Inter-applicataion interface system

• US 5,175,854 A
• Filed: 05/29/1992
• Issued: 12/29/1992
• Est. Priority Date: 06/19/1989
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Cheung, Baldwin K., Cohen, Seth S., Jacobson, Neal F., Travis, Robert L.
• Primary Examiner(s): Heckler, Thomas M.
• Assistant Examiner(s): BUTLER, DENNIS
• Application Number:
  US07/892,609
• Time in Patent Office: 214 Days
• Field of Search: 395/650, 364/231.6, 364/231.7, 364/242.5, 364/281.4, 364/284.3
• US Class Current: 718/100
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/54 Interprogram communication

Abstract

A new processing system includes a child system and a parent system. The child system performs operations in a session, and includes a child application and a child-parent interface for receiving communications from a parent to control said child application. The parent system includes a child application invocation portion for enabling a child application to be invoked, a parent-child interface for generating communication for transfer to said child-parent interface, and a parent application for controlling the child application invocation portion and said child parent interface to enable invocation of said child application and for thereafter enabling said child application to perform processing operations in a series of processing sessions.

Claims

1. A method of operating a digital computer system in which a first process in said digital computer system invokes a second process in said digital computer system, said digital computer system having a system executive for maintaining a plurality of current process contexts and for scheduling and de-scheduling execution of processes, each of said processes having a respective one of said current process contexts, said method comprising the steps of:

(a) said first process transmitting to said system executive an invocation request for invocation of said second process, said invocation request including a first callback parameter identifying a first entry point of said first process;

(b) said system executive receiving said invocation request from said first process, and in response, creating a process context for said second process and scheduling said second process for execution with said first callback parameter;

said second process being executed with said first callback parameter in response to being scheduled by said system executive for execution with said first callback parameter;

said second process returning a first acknowledgement to said first entry point of said first process, said first acknowledgement including an invocation status indicating whether said second process is in a condition for beginning processing for said first process;

(c) when said invocation status indicates that said second process is in a condition for beginning processing for said first process, said first process responding to said first acknowledgement by sending an initialize session request to said second process;

said initialize session request including a second callback parameter identifying a second entry point of said first process;

(d) said second process responding to said initialize session request by adjusting address space for performing data processing for said first process, and returning a second acknowledgement to said second entry point of said first process, said second acknowledgement including an initialization status indicating whether said second process has adjusted its address space for performing said data processing for said first process;

(e) when said initialization status indicates that said second process has adjusted its address space, said first process responding to said second acknowledgement by sending a data transfer request to said second process, said data transfer request including identification of data to be transferred from memory to said second process, said data transfer request also including a third callback parameter identifying a third entry point of said first process;

(f) said second process responding to said data transfer request by attempting to access said data in said memory, and returning a third acknowledgement to said third entry point of said first process, said third acknowledgement including a data transfer status indicating whether said data in said memory is successfully accessed by said second process, and when said data in said memory is successfully accessed by said second process, said second process obtaining said data from said memory;

(g) when said data transfer status indicates that said second process has successfully accessed said data in said memory, said first process responding to said third acknowledgement by sending an execute session request to said second process, said execute session request identifying at least one operation to be performed by said second process in connection with said data, said execute session request including a fourth callback parameter identifying a fourth entry point in said first process;

(h) said second process responding to said execute session request by performing said at least one operation in connection with said data to modify said data, transmitting the modified data to said first process, and transmitting a session exit request to said fourth entry point of said first process upon completion of performance of said at least one operation;

(i) in response to said session exit request, said first process deciding whether to either request additional processing by said second process or to request termination of said second process; and

when deciding to request additional processing by said second process, sending a request for additional processing to said second process, and when deciding to terminate said second process, sending a termination request to said second process; and

(j) said second process performing said additional processing upon receiving said request for additional processing, and terminating upon receiving said termination request.

2. The method as claimed in claim 1, wherein said request for additional processing includes another initialize session request.

3. The method as claimed in claim 1, wherein said second process generates an action item list in response to said invocation request, said action item list including action items selectable by said first process and a respective call address in said second process for each of said action items;

said initialize session request includes an identification of one of said action items to initialize said second process to receive a session request;

said step (d) includes using said action item list to find the respective call address for said one of said action items and calling the respective call address for said one of said action items;

said execute session request includes an identification of another one of said action items to select said at least one operation to be performed by said second process in connection with said data; and

said step (h) includes using said action item list to find the call address for said another one of said action items and calling said second process at the call address for said another one of said action items.

4. The method as claimed in claim 1, wherein said identification of data to be transferred indicates a file name, and said data transfer request further includes control information indicating whether or not said second process is to create a new file with the same file name, even when a file with the indicated file name already exists, and indicating whether or not said second process is to create a new file with the indicated file name when a file with said file name does not exist, and wherein said second process selectively creates a new file in accordance with said control information.

