Abstract:
A filter module for a WOSA/XFS transaction processing system is disclosed. The system includes a WOSA transaction manager which is responsive to transaction requests from at least one application. A service provider layer is adapted to relay transaction requests passed from the transaction manager to associated hardware for execution. The filter module is adapted to intercept transaction requests from the transaction manager to the service provider layer and to process the requests. The filter module is further adapted to intercept transaction responses form the service provider layer to the transaction manager and the at least one application and to process these responses.

Description:
FIELD OF THE INVENTION 
   The present invention relates to a filter module for a transaction processing system. 
   BACKGROUND OF THE INVENTION 
   WOSA/XFS (Windows Open Services Architecture for Extended Financial Services) is an emerging standard enabling financial institutions, whose branch and office solutions run on the Windows NT platform, to develop applications independent of vendor equipment. 
     FIG. 1  shows the standard WOSA model in solid lines. Using this model, an application  10  communicates hardware requests  12  to various hardware devices in an ATM  14  via a WOSA manager  20 . The application issues transaction requests  12  which are hardware independent, and thus vendor independent. The requests are queued by the WOSA manager  20  which manages concurrent access to the ATM hardware  14  from any number of applications  10 . 
   When a piece of hardware is installed on the ATM, it registers its controlling software, known as a service provider module (SPM)  30 , with the WOSA manager by using, for example, the Windows registry. The WOSA manager  20  is thus able to relay a hardware request  12  to an appropriate SPM  30 , using the Windows registry as a look-up table. The SPM  30  takes relayed hardware independent requests  16  from the WOSA manager and actuates the appropriate piece of hardware to process the requests. The results of a request can be returned to the application by an SPM  30  synchronously via the WOSA manager  20  or asynchronously directly to the application  10 . 
   During development, it can be very difficult to debug a WOSA system, because at run-time a number of applications may be generating hardware requests and receiving responses either synchronously or asynchronously at any given time. Messages are transmitted via many routes at run-time and the operation of one application&#39;s requests and responses could interfere with those of another application. 
   It can also be desirable in an installed system to keep track of or log the operation of sensitive parts of a WOSA system. It may be desirable to track applications who are requesting access to a cash dispenser and the responses of the cash dispenser to those requests. Also, for example, keeping track of the number of bad card reads might indicate the card reader is coming to the end of its life or needs cleaning. Similarly, the number of uses of the printer can be tracked to determine when the printer ribbon needs to be replaced, as well as numerous other examples. 
   It is an object of the present invention to provide a filter module to solve these problems. 
   SUMMARY OF THE INVENTION 
   Accordingly, the present invention provides a filter module for a transaction processing system in which a transaction manager responsive to transaction requests from at least one applications and a service provider layer is adapted to relay transaction requests passed from said transaction manager to associated hardware for execution; said filter module being adapted to intercept transaction requests from said transaction manager to said service provider layer and to process said requests, said filter module being further adapted to intercept transaction responses from said service provider layer to said transaction manager and at least one application and to process said responses. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a standard WOSA single process transaction processing system including a filter module according to the invention (shown shaded); 
       FIG. 2  shows an alternative transaction processing system including the filter module of  FIG. 1  (shown shaded); 
       FIG. 3  shows a server component of the transaction processing system of  FIG. 2  in more detail; 
       FIG. 4  is a schematic view of a portion of a Windows NT registry employed by a WOSA manager; and 
       FIG. 5  is a schematic diagram of an ATM including a transaction processing system according to the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The standard WOSA model includes three layers,  FIG. 1 . An application layer  10  issues transaction requests in the form of hardware independent Application Programming Interface (API) calls  12  to a WOSA Manager  20  layer in order to access services from a Service Provider  30 ,  37  layer. All components exist within the same process (the Application&#39;s) and memory address space. 
   WOSA is a classic single process model, where all components of the solution run in the same process. If a single thread within this process abends, it will normally take the entire process down. Although this is acceptable in non-critical applications, for example printing, it is not acceptable where security is involved and where detailed audit trails are required. The best example of this case is where ATM cash dispensing is involved. If the process abends while a dispense is taking place, the error needs to be recoverable in order to determine the disposition of the cash involved. 
