Patent Publication Number: US-2023153034-A1

Title: Accelerate memory decompression of a large physically scattered buffer on a multi-socket symmetric multiprocessing architecture

Description:
BACKGROUND 
     The present invention generally relates to programmable computing systems, and more specifically, to programmable computing systems configured to accelerate memory decompression of large physically scattered buffer on a multi-socket symmetric multiprocessing architecture. 
     Signal processing is the manipulation of digital signals within a computer system. As part of signal processing, data is compressed by encoding data to use fewer bits than an original state of the data. The compressed data is decompressed by decoding the data to return the data to its original state. The more complex a data compression algorithm is, the greater the number of clock cycles are needed to complete the compression and decompression. The latency of applications requesting information is based in part of a number of clock cycles necessary to perform the compressing and decompressing of requested data. 
     SUMMARY 
     Embodiments of the present invention are directed to a computer-implemented method for accelerating memory decompression of large physically scattered buffer on a multi-socket symmetric multiprocessing architecture. A non-limiting example of the computer-implemented method includes identifying a first subsystem and a second subsystem of a plurality of subsystems respectively storing a first compressed data and a second compressed data, wherein the first compressed data and the second compressed data are fragments of a requested data. A compression method used to compress the first compressed data and second compressed data is identified. A first accelerator of the first subsystem and a second accelerator of the second subsystem are identified. The first compressed data from a first local memory of the first subsystem is offloaded to the first accelerator, and the second compressed data from a second local memory of the second subsystem is offloaded to the second accelerator, wherein offloading comprises provided a decompression method for the first compressed data and the second compressed data. 
     Other embodiments of the present invention implement features of the above-described method in computer systems and computer program products. 
     Additional technical features and benefits are realized through the techniques of the present invention. Embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed subject matter. For a better understanding, refer to the detailed description and to the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The specifics of the exclusive rights described herein are particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the embodiments of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
         FIG.  1    illustrates a system for accelerating memory decompression of large physically scattered buffer on a multi-socket symmetric multiprocessing architecture in accordance with one or more embodiments of the present invention; 
         FIG.  2    illustrates a first socket and a second socket of a printed circuit board in communication with a memory buffer and two accelerators in accordance with one or more embodiments of the present invention; 
         FIG.  3    illustrates a process flow for accelerating memory decompression of large physically scattered buffer on a multi-socket symmetric multiprocessing architecture in accordance with one or more embodiments of the present invention; and 
         FIG.  4    illustrates a block diagram of a computer system for use in implementing one or more embodiments of the present invention. 
     
    
    
     The diagrams depicted herein are illustrative. There can be many variations to the diagram or the operations described therein without departing from the spirit of the invention. For instance, the actions can be performed in a differing order or actions can be added, deleted or modified. Also, the term “coupled” and variations thereof describes having a communications path between two elements and does not imply a direct connection between the elements with no intervening elements/connections between them. All of these variations are considered a part of the specification. 
     DETAILED DESCRIPTION 
     One or more embodiments of the present invention provide computer-implemented methods, computer systems, and computer program products that offloads scattered fragments of data from a memory buffer of a central processing unit to respective local accelerators to speed up decompression. The scattered data is offloaded to a hardware accelerator based on the physical proximity to the scattered data, which accelerates the decompression process. 
     Database management systems use decompression algorithms that expand a compressed version of a file back to the original size of the file. In the instance that data from a compressed file is requested, a database management system assigns the compressed file to a processor to perform the decompression. The database management system selects the processor on a first-come, first-serve basis. This assignment method does not account for the physical layout of the database or processor and results in a longer than necessary time to perform the decompression. 
     One or more embodiments of the present invention address one or more of the above-described shortcomings by providing computer-implemented methods, computer systems, and computer program products that determine where a physical block of compressed data is scattered in a memory buffer. For each identified fragment of compressed data, an accelerator having the closest physical proximity is identified, and the fragment of compressed data is assigned to said accelerator. Each fragment of data is analyzed to determine a method of compressing the data. Based on the method of compression, the system software selects the decompression method. By leveraging the physical proximity of the accelerator to the fragment of compressed data, the herein described embodiments save clock cycles required to get the data to the processor and reduce the time required to complete the decompression. 
