Extracted Process Control to separate interface to allow better tests

src/ProcessControl/Wait.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace Toalett\Multiprocessing\ProcessControl;
+
+class Wait
+{
+	public int $pid;
+	public int $status;
+
+	public function __construct(int $pid, int $status = 0)
+	{
+		$this->pid = $pid;
+		$this->status = $status;
+	}
+
+	public function childStopped(): bool
+	{
+		return $this->pid > 0;
+	}
+
+	public function failed(): bool
+	{
+		return $this->pid < 0;
+	}
+}