1. A computer program product for executing an instruction within a computing environment, said computer program product comprising: a non-transitory computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: obtaining a machine instruction for execution, the machine instruction being a transaction abort machine instruction having associated therewith: an operation code to specify a transaction abort operation; and at least one field to be used to specify an abort code, wherein the abort code provides a specific reason why a transaction executing within the computing environment is to be aborted; and executing the machine instruction to explicitly abort the transaction, the executing comprising: aborting the transaction that is executing, wherein the transaction ends prior to completion; and providing a condition code based on the abort code specified by the at least one field of the machine instruction, the condition code to indicate whether re-execution of the transaction is recommended, and wherein the providing the condition code comprises setting the condition code to a first value based on a specified portion of the abort code specified by the at least one field of the machine instruction being one value and setting the condition code to a second value based on the specified portion of the abort code specified by the at least one field of the machine instruction being another value.