3 ms·

But don't threads run cpu-stuff in 1 thread, by not switching? (in python) The same as async but more overhead/slower.

• paulddraper 10y ago
  Only one thread runs at a time because of the GIL, but the threads can preempt each other wherever between opcodes (http://effbot.org/zone/thread-synchronization.htm#atomic-operations http://effbot.org/zone/thread-synchronization.htm#atomic-ope...) Imagine two threads running a += 1 That's four opcodes. Only one operation will run at a time, but one thread might preempt the other midway through the four operations, and `a` will have been incremented by 1, not two. In some sense, mulithreading with Python's GIL is the worst of both worlds: you can use only one CPU, but you still need to account for concurrent state mutation. (Of course, it doesn't have the function color problem of asyncio http://journal.stuffwithstuff.com/2015/02/01/what-color-is-your-function/ http://journal.stuffwithstuff.com/2015/02/01/what-color-is-y...)