checkpoint

checkpoint [′chek‚pȯint]

(cell and molecular biology)

A point in the eukaryotic cell cycle at which the cycle may continue if specific conditions are present or will stop if conditions are not right.

(computer science)

That place in a routine at which the entire state of the computer (memory, registers, and so on) is written out on auxiliary storage (tape, disk, cards) from which it may be read back into the computer if the program is to be restarted later.

(navigation)

Geographical location on land or water above which the position of an aircraft in flight may be determined by observation or by electronic means.

---

(programming)

checkpoint - Saving the current state of a program and its data, including intermediate results, to disk or other non-volatile storage, so that if interrupted the program could be restarted at the point at which the last checkpoint occurred. This facility came into popular use in mainframe operating systemss such as OS/360 in which programs frequently ran for longer than the mean time between system failures. If a program run fails because of some event beyond the program's control (e.g. hardware or operating system failure) then the processor time invested before the checkpoint will not have been wasted.