Patent Publication Number: US-6665819-B1

Title: Data capture and analysis for embedded systems

Description:
FIELD OF THE INVENTION 
     This invention relates generally to embedded systems, and more particularly to debugging, profiling, performance-enhancing, optimizing, etc., embedded systems. 
     BACKGROUND OF THE INVENTION 
     Embedded systems are the most prevalent of all computer systems used today, accounting for the vast majority of microprocessors sold. Advances in processor technology and memory technology and their associated low cost allow them to be considered for a large number of applications. The size and sophistication of embedded applications has correspondingly grown. 
     Embedded systems share most of the following characteristics. They generally are developed around custom hardware, require high quality and reliability, and frequently deal with real-time issues. The applications running on these systems can be very large and complex. Examples of such systems include telecommunication switching systems, aircraft, spacecraft, and weapons systems, and a multitude of applications in the car and in the house. Other examples of embedded systems include cellular phones, set-top boxes, and personal-digital assistant (PDA) devices. 
     Because of their required reliable and often real-time nature, embedded systems generally require careful debugging to ensure that they work as intended. However, debugging embedded systems can be difficult. Usually, developers are required to utilize a wide variety of software tools developed by different vendors in order to solve their problems. Such tools frequently use different mechanisms and protocols for measuring (i.e., collecting) and analyzing data from the target embedded system. Thus, many of these tools are very specialized in purpose, and usually cannot be extended to collect and analyze data other than that for which they were initially developed. This is an inconvenience for the developers, since they may have to use many different tools to debug a single problem in their target embedded systems. 
     For these and other reasons, therefore, there is a need for the present invention. 
     SUMMARY OF THE INVENTION 
     The invention relates to data capture and analysis for debugging embedded systems. In one embodiment, a system Go includes a target and a host. The term “target” non-restrictively and in a non-limiting manner refers to hardware, such as a processor, that is part of an embedded system, and which is desired to be debugged, and/or the software of the embedded system, such as its operating system (OS). The term “host” non-restrictively and in a non-limiting manner refers to a system, such as a desktop computer, to which the target is communicatively coupled for debugging and other purposes. In one embodiment, the target includes at least one data collector, each of which publishes predetermined data of the target, and a collection manager for managing the data collectors. In one embodiment, the host includes at least one viewer, each of which subscribes to the predetermined data of a data collector, for processing thereof, and a viewer manager for managing the viewers. (The phrase predetermined data is used to identify a type of data, that can be identified, for example, by a unique identifier, and is not meant to imply that the data is constant or static.) 
     Embodiments of the invention provide for advantages not found within the prior art. The use of data collectors and corresponding viewers allows for extensibility of the capture and analysis of embedded system data when debugging. New data collectors, for example, can be added to collect data for the embedded system that is not currently being collected. Similarly, new data viewers can be added to process the collected data (e.g., visualize the data, analyze the data, etc.) in a manner not currently being processed. That is, developers do not have to resort to a multitude of different software tools to debug their embedded system, since embodiments of the invention provide for an extensible data collection and analysis architecture. 
    
    
     The invention includes computer-implemented methods, machine-readable media, computerized systems, and computers of varying scopes. Other aspects, embodiments and advantages of the invention, beyond those described here, will become apparent by reading the detailed description and with reference to the drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a diagram of an operating environment in conjunction with which embodiments of the invention can be practiced; 
     FIG. 2 is a diagram of a system according to an embodiment of the invention; and, 
     FIG. 3 is a flowchart of a method according to an embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims. 
     Some portions of the detailed descriptions which follow are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. An algorithm is here, and generally, conceived to be a self-consistent sequence of steps leading to a desired result. The steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. 
     It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, or the like. It should be borne in mind, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless specifically stated otherwise as apparent from the following discussions, it is appreciated that throughout the present invention, discussions utilizing terms such as processing or computing or calculating or determining or displaying or the like, refer to the action and processes of a computer system, or similar electronic computing device, that manipulates and transforms data represented as physical (electronic) quantities within the computer system&#39;s registers and memories into other data similarly represented as physical quantities within the computer system memories or registers or other such information storage, transmission or display devices. 
     Operating Environment 
     Referring to FIG. 1, a diagram of the hardware and operating environment in conjunction with which embodiments of the invention may be practiced is shown. The description of FIG. 1 is intended to provide a brief, general description of suitable computer hardware and a suitable computing environment in conjunction with which the invention may be implemented. Although not required, the invention is described in the general context of computer-executable instructions, such as program modules, being executed by a computer, such as a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc., that perform particular tasks or implement particular abstract data types. 
     Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multiprocessor systems, microprocessor-based or programmable consumer electronics, network PC&#39;s, minicomputers, mainframe computers, and the like. The invention may also be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices. 
     The exemplary hardware and operating environment of FIG. 1 for implementing the invention includes a general purpose computing device in the form of a computer  20 , including a processing unit  21 , a system memory  22 , and a system bus  23  that operatively couples various system components include the system memory to the processing unit  21 . There may be only one or there may be more than one processing unit  21 , such that the processor of computer  20  comprises a single central-processing unit (CPU), or a plurality of processing units, commonly referred to as a parallel processing environment. The computer  20  may be a conventional computer, a distributed computer, or any other type of computer; the invention is not so limited. 
     The system bus  23  may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. The system memory may also be referred to as simply the memory, and includes read only memory (ROM)  24  and random access memory (RAM)  25 . A basic input/output system (BIOS)  26 , containing the basic routines that help to transfer information between elements within the computer  20 , such as during start-up, is stored in ROM  24 . The computer  20  further includes a hard disk drive  27  for reading from and writing to a hard disk, not shown, a magnetic disk drive  28  for reading from or writing to a removable magnetic disk  29 , and an optical disk drive  30  for reading from or writing to a removable optical disk  31  such as a CD ROM or other optical media. 
     The hard disk drive  27 , magnetic disk drive  28 , and optical disk drive  30  are connected to the system bus  23  by a hard disk drive interface  32 , a magnetic disk drive interface  33 , and an optical disk drive interface  34 , respectively. The drives and their associated computer-readable media provide nonvolatile storage of computer-readable instructions, data structures, program modules and other data for the computer  20 . It should be appreciated by those skilled in the art that any type of computer-readable media which can store data that is accessible by a computer, such as magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memories (RAMs), read only memories (ROMs), and the like, may be used in the exemplary operating environment. 
     A number of program modules may be stored on the hard disk, magnetic disk  29 , optical disk  31 , ROM  24 , or RAM  25 , including an operating system  35 , one or more application programs  36 , other program modules  37 , and program data  38 . A user may enter commands and information into the personal computer  20  through input devices such as a keyboard  40  and pointing device  42 . Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit  21  through a serial port interface  46  that is coupled to the system bus, but may be connected by other interfaces, such as a parallel port, game port, or a universal serial bus (USB). A monitor  47  or other type of display device is also connected to the system bus  23  via an interface, such as a video adapter  48 . In addition to the monitor, computers typically include other peripheral output devices (not shown), such as speakers and printers. 
     The computer  20  may operate in a networked environment using logical connections to one or more remote computers, such as remote computer  49 . These logical connections are achieved by a communication device coupled to or a part of the computer  20 ; the invention is not limited to a particular type of communications device. The remote computer  49  may be another computer, a server, a router, a network PC, a client, a peer device or other common network node, and typically includes many or all of the elements described above relative to the computer  20 , although only a memory storage device  50  has been illustrated in FIG.  1 . The logical connections depicted in FIG. 1 include a local-area network (LAN)  51  and a wide-area network (WAN)  52 . Such networking environments are commonplace in office networks, enterprise-wide computer networks, intranets and the Internal, which are all types of networks. 
     When used in a LAN-networking environment, the computer  20  is connected to the local network  51  through a network interface or adapter  53 , which is one type of communications device. When used in a WAN-networking environment, the computer  20  typically includes a modem  54 , a type of communications device, or any other type of communications device for establishing communications over the wide area network  52 , such as the Internet. The modem  54 , which may be internal or external, is connected to the system bus  23  via the serial port interface  46 . In a networked environment, program modules depicted relative to the personal computer  20 , or portions thereof, may be stored in the remote memory storage device. It is appreciated that the network connections shown are exemplary and other means of and communications devices for establishing a communications link between the computers may be used. 
     Systems 
     In this section of the detailed description, systems according to varying embodiments of the invention are described, with reference to FIG. 2, which is a diagram of a system  200  according to one embodiment. The system  200  includes a host  202  and a target  204 . The target  204  can in one embodiment correspond to an embedded system being debugged, or components of the embedded system being debugged, such as the hardware of the system, such as a processor, and/or the software of the system, such as an operating system, its kernel, etc. The host  202  is a system to which the target  204  is communicatively coupled for debugging and other purposes, and can be in one embodiment a desktop computer, such as that which was described in the previous section of the detailed description in conjunction with FIG.  1 . Thus, each of the host  202  and the target  204  can be considered a system in its own right in one embodiment. 
