Processing of data to monitor input/output operations
First Claim
1. A computer program product for processing communications between a control unit and a channel subsystem in an input/output processing system, comprising a non-transitory tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
- sending a command from the channel subsystem to the control unit to initiate an input/output operation, the sending of the command for opening a first exchange with the control unit, the first exchange identified by a first identifier, the command including a transport command control block (TCCB), the TCCB including at least one device control word (DCW) and the TCCB being obtained by a location identified by a transport control word (TCW);
setting a time period for completion of the input/output operation; and
based on the input/output operation not completing within the time period, sending a message to determine whether the control unit has the first exchange, identified by the first identifier, open for the command, the sending of the message for opening a second exchange, the second exchange identified by a second identifier, wherein the message interrogates the control unit to determine whether the control unit has received the command.
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Accused Products
Abstract
A computer program product, an apparatus, and a method for processing communications between a control unit and a channel subsystem in an input/output processing system are provided. The computer program product includes a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method. The method includes: sending a command from the channel subsystem to the control unit to initiate an input/output operation; setting a time period for completion of the operation; and responsive to the operation not completing within the time period, sending a message to determine whether the control unit has an exchange open for the command.
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Citations
24 Claims
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1. A computer program product for processing communications between a control unit and a channel subsystem in an input/output processing system, comprising a non-transitory tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
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sending a command from the channel subsystem to the control unit to initiate an input/output operation, the sending of the command for opening a first exchange with the control unit, the first exchange identified by a first identifier, the command including a transport command control block (TCCB), the TCCB including at least one device control word (DCW) and the TCCB being obtained by a location identified by a transport control word (TCW); setting a time period for completion of the input/output operation; and based on the input/output operation not completing within the time period, sending a message to determine whether the control unit has the first exchange, identified by the first identifier, open for the command, the sending of the message for opening a second exchange, the second exchange identified by a second identifier, wherein the message interrogates the control unit to determine whether the control unit has received the command. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 22)
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9. An apparatus for processing communications in an input/output processing system, comprising:
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a channel subsystem of a host computer system configured for communication with a control unit capable of commanding and determining status of an I/O device, the channel subsystem performing; sending a command to the control unit to initiate an input/output operation, the sending of the command for opening a first exchange with the control unit, the first exchange identified by a first identifier, the command including a transport command control block (TCCB), the TCCB including at least one device control word (DCW) and the TCCB being obtained by a location identified by a transport control word (TCW); setting a time period for completion of the input/output operation; and based on the input/output operation not completing within the time period, sending a message to determine whether the control unit has the first exchange, identified by the first identifier, open for the command, the sending of the message for opening a second exchange, the second exchange identified by a second identifier, wherein the message interrogates the control unit to determine whether the control unit has received the command. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 23)
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17. A method of processing communications between a control unit and a channel subsystem in an input/output processing system, the method comprising:
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sending a command from the channel subsystem to the control unit to initiate an input/output operation, the sending of the command for opening a first exchange with the control unit, the first exchange identified by a first identifier, the command including a transport command control block (TCCB), the TCCB including at least one device control word (DCW) and the TCCB being obtained by a location identified by a transport control word (TCW); setting a time period for completion of the input/output operation; and based on the input/output operation not completing within the time period, sending a message to determine whether the control unit has the first exchange, identified by the first identifier, open for the command, the sending of the message for opening a second exchange, the second exchange identified by a second identifier, wherein the message interrogates the control unit to determine whether the control unit has received the command. - View Dependent Claims (18, 19, 20, 21, 24)
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Specification