Reentrancy (computing)

In programming, a routine or method ( reentrant English) as reentrant or reentrant called when it is implemented so that it can be called just once at a premature termination and thereby returns the originally expected result. This includes not only the return value, but all can be influenced by the method of program parameters. A reentrant method therefore behaves as if it were implicitly encapsulated in a transaction. Also, all computer programs or scripts are assessed in this light.

Often applies to reentrant methods that simultaneously can not influence each other running instances. The execution of each instance then runs the same, no matter how many instances there are of this method. The aim of the design of such a re-entrant method is to ensure that no part of the program code itself is modified by the method, and that process their own information, such as local variables in separate storage areas are kept.

Reentrant program constructs are the basis for many multitasking systems ( thread safe ).

• Parallel processing