     Referring to  FIG.  1   , a symmetric multiprocessing system  100 , hereinafter the system  100 , for accelerating memory decompression of a large physically scattered buffer is shown in accordance with one or more embodiments of the present invention. A symmetric multiprocessing system is a computer system that includes two or more processors that share a common memory and data path. A single operating system (not shown) controls each processor of the system  100 . 
     As described herein, the system  100  includes a first subsystem  102  and a second subsystem  104 . The first subsystem  102  includes a first processor  106  referred to as a first socket. The second subsystem  104  includes a second processor  108  referred to as a second socket. Each of the first processor  106  and the second processor  108  is connected to a first accelerator  110  and a second accelerator  112 , respectively. Each accelerator is specialized hardware designed to receive offloaded data from the symmetric multiprocessing system and perform the decompression. Additionally, each of the first processor  106  and the second processor  108  have access to a first local memory  114  and a second local memory  118  located in main memory  118 . In some embodiments of the present invention, each the first local memory  114  and the second local memory  118  are a cache memory. When an application requests memory, the single operating system may provide the application a buffer that includes a range of virtual addresses corresponding to physical address spaces distributed across the first local memory  114  and the second local memory  118  of the first subsystem  102  and the second subsystem  104 . It should be appreciated that although two subsystems are illustrated, the system  100  could include any number of subsystems greater than one. 
     A decompression agent  120  receives a read memory request from an application. The decompression agent  120  is a software algorithm for decompressing a block of data using various decompression algorithms. Based on the read memory request, the decompression agent  120  identifies the virtual addresses of the requested data. The virtual addresses include a virtual page number and offsets within the page. The decompression agent  120  translates the virtual page numbers and offsets into physical addresses of the requested data. The physical address enables the decompression agent  120  to determine where the fragments that make up the requested data are located in the first local memory  114  or the second local memory  118 . In addition to determining the physical address of the requested data, the decompression agent  120  can read the data stored at the physical address and determine that the data is compressed, including an algorithm used to compress the data, as well as the boundaries of the data. The decompression agent  120  further determines a compression method used to compress the requested data. In some instances, the requested data includes a file extension that identifies the compression method. In some instances, decompression agent  120  determines the compression method based on the nature of the compressed data. The decompression agent  120  compares the state of the bits to states of compressed bits from dictionaries associated with different compression methods. For example, by analyzing a state of the bits of a fragment, the decompression agent  120  determines the compression method. In some instances, the decompression agent  120  retrieves an initial set of bits from a fragment of the requested data. The initial set of bits being fewer than the total number of bits in the fragment of the requested data. Based on a state of the initial set of bits, the decompression agent  120  identifies one or more potential compression methods used to compress the requested data. The decompression agent  120  then selects decompression algorithms from a decompression library based on the one or more potential compression algorithms. The decompression agent  120  then decompresses the initial set of bits to verify which compression algorithm was used to compress the requested data. Once the compression method is identified, the decompression agent  120  accesses a table to determine which decompression method to use. As data that is stored as fragments across a memory buffer will have been compressed using the same method, the decompression agent  120  associates the compression method with each fragment of the requested data. The boundaries enable the decompression agent  120  to recognize where each parameter of the requested data begins and where the parameter ends. The boundaries include the boundaries as utilized by the decompression agent  120 , but also additional boundaries as defined by the compression algorithm used to compress the data as well. The boundaries used by the compression algorithm enable a multi-block decompression algorithm to process the data and decompress multiple blocks in parallel. 
     The decompression agent  120  then offloads the fragments of compressed data from the first local memory  114  and second local memory  118 , including an identity of the compression algorithm, to the respective first accelerator  110  or second accelerator  112  for decompression. For example, if a fragment of data is located in the first local memory, the decompression agent  120  offloads the fragment to the first accelerator  110 , and not the second accelerator  112 . The decompression algorithm is based on the identity of the compression algorithm. The first accelerator  110  and the second accelerator  112  are operable to use various decompression algorithms to decompress the compressed data. For example, the first accelerator  110  and the second accelerator  112  can execute a fixed Huffman table (FHT) algorithm to decompress the compressed data. This method uses a pre-defined universal dictionary (FHT) decompressing the data and permits parallel decompression by the decompression units of the first accelerator  110  and the second accelerator  112 . The first accelerator  110  and the second accelerator  112  are also operable to use a dynamic Huffman table (DHT) with full flush mode. Each of the first accelerator  110  and the second accelerator  112  include two or more decompression units that can decompress data independently and in parallel to each other for above mentioned compression methods. The first accelerator  110  and the second accelerator  112  are also operable to use a dynamic Huffman table (DHT) without full flush mode. The method uses a data-defined dictionary (DHT) based on the input data used during compression. The DHT has code and back-reference information (also called history data), which is used during decompression. This method does not permit parallel decompression by the decompression units of the first accelerator  110  and the second accelerator  112 , and parallel decompression by the different accelerators. 
