testing/xvfb.py

   1 #!/usr/bin/env python
   2 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
   3 # Use of this source code is governed by a BSD-style license that can be
   4 # found in the LICENSE file.
   5
   6 """Runs the test with xvfb on linux. Runs the test normally on other platforms.
   7
   8 For simplicity in gyp targets, this script just runs the test normal on
   9 non-linux platforms.
  10 """
  11
  12 import os
  13 import platform
  14 import signal
  15 import subprocess
  16 import sys
  17
  18 import test_env
  19
  20
  21 def kill(pid):
  22   """Kills a process and traps exception if the process doesn't exist anymore.
  23   """
  24   # If the process doesn't exist, it raises an exception that we can ignore.
  25   try:
  26     os.kill(pid, signal.SIGKILL)
  27   except OSError:
  28     pass
  29
  30
  31 def get_xvfb_path(server_dir):
  32   """Figures out which X server to use."""
  33   xvfb_path = os.path.join(server_dir, 'Xvfb.' + platform.architecture()[0])
  34   if not os.path.exists(xvfb_path):
  35     xvfb_path = os.path.join(server_dir, 'Xvfb')
  36   if not os.path.exists(xvfb_path):
  37     print >> sys.stderr, (
  38         'No Xvfb found in designated server path: %s' % server_dir)
  39     raise Exception('No virtual server')
  40   return xvfb_path
  41
  42
  43 def start_xvfb(xvfb_path, display):
  44   """Starts a virtual X server that we run the tests in.
  45
  46   This makes it so we can run the tests even if we didn't start the tests from
  47   an X session.
  48
  49   Args:
  50     xvfb_path: Path to Xvfb.
  51   """
  52   cmd = [xvfb_path, display, '-screen', '0', '1024x768x24', '-ac',
  53          '-nolisten', 'tcp', '-dpi', '96']
  54   try:
  55     proc = subprocess.Popen(
  56         cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  57   except OSError:
  58     print >> sys.stderr, 'Failed to run %s' % ' '.join(cmd)
  59     return
  60   return proc
  61
  62
  63 def wait_for_xvfb(xdisplaycheck, env):
  64   """Waits for xvfb to be fully initialized by using xdisplaycheck."""
  65   try:
  66     _logs = subprocess.check_output(
  67         [xdisplaycheck],
  68         stderr=subprocess.STDOUT,
  69         env=env)
  70   except OSError:
  71     print >> sys.stderr, 'Failed to load %s with cwd=%s' % (
  72         xdisplaycheck, os.getcwd())
  73     return False
  74   except subprocess.CalledProcessError as e:
  75     print >> sys.stderr, (
  76         'Xvfb failed to load properly (code %d) according to %s' %
  77         (e.returncode, xdisplaycheck))
  78     return False
  79
  80   return True
  81
  82
  83 def run_executable(cmd, build_dir, env):
  84   """Runs an executable within a xvfb buffer on linux or normally on other
  85   platforms.
  86
  87   Requires that both xvfb and openbox are installed on linux.
  88
  89   Detects recursion with an environment variable and do not create a recursive X
  90   buffer if present.
  91   """
  92   # First look if we are inside a display.
  93   if env.get('_CHROMIUM_INSIDE_XVFB') == '1':
  94     # No need to recurse.
  95     return test_env.run_executable(cmd, env)
  96
  97   xvfb_proc = None
  98   xvfb = 'Xvfb'
  99   try:
 100     if sys.platform == 'linux2':
 101       # Defaults to X display 9.
 102       display = ':9'
 103       xvfb_proc = start_xvfb(xvfb, display)
 104       if not xvfb_proc or not xvfb_proc.pid:
 105         return 1
 106       env['DISPLAY'] = display
 107       if not wait_for_xvfb(os.path.join(build_dir, 'xdisplaycheck'), env):
 108         rc = xvfb_proc.poll()
 109         if rc is None:
 110           print 'Xvfb still running, stopping.'
 111           xvfb_proc.terminate()
 112         else:
 113           print 'Xvfb exited, code %d' % rc
 114
 115         print 'Xvfb output:'
 116         for l in xvfb_proc.communicate()[0].splitlines():
 117           print '> %s' % l
 118
 119         return 3
 120       # Inhibit recursion.
 121       env['_CHROMIUM_INSIDE_XVFB'] = '1'
 122       # Some ChromeOS tests need a window manager. Technically, it could be
 123       # another script but that would be overkill.
 124       try:
 125         wm_cmd = ['openbox']
 126         subprocess.Popen(
 127             wm_cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env)
 128       except OSError:
 129         print >> sys.stderr, 'Failed to run %s' % ' '.join(wm_cmd)
 130         return 1
 131     return test_env.run_executable(cmd, env)
 132   finally:
 133     # When the X server dies, it takes down the window manager with it.
 134     if xvfb_proc and xvfb_proc.pid:
 135       kill(xvfb_proc.pid)
 136
 137
 138 def main():
 139   if len(sys.argv) < 3:
 140     print >> sys.stderr, (
 141         'Usage: xvfb.py [path to build_dir] [command args...]')
 142     return 2
 143   return run_executable(sys.argv[2:], sys.argv[1], os.environ.copy())
 144
 145
 146 if __name__ == "__main__":
 147   sys.exit(main())