[gvfs] tests: Fix race condition in FTP server setup

[Martin Pitt <martinpitt src gnome org>]

commit 2f83f3a4f883e33cf44e4a53549e26def7f5953d
Author: Martin Pitt <martin pitt ubuntu com>
Date:   Thu May 15 11:18:37 2014 +0200

    tests: Fix race condition in FTP server setup
    
    Don't sleep for 0.5 seconds but repeatedly ping the FTP server until it is
    started up. Time out after 5 s.

 test/gvfs-test |   15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)
---
diff --git a/test/gvfs-test b/test/gvfs-test
index 911ace3..623743f 100755
--- a/test/gvfs-test
+++ b/test/gvfs-test
@@ -33,6 +33,7 @@ import fcntl
 import re
 import locale
 import signal
+import socket
 from glob import glob
 
 from gi.repository import GLib, Gio
@@ -555,8 +556,18 @@ class Ftp(GvfsTestCase):
                                       '-r', self.workdir,
                                       '--auth', 'memory:testuser:pwd1'],
                                      stdout=subprocess.PIPE)
-        # give ftp server some time to start up
-        time.sleep(0.5)
+        # wait until server is started up
+        s = socket.socket()
+        for timeout in range(50):
+            try:
+                s.connect(('127.0.0.1', 2121))
+                s.close()
+                break
+            except ConnectionRefusedError:
+                time.sleep(0.01)
+                pass
+        else:
+            self.fail('timed out waiting for test FTP server')
  
     def tearDown(self):
         '''Shut down FTP server'''