The document of `Future` lacks the specification to say every calling to `poll` of the same future shall happens-before another

Location (URL)

https://doc.rust-lang.org/core/future/trait.Future.html

https://doc.rust-lang.org/std/future/trait.Future.html

Summary

The current document of Future doesn't specify the ordering relationship for every call to Future::poll. This point is especially critical for these runtimes that have the characteristic of stealing tasks for idle threads. According to the signature of poll, whose receiver type is Pin<& mut Self>, which may be used to modify its internal fields, and the next polling might do the same thing or just a read, however, these operations shouldn't contribute to a data race, even though the future is polling again in another thread.

That is, it is plausible to say every previous call to poll() happens-before the subsequent one of the same future in any case. However, this guarantee is lacking in the current document.

Read the Future trait documentation at the core and std URLs, focusing on the Future::poll contract and its wording about repeated polling. Determine the precise ordering guarantee the specification should state, then update both documented locations and verify that the wording consistently describes the intended happens-before relationship.