class KernelTimeout

Construct an absolute timeout that should expire at `t`.

Construct a relative timeout that should expire after `d`.

Infinite timeout.

Convert to `struct timespec` for interfaces that expect an absolute

timeout. If !has_timeout() or is_relative_timeout(), attempts to convert to

a reasonable absolute timeout, but callers should to test has_timeout() and

is_relative_timeout() and prefer to use a more appropriate interface.

Convert to `struct timespec` for interfaces that expect a relative

timeout. If !has_timeout() or is_absolute_timeout(), attempts to convert to

a reasonable relative timeout, but callers should to test has_timeout() and

is_absolute_timeout() and prefer to use a more appropriate interface. Since

the return value is a relative duration, it should be recomputed by calling

this method in the case of a spurious wakeup.

Convert to `struct timespec` for interfaces that expect an absolute timeout

on a specific clock `c`. This is similar to `MakeAbsTimespec()`, but

callers usually want to use this method with `CLOCK_MONOTONIC` when

relative timeouts are requested, and when the appropriate interface expects

an absolute timeout relative to a specific clock (for example,

pthread_cond_clockwait() or sem_clockwait()). If !has_timeout(), attempts

to convert to a reasonable absolute timeout, but callers should to test

has_timeout() prefer to use a more appropriate interface.

Convert to unix epoch nanos for interfaces that expect an absolute timeout

in nanoseconds. If !has_timeout() or is_relative_timeout(), attempts to

convert to a reasonable absolute timeout, but callers should to test

has_timeout() and is_relative_timeout() and prefer to use a more

appropriate interface.

A more explicit factory for those who prefer it.

Equivalent to `KernelTimeout()`.

Convert to std::chrono::time_point for interfaces that expect an absolute

timeout, like std::condition_variable::wait_until(). If !has_timeout() or

is_relative_timeout(), attempts to convert to a reasonable absolute

timeout, but callers should test has_timeout() and is_relative_timeout()

and prefer to use a more appropriate interface.

Convert to std::chrono::time_point for interfaces that expect a relative

timeout, like std::condition_variable::wait_for(). If !has_timeout() or

is_absolute_timeout(), attempts to convert to a reasonable relative

timeout, but callers should test has_timeout() and is_absolute_timeout()

and prefer to use a more appropriate interface. Since the return value is a

relative duration, it should be recomputed by calling this method in the

case of a spurious wakeup.

Returns true if there is a timeout that will eventually expire.

Returns false if the timeout is infinite.

If `has_timeout()` is true, returns true if the timeout was provided as an

`absl::Time`. The return value is undefined if `has_timeout()` is false

because all indefinite timeouts are equivalent.

If `has_timeout()` is true, returns true if the timeout was provided as an

`absl::Duration`. The return value is undefined if `has_timeout()` is false

because all indefinite timeouts are equivalent.

Returns true if steady (aka monotonic) clocks are supported by the system.

This method exists because go/btm requires synchronized clocks, and

thus requires we use the system (aka walltime) clock.