[hamidreza-s]

Although writing C code for NIFs is not a regular task for Erlang developers, it must be done with extreme care because not only a long-running NIF could degrade the responsiveness of the VM, but also when it crashes the whole VM will crash.

However when there is no other options except writing a NIF, there are ways to protect yourself:

1. Your NIF should return less than a millisecond.

2. If the item 1 is not possible, split it into shorter NIF calls.

3. If item 1 and 2 are not possible so you have a dirty NIF. It is a NIF that cannot be split and cannot execute in a millisecond or less. There is an experimental feature in Erlang virtual machine which is called "dirty scheduler". When it is enabled some other schedulers are ready to execute the dirty NIFs, so they won't interfere with the normal operation of schedulers.

4. If item 1 and 2 are not possible and you don't want to use dirty schedulers, the +sfwi emulator flag is available to force normal schedulers to wake up again from the collapse situation.

These items are some solutions to remain in normal scheduling state even in case of writing the native functions in C (NIF), but what the article says is about just Erlang code which is run by schedulers and are preempted with no trouble as soon as they reach the reduction limit.