     The target  204  includes a collection manager  210  and a data collector  212 , as shown in FIG.  2 . Although only one data collector is shown, this is for purposes of illustrative clarity only, and there can be and typically are more than one data collector, as can be appreciated by those of ordinary skill within the art. The data collector  212  collects data regarding the target  204  for debugging or other purposes. For example, such data can include memory heap data, synchronization data, etc., as known within the art. The collector  212  transmits the data it collects to the collection manager  210 , which manages all the data from the data collectors (and thus, manages all the collectors), for transmission to the host  202  for analysis. 
     In one embodiment, the collector  212  publishes the data to the manager  210  upon a predetermined event occurring. For example, when a certain address has changed its content, the collector  212  may on the basis of this event take a snapshot of the data within a predetermined range of addresses, and convey this to the manager  210 . It is noted that the invention itself is not so limited, however. Thus, each collector within the system is responsible for tracking predetermined data in accordance with predetermined events, where the data and the events of the collectors can be the same or different from one another. For example, one collector may be responsible for tracking a certain range in response to a first event, while a second collector may be responsible for tracking the same in range but in response to a different event. 
     In one embodiment, each of the collector  212  and the manager  210  is a software component, or object or module, or a computer program. The data gathered by the collector  212  can be of a certain nature pertaining to a particular data type, or other, more abstract classification of information. The collectors exist desirably only to provide data, and desirably perform little or no time-expensive processing on the data before passing it up to the manager  210 . The predetermined data collected by the collector  212  can have a structure similar to a data structure in the C++ programming language, as known within the art, and also a unique identifier, such as what is known in the art as a Globally Unique IDentifier (GUID), although the invention is not so limited. 
     The host  202  includes a data viewer  206  and a viewer manager  208 , as shown in FIG.  2 . Although only one data viewer is shown, this is for purposes of illustrative clarity only, and there can be and typically are more than one data viewer, as can be appreciated by those of ordinary skill within the art. The data viewer  206  processes the data regarding the target  204 , as collected by the collector  212 , for debugging and other purposes. For example, such processing can include analysis, transformation, visualization, and other types of processing. A data viewer can in one embodiment abstract and/or transform the data provided to other data, for analysis by a different data viewer (that is, a hierarchy of data viewers can exist). The viewer manager  208  manages the data received from the target  204 , and transmits the data to the viewer  206  (or, where there is more than one viewer, to the appropriate viewer). 
     In one embodiment, the viewer  206  subscribes to the data collected by a particular collector, such as the collector  212 . Desirably, the collector  212  only publishes the data if there is a corresponding viewer that has subscribed to the data that is to be collected by this collector. Thus, the collector  212  may have an internal flag indicating that a viewer has subscribed to the data it is collecting. Therefore, in one embodiment, the viewer  206  and the collector  212  can be considered as part of a publish-and-subscribe system, as such are known within the art. Such a system is generally referred to as the providing by a source of information that subscribers select from and then receive on a regular basis or when certain events occur. 
     In one embodiment, each of the viewer  206  and the viewer manager  208  is a software component, or object or module, or a computer program. The viewers are desirably host-side components that process and represent data ultimately delivered to them from target-side collectors. In one embodiment, viewers register themselves with the viewer manager  208 , which can send control data and receive run-time data from the collection manager  210 , and its respective collectors. The viewers are responsible for controlling the data streams in one embodiment, via control data ultimately sent to the collectors in one embodiment (i.e., the viewers indicate to a collector that they desire to subscribe to the data collected by the collector). The viewers can also contain and provide a user interface for displaying the data to be viewed. The viewers can also post-process the data as necessary. Examples of processing the data including graphing, transforming, sorting, or statistically manipulating, in addition to those already described. As another example, the data can be stored in a data file. 
     In one embodiment, the host  202  communicates with the target  204  by the viewer manager  208  of the former communicating with the collection manager  210  of the latter. The host  202  is desirably communicatively coupled to the target  204  via a standard communication link, such as a serial cable, an Ethernet connection, etc. Especially with an Ethernet connection, the collection manager  210  and the viewer manager  208  transmit data to each other in a packetized manner, although the invention itself is not so particularly limited. 
