How to simulate the operation of the encoder (programmatically)?

Question

C++ / C#

The encoder pulses are handled by the library using an external interrupt. It is necessary to simulate its work by a simple increment of the counter, depending on the speed specified by the user. It turns out that inside the interrupt every 100 µs in a given range of rotation speeds, a situation is possible where the increment is greater than 1 and when the increment does not occur 1 or more times in a row.
Is there an adequate solution in such conditions?