Guard against garbage collection invoking close() on an already destructed file

Unfortunately this has to live inside the async() block as microtasks race depending on the order of execution of destructors.

Author: bwoebi

src/Driver/ParallelFile.php

@@ -64,6 +64,7 @@ public function __destruct()
     {
         if ($this->id !== null && $this->worker->isRunning()) {
             $id = $this->id;
+            $this->id = null;
             $worker = $this->worker;
             EventLoop::queue(static fn () => $worker->execute(new Internal\FileTask('fclose', [], $id)));
         }
@@ -88,14 +89,19 @@ public function close(): void
 
         $this->closing = async(function (): void {
             $id = $this->id;
-            $this->id = null;
-            $this->worker->execute(new Internal\FileTask('fclose', [], $id));
+            // Guard against explicit close calls happening inside garbage collection
+            if ($id !== null) {
+                $this->id = null;
+                $this->worker->execute(new Internal\FileTask('fclose', [], $id));
+            }
         });
 
         try {
             $this->closing->await();
         } finally {
-            $this->onClose->complete();
+            if (!$this->onClose->isComplete()) {
+                $this->onClose->complete();
+            }
             $this->lockType = null;
         }
     }