How to call multiples functions within the loop{ } and have them execute in parallel

[gcjr]

@wildbill

This sounds like code for a road crossing for a model railway. The usual millis techniques will easily take care of it as gcjr showed.

@helloworld21

i need to

if (condition ) {
ring the Bell()
Flashes the LEDs()
Servos Open gates()
all at the same time. the servo can finish their jobs after a while, but the bells and flash_LED() must go on.
}

"at the same time" is relative -- while the bell is being rung, while the LEDs are flashing, the gate is moving