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Node.js v4.0.0-rc.2 Documentation
Table of Contents
Timers#
Stability: 3 - Locked
All of the timer functions are globals. You do not need to require()
this module in order to use them.
setTimeout(callback, delay[, arg][, ...])#
To schedule execution of a one-time callback
after delay
milliseconds. Returns a
timeoutObject
for possible use with clearTimeout()
. Optionally you can
also pass arguments to the callback.
It is important to note that your callback will probably not be called in exactly
delay
milliseconds - Node.js makes no guarantees about the exact timing of when
the callback will fire, nor of the ordering things will fire in. The callback will
be called as close as possible to the time specified.
clearTimeout(timeoutObject)#
Prevents a timeout from triggering.
setInterval(callback, delay[, arg][, ...])#
To schedule the repeated execution of callback
every delay
milliseconds.
Returns a intervalObject
for possible use with clearInterval()
. Optionally
you can also pass arguments to the callback.
clearInterval(intervalObject)#
Stops an interval from triggering.
unref()#
The opaque value returned by setTimeout
and setInterval
also has the method
timer.unref()
which will allow you to create a timer that is active but if
it is the only item left in the event loop, it won't keep the program running.
If the timer is already unref
d calling unref
again will have no effect.
In the case of setTimeout
when you unref
you create a separate timer that
will wakeup the event loop, creating too many of these may adversely effect
event loop performance -- use wisely.
ref()#
If you had previously unref()
d a timer you can call ref()
to explicitly
request the timer hold the program open. If the timer is already ref
d calling
ref
again will have no effect.
setImmediate(callback[, arg][, ...])#
To schedule the "immediate" execution of callback
after I/O events
callbacks and before setTimeout
and setInterval
. Returns an
immediateObject
for possible use with clearImmediate()
. Optionally you
can also pass arguments to the callback.
Callbacks for immediates are queued in the order in which they were created. The entire callback queue is processed every event loop iteration. If you queue an immediate from inside an executing callback, that immediate won't fire until the next event loop iteration.
clearImmediate(immediateObject)#
Stops an immediate from triggering.