#
# ***** BEGIN LICENSE BLOCK *****
# Version: MPL 1.1/GPL 2.0/LGPL 2.1
#
# The contents of this file are subject to the Mozilla Public License Version
# 1.1 (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
# http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
# for the specific language governing rights and limitations under the
# License.
#
# The Original Code is mozilla.org code.
#
# The Initial Developer of the Original Code is
# Mozilla Foundation.
# Portions created by the Initial Developer are Copyright (C) 2008
# the Initial Developer. All Rights Reserved.
#
# Contributor(s):
#   Robert Sayre <sayrer@gmail.com>
#   Jeff Walden <jwalden+bmo@mit.edu>
#
# Alternatively, the contents of this file may be used under the terms of
# either the GNU General Public License Version 2 or later (the "GPL"), or
# the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
# in which case the provisions of the GPL or the LGPL are applicable instead
# of those above. If you wish to allow use of your version of this file only
# under the terms of either the GPL or the LGPL, and not to allow others to
# use your version of this file under the terms of the MPL, indicate your
# decision by deleting the provisions above and replace them with the notice
# and other provisions required by the GPL or the LGPL. If you do not delete
# the provisions above, a recipient may use your version of this file under
# the terms of any one of the MPL, the GPL or the LGPL.
#
# ***** END LICENSE BLOCK *****

import codecs
from datetime import datetime, timedelta
import itertools
import logging
import os
import re
import select
import shutil
import signal
import subprocess
import sys
import threading
import tempfile
import zipfile
import sqlite3

SCRIPT_DIR = os.path.abspath(os.path.realpath(os.path.dirname(sys.argv[0])))
sys.path.insert(0, SCRIPT_DIR)
import automationutils

_DEFAULT_WEB_SERVER = "127.0.0.1"
_DEFAULT_HTTP_PORT = 8888
_DEFAULT_SSL_PORT = 4443
_DEFAULT_WEBSOCKET_PORT = 9988

#expand _DIST_BIN = __XPC_BIN_PATH__
#expand _IS_WIN32 = len("__WIN32__") != 0
#expand _IS_MAC = __IS_MAC__ != 0
#expand _IS_LINUX = __IS_LINUX__ != 0
#ifdef IS_CYGWIN
#expand _IS_CYGWIN = __IS_CYGWIN__ == 1
#else
_IS_CYGWIN = False
#endif
#expand _IS_CAMINO = __IS_CAMINO__ != 0
#expand _BIN_SUFFIX = __BIN_SUFFIX__
#expand _PERL = __PERL__

#expand _DEFAULT_APP = "./" + __BROWSER_PATH__
#expand _CERTS_SRC_DIR = __CERTS_SRC_DIR__
#expand _IS_TEST_BUILD = __IS_TEST_BUILD__
#expand _IS_DEBUG_BUILD = __IS_DEBUG_BUILD__
#expand _CRASHREPORTER = __CRASHREPORTER__ == 1


if _IS_WIN32:
  import ctypes, ctypes.wintypes, time, msvcrt
else:
  import errno


# We use the logging system here primarily because it'll handle multiple
# threads, which is needed to process the output of the server and application
# processes simultaneously.
_log = logging.getLogger()
handler = logging.StreamHandler(sys.stdout)
_log.setLevel(logging.INFO)
_log.addHandler(handler)


#################
# PROFILE SETUP #
#################

class SyntaxError(Exception):
  "Signifies a syntax error on a particular line in server-locations.txt."

  def __init__(self, lineno, msg = None):
    self.lineno = lineno
    self.msg = msg

  def __str__(self):
    s = "Syntax error on line " + str(self.lineno)
    if self.msg:
      s += ": %s." % self.msg
    else:
      s += "."
    return s


class Location:
  "Represents a location line in server-locations.txt."

  def __init__(self, scheme, host, port, options):
    self.scheme = scheme
    self.host = host
    self.port = port
    self.options = options

class Automation(object):
  """
  Runs the browser from a script, and provides useful utilities
  for setting up the browser environment.
  """