     Referring to  FIG.  2   , an illustration of a decompression process  200  is shown in accordance with one or more embodiments of the present invention. As illustrated, a memory buffer  202  holds virtual addresses for block 0 to data block N of data. As illustrated, an application has requested data, in which a first data fragment  204  of the requested data is stored in the first local memory  114  of a first subsystem  102  and a second data fragment  206  is stored in the second local memory  118  of a second subsystem  104 . The first data fragment  204  is offloaded to a first accelerator  110  via a first processor  106 . Additionally, the second data fragment  206  is offloaded to a second accelerator  112  via a second processor  108 . As illustrated, the second data fragment  206  is stored in the local memory of a separate subsystem than the first data fragment  204 . Blocks 0 - N are not stored in a physically contiguous location, and are scattered throughout the memory buffer  202 . In other words, blocks 0 - N are not all held in sequential memory addresses and can be separated by unrelated data pages. 
     The first processor  106  and the second processor  108  are each operable to perform direct memory access (DMA) between the two above referenced processor subsystems. The first processor  106  and the second processor  108  can execute a local direct memory access first processor  106  and the second processor  108  and instruct the local memory of the processor subsystems to respectively send the first data fragment  204  and the second data fragment  216  directly to the first accelerator  210  and the second accelerator  212 . In other words, a decompression agent  120  restricts the decompression operations to accelerators that are local to the local memory of each subsystem. This local DMA results in lower latency than if the decompression agent  120  instructed a local memory to transmit a data fragment to a remote accelerator. 
     Referring to  FIG.  3   , a process  300  for accelerating memory decompression of a large physically scattered buffer on a multi-socket symmetric multiprocessing architecture. It should be appreciated that all or a portion of the process can be performed on a computer system  400  as illustrated in  FIG.  4   . At block  302 , decompression agent  120  locates a first requested data in a first local memory  114  of a first subsystem  102  of a symmetric multiprocessing system. The decompression agent  120  further locates a second requested data in a second local memory  116  of a second subsystem  104  of a symmetric multiprocessing system. In some embodiments of the present invention, the decompression agent  120  receives a read memory request and identifies a virtual addresses of the requested data. The decompression agent  120  translates the virtual addresses into physical addresses of the requested data. The decompression agent  120  further determines that the requested data comprises the first requested data and the second requested data. In addition, the decompression agent  120  can read the data stored at the physical address and determine that the data is compressed, including an algorithm used to compress the data, as well as the boundaries of the data. 
     At block  304 , the decompression agent  120  identifies a first accelerator  110  and the second accelerator  112  based on the first local memory  114  and the first accelerator being a part of a first subsystem  102 ; and the second local memory  118  and the second accelerator  112  being a part of a second subsystem  104 . 
     At block  306 , the decompression agent  120  retrieves the compressed data from the first local memory  114  and second local memory  118 ; and offloads the data to the first accelerator  110  and the second accelerator  112 . The decompression agent  120  further provides the compression method used to compress the data, and further instructs the first accelerator  110  and the second accelerator  112  on which decompression method to use. 
     In one or more embodiments of the present invention, the hardware/software modules in the system  100  from  FIG.  1    can be implemented on the processing system  400  found in  FIG.  4   . Turning now to  FIG.  4   , a computer system  400  is generally shown in accordance with an embodiment. The computer system  400  can be an electronic, computer framework comprising and/or employing any number and combination of computing devices and networks utilizing various communication technologies, as described herein. The computer system  400  can be easily scalable, extensible, and modular, with the ability to change to different services or reconfigure some features independently of others. The computer system  400  may be, for example, a server, desktop computer, laptop computer, tablet computer, or smartphone. Computer system  400  may be described in the general context of computer system executable instructions, such as program modules, being executed by a computer system. Generally, program modules may include routines, programs, objects, components, logic, data structures, and so on that perform particular tasks or implement particular abstract data types. Computer system  400  may be practiced in distributed cloud computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed cloud computing environment, program modules may be located in both local and remote computer system storage media including memory storage devices. 
