from or write to a removable magnetic disk  718 , and an optical disk drive  720  to read from or write to a removable optical disk  722  (e.g., a CD-ROM or DVD). In some embodiments, the computer  702  may be coupled with an external HDD  714 - 2 . The internal HDD  714 - 1 , the external HHD  714 - 2 , FDD  716  and optical disk drive  720  can be connected to the system bus  708  by a HDD interface  724 , an FDD interface  726  and an optical drive interface  728 , respectively. The HDD interface  724  for external drive implementations can include at least one or both of Universal Serial Bus (USB) and IEEE 1394 interface technologies. 
     The drives and associated computer-readable media provide volatile and/or nonvolatile storage of data, data structures, computer-executable instructions, and so forth. For example, a number of program modules can be stored in the drives and memory units  710 ,  712 , including an operating system  730 , one or more application programs  732 , other program modules  734 , and program data  736 . The one or more application programs  732 , other program modules  734 , and program data  736  can include, for example, the IPC system  100 , the IPC component  140 , the remote event bridge  130 , and other software elements described with the embodiments. 
     A user can enter commands and information into the computer  702  through one or more wire/wireless input devices, for example, a keyboard  738  and a pointing device, such as a mouse  740 . Other input devices may include a microphone, an infra-red (IR) remote control, a joystick, a game pad, a stylus pen, touch screen, or the like. These and other input devices are often connected to the processing unit  704  through an input device interface  742  that is coupled to the system bus  708 , but can be connected by other interfaces such as a parallel port, IEEE 1394 serial port, a game port, a USB port, an IR interface, and so forth. 
     A monitor  744  or other type of display device is also connected to the system bus  708  via an interface, such as a video adaptor  746 . In addition to the monitor  744 , a computer typically includes other peripheral output devices, such as speakers, printers, and so forth. 
     The computer  702  may operate in a networked environment using logical connections via wire and/or wireless communications to one or more remote computers, such as a remote computer  748 . The remote computer  748  can be a workstation, a server computer, a router, a personal computer, portable computer, microprocessor-based entertainment appliance, a peer device or other common network node, and typically includes many or all of the elements described relative to the computer  702 , although, for purposes of brevity, only a memory/storage device  750  is illustrated. The logical connections depicted include wire/wireless connectivity to a local area network (LAN)  752  and/or larger networks, for example, a wide area network (WAN)  754 . Such LAN and WAN networking environments are commonplace in offices and companies, and facilitate enterprise-wide computer networks, such as intranets, all of which may connect to a global communications network, for example, the Internet. 
     When used in a LAN networking environment, the computer  702  is connected to the LAN  752  through a wire and/or wireless communication network interface or adaptor  756 . The adaptor  756  can facilitate wire and/or wireless communications to the LAN  752 , which may also include a wireless access point disposed thereon for communicating with the wireless functionality of the adaptor  756 . 
     When used in a WAN networking environment, the computer  702  can include a modem  758 , or is connected to a communications server on the WAN  754 , or has other means for establishing communications over the WAN  754 , such as by way of the Internet. The modem  758 , which can be internal or external and a wire and/or wireless device, connects to the system bus  708  via the input device interface  742 . In a networked environment, program modules depicted relative to the computer  702 , or portions thereof, can be stored in the remote memory/storage device  750 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers can be used. 
     The computer  702  is operable to communicate with wire and wireless devices or entities using the IEEE 802 family of standards, such as wireless devices operatively disposed in wireless communication (e.g., IEEE 802.11 over-the-air modulation techniques) with, for example, a printer, scanner, desktop and/or portable computer, personal digital assistant (PDA), communications satellite, any piece of equipment or location associated with a wirelessly detectable tag (e.g., a kiosk, news stand, restroom), and telephone. This includes at least Wi-Fi (or Wireless Fidelity), WiMax, and Bluetooth™ wireless technologies. Thus, the communication can be a predefined structure as with a conventional network or simply an ad hoc communication between at least two devices. Wi-Fi networks use radio technologies called IEEE 802.11x (a, b, g, etc.) to provide secure, reliable, fast wireless connectivity. A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wire networks (which use IEEE 802.3-related media and functions). 
       FIG. 8  illustrates a block diagram of an exemplary communications architecture  800  suitable for implementing various embodiments as previously described. The communications architecture  800  includes various common communications elements, such as a transmitter, receiver, transceiver, radio, network interface, baseband processor, antenna, amplifiers, filters, and so forth. The embodiments, however, are not limited to implementation by the communications architecture  800 . 
