fix psalm common

Author: transistive

src/Common/GeneratorHelper.php

@@ -34,7 +34,7 @@ public static function getReturnFromGenerator(Generator $generator, float $timeo
     {
         $start = microtime(true);
         while ($generator->valid()) {
-            if ($timeout) {
+            if ($timeout !== null) {
                 self::guardTiming($start, $timeout);
             }
             $generator->next();

src/Common/SysVSemaphore.php

@@ -29,19 +29,25 @@
 
 class SysVSemaphore implements SemaphoreInterface
 {
-    /**
-     * @param resource $semaphore
-     */
     private function __construct(
-        private $semaphore
+        private readonly \SysvSemaphore $semaphore
     ) {}
 
     public static function create(string $key, int $max): self
     {
         $key = hash('sha512', $key, true);
         $key = substr($key, 0, 8);
 
-        return new self(sem_get(hexdec($key), $max));
+        if (!function_exists('sem_get')) {
+            throw new RuntimeException('Can only create a semaphore if the sysv extension is installed');
+        }
+
+        $semaphore = sem_get(hexdec($key), $max);
+        if ($semaphore === false) {
+            throw new RuntimeException('Could not create semaphore');
+        }
+
+        return new self($semaphore);
     }
 
     public function wait(): Generator