On 25.08.2016 20:10, Ben Hoyt wrote:
As long as Python uses a GIL to protect C level function calls, you can use an iterator for this:
import itertools x = itertools.count() ... mycount = next(x)
Yeah, that's a neat hack -- I saw it recommended on StackOverflow, and saw it used in the standard library somewhere. I think that's probably okay in the *CPython* stdlib, because it's CPython so you know it has the GIL. But this wouldn't work in other Python implementations, would it (IronPython and Jython don't have a GIL). Or when itertools.count() is implemented in pure Python on some system? Seems like it could blow up in someone's face when they're least expecting it. I also think using *iter*tools is a pretty non-obvious way to get a thread-safe counter.
All true.
Having an implementation in threading which hides away the details would be nice. On CPython using iterators would certainly be one of the most efficient ways of doing this.