Fixed the dead cycle caused by socket closed.

src/process/src/AbstractProcess.php

@@ -18,6 +18,7 @@ use Hyperf\ExceptionHandler\Formatter\FormatterInterface;
 use Hyperf\Process\Event\AfterProcessHandle;
 use Hyperf\Process\Event\BeforeProcessHandle;
 use Hyperf\Process\Event\PipeMessage;
+use Hyperf\Process\Exception\SocketClosedException;
 use Psr\Container\ContainerInterface;
 use Psr\EventDispatcher\EventDispatcherInterface;
 use Swoole\Coroutine\Channel;
@@ -137,6 +138,9 @@ abstract class AbstractProcess implements ProcessInterface
                     /** @var \Swoole\Coroutine\Socket $sock */
                     $sock = $this->process->exportSocket();
                     $recv = $sock->recv($this->recvLength, $this->recvTimeout);
+                    if ($recv === '') {
+                        throw new SocketClosedException('Socket is closed.');
+                    }
                     if ($this->event && $recv !== false && $data = unserialize($recv)) {
                         $this->event->dispatch(new PipeMessage($data));
                     }
@@ -146,6 +150,10 @@ abstract class AbstractProcess implements ProcessInterface
                         $formatter = $this->container->get(FormatterInterface::class);
                         $logger->error($formatter->format($exception));
                     }
+
+                    if ($exception instanceof SocketClosedException) {
+                        throw $exception;
+                    }
                 }
             }
             $quit->close();

src/process/src/Exception/SocketClosedException.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+/**
+ * This file is part of Hyperf.
+ *
+ * @link     https://www.hyperf.io
+ * @document https://doc.hyperf.io
+ * @contact  group@hyperf.io
+ * @license  https://github.com/hyperf/hyperf/blob/master/LICENSE
+ */
+
+namespace Hyperf\Process\Exception;
+
+use RuntimeException;
+
+class SocketClosedException extends RuntimeException
+{
+}