Leaving recursive functions running forever?

问题

I came across a function where it had a setTimeout inside with a timeout growing exponentially (timeout *= 2).

let timeout = 10000
function foo() {
    // doSomething without breaking, returning
    setTimeout(foo, timeout)
    timeout *= 2;
}
foo()

It seems that this should not be a problem and intuitively feels like setInterval is kinda doing the same already (having an infinite loop until it's cancelled if ever), however, my question is in the approach itself.

• Is this something that could lead to memory leaks?
• Is it better/clearer to still limit the number of calls to the function?
• Would other languages use such approach or are there different mindsets outside of JS world?

回答1:

This is not a recursive function call. The call to setTimeout will cause foo to be called by the JavaScript event loop at a later time.

This code will not cause a stack overflow or any such problems. It should be completely safe.

To understand how this works in-depth, I suggest reading up on the JS event loop and microtasks.

回答2:

Is this something that could lead to memory leaks?

-If the function FOO() runs to completion before the timeout calls it again then no. The stack should be cleared.

Is it better/clearer to still limit the number of calls to the function?

-Yes, since your timeout variable will eventually overflow and may cause unintended results.

Would other languages use such approach or are there different mindsets outside of JS world?

-Depends on how the timer functions works for the library/language you use. But this seems like a simple way and valid way to have an increasing timeout.

来源：https://stackoverflow.com/questions/50676564/leaving-recursive-functions-running-forever