  DIST_BIN = _DIST_BIN
  IS_WIN32 = _IS_WIN32
  IS_MAC = _IS_MAC
  IS_LINUX = _IS_LINUX
  IS_CYGWIN = _IS_CYGWIN
  IS_CAMINO = _IS_CAMINO
  BIN_SUFFIX = _BIN_SUFFIX
  PERL = _PERL

  UNIXISH = not IS_WIN32 and not IS_MAC

  DEFAULT_APP = _DEFAULT_APP
  CERTS_SRC_DIR = _CERTS_SRC_DIR
  IS_TEST_BUILD = _IS_TEST_BUILD
  IS_DEBUG_BUILD = _IS_DEBUG_BUILD
  CRASHREPORTER = _CRASHREPORTER

  # timeout, in seconds
  DEFAULT_TIMEOUT = 60.0
  DEFAULT_WEB_SERVER = _DEFAULT_WEB_SERVER
  DEFAULT_HTTP_PORT = _DEFAULT_HTTP_PORT
  DEFAULT_SSL_PORT = _DEFAULT_SSL_PORT
  DEFAULT_WEBSOCKET_PORT = _DEFAULT_WEBSOCKET_PORT

  def __init__(self):
    self.log = _log
    self.lastTestSeen = "automation.py"
    self.haveDumpedScreen = False

  def setServerInfo(self, 
                    webServer = _DEFAULT_WEB_SERVER, 
                    httpPort = _DEFAULT_HTTP_PORT, 
                    sslPort = _DEFAULT_SSL_PORT,
                    webSocketPort = _DEFAULT_WEBSOCKET_PORT):
    self.webServer = webServer
    self.httpPort = httpPort
    self.sslPort = sslPort
    self.webSocketPort = webSocketPort

  @property
  def __all__(self):
    return [
           "UNIXISH",
           "IS_WIN32",
           "IS_MAC",
           "log",
           "runApp",
           "Process",
           "addCommonOptions",
           "initializeProfile",
           "DIST_BIN",
           "DEFAULT_APP",
           "CERTS_SRC_DIR",
           "environment",
           "IS_TEST_BUILD",
           "IS_DEBUG_BUILD",
           "DEFAULT_TIMEOUT",
          ]

  class Process(subprocess.Popen):
    """
    Represents our view of a subprocess.
    It adds a kill() method which allows it to be stopped explicitly.
    """

    def __init__(self,
                 args,
                 bufsize=0,
                 executable=None,
                 stdin=None,
                 stdout=None,
                 stderr=None,
                 preexec_fn=None,
                 close_fds=False,
                 shell=False,
                 cwd=None,
                 env=None,
                 universal_newlines=False,
                 startupinfo=None,
                 creationflags=0):
      args = automationutils.wrapCommand(args)
      print "args: %s" % args
      subprocess.Popen.__init__(self, args, bufsize, executable,
                                stdin, stdout, stderr,
                                preexec_fn, close_fds,
                                shell, cwd, env,
                                universal_newlines, startupinfo, creationflags)
      self.log = _log

    def kill(self):
      if Automation().IS_WIN32:
        import platform
        pid = "%i" % self.pid
        if platform.release() == "2000":
          # Windows 2000 needs 'kill.exe' from the 
          #'Windows 2000 Resource Kit tools'. (See bug 475455.)
          try:
            subprocess.Popen(["kill", "-f", pid]).wait()
          except:
            self.log.info("TEST-UNEXPECTED-FAIL | automation.py | Missing 'kill' utility to kill process with pid=%s. Kill it manually!", pid)
        else:
          # Windows XP and later.
          subprocess.Popen(["taskkill", "/F", "/PID", pid]).wait()
      else:
        os.kill(self.pid, signal.SIGKILL)

  def readLocations(self, locationsPath = "server-locations.txt"):
    """
    Reads the locations at which the Mochitest HTTP server is available from
    server-locations.txt.
    """

    locationFile = codecs.open(locationsPath, "r", "UTF-8")

