Merge pull request #208 from clue-labs/windows-connections

Fix reporting refused connections with StreamSelectLoop on Windows

Author: jsor

src/StreamSelectLoop.php

@@ -269,10 +269,30 @@ private function waitForStreamActivity($timeout)
     private function streamSelect(array &$read, array &$write, $timeout)
     {
         if ($read || $write) {
+            // We do not usually use or expose the `exceptfds` parameter passed to the underlying `select`.
+            // However, Windows does not report failed connection attempts in `writefds` passed to `select` like most other platforms.
+            // Instead, it uses `writefds` only for successful connection attempts and `exceptfds` for failed connection attempts.
+            // We work around this by adding all sockets that look like a pending connection attempt to `exceptfds` automatically on Windows and merge it back later.
+            // This ensures the public API matches other loop implementations across all platforms (see also test suite or rather test matrix).
+            // Lacking better APIs, every write-only socket that has not yet read any data is assumed to be in a pending connection attempt state.
+            // @link https://docs.microsoft.com/de-de/windows/win32/api/winsock2/nf-winsock2-select
             $except = null;
+            if (\DIRECTORY_SEPARATOR === '\\') {
+                $except = array();
+                foreach ($write as $key => $socket) {
+                    if (!isset($read[$key]) && @\ftell($socket) === 0) {
+                        $except[$key] = $socket;
+                    }
+                }
+            }
 
             // suppress warnings that occur, when stream_select is interrupted by a signal
-            return @\stream_select($read, $write, $except, $timeout === null ? null : 0, $timeout);
+            $ret = @\stream_select($read, $write, $except, $timeout === null ? null : 0, $timeout);
+
+            if ($except) {
+                $write = \array_merge($write, $except);
+            }
+            return $ret;
         }
 
         if ($timeout > 0) {

tests/AbstractLoopTest.php

@@ -111,16 +111,11 @@ public function testAddWriteStreamTriggersWhenSocketConnectionSucceeds()
 
     public function testAddWriteStreamTriggersWhenSocketConnectionRefused()
     {
-        // @link https://github.com/reactphp/event-loop/issues/206
-        if ($this->loop instanceof StreamSelectLoop && DIRECTORY_SEPARATOR === '\\') {
-            $this->markTestIncomplete('StreamSelectLoop does not currently support detecting connection refused errors on Windows');
-        }
-
         // first verify the operating system actually refuses the connection and no firewall is in place
         // use higher timeout because Windows retires multiple times and has a noticeable delay
         // @link https://stackoverflow.com/questions/19440364/why-do-failed-attempts-of-socket-connect-take-1-sec-on-windows
         $errno = $errstr = null;
-        if (@stream_socket_client('127.0.0.1:1', $errno, $errstr, 10.0) !== false || $errno !== SOCKET_ECONNREFUSED) {
+        if (@stream_socket_client('127.0.0.1:1', $errno, $errstr, 10.0) !== false || (defined('SOCKET_ECONNREFUSED') && $errno !== SOCKET_ECONNREFUSED)) {
             $this->markTestSkipped('Expected host to refuse connection, but got error ' . $errno . ': ' . $errstr);
         }