pub fn try_page_size() -> Result<usize, VmemError>Expand description
Fallible page_size: the same cached
one-time OS page-size query, with a channel for the one thing page_size
cannot report — the query itself having failed.
page_size is deliberately infallible: it
returns the conservative MIN_PAGE floor when the
one-time OS query produced an unusable answer, and the crate fails every
page-granular state operation closed from then on (see page_size’s own
“If the one-time OS query fails” paragraph). This twin is the upfront
detector: a caller that wants to choose a strategy at startup — rather
than discover the degraded state through try_decommit errors — asks
here once.
§Errors
VmemError::os_refusal_unknown_code if the OS page-size query failed
(not observed on any supported platform; see page_size’s rustdoc for
why). The error is an OS-side no-code failure, NOT
VmemError::invalid_argument — the caller did nothing wrong.
On success, the returned value is identical to page_size()’s: a power
of two >= MIN_PAGE, stable for the process lifetime.