1 files changed, 82 insertions, 0 deletions
diff --git a/vendor/open-telemetry/sdk/Common/Util/ShutdownHandler.php b/vendor/open-telemetry/sdk/Common/Util/ShutdownHandler.php
new file mode 100644
index 000000000..2de6d47df
--- /dev/null
+++ b/vendor/open-telemetry/sdk/Common/Util/ShutdownHandler.php
@@ -0,0 +1,82 @@
+<?php
+
+declare(strict_types=1);
+
+namespace OpenTelemetry\SDK\Common\Util;
+
+use function array_key_last;
+use ArrayAccess;
+use Closure;
+use function register_shutdown_function;
+
+final class ShutdownHandler
+{
+    /** @var array<int, Closure>|null */
+    private static ?array $handlers = null;
+    /** @var ArrayAccess<object, self>|null  */
+    private static ?ArrayAccess $weakMap = null;
+
+    private array $ids = [];
+
+    private function __construct()
+    {
+    }
+
+    public function __destruct()
+    {
+        if (!self::$handlers) {
+            return;
+        }
+        foreach ($this->ids as $id) {
+            unset(self::$handlers[$id]);
+        }
+    }
+
+    /**
+     * Registers a function that will be executed on shutdown.
+     *
+     * If the given function is bound to an object, then the function will only
+     * be executed if the bound object is still referenced on shutdown handler
+     * invocation.
+     *
+     * ```php
+     * ShutdownHandler::register([$tracerProvider, 'shutdown']);
+     * ```
+     *
+     * @param callable $shutdownFunction function to register
+     *
+     * @see register_shutdown_function
+     */
+    public static function register(callable $shutdownFunction): void
+    {
+        self::registerShutdownFunction();
+        self::$handlers[] = weaken(closure($shutdownFunction), $target);
+
+        if (!$object = $target) {
+            return;
+        }
+
+        self::$weakMap ??= WeakMap::create();
+        $handler = self::$weakMap[$object] ??= new self();
+        $handler->ids[] = array_key_last(self::$handlers);
+    }
+
+    private static function registerShutdownFunction(): void
+    {
+        if (self::$handlers === null) {
+            register_shutdown_function(static function (): void {
+                $handlers = self::$handlers;
+                self::$handlers = null;
+                self::$weakMap = null;
+
+                // Push shutdown to end of queue
+                // @phan-suppress-next-line PhanTypeMismatchArgumentInternal
+                register_shutdown_function(static function (array $handlers): void {
+                    foreach ($handlers as $handler) {
+                        $handler();
+                    }
+                }, $handlers);
+            });
+        }
+    }
+}