A core problem is that it's now clear most apps have hundreds or thousands of little tasks going, increasingly bound by network, IO, and similar. Async gives nice semantics for implementing cooperative multitasking, without introducing nearly as many thread coherency issues as preemptive.
I can do things atomically. Yay! Code literally cooperates better. I don't have the messy semantics of a Windows 3.1 event loop. I suspect it will take over more and more into all walks of code.
Other models are better for either:
- Highly parallel compute-bound code (where SIMD/MIMD/CUDA-style models are king)
- Highly independent code, such as separate apps, where there are no issues around cooperation. Here, putting each task on a core, and then preemptive, obviously wins.
What's interesting is all three are widely used on my system. My tongue-in-cheek comment about cooperative multitasking winning was only a little bit wrong. It didn't quite win in the sense of taking over other models, but it's in widespread use now. If code needs to cooperate, async sure beats semaphores, mutexes, and all that jazz.
Async programming is not an alternative to semaphores and mutexes. It is an alternative to having more threads. The substantial drawback of async programming in most implementations is that stack traces and debuggers become almost useless; at least very hard to use productively.
A core problem is that it's now clear most apps have hundreds or thousands of little tasks going, increasingly bound by network, IO, and similar. Async gives nice semantics for implementing cooperative multitasking, without introducing nearly as many thread coherency issues as preemptive.
I can do things atomically. Yay! Code literally cooperates better. I don't have the messy semantics of a Windows 3.1 event loop. I suspect it will take over more and more into all walks of code.
Other models are better for either:
- Highly parallel compute-bound code (where SIMD/MIMD/CUDA-style models are king)
- Highly independent code, such as separate apps, where there are no issues around cooperation. Here, putting each task on a core, and then preemptive, obviously wins.
What's interesting is all three are widely used on my system. My tongue-in-cheek comment about cooperative multitasking winning was only a little bit wrong. It didn't quite win in the sense of taking over other models, but it's in widespread use now. If code needs to cooperate, async sure beats semaphores, mutexes, and all that jazz.