Transport control channel program chain linking including determining sequence order
First Claim
1. A computer program product for processing a chain linked transport control channel program at a control unit configured for communication with an input/output (I/O) subsystem in an I/O processing system, the computer program product comprising:
- a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising;
receiving a first command message at the control unit from the I/O subsystem, the first command message including a first set of one or more I/O commands to be performed and specifying a first predetermined sequence number for performing the first set of one or more commands as part of an I/O operation;
receiving a second command message at the control unit from the I/O subsystem, the second command message including a second set of one or more I/O commands to be performed and specifying a second predetermined sequence number for performing the second set of one or more commands as part of the I/O operation;
comparing the sequence numbers of the command messages received to a next expected predetermined sequence number to determine an order of performing the first set of one or more commands received relative to the second set of one or more commands received as a first execution set and a second execution set without regard to the order received; and
executing the first and second execution sets in the determined order to perform the I/O operation.
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Accused Products
Abstract
A method, apparatus, and computer program product for processing a chain linked transport control channel program in an I/O processing system is provided. The method includes receiving a first command message at a control unit specifying a first predetermined sequence number for performing a first set of one or more commands as part of an I/O operation. The method further includes receiving a second command message specifying a second predetermined sequence number for performing a second set of one or more commands as part of the I/O operation. The method also includes comparing the sequence numbers to a next expected predetermined sequence number to determine an order of performing the commands. The method additionally includes executing the commands in the determined order to perform the I/O operation.
167 Citations
23 Claims
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1. A computer program product for processing a chain linked transport control channel program at a control unit configured for communication with an input/output (I/O) subsystem in an I/O processing system, the computer program product comprising:
a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising; receiving a first command message at the control unit from the I/O subsystem, the first command message including a first set of one or more I/O commands to be performed and specifying a first predetermined sequence number for performing the first set of one or more commands as part of an I/O operation; receiving a second command message at the control unit from the I/O subsystem, the second command message including a second set of one or more I/O commands to be performed and specifying a second predetermined sequence number for performing the second set of one or more commands as part of the I/O operation; comparing the sequence numbers of the command messages received to a next expected predetermined sequence number to determine an order of performing the first set of one or more commands received relative to the second set of one or more commands received as a first execution set and a second execution set without regard to the order received; and executing the first and second execution sets in the determined order to perform the I/O operation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. An apparatus for processing a chain linked transport control channel program at a control unit in an I/O processing system, the apparatus comprising:
a control unit configured for communication with an I/O subsystem of the I/O processing system, the control unit performing a method comprising; receiving a first command message at the control unit from the I/O subsystem, the first command message including a first set of one or more I/O commands to be performed and specifying a first predetermined sequence number for performing the first set of one or more commands as part of an I/O operation; receiving a second command message at the control unit from the I/O subsystem, the second command message including a second set of one or more I/O commands to be performed and specifying a second predetermined sequence number for performing the second set of one or more commands as part of the I/O operation; comparing the sequence numbers of the command messages received to a next expected predetermined sequence number to determine an order of performing the first set of one or more commands received relative to the second set of one or more commands received as a first execution set and a second execution set without regard to the order received; and executing the first and second execution sets in the determined order to perform the I/O operation. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16)
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17. A method for processing a chain linked transport control channel program at a control unit configured for communication with an input/output (I/O) subsystem in an I/O processing system, the method comprising:
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receiving a first command message at the control unit from the I/O subsystem, the first command message including a first set of one or more I/O commands to be performed and specifying a first predetermined sequence number for performing the first set of one or more commands as part of an I/O operation; receiving a second command message at the control unit from the I/O subsystem, the second command message including a second set of one or more I/O commands to be performed and specifying a second predetermined sequence number for performing the second set of one or more commands as part of the I/O operation; comparing the sequence numbers of the command messages received to a next expected predetermined sequence number to determine an order of performing the first set of one or more commands received relative to the second set of one or more commands received as a first execution set and a second execution set without regard to the order received; and executing the first and second execution sets in the determined order to perform the I/O operation. - View Dependent Claims (18, 19)
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20. A computer program product for processing a chain linked transport control channel program at a channel subsystem configured for communication with a control unit in an input/output (I/O) processing system, computer program comprising:
a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising; configuring a first command message specifying a first predetermined sequence number for performing a first set of one or more commands as part of an I/O operation; configuring a second command message specifying a second predetermined sequence number for performing a second set of one or more commands as part of the I/O operation; establishing a chain link between the first and second command messages, the predetermined sequence numbers providing an order of performing the first set of one or more commands relative to the second set of one or more commands without regard to the order received at the control unit; setting a chain linked flag in the first command message to notify the control unit to expect a subsequent command message to follow the first command message as part of the I/O operation; setting a command chain flag associated with a command in a subsequent set of one or more commands to identify a final chain linked command, the subsequent set of one or more commands including the second set of one or more commands or an additional set of one or more commands in an additional command message; transmitting the first command message and at least one of the second command message and the additional command message from the channel subsystem to the control unit; receiving a transport response message without extended status in response to transmitting the first command message; and receiving a transport response message with extended status in response to transmitting the subsequent set of one or more commands including the final chain linked command. - View Dependent Claims (21, 22)
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23. A computer program product for processing a chain linked transport control channel program at a channel subsystem configured for communication with a control unit in an input/output (I/O) processing system, the computer program product comprising:
a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising; configuring a first command message specifying a first predetermined sequence number for performing a first set of one or more commands as part of an I/O operation; configuring a second command message specifying a second predetermined sequence number for performing a second set of one or more commands as part of the I/O operation; establishing a chain link between the first and second command messages, the predetermined sequence numbers providing an order of performing the first set of one or more commands relative to the second set of one or more commands without regard to the order received at the control unit; transmitting a login request message including a channel maximum linked commands field indicating a maximum count of additional command messages queued after the first command message that the channel subsystem supports; receiving a login accept message in response to the login request message, the login accept message including a control unit maximum linked commands field indicating a maximum count of additional command messages queued after the first command message that the control unit supports; transmitting the first and second command messages from the channel subsystem to the control unit; and limiting transmission of command messages to the control unit to comply with the control unit maximum linked commands field.
Specification