   In an alternative server model,  FIG. 2 , the application  10  and WOSA Manager  20  exist within the same user application process. The WOSA manager  20 , however, communicates with stub Dynamic Link Libraries (DLLs)  35  each corresponding to a respective SPM  30  of  FIG. 1 . Transaction requests  12  from the application layer  10  pass through the WOSA Manager  20  to the stub DLLs  35 , where the data is repackaged and passed across process boundaries to a server  40  running in a separate process, where the required transaction request is actually executed. Once a request is received, the server  40  communicates with SPM&#39;s  30  to execute the transaction request. 
   In either model, any execution results are either passed back from the SPMs to the application  10  through the WOSA manager  20  (via the stub DLLs  35  in the case of  FIG. 2 ) or directly to the application  10 . 
   In a Windows NT operating system embodiment of the invention, the SPMs  30  generate windows events using a window handle nominated by an application, whereas in an embodiment of the invention using IBM&#39;s OS/2 operating system, the SPMs generate presentation manager events. 
   In either case, the application  10  passes an identifier (either a window handle or presentation manager event) corresponding to the application itself (asynchronous) or the WOSA manager (synchronous) to an SPM so that the SPM knows where to send its response. 
   Similarly, the stub modules  35  also communicate messages to the WOSA manager  20  via the operating system messenger, because the window handle or presentation manager event for the WOSA manager  20  will be included in the response returned from the server  40 . 
   The method of response is therefore determined by the application  10 , depending on whether a transaction request issued is specified as synchronous (the server responds through the stub DLL mechanism) or asynchronous (the server responds via the Windows Event mechanism). 
   Information is also accessible by both the application  10  and the SPMs using shared memory. When, for example, an SPM  30  wishes to transmit information to an application  10 , the SPM sends a WOSA call to the WOSA manager  20  which communicates with an operating system memory manager  55  to allocate the shared memory. Once allocated, then SPMs  30  in the server  40  process or applications  10  can read or write information from this shared memory. 
     FIG. 3 , shows the server  40  in more detail. The server is a multi-threaded application supporting the simultaneous execution of transaction requests on all of its supported WOSA device classes explained below. The server  40  consists of the following major components: 
   A server object  41  runs in its own thread and has responsibility for creating and monitoring memory ‘pipes’  42  connecting the server process to respective stub DLLs  35 , running in the user application process. When the server object detects a transaction request packet from one of the stub DLLs  35  waiting in its associated ‘pipe’  42 , it moves the packet into a master queue  43  and thus frees the pipe for more communications. The server also detects packets in the master queue  43  that are response packets from service provider modules  30 , and channels these back through the ‘pipes’ to the correct stub DLL  35 , which then passes the response back to the user application  10  via the WOSA Manager. 
   The memory pipes  42  are implemented in a class including essentially three methods: readpipe( ), writePipe( ), querypipe( ) with the methods being passed an identifier corresponding to the stub DLL associated with the pipe. In the application process, a stub DLL  35  receives a WOSA transaction request from the transaction manager and calls the writePipe method to place the request in its pipe  42 . writePipe essentially writes a message to a designated location in shared memory with a flag indicating that the message needs to be read. Once the stub DLL  35  has written the message to the pipe, it then polls its pipe  42  continually using queryPipe to determine when a response has been sent from the server  41  or if the message has been read. 
   Within the server process, the server object  41  continually polls each of the pipes  42  using the queryPipe method for each pipe in turn to determine if messages are waiting to be processed. If a pipe has a message, the server calls readpipe to read the message from the pipe, resets the message flag indicating that the message has been read and places the message in the master queue  43 . The server also interrogates the master queue  43 , and if a message for the server  41  is in the master queue  43 , the server  41  pops the messages from the queue and calls writePipe to place the message in the appropriate pipe and thereafter reverts back to querying the pipe for the next message. 
