time.steady_timer

local timer = require('time').steady_timer
local t = timer.new()

spawn(function() print('Hello') end)

t:expires_after(2) --< 2 seconds
t:wait()
print('World')

A monotonic timer (i.e. the time points of the underlying clock cannot decrease as physical time moves forward). As in Boost.Asio:

A waitable timer is always in one of two states: "expired" or "not expired". If the wait() or async_wait() function is called on an expired timer, the wait operation will complete immediately.

Changing an active waitable timer’s expiry time

Changing the expiry time of a timer while there are pending asynchronous waits causes those wait operations to be cancelled.

Functions

new() → steady_timer

local t = steady_timer.new()

Constructor. Returns a new steady_timer object.

expires_at(self, tp: time.steady_clock.time_point) → integer

Forward the call to the function with same name in Boost.Asio:

Set the timer’s expiry time as an absolute time. Any pending asynchronous wait operations will be cancelled. The handler for each cancelled operation will be invoked with the boost::asio::error::operation_aborted error code.

Return Value

The number of asynchronous operations that were cancelled.

expires_after(self, secs: number) → integer

Forward the call to the function with same name in Boost.Asio:

Set the timer’s expiry time relative to now. Any pending asynchronous wait operations will be cancelled. The handler for each cancelled operation will be invoked with the boost::asio::error::operation_aborted error code.

Return Value

The number of asynchronous operations that were cancelled.

Expiry time is given in seconds.

wait(self)

Initiate a wait operation on the timer and blocks current fiber until one of the events occur:

  • The timer has expired.

  • The timer was cancelled, in which case it raises boost::asio::error::operation_aborted.

cancel(self) → integer

Cancel any operations that are waiting on the timer. Returns the number of asynchronous operations that were cancelled.

Properties

expiry: time.steady_clock.time_point

The timer’s expiry time as an absolute time.

Whether the timer has expired or not does not affect this value.