Conditional transaction end instruction

摘要

A Conditional Transaction End (CTEND) instruction is provided that allows a program executing in a nonconstrained transactional execution mode to inspect a storage location that is modified by either another central processing unit or the Input/Output subsystem. Based on the inspected data, transactional execution may be ended or aborted, or the decision to end/abort may be delayed, e.g., until a predefined event occurs. For instance, when the instruction executes, the processor is in a nonconstrained transaction execution mode, and the transaction nesting depth is one at the beginning of the instruction, a second operand of the instruction is inspected, and based on the inspected data, transaction execution may be ended or aborted, or the decision to end/abort may be delayed, e.g., until a predefined event occurs, such as the value of the second operand becomes a prespecified value or a time interval is exceeded.

主权项

1. A computer program product for executing a machine instruction in a computing environment, said computer program product comprising:
a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising:
obtaining, by a processor, the machine instruction for execution, the machine instruction being defined for computer execution according to a computer architecture, the machine instruction comprising:
an operation code to specify a conditional transaction end operation; andone or more fields to provide a location of an operand; andexecuting, by the processor, the machine instruction, the executing comprising:
fetching the operand from the location;based on the operand comprising a first value, aborting transactional execution of a transaction associated with the machine instruction;based on the operand comprising a second value, ending the transaction; andbased on the operand comprising a third value, delaying completion of the machine instruction until a predefined action occurs.