   A client object  44  runs in its own thread and is responsible for creating and managing the supported service provider modules  30  below it. The client object  44  monitors the server master queue  43  and when it detects an inbound packet for one of its managed hardware devices, it moves the packet from the queue  43  on to a private queue  45  associated with a target device. 
   Instances of service provider module objects  30  are created at startup time by the client. In the case of an ATM, objects would be instantiated for a journal printer, receipt printer, passbook printer, statement printer, deposit unit, cash dispenser, magnetic card reader/smart card reader, sensors and indicators unit, pinpad unit, encryptor unit, vendor dependant mode (VDM) unit, and text terminal unit. Each instantiation spawns its own control thread that is responsible for monitoring its own private queue  45  for requests that are placed there by the client object  44 . When an SPM object  30  detects a request waiting on its private queue  45 , or if there is a request pending execution and it is time to attempt to process pending requests again, the SPM object spawns an execution thread that handles the execution of that single request. The execution thread has the responsibility of processing the request to its conclusion, either returning the relevant data to the caller application  10  via events, marking the request as ‘pending’ on the queue  45  and completing, or returning a response by returning a completed packet back to the server queue  43  for transmission to the stub DLL  35  associated with that hardware device. 
   Each SPM  30  converts all WOSA transaction requests into one or more generic commands that are processed by a layer of small hardware DLLs  46 . An Application Programming Interface (API) for each type of hardware device is published by the hardware vendor and consists of the minimum number of hardware level commands (example read_card on a magnetic stripe reader device, or dispense_cash on a dispenser) that can satisfy the complete set of WOSA transaction requests for that device type. For example, a respective hardware DLL is supplied for both an IBM Dispenser and an Olivetti dispenser. The user only has to change which DLL is active, by updating the Windows registry in order to switch between the different devices. At the application and server layers, nothing changes. The same is true for all device types. 
   The Windows NT registry is a hierarchy of keys,  FIG. 4 , each key containing one or more data values. The WOSA Manager  20  uses the system provided HKEY_CLASSES_ROOT key to store and obtain data on Logical Service Providers, for example, “msrspm”. The application  10  opens a service by providing the WOSA manager with that service&#39;s logical name. The manager finds the key entry, “msrspm” in the HKEY_CLASSES_ROOT\WOSA/XFS_ROOT\LOGICAL_SERVICES key for that service. One of the data fields, “provider”, within that key is an entry describing the service provider key name, “testmsr”. The manager then accesses the relevant service provider key within the HKEY_CLASSES_ROOT\WOSA/XFS_ROOT\SERVICE_PROVIDERS key, which will contain an entry describing the exact path to the physical dynamic link library (dll) that contains the executable code for that service provider, “d:\path\msrdll.dll”. 
   In the conventional WOSA transaction processing system of  FIG. 1 , the path to the physical file in the Windows registry will point to a service provider module  30 . For service providers who support the alternative server model of  FIG. 2 , the path points to a stub DLL  35 . This stub DLL  35  will thus direct any WOSA transaction requests across the process boundary to the server  40  as described above. If some vendor devices do not support the alternative server model, because they do not provide stub modules, then their respective SPMs can communicate directly with the WOSA manager  20  within the same process, as in the case of the SPM  37  in  FIG. 2 . 
   In the server models of  FIGS. 1 and 2 , the WOSA manager  20  can essentially regard any communication as being with a service provider layer. In the case of  FIG. 1 , communication with the service provider layer is more direct with the manager  20  communicating with the SPM&#39;s  30 . In the case of  FIG. 2 , communication is less direct with the stub modules  35  representing the interface between the WOSA manager and the service provider layer. 
   In the present invention, one or more filter modules  36  are located in the communications channel between the WOSA manager and selected portions of the service provider layer, for example, the cash dispenser service provider module. This is accomplished during installation of the filter module, by updating the Windows registry with the location of the filter module  36  instead of the location of the appropriate SPM  37  in  FIGS. 1 and 2  or stub module  38  in  FIG. 2 . During installation, the filter module is also updated with the location of the SPM or stub module it has replaced. 
