“Atomic” timing of IRQs

[mdaeron]

I am wondering what kind of “atomicity” there is in the treatment of regular MicroPython instructions and interrupt callbacks. Let's say I want to print out or modify the contents of an array:

for k in range(len(myarray)):
    myarray[k] = myarray[k] * 2
print(myarray)

Is there any chance that an IRQ will modify the contents of myarray while in the for loop (I believe the answer is yes)? What about during the print() call?

What are the best practices when manipulating arrays which might potentially be modified by IRQs? Should I make a copy of such an array first, as in: myarray_copy[:] = myarray[:], presuming that such a single line of code will be treated as “atomic” (non-interruptable)?

[robert-hh]

You can disable and enable interrupts during critical phases of your code. See https://docs.micropython.org/en/latest/library/machine.html?highlight=disable#machine.disable_irq

[peterhinch]

These docs discuss the issues involved with concurrency.
Official docs
Threading includes details of ISR concurrency.
Alternatives to interrupts Does an application really need an IRQ?