[herobird]

Yes, rational is to provide a pragmatic and efficient solution to infinite loops.

There is a variety of ways to implement fuel metering with varying trade-offs, e.g. performance, determinism and precision.

In this comment I roughly described how Wasmi implements its fuel metering: https://news.ycombinator.com/item?id=44229953

Wasmi's design focuses on performance and determinism but isn't as precise since instructions are always considered as group.