Even if you kill() a thread, the isStarted() method will still return true.
(PECL pthreads >= 2.0.0)
Thread::isStarted — State Detection
This function has no parameters.
Example #1 Tell if the referenced Thread was started
<?php
$worker = new Worker();
$worker->start();
var_dump($worker->isStarted());
?>
The above example will output:
bool(true)
Even if you kill() a thread, the isStarted() method will still return true.