[tialaramex]

In practice it's not desirable to go without an explicit wake feature, we need some way to know that now it's likely to succeed. The mechanism needn't be 100% reliable but "Always try again" is essentially exactly as useless as blocking.

[loeg]

I work on a widely deployed (~11,000 servers and growing) piece of software that does not use any OS sleep/wake primitive for our MPSC queues -- just polling. It works really well with the right overall design.

[duped]

No it's not, that's the whole point of using polling.