fall back to sync worker on windows

Author: matthi4s

README.md

@@ -15,6 +15,9 @@ on a webserver.
 
 Tasks can communicate back to the main process during execution and handle results and errors gracefully.
 
+This library is not supported on Windows due to a lack of essential features. The autodetect falls back to the
+sync worker on Windows, so running tasks should be possible, but running tasks in parallel does not work.
+
 <!-- TOC -->
 * [Installation](#installation)
 * [Basic Example](#basic-example)

src/Taskmaster.php

@@ -465,7 +465,7 @@ public function autoDetectWorkers(int $count, bool $loadFromEnv = true, bool $al
         if (!$worker) {
             if (extension_loaded("pcntl")) {
                 $worker = new ForkWorker();
-            } elseif (function_exists("proc_open")) {
+            } elseif (function_exists("proc_open") && PHP_OS_FAMILY !== "Windows") {
                 $worker = new ProcessWorker();
             } else {
                 $worker = new SyncWorker();