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   try:
  54     proc = subprocess.Popen(
  55         cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
  56   except OSError:
  57     print >> sys.stderr, 'Failed to run %s' % ' '.join(cmd)
  58     return
  59   return proc
  60
  61
  62 def wait_for_xvfb(xdisplaycheck, env):
  63   """Waits for xvfb to be fully initialized by using xdisplaycheck."""
  64   try:
  65     _logs = subprocess.check_output(
  66         [xdisplaycheck],
  67         stderr=subprocess.STDOUT,
  68         env=env)
  69   except OSError:
  70     print >> sys.stderr, 'Failed to load %s with cwd=%s' % (
  71         xdisplaycheck, os.getcwd())
  72     return False
  73   except subprocess.CalledProcessError as e:
  74     print >> sys.stderr, (
  75         'Xvfb failed to load properly (code %d) according to %s' %
  76         (e.returncode, xdisplaycheck))
  77     return False
  78
  79   return True
  80
  81
  82 def run_executable(cmd, build_dir, env):
  83   """Runs an executable within a xvfb buffer on linux or normally on other
  84   platforms.
  85
  86   Requires that both xvfb and openbox are installed on linux.
  87
  88   Detects recursion with an environment variable and do not create a recursive X
  89   buffer if present.
  90   """
  91   # First look if we are inside a display.
  92   if env.get('_CHROMIUM_INSIDE_XVFB') == '1':
  93     # No need to recurse.
  94     return test_env.run_executable(cmd, env)
  95
  96   pid = None
  97   xvfb = 'Xvfb'
  98   try:
  99     if sys.platform == 'linux2':
 100       # Defaults to X display 9.
 101       display = ':9'
 102       xvfb_proc = start_xvfb(xvfb, display)
 103       if not xvfb_proc or not xvfb_proc.pid:
 104         return 1
 105       env['DISPLAY'] = display
 106       if not wait_for_xvfb(os.path.join(build_dir, 'xdisplaycheck'), env):
 107         rc = xvfb_proc.poll()
 108         if rc is None:
 109           print 'Xvfb still running, stopping.'
 110           xvfb_proc.terminate()
 111         else:
 112           print 'Xvfb exited, code %d' % rc
 113
 114         print 'Xvfb output:'
 115         for l in xvfb_proc.communicate()[0].splitlines():
 116           print '> %s' % l
 117
 118         return 3
 119       # Inhibit recursion.
 120       env['_CHROMIUM_INSIDE_XVFB'] = '1'
 121       # Some ChromeOS tests need a window manager. Technically, it could be
 122       # another script but that would be overkill.
 123       try:
 124         wm_cmd = ['openbox']
 125         subprocess.Popen(
 126             wm_cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env)
 127       except OSError:
 128         print >> sys.stderr, 'Failed to run %s' % ' '.join(wm_cmd)
 129         return 1
 130     return test_env.run_executable(cmd, env)
 131   finally:
 132     if pid:
 133       kill(pid)
 134
 135
 136 def main():
 137   if len(sys.argv) < 3:
 138     print >> sys.stderr, (
 139         'Usage: xvfb.py [path to build_dir] [command args...]')
 140     return 2
 141   return run_executable(sys.argv[2:], sys.argv[1], os.environ.copy())
 142
 143
 144 if __name__ == "__main__":
 145   sys.exit(main())