Initial Commit

dependencies/amphp/sync/src/SemaphoreMutex.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace WP_Ultimo\Dependencies\Amp\Sync;
+
+use WP_Ultimo\Dependencies\Amp\Promise;
+use function WP_Ultimo\Dependencies\Amp\call;
+class SemaphoreMutex implements Mutex
+{
+    /** @var Semaphore */
+    private $semaphore;
+    /**
+     * @param Semaphore $semaphore A semaphore with a single lock.
+     */
+    public function __construct(Semaphore $semaphore)
+    {
+        $this->semaphore = $semaphore;
+    }
+    /** {@inheritdoc} */
+    public function acquire() : Promise
+    {
+        return call(function () : \Generator {
+            /** @var \Amp\Sync\Lock $lock */
+            $lock = (yield $this->semaphore->acquire());
+            if ($lock->getId() !== 0) {
+                $lock->release();
+                throw new \Error("Cannot use a semaphore with more than a single lock");
+            }
+            return $lock;
+        });
+    }
+}