Separate xvfb.py logic into its own script

testing/xvfb.py

+#!/usr/bin/env python
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Runs the test with xvfb on linux.
+
+For simplicity in gyp targets, this script has no effect on the other platforms.
+"""
+
+import os
+import platform
+import signal
+import subprocess
+import sys
+
+import test_env
+
+
+def kill(pid):
+  """Kills a process and traps exception if the process doesn't exist anymore.
+  """
+  # If the process doesn't exist, it raises an exception that we can ignore.
+  try:
+    os.kill(pid, signal.SIGKILL)
+  except OSError:
+    pass
+
+
+def get_xvfb_path(server_dir):
+  """Figures out which X server to use."""
+  xvfb_path = os.path.join(server_dir, 'Xvfb.' + platform.architecture()[0])
+  if not os.path.exists(xvfb_path):
+    xvfb_path = os.path.join(server_dir, 'Xvfb')
+  if not os.path.exists(xvfb_path):
+    print >> sys.stderr, (
+        'No Xvfb found in designated server path: %s' % server_dir)
+    raise Exception('No virtual server')
+  return xvfb_path
+
+
+def start_xvfb(xvfb_path, display):
+  """Starts a virtual X server that we run the tests in.
+
+  This makes it so we can run the tests even if we didn't start the tests from
+  an X session.
+
+  Args:
+    xvfb_path: Path to Xvfb.
+  """
+  proc = subprocess.Popen(
+      [xvfb_path, display, '-screen', '0', '1024x768x24', '-ac'],
+      stdout=subprocess.PIPE,
+      stderr=subprocess.STDOUT)
+  return proc.pid
+
+
+def wait_for_xvfb(xdisplaycheck, env):
+  """Waits for xvfb to be fully initialized by using xdisplaycheck."""
+  try:
+    subprocess.check_call(
+        [xdisplaycheck],
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT,
+        env=env)
+  except subprocess.CalledProcessError:
+    print >> sys.stderr, 'Xvfb failed to load properly.'
+    return False
+  return True
+
+
+def run_executable(cmd, build_dir, env):
+  """Runs an executable within a xvfb buffer on linux.
+
+  Runs the test normally on other platforms. Requires that both xvfb and icewm
+  are installed on linux.
+  """
+  pid = None
+  xvfb = 'Xvfb'
+  try:
+    if sys.platform == 'linux2':
+      # Defaults to X display 9.
+      display = ':9'
+      pid = start_xvfb(xvfb, display)
+      env['DISPLAY'] = display
+      if not wait_for_xvfb(os.path.join(build_dir, 'xdisplaycheck'), env):
+        return 3
+      # Some ChromeOS tests need a window manager. Technically, it could be
+      # another script but that would be overkill.
+      subprocess.Popen(
+          'icewm', stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env)
+    return test_env.run_executable(cmd, env)

[Roger Tawa OOO till Jul 10th, 2012/03/07 19:51:27]

should this be indented two more?  the comment at the top of the file says it
does nothing on non-linux platforms.

[M-A Ruel, 2012/03/07 20:21:05]

I fixed the comment to be more sensical.

+  finally:
+    if pid:
+      kill(pid)
+
+
+def main():
+  if len(sys.argv) < 3:
+    print >> sys.stderr, (
+        'Usage: xvfb.py [path to build_dir] [command args...]')
+    return 2
+  return run_executable(sys.argv[2:], sys.argv[1], os.environ.copy())
+
+
+if __name__ == "__main__":
+  sys.exit(main())