     As shown in  FIG.  4   , the computer system  400  has one or more central processing units (CPU(s))  401   a ,  401   b ,  401   c , etc. (collectively or generically referred to as processor(s)  401 ). The processors  401  can be a single-core processor, multi-core processor, computing cluster, or any number of other configurations. The processors  401 , also referred to as processing circuits, are coupled via a system bus  402  to a system memory  403  and various other components. The system memory  403  can include a read only memory (ROM)  404  and a random access memory (RAM)  405 . The ROM  404  is coupled to the system bus  402  and may include a basic input/output system (BIOS), which controls certain basic functions of the computer system  400 . The RAM is read-write memory coupled to the system bus  402  for use by the processors  401 . The system memory  403  provides temporary memory space for operations of said instructions during operation. The system memory  403  can include random access memory (RAM), read only memory, flash memory, or any other suitable memory systems. 
     The computer system  400  comprises an input/output (I/O) adapter  406  and a communications adapter  407  coupled to the system bus  402 . The I/O adapter  406  may be a small computer system interface (SCSI) adapter that communicates with a hard disk  408  and/or any other similar component. The I/O adapter  406  and the hard disk  408  are collectively referred to herein as a mass storage  410 . 
     Software  411  for execution on the computer system  400  may be stored in the mass storage  410 . The mass storage  410  is an example of a tangible storage medium readable by the processors  401 , where the software  411  is stored as instructions for execution by the processors  401  to cause the computer system  400  to operate, such as is described herein below with respect to the various Figures. Examples of computer program product and the execution of such instruction is discussed herein in more detail. The communications adapter  407  interconnects the system bus  402  with a network  412 , which may be an outside network, enabling the computer system  400  to communicate with other such systems. In one embodiment, a portion of the system memory  403  and the mass storage  410  collectively store an operating system, which may be any appropriate operating system, such as the z/OS, Linux, or AIX operating system from IBM Corporation, to coordinate the functions of the various components shown in  FIG.  4   . 
     Additional input/output devices are shown as connected to the system bus  402  via a display adapter  415  and an interface adapter  416  and. In one embodiment, the adapters  406 ,  407 ,  415 , and  416  may be connected to one or more I/O buses that are connected to the system bus  402  via an intermediate bus bridge (not shown). A display  419  (e.g., a screen or a display monitor) is connected to the system bus  402  by a display adapter  415 , which may include a graphics controller to improve the performance of graphics intensive applications and a video controller. A keyboard  421 , a mouse  422 , a speaker  423 , etc. can be interconnected to the system bus  402  via the interface adapter  416 , which may include, for example, a Super I/O chip integrating multiple device adapters into a single integrated circuit. Suitable I/O buses for connecting peripheral devices such as hard disk controllers, network adapters, and graphics adapters typically include common protocols, such as the Peripheral Component Interconnect (PCI). Thus, as configured in  FIG.  4   , the computer system  400  includes processing capability in the form of the processors  401 , and, storage capability including the system memory  403  and the mass storage  410 , input means such as the keyboard  421  and the mouse  422 , and output capability including the speaker  423  and the display  419 . 
     In some embodiments, the communications adapter  407  can transmit data using any suitable interface or protocol, such as the internet small computer system interface, among others. The network  412  may be a cellular network, a radio network, a wide area network (WAN), a local area network (LAN), or the Internet, among others. An external computing device may connect to the computer system  400  through the network  412 . In some examples, an external computing device may be an external webserver or a cloud computing node. 
     It is to be understood that the block diagram of  FIG.  4    is not intended to indicate that the computer system  400  is to include all of the components shown in  FIG.  4   . Rather, the computer system  400  can include any appropriate fewer or additional components not illustrated in  FIG.  4    (e.g., additional memory components, embedded controllers, modules, additional network interfaces, etc.). Further, the embodiments described herein with respect to computer system  400  may be implemented with any appropriate logic, wherein the logic, as referred to herein, can include any suitable hardware (e.g., a processor, an embedded controller, or an application specific integrated circuit, among others), software (e.g., an application, among others), firmware, or any suitable combination of hardware, software, and firmware, in various embodiments. 
     Various embodiments of the invention are described herein with reference to the related drawings. Alternative embodiments of the invention can be devised without departing from the scope of this invention. Various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and/or positional relationships, unless specified otherwise, can be direct or indirect, and the present invention is not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship. Moreover, the various tasks and process steps described herein can be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. 