   The filter module  36  of the present embodiment, monitors communications both from the manager  20  to the service provider layer and vice versa. In the case of the former, transaction requests are initially passed through to the filter module  36  from the WOSA manager, the filter module records these requests in a log  90  and then passes the requests on to the SPM or stub module. 
   Before passing the request on, however, the filter module alters the contents of the transaction request to change the window handle identifier to which the SPM must return its response, to that of the window handle of the filter module. 
   Thus, in the model of  FIG. 1 , the transaction request is first recorded by the filter module in the log  90 , the window handle for the response is updated to that of the filter module and the original window handle destination for the response is saved, before passing the request to an SPM  37 . The SPM passes the request to the ATM hardware and receives a response. Regardless of whether the original transaction request required a synchronous or asynchronous response, the response is passed from the SPM back to the filter module, which records the response in the log  90 . 
   The filter module now passes the response back to the destination originally specified in the transaction request, that is, the WOSA manager  20  for synchronous requests or the application  10  for asynchronous requests. 
   In the case of  FIG. 2 , the steps of recording the transaction request and relaying the request to the service provider layer are the same as for  FIG. 1 , except that the requests are relayed to either a stub module  35  or a SPM  37  not compliant with the model of  FIG. 2 . For asynchronous responses, the messages passed from the SPMs  30  to the application  10 ,  FIG. 3 , are now directed to the filter module  36  corresponding to the SPM. The filter module  36  receives the responses, records them in the log  90  and relays the responses to the application  10 . For synchronuous responses, the SPM&#39;s relay their responses through their associated queue  45  and then through to the stub modules  35  as normal. However, where a filter according to the present invention has been deployed, the stub modules  35  pass their response to the filter module  36  which records the response and relays the response to the WOSA manager  20 . 
   It will be seen from the above embodiments, that neither the vendor SPM nor the application is aware that anything has happened and takes no part in the filter procedure. 
   It will also be seen that filter modules can be cascaded, so that one or more filters each dedicated to a particular task can be set between the WOSA manager and the service provider layer. An example of a type of filter module which could operate with the filter module according to the invention, is a security module for checking an application&#39;s right to access hardware described in Applicant&#39;s co-pending British Patent Application No. 9801931.8 (IBM Docket No. UK9-98-009). 
   The above description has extended only to traditional applications running on an ATM. However, a number of companies other than the Applicant, including Microsoft Corporation, Keybank incorporated of Cleveland, Ohio and Diebold Incorporated of Canton, Ohio have mooted the idea of using an automatic teller machine (ATM) to provide access to Internet services, for example, for executing financial transactions, ticket reservation and information retrieval. Thus, a web ATM (Automatic Teller Machine) includes appropriate Internet browser software, for example Internet Explorer from Microsoft as an application running with the transaction processing system according to the model of  FIG. 1  or  FIG. 2 . The browser takes the place of the application  10  of  FIGS. 1 and 2 , and runs a Bank ATM Application written in the form of a page, or series of pages located on a bank web server (or cached on the local machine). The bank application, via its web pages, can prompt a web ATM user to swap web pages within the bank web site or to swap to web pages of any other web sites, for example, an airline web page or a supermarket web page. 
   The ATM Application pages are able to call methods for reading the users card and PIN number, for example, thus verifying the user&#39;s identity. The ATM Application can then prompt the ATM user to swap to other sites by, for example, displaying buttons on the ATM screen which can be touched by the user to select a site. By swapping to other sites, for example, an Airline booking system site, the user can for example select a flight and pay for the flight directly from the ATM using the user&#39;s bank account information. Other sites could be utility company sites, at which the user could pay a bill, or supermarket sites, at which a user could cash in loyalty points. 
   Thus, it will also be seen that the filter module and transaction processing system according to the invention can operate with more than one application  10  at any given time or, in the case of a web ATM, many web applications can run through the web browser along with conventional applications  10 .