On Sat, Jun 27, 2015 at 2:07 AM, R. David Murray <rdmurray@bitdance.com> wrote:
On Sat, 27 Jun 2015 01:10:33 +1000, Chris Angelico <rosuav@gmail.com> wrote:
The way I'm seeing it, coroutines are like cooperatively-switched threads; you don't have to worry about certain operations being interrupted (particularly low-level ones like refcount changes or list growth), but any time you hit an 'await', you have to assume a context switch. That's all very well, but I'm not sure it's that big a problem to accept that any call could context-switch; atomicity is already a concern in other cases, which is why we have principles like EAFP rather than LBYL.
Read Glyph's article, it explains why:
Makes some fair points, but IMO it emphasizes what I'm saying about atomicity. If you really need it, establish it by something other than just having code that naively progresses through. That's what databasing is for, after all. Threading and signals force you to think about concurrency; other models *may* allow you to pretend it doesn't exist. Anyway, that answers my question about why the explicit "this can let other things run" marker. Thanks all. ChrisA