5. The method as claimed in claim 4, wherein said control information consists of a "file create flag" indicating whether or not said second process is to create a new file with the same file name, even when a file with the indicated file name already exists, and a "create if not exist" flag indicating whether or not said second process is to create a new file with the indicated file name when a file with said file name does not exist.

6. The method as claimed in claim 1, wherein said identification of data to be transferred includes a buffer descriptor identifying a buffer base address and a buffer length.

7. The method as claimed in claim 1, wherein said identification of data to be transferred includes a list of a plurality of buffer descriptors;

each of said buffer descriptors identifying a buffer base address, a buffer length, and a sequence indicator identifying a buffer data item within a sequence of related data items.

8. The method as claimed in claim 1, wherein said one of said operations includes storing processed data in an output object and transmitting an output object message to said first process, said output object message identifying the output object.

9. The method as claimed in claim 8, wherein said output object comprises a file identified by a file name, and said output object message indicates the file name.

10. The method as claimed in claim 8, wherein said output object comprises a buffer, and said output object message identifies a base address and a length of said buffer.

11. The method as claimed in claim 8, wherein said output object comprises a plurality of buffers, and said output object message identifies a list of buffer descriptors, each of said buffer descriptors identifying a respective one of said plurality of buffers, and each of said buffer descriptors identifying a base address, a length, and a sequence number identifying a buffer data item within a sequence of related data items.

12. A method of operating a digital computer system in which a first process in said digital computer system invokes a second process in said digital computer system, said digital computer system having a system executive for maintaining a plurality of current process contexts and for scheduling and de-scheduling execution of processes, each of said processes having a respective one of said current process contexts, said method comprising the steps of:

(a) said first process transmitting to said system executive an invocation request for invocation of said second process;

(b) said system executive receiving said invocation request from said first process, and in response, creating a process context for said second process and scheduling said second process for execution;

said second process being executed in response to being scheduled by said system executive for execution;

said second process generating an action item list including action items indicating operations of said second process that are selectable by said first process, said action item list further including a respective call address in said second process for each of said action items, and said second process returning an acknowledgment of invocation to said first process;

(c) after receiving said acknowledgement of invocation from said second process, said first process sending a first action request to said second process to perform a first operation of a first one of said action items, said first action request including an identification of a first one of said action items;

(d) said second process responding to said first action request by using said action item list to find the respective call address for said first one of said action items and calling the call address for said first one of said action items to perform said first operation, and transmitting an acknowledgement of completion to said first process upon completion of performance of said first operation;

(e) in response to said acknowledgement of completion, said first process deciding whether to either request additional processing by said second process or to request termination of said second process; and

when deciding to request additional processing by said second process, sending a second action request to said second process for processing of a second operation of a second action item, said second action request including an identification of a second one of said action items, and when deciding to terminate said second process, sending a termination request to said second process; and

(f) said second process performing said second operation of said second action item upon receiving said second action request, and terminating upon receiving said termination request.

13. The method as claimed in claim 12, wherein said operations of said action items include a data transfer operation for transferring data from memory to said second process;

said first process sends a data transfer action request to said second process for said data transfer operation, said data transfer action request including identification of said data to be transferred from said memory to said second process; and

wherein said second process responds to said data transfer action request by obtaining from memory said data to be transferred from said memory to said second process.

14. The method as claimed in claim 13, wherein said identification of data to be transferred indicates a file name, and said data transfer request further includes control information indicating whether or not said second process is to create a new file with the same file name, even when a file with the indicated file name already exists, and indicating whether or not said second process is to create a new file with the indicated file name when a file with said file name does not exist, and wherein said second process selectively creates a new file in accordance with said control information.

15. The method as claimed in claim 14, wherein said control information consists of a "file create flag" indicating whether or not said second process is to create a new file with the same file name, even when a file with the indicated file name already exists, and a "create if not exist" flag indicating whether or not said second process is to create a new file with the indicated file name when a file with said file name does not exist.

16. The method as claimed in claim 13, wherein said identification of data to be transferred includes a buffer descriptor identifying a buffer base address and a buffer length.

17. The method as claimed in claim 13, wherein said identification of data to be transferred includes a list of a plurality of buffer descriptors;

each of said buffer descriptors identifying a buffer base address, a buffer length, and a sequence indicator identifying a buffer data item within a sequence of related data items.

18. The method as claimed in claim 12, wherein said operations of said action items include storing processed data in an output object and transmitting an output object message to said first process, said output object message identifying the output object.

19. The method as claimed in claim 18, wherein said output object comprises a file identified by a file name, and said output object message indicates the file name.

20. The method as claimed in claim 18, wherein said output object comprises a buffer, and said output object message identifies a base address and a length of said buffer.

21. The method as claimed in claim 18, wherein said output object comprises a plurality of buffers, and said output object message identifies a list of buffer descriptors, each of said buffer descriptors identifying a respective one of said plurality of buffers, and each of said buffer descriptors identifying a base address, a length, and a sequence number identifying a buffer data item within a sequence of related data items.