     As shown in  FIG. 8 , the communications architecture  800  comprises includes one or more clients  802  and servers  804 . The clients  802  may implement the client computing device  304 . The servers  804  may implement the server computing device  302 . The clients  802  and the servers  804  are operatively connected to one or more respective client data stores  808  and server data stores  810  that can be employed to store information local to the respective clients  802  and servers  804 , such as cookies and/or associated contextual information. 
     The clients  802  and the servers  804  may communicate information between each other using a communication framework  806 . The communications framework  806  may implement any well-known communications techniques, such as techniques suitable for use with packet-switched networks (e.g., public networks such as the Internet, private networks such as an enterprise intranet, and so forth), circuit-switched networks (e.g., the public switched telephone network), or a combination of packet-switched networks and circuit-switched networks (with suitable gateways and translators). The clients  802  and the servers  804  may include various types of standard communication elements designed to be interoperable with the communications framework  806 , such as one or more communications interfaces, network interfaces, network interface cards (NIC), radios, wireless transmitters/receivers (transceivers), wired and/or wireless communication media, physical connectors, and so forth. By way of example, and not limitation, communication media includes wired communications media and wireless communications media. Examples of wired communications media may include a wire, cable, metal leads, printed circuit boards (PCB), backplanes, switch fabrics, semiconductor material, twisted-pair wire, co-axial cable, fiber optics, a propagated signal, and so forth. Examples of wireless communications media may include acoustic, radio-frequency (RF) spectrum, infrared and other wireless media. One possible communication between a client  802  and a server  804  can be in the form of a data packet adapted to be transmitted between two or more computer processes. The data packet may include a cookie and/or associated contextual information, for example. 
     Various embodiments may be implemented using hardware elements, software elements, or a combination of both. Examples of hardware elements may include devices, components, processors, microprocessors, circuits, circuit elements (e.g., transistors, resistors, capacitors, inductors, and so forth), integrated circuits, application specific integrated circuits (ASIC), programmable logic devices (PLD), digital signal processors (DSP), field programmable gate array (FPGA), memory units, logic gates, registers, semiconductor device, chips, microchips, chip sets, and so forth. Examples of software elements may include software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. Determining whether an embodiment is implemented using hardware elements and/or software elements may vary in accordance with any number of factors, such as desired computational rate, power levels, heat tolerances, processing cycle budget, input data rates, output data rates, memory resources, data bus speeds and other design or performance constraints, as desired for a given implementation. 
     Some embodiments may comprise an article of manufacture. An article of manufacture may comprise a storage medium to store logic. Examples of a storage medium may include one or more types of computer-readable storage media capable of storing electronic data, including volatile memory or non-volatile memory, removable or non-removable memory, erasable or non-erasable memory, writeable or re-writeable memory, and so forth. Examples of the logic may include various software elements, such as software components, programs, applications, computer programs, application programs, system programs, machine programs, operating system software, middleware, firmware, software modules, routines, subroutines, functions, methods, procedures, software interfaces, application program interfaces (API), instruction sets, computing code, computer code, code segments, computer code segments, words, values, symbols, or any combination thereof. In one embodiment, for example, an article of manufacture may store executable computer program instructions that, when executed by a computer, cause the computer to perform methods and/or operations in accordance with the described embodiments. The executable computer program instructions may include any suitable type of code, such as source code, compiled code, interpreted code, executable code, static code, dynamic code, and the like. The executable computer program instructions may be implemented according to a predefined computer language, manner or syntax, for instructing a computer to perform a certain function. The instructions may be implemented using any suitable high-level, low-level, object-oriented, visual, compiled and/or interpreted programming language. 
     Some embodiments may be described using the expression “one embodiment” or “an embodiment” along with their derivatives. These terms mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment. 
     Some embodiments may be described using the expression “coupled” and “connected” along with their derivatives. These terms are not necessarily intended as synonyms for each other. For example, some embodiments may be described using the terms “connected” and/or “coupled” to indicate that two or more elements are in direct physical or electrical contact with each other. The term “coupled,” however, may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. 
     It is emphasized that the Abstract of the Disclosure is provided to comply with 37 C.F.R. Section 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Moreover, the terms “first,” “second,” “third,” and so forth, are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.