Method, system and program product for closing a communication session with outstanding data commands on a transport communication system

• US 7,970,915 B2
• Filed: 09/28/2004
• Issued: 06/28/2011
• Est. Priority Date: 09/28/2004
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wigger, William D., Gilgen, David B., Burckart, Erik J., Lanzen, Craig A.
• Primary Examiner(s): Nguyen; Phuoc
• Assistant Examiner(s): Fearer; Mark D
• Application Number:
  US10/952,106
• Publication Number:
  US 20060075125A1
• Time in Patent Office: 2,464 Days
• Field of Search: 709/229, 709/224, 709/204, 709/250, 370/396
• US Class Current: 709/229
• CPC Class Codes: H04L 63/10 for controlling access to devices or network resources
• CPC Class Codes: H04L 69/16 Implementation or adaptation of Internet protocol [IP], of transmission control protocol [TCP] or of user datagram protocol [UDP]

Abstract

Under the present invention, when a TCS receives a data command (e.g., a read or write command) pursuant to a communication session between the TCS and an application, it will first request permission from a permission system to execute the data command. By applying a set of rules to a setting of a state variable associated with the TCS, the permission system will determine whether to grant the permission. If so, the TCS will execute the data command and change the setting of the state variable. If a close command is later received by the TCS to close the communication session, permission will once again be requested from the permission system, which will again apply a set of rules to the current setting of the state variable to determine if the session can be safely closed.

Claims

1. A method for managing a communication session on a Transport Communication System (TCS), comprising:

receiving a data command in a TCS for the communication session, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

before executing the data command, requesting permission from a permission system to execute the data command; and

,

receiving a response to the request from the permission system, wherein the permission system determines whether to grant the permission by applying a set of rules to a current setting of a state variable associated with the TCS, wherein, if data command is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another read or write data command or the session is closing; and

wherein, if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done.

2. The method of claim 1, further comprising:

executing the data command if the permission system grants the permission; and

setting the state variable to a particular setting based on the execution to reflect at least one of the data command is pending, that the data command is finishing, that the data command is done and a close has been allowed.

3. The method of claim 2, wherein the setting step is performed by a transport layer in the TCS executing the data command.

4. The method of claim 1, further comprising the permission system setting the state variable to another setting indicating that a close is pending if the permission to execute the close command is granted.

5. The method of claim 1, wherein the set of rules set forth situations where permissions can be granted based on settings of the state variable.

6. A system for managing a communication session on a Transport Communication System (TCS), comprising:

a TCS for receiving and executing commands from an application pursuant to a communication session between the TCS and the application, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, and the TCS being configured to request permission to execute the commands, the commands comprising one of;

read, write or close command; and

a permission system for determining, before the TCS executes the commands, whether to grant permission to execute the commands by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data command is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous data command is done, or that the session is allowed to close and wherein if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another read or write data command or the session is closing; and

wherein if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done.

7. The system of claim 6, wherein the command is a data command, and wherein the TCS executes the data command if the permission system grants the permission, sets the state variable to a particular setting based on the execution to reflect at least one of the data command is pending, that the data command is finishing, that the data command is done and a close has been allowed.

8. The system of claim 7, wherein the permission system further sets the state variable to another setting indicating that a close is pending if the permission to execute the close command is granted.

9. The system of claim 6, wherein the set of rules set forth situations where permissions can be granted based on settings of the state variable.

10. A method for managing a communication session on a Transport Communication System (TCS), comprising:

receiving a request from a TCS for permission to execute a data command received on the TCS, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

before executing the data command, determining whether to grant the permission by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data command is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another read or write data command or the session is closing; and

wherein if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done; and

outputting a result of the determining to the TCS.

11. The method of claim 10, further comprising changing the setting of the state variable to indicate that a close is pending if the permission to execute the close command is granted.

12. The method of claim 10, wherein the set of rules set forth situations where permissions can be granted based on settings of the state variable.

13. A system for managing a communication session on a Transport Communication System (TCS), comprising:

a system for receiving a request from a TCS for permission to execute a data command received on the TCS, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

a system for determining, before the TCS executes the data command, whether to grant the permission by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data comand is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another data read or write command or the session is closing; and

wherein, if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done; and

a system for outputting a result of the permission processing system to the TCS.

14. The system of claim 13, further comprising a system for changing the setting of the state variable to indicate that a close is pending if the permission to execute the close command is granted.

15. The system of claim 13, wherein the set of rules set forth situations where permissions can be granted based on settings of the state variable.

16. A program product stored on a recordable storage media for closing managing a communication session on a Transport Communication System (TCS), which when executed, comprises:

program code for receiving a request from a TCS for permission to execute a data command received on the TCS, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

program code for determining, before the TCS executes the data command, whether to grant the permission by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data command is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another data read or write command or the session is closing; and

wherein, if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done; and

program code for outputting a result of the permission processing system to the TCS.

17. The program product of claim 16, further comprising program code for changing the setting of the state variable to indicate that a close is pending if the permission to execute the close command is granted.

18. The program product of claim 16, wherein the set of rules set forth situations where permissions can be granted based on settings of the state variable.

19. A method for deploying an application for managing a communication session on a Transport Communication System (TCS), comprising:

providing a computer infrastructure being operable to;

receive a request from a TCS for permission to execute a data command received on the TCS, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

determine, before the TCS executes the data command, whether to grant the permission by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data comand is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another data read or write command or the session is closing; and

wherein, if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done; and

output a result of the permission processing system to the TCS.

20. Computer software embodied in a physical computer readable storage media for managing a communication session on a Transport Communication System (TCS), the computer software comprising instructions to cause a computer system to perform the following functions:

receive a request from a TCS for permission to execute a data command received on the TCS, the TCS being a series of channels, every channel being a layer of software that implements a specific function, the channels being linked together for processing a piece of data, the data flowing bi-directionally between channels in the series, the data command comprising one of;

a read, write or close command;

before executing the data command, determining whether to grant the permission by applying a set of rules to a setting of a state variable associated with the TCS, wherein, if data command is a close command, the set of rules grant permission when the state variable indicates one of;

that the TCS is not in use, that a previous read or write data command is done, or that the session is allowed to close and wherein, if data command is a close command, the set of rules do not grant permission when the state variable indicates one of;

that the TCS is processing another read or write data command or the session is closing; and

wherein if the data command is a read or write command, the set of rules denies permission when the state variable indicates a close command is pending or has been allowed and grants permission when the state variable indicates that no close command is pending or has been allowed;

wherein the setting is selected from the group consisting of not in use, read pending, close allowed, close pending, read command finishing, read done, write pending, write finishing and write done; and

output a result of the determining to the TCS.