     Thus, the collection manager  210  acts as a messenger between each collector and the host  202 . In one embodiment, there may exist a transport layer at the target  204  through which the collection manager  210  communicates with the host  202 . As known within the art, a transport layer is generally a service within a protocol stack that provides end-to-end management of communications sessions. In one embodiment, the manager  210  performs multiplexing of the data sent by the collectors. It is responsible desirably for the creation, destruction, and management of the collectors, for example, as a hierarchy thereof, based on control and status messages received from the viewer manager  208 . The behavior of the manager  210  is desirably controlled by the control data received from the host  202  (for example, which can originate by the viewers of the host  202  themselves, as has been described). That is, the collection manager  210  indicates to collectors that viewers desire to subscribe to their data, such that the collectors transmit the data to the collection manager  210 , which then transmits the data to the viewer manager  208 . 
     The viewer manager  208  is responsible for providing a communication interface between the viewers and the target  204 . In one embodiment, there may exist a transport layer at the host  202  through which the viewer manager  208  communicates with the target  204 . The viewer manager  208  in one embodiment passes control data from the viewers to the target  204  (for ultimate delivery to the appropriate collectors), and relays data delivered from the target  204  to the appropriate viewers. The manager  208  also manages the creation and destruction of the viewers (e.g., as in a viewer hierarchy). Because in one embodiment the collectors depend on having corresponding viewers before they will publish any data, the manager  208  in this embodiment also announces each viewer to the collection manager  210  via control data so that the collection manager  210  can notify the appropriate collector. 
     Thus, when a viewer is first created, it indicates to the viewer manager  208  that it wishes to subscribe to the predetermined data of a given collector. The viewer manager  208  communicates this control data to the collection manager  210 , which passes it to the appropriate collector, which may set a flag to indicate that it is now to publish data that it collects. When a predetermined event occurs, the collector collects its predetermined data, and passes it to the collection manager  210 , which passes it to the viewer manager  208 , which passes it to the viewer that had subscribed to this data. (In one embodiment, there can be buffering of the data before it is sent.) Thus, generally (although the invention is not so limited), the viewer manager  208  passes control data down to the collection manager  210 , while the collection manager  210  passes data collected by the collectors up to the viewer manager  208 . It is noted that a one-to-one correspondence between viewers and collectors is not necessary—e.g., there may be more than one viewer processing data from one collector, and/or one viewer processing data from many collectors. 
     Methods 
     In this section of the detailed description, methods according to varying embodiments of the invention are described. The methods can in some embodiments be computer-implemented. A computer-implemented method is desirably realized at least in part as one or more programs running on a computer—that is, as a program executed from a computer-readable medium such as a memory by a processor of a computer. The programs are desirably storable on a machine-readable medium such as a floppy disk or a CD-ROM, for distribution and installation and execution on another computer. The program or programs can be a part of a computer system or a computer, such as that described in conjunction with FIG. 1 in a previous section of the detailed description. The invention is not so limited, however. 
     Referring to FIG. 3, a flowchart of a method  300  according to an embodiment of the invention is shown. In  302 , a data viewer subscribes to the predetermined data that is collected by a given data collector. That is, the data viewer passes control data indicating its subscription to the viewer manager, which passes the information to the collection manager, which indicates to the data collector that a viewer has subscribed to its data. The data collector may then set an internal flag to indicate that it should publish its data for the viewer. 
     In  304 , upon the occurrence of a predetermined event, or on a regular basis, the data collector collects its predetermined data, and in  306 , publishes the data to the collection manager. That is, the collector transmits its data to the collection manager. In  308 , the collection manager transmits the data to the viewer manager, for example, over a standard communications link, such as Ethernet or a serial cable. In  310 , the viewer manager transmits the data to the viewer or viewers that subscribed to this data. Finally, in  312 , the viewer processes the data—for example, analyzing it, or displaying the data for the benefit of the developer. 
     It is noted that other functionality is covered by the invention than that which is described in conjunction with FIG.  3 . As an example, the viewers can control the behavior of the collector via commands. Furthermore, the viewers themselves can publish data for use by other viewers. 
     Conclusion 
     It is noted that, although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement which is calculated to achieve the same purpose may be substituted for the specific embodiments shown. This application is intended to cover any adaptations or variations of the present invention. Therefore, it is manifestly intended that this invention be limited only by the claims and equivalents thereof.