Improve error messages when accepting connections with errno/errstr

src/SocketServer.php

@@ -90,4 +90,44 @@ public function close()
     {
         $this->server->close();
     }
+
+    /**
+     * [internal] Internal helper method to accept new connection from given server socket
+     *
+     * @param resource $socket server socket to accept connection from
+     * @return resource new client socket if any
+     * @throws \RuntimeException if accepting fails
+     * @internal
+     */
+    public static function accept($socket)
+    {
+        $newSocket = @\stream_socket_accept($socket, 0);
+
+        if (false === $newSocket) {
+            // Match errstr from PHP's warning message.
+            // stream_socket_accept(): accept failed: Connection timed out
+            $error = \error_get_last();
+            $errstr = \preg_replace('#.*: #', '', $error['message']);
+
+            // Go through list of possible error constants to find matching errno.
+            // @codeCoverageIgnoreStart
+            $errno = 0;
+            if (\function_exists('socket_strerror')) {
+                foreach (\get_defined_constants(false) as $name => $value) {
+                    if (\strpos($name, 'SOCKET_E') === 0 && \socket_strerror($value) === $errstr) {
+                        $errno = $value;
+                        break;
+                    }
+                }
+            }
+            // @codeCoverageIgnoreEnd
+
+            throw new \RuntimeException(
+                'Unable to accept new connection: ' . $errstr,
+                $errno
+            );
+        }
+
+        return $newSocket;
+    }
 }

src/TcpServer.php

@@ -211,10 +211,10 @@ public function resume()
 
         $that = $this;
         $this->loop->addReadStream($this->master, function ($master) use ($that) {
-            $newSocket = @\stream_socket_accept($master, 0);
-            if (false === $newSocket) {
-                $that->emit('error', array(new \RuntimeException('Error accepting new connection')));
-
+            try {
+                $newSocket = SocketServer::accept($master);
+            } catch (\RuntimeException $e) {
+                $that->emit('error', array($e));
                 return;
             }
             $that->handleConnection($newSocket);

src/UnixServer.php

@@ -113,10 +113,10 @@ public function resume()
 
         $that = $this;
         $this->loop->addReadStream($this->master, function ($master) use ($that) {
-            $newSocket = @\stream_socket_accept($master, 0);
-            if (false === $newSocket) {
-                $that->emit('error', array(new \RuntimeException('Error accepting new connection')));
-
+            try {
+                $newSocket = SocketServer::accept($master);
+            } catch (\RuntimeException $e) {
+                $that->emit('error', array($e));
                 return;
             }
             $that->handleConnection($newSocket);

tests/TcpServerTest.php

@@ -287,7 +287,10 @@ public function testEmitsErrorWhenAcceptListenerFails()
 
         $server = new TcpServer(0, $loop);
 
-        $server->on('error', $this->expectCallableOnceWith($this->isInstanceOf('RuntimeException')));
+        $exception = null;
+        $server->on('error', function ($e) use (&$exception) {
+            $exception = $e;
+        });
 
         $this->assertNotNull($listener);
         $socket = stream_socket_server('tcp://127.0.0.1:0');
@@ -297,6 +300,23 @@ public function testEmitsErrorWhenAcceptListenerFails()
         $time = microtime(true) - $time;
 
         $this->assertLessThan(1, $time);
+
+        $this->assertInstanceOf('RuntimeException', $exception);
+        assert($exception instanceof \RuntimeException);
+        $this->assertStringStartsWith('Unable to accept new connection: ', $exception->getMessage());
+
+        return $exception;
+    }
+
+    /**
+     * @param \RuntimeException $e
+     * @requires extension sockets
+     * @depends testEmitsErrorWhenAcceptListenerFails
+     */
+    public function testEmitsTimeoutErrorWhenAcceptListenerFails(\RuntimeException $exception)
+    {
+        $this->assertEquals('Unable to accept new connection: ' . socket_strerror(SOCKET_ETIMEDOUT), $exception->getMessage());
+        $this->assertEquals(SOCKET_ETIMEDOUT, $exception->getCode());
     }
 
     public function testListenOnBusyPortThrows()

tests/UnixServerTest.php

@@ -292,7 +292,10 @@ public function testEmitsErrorWhenAcceptListenerFails()
 
         $server = new UnixServer($this->getRandomSocketUri(), $loop);
 
-        $server->on('error', $this->expectCallableOnceWith($this->isInstanceOf('RuntimeException')));
+        $exception = null;
+        $server->on('error', function ($e) use (&$exception) {
+            $exception = $e;
+        });
 
         $this->assertNotNull($listener);
         $socket = stream_socket_server('tcp://127.0.0.1:0');
@@ -302,6 +305,23 @@ public function testEmitsErrorWhenAcceptListenerFails()
         $time = microtime(true) - $time;
 
         $this->assertLessThan(1, $time);
+
+        $this->assertInstanceOf('RuntimeException', $exception);
+        assert($exception instanceof \RuntimeException);
+        $this->assertStringStartsWith('Unable to accept new connection: ', $exception->getMessage());
+
+        return $exception;
+    }
+
+    /**
+     * @param \RuntimeException $e
+     * @requires extension sockets
+     * @depends testEmitsErrorWhenAcceptListenerFails
+     */
+    public function testEmitsTimeoutErrorWhenAcceptListenerFails(\RuntimeException $exception)
+    {
+        $this->assertEquals('Unable to accept new connection: ' . socket_strerror(SOCKET_ETIMEDOUT), $exception->getMessage());
+        $this->assertEquals(SOCKET_ETIMEDOUT, $exception->getCode());
     }
 
     public function testListenOnBusyPortThrows()