(This PR is more of a question mark, there's an unpleasant change to make this POC work, and perhaps domainslib shouldn't provide this primitive?)
When using a lockfree datastructure to communicate between tasks, I didn't find a way to write the basic strategy "failed to make progress, retry later". With standard domains, we can use Domain.cpu_relax () to spinlock a bit... but with tasks this can deadlock the current domain (if we are waiting on a task scheduled on the same domain, we'll never give it a chance to run). Of course it (slowly) works if another domain steals our pending tasks, but all the domains may actually be stuck and unable to help.
I've included a small artificial example to demonstrate the issue :)
(This PR is more of a question mark, there's an unpleasant change to make this POC work, and perhaps
domainslibshouldn't provide this primitive?)When using a lockfree datastructure to communicate between tasks, I didn't find a way to write the basic strategy "failed to make progress, retry later". With standard domains, we can use
Domain.cpu_relax ()to spinlock a bit... but with tasks this can deadlock the current domain (if we are waiting on a task scheduled on the same domain, we'll never give it a chance to run). Of course it (slowly) works if another domain steals our pending tasks, but all the domains may actually be stuck and unable to help.I've included a small artificial example to demonstrate the issue :)