EvPeriodic
final class EvPeriodic extends EvWatcher (View source)
Class EvPeriodic
Periodic watchers are also timers of a kind, but they are very versatile.
Unlike EvTimer, EvPeriodic watchers are not based on real time (or relative time, the physical time that passes) but on wall clock time (absolute time, calendar or clock). The difference is that wall clock time can run faster or slower than real time, and time jumps are not uncommon (e.g. when adjusting it).
EvPeriodic watcher can be configured to trigger after some specific point in time. For example, if an EvPeriodic watcher is configured to trigger "in 10 seconds" (e.g. EvLoop::now() + 10.0 , i.e. an absolute time, not a delay), and the system clock is reset to January of the previous year , then it will take a year or more to trigger the event (unlike an EvTimer , which would still trigger roughly 10 seconds after starting it as it uses a relative timeout).
As with timers, the callback is guaranteed to be invoked only when the point in time where it is supposed to trigger has passed. If multiple timers become ready during the same loop iteration then the ones with earlier time-out values are invoked before ones with later time-out values (but this is no longer true when a callback calls EvLoop::run() recursively).
Properties
| bool | $is_active | from EvWatcher | |
| bool | $is_pending | from EvWatcher | |
| mixed | $data | from EvWatcher | |
| int | $priority | from EvWatcher | |
| float | $offset | ||
| float | $interval |
Methods
Constructs EvPeriodic watcher object.
Invokes the watcher callback with the given received events bit mask.
Simply stops and restarts the periodic watcher again.
Returns the absolute time that this watcher is supposed to trigger next.
Create a stopped EvPeriodic watcher
Configures the watcher
Details
__construct(float $offset, float $interval, null|callable $reschedule_cb, callable $callback, mixed $data = null, int $priority = 0)
Constructs EvPeriodic watcher object.
Constructs EvPeriodic watcher object and starts it automatically. EvPeriodic::createStopped() method creates stopped periodic watcher.
int
clear()
Clear watcher pending status.
If the watcher is pending, this method clears its pending status and returns its revents bitset (as if its callback was invoked). If the watcher isn't pending it does nothing and returns 0.
Sometimes it can be useful to "poll" a watcher instead of waiting for its callback to be invoked, which can be accomplished with this function.
feed(int $revents)
Feeds the given revents set into the event loop.
Feeds the given revents set into the event loop, as if the specified event had happened for the watcher.
EvLoop
getLoop()
Returns the loop responsible for the watcher.
invoke(int $revents)
Invokes the watcher callback with the given received events bit mask.
keepalive(bool $value = true)
Configures whether to keep the loop from returning.
Configures whether to keep the loop from returning. With keepalive value set to FALSE the watcher won't keep Ev::run() / EvLoop::run() from returning even though the watcher is active.
Watchers have keepalive value TRUE by default.
Clearing keepalive status is useful when returning from Ev::run() / EvLoop::run() just because of the watcher is undesirable. It could be a long running UDP socket watcher or so.
setCallback(callable $callback)
Sets new callback for the watcher.
start()
Starts the watcher.
Marks the watcher as active. Note that only active watchers will receive events.
stop()
Stops the watcher.
Marks the watcher as inactive. Note that only active watchers will receive events.
void
again()
Simply stops and restarts the periodic watcher again.
Simply stops and restarts the periodic watcher again. This is only useful when attributes are changed.
float
at()
Returns the absolute time that this watcher is supposed to trigger next.
When the watcher is active, returns the absolute time that this watcher is supposed to trigger next. This is not the same as the offset argument to EvPeriodic::set() or EvPeriodic::__construct(), but indeed works even in interval mode.
final static EvPeriodic
createStopped(float $offset, float $interval, mixed $reschedule_cb, mixed $callback, mixed $data = null, int $priority = 0)
Create a stopped EvPeriodic watcher
Create EvPeriodic object. Unlike EvPeriodic::__construct() this method doesn't start the watcher automatically.
void
set(float $offset, float $interval, null|callable $reschedule_cb = null)
Configures the watcher