     One or more of the methods described herein can be implemented with any or a combination of the following technologies, which are each well known in the art: a discrete logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc. 
     For the sake of brevity, conventional techniques related to making and using aspects of the invention may or may not be described in detail herein. In particular, various aspects of computing systems and specific computer programs to implement the various technical features described herein are well known. Accordingly, in the interest of brevity, many conventional implementation details are only mentioned briefly herein or are omitted entirely without providing the well-known system and/or process details. 
     In some embodiments, various functions or acts can take place at a given location and/or in connection with the operation of one or more apparatuses or systems. In some embodiments, a portion of a given function or act can be performed at a first device or location, and the remainder of the function or act can be performed at one or more additional devices or locations. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof. 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments were chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated. 
     The diagrams depicted herein are illustrative. There can be many variations to the diagram or the steps (or operations) described therein without departing from the spirit of the disclosure. For instance, the actions can be performed in a differing order or actions can be added, deleted or modified. Also, the term “coupled” describes having a signal path between two elements and does not imply a direct connection between the elements with no intervening elements/connections therebetween. All of these variations are considered a part of the present disclosure. 
     The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus. 
     Additionally, the term “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms “at least one” and “one or more” are understood to include any integer number greater than or equal to one, i.e. one, two, three, four, etc. The terms “a plurality” are understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term “connection” can include both an indirect “connection” and a direct “connection.” 
     The terms “about,” “substantially,” “approximately,” and variations thereof, are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ± 8% or 5%, or 2% of a given value. 
     The present invention may be a system, a method, and/or a computer program product at any possible technical detail level of integration. The computer program product may include a computer readable storage medium (or media) having computer readable program instructions thereon for causing a processor to carry out aspects of the present invention. 
     The computer readable storage medium can be a tangible device that can retain and store instructions for use by an instruction execution device. The computer readable storage medium may be, for example, but is not limited to, an electronic storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the foregoing. A non-exhaustive list of more specific examples of the computer readable storage medium includes the following: a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanically encoded device such as punch-cards or raised structures in a groove having instructions recorded thereon, and any suitable combination of the foregoing. A computer readable storage medium, as used herein, is not to be construed as being transitory signals per se, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission media (e.g., light pulses passing through a fiber-optic cable), or electrical signals transmitted through a wire. 
     Computer readable program instructions described herein can be downloaded to respective computing/processing devices from a computer readable storage medium or to an external computer or external storage device via a network, for example, the Internet, a local area network, a wide area network and/or a wireless network. The network may comprise copper transmission cables, optical transmission fibers, wireless transmission, routers, firewalls, switches, gateway computers and/or edge servers. A network adapter card or network interface in each computing/processing device receives computer readable program instructions from the network and forwards the computer readable program instructions for storage in a computer readable storage medium within the respective computing/processing device. 
     Computer readable program instructions for carrying out operations of the present invention may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine dependent instructions, microcode, firmware instructions, state-setting data, configuration data for integrated circuitry, or either source code or object code written in any combination of one or more programming languages, including an object oriented programming language such as Smalltalk, C++, or the like, and procedural programming languages, such as the “C” programming language or similar programming languages. The computer readable program instructions may execute entirely on the user’s computer, partly on the user’s computer, as a stand-alone software package, partly on the user’s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user’s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic circuitry including, for example, programmable logic circuitry, field-programmable gate arrays (FPGA), or programmable logic arrays (PLA) may execute the computer readable program instruction by utilizing state information of the computer readable program instructions to personalize the electronic circuitry, in order to perform aspects of the present invention. 
     Aspects of the present invention are described herein with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer readable program instructions. 
     These computer readable program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. These computer readable program instructions may also be stored in a computer readable storage medium that can direct a computer, a programmable data processing apparatus, and/or other devices to function in a particular manner, such that the computer readable storage medium having instructions stored therein comprises an article of manufacture including instructions which implement aspects of the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device to cause a series of operational steps to be performed on the computer, other programmable apparatus or other device to produce a computer implemented process, such that the instructions which execute on the computer, other programmable apparatus, or other device implement the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function(s). In some alternative implementations, the functions noted in the blocks may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts or carry out combinations of special purpose hardware and computer instructions. 
     The descriptions of the various embodiments of the present invention have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to best explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments described herein.