# EvPeriodic::__construct

(PECL ev >= 0.2.0)

EvPeriodic::__construct — Constructs EvPeriodic watcher object

### Description

public EvPeriodic::__construct ( float `$offset` , string `$interval` , callable `$reschedule_cb` , callable `$callback` [, mixed `$data` = `NULL` [, int `$priority` = 0 ]] )

Constructs EvPeriodic watcher object and starts it automatically. EvPeriodic::createStopped() method creates stopped periodic watcher.

### Parameters

`offset`

  See Periodic watcher operation modes

`interval`

  See Periodic watcher operation modes

`reschedule_cb`

  Reschedule callback. You can pass `NULL`. See Periodic watcher operation modes

`callback`

  See Watcher callbacks .

`data`

  Custom data associated with the watcher.

`priority`

  Watcher priority

### Return Values

Returns EvPeriodic object on success.

### Examples

Example #1 Periodic timer. Use reschedule callback

`<?php
// Tick each 10.5 seconds
function reschedule_cb ($watcher, $now) {
return $now + (10.5. - fmod($now, 10.5));
}
$w = new EvPeriodic(0., 0., "reschedule_cb", function ($w, $revents) {
echo time(), PHP_EOL;
});
Ev::run();
?>`

Example #2 Periodic timer. Tick every 10.5 seconds starting at now

`<?php
// Tick every 10.5 seconds starting at now
$w = new EvPeriodic(fmod(Ev::now(), 10.5), 10.5, NULL, function ($w, $revents) {
echo time(), PHP_EOL;
});
Ev::run();
?>`

Example #3 Hourly watcher

`<?php
$hourly = EvPeriodic(0, 3600, NULL, function () {
echo "once per hour\n";
});
?>`

### See Also

- Periodic watcher operation modes
- EvTimer
- EvPeriodic::createStopped() - Create a stopped EvPeriodic watcher