    # Perhaps more detail than necessary, but it's the easiest way to make sure
    # we get exactly the format we want.  See server-locations.txt for the exact
    # format guaranteed here.
    lineRe = re.compile(r"^(?P<scheme>[a-z][-a-z0-9+.]*)"
                      r"://"
                      r"(?P<host>"
                        r"\d+\.\d+\.\d+\.\d+"
                        r"|"
                        r"(?:[a-z0-9](?:[-a-z0-9]*[a-z0-9])?\.)*"
                        r"[a-z](?:[-a-z0-9]*[a-z0-9])?"
                      r")"
                      r":"
                      r"(?P<port>\d+)"
                      r"(?:"
                      r"\s+"
                      r"(?P<options>\S+(?:,\S+)*)"
                      r")?$")
    locations = []
    lineno = 0
    seenPrimary = False
    for line in locationFile:
      lineno += 1
      if line.startswith("#") or line == "\n":
        continue
      
      match = lineRe.match(line)
      if not match:
        raise SyntaxError(lineno)

      options = match.group("options")
      if options:
        options = options.split(",")
        if "primary" in options:
          if seenPrimary:
            raise SyntaxError(lineno, "multiple primary locations")
          seenPrimary = True
      else:
        options = []

      locations.append(Location(match.group("scheme"), match.group("host"),
                                match.group("port"), options))

    if not seenPrimary:
      raise SyntaxError(lineno + 1, "missing primary location")

    return locations

  def setupPermissionsDatabase(self, profileDir, permissions):
    # Open database and create table
    permDB = sqlite3.connect(os.path.join(profileDir, "permissions.sqlite"))
    cursor = permDB.cursor();
    # SQL copied from nsPermissionManager.cpp
    cursor.execute("""CREATE TABLE moz_hosts (
       id INTEGER PRIMARY KEY,
       host TEXT,
       type TEXT,
       permission INTEGER,
       expireType INTEGER,
       expireTime INTEGER)""")

    # Insert desired permissions
    c = 0
    for perm in permissions.keys():
      for host,allow in permissions[perm]:
        c += 1
        cursor.execute("INSERT INTO moz_hosts values(?, ?, ?, ?, 0, 0)",
                       (c, host, perm, 1 if allow else 2))

    # Commit and close
    permDB.commit()
    cursor.close()

  def initializeProfile(self, profileDir, extraPrefs = [], useServerLocations = False):
    " Sets up the standard testing profile."

    prefs = []
    # Start with a clean slate.
    shutil.rmtree(profileDir, True)
    os.mkdir(profileDir)

    # Set up permissions database
    locations = self.readLocations()
    self.setupPermissionsDatabase(profileDir,
      {'allowXULXBL':[(l.host, 'noxul' not in l.options) for l in locations]});

    part = """\
user_pref("browser.console.showInPanel", true);
user_pref("browser.dom.window.dump.enabled", true);
user_pref("dom.allow_scripts_to_close_windows", true);
user_pref("dom.disable_open_during_load", false);
user_pref("dom.max_script_run_time", 0); // no slow script dialogs
user_pref("dom.max_chrome_script_run_time", 0);
user_pref("dom.popup_maximum", -1);
user_pref("dom.successive_dialog_time_limit", 0);
user_pref("signed.applets.codebase_principal_support", true);
user_pref("security.warn_submit_insecure", false);
user_pref("browser.shell.checkDefaultBrowser", false);
user_pref("shell.checkDefaultClient", false);
user_pref("browser.warnOnQuit", false);
user_pref("accessibility.typeaheadfind.autostart", false);
user_pref("javascript.options.showInConsole", true);
user_pref("devtools.errorconsole.enabled", true);
user_pref("layout.debug.enable_data_xbl", true);
user_pref("browser.EULA.override", true);
user_pref("javascript.options.tracejit.content", true);
user_pref("javascript.options.methodjit.content", true);
user_pref("javascript.options.jitprofiling.content", true);
user_pref("gfx.color_management.force_srgb", true);
user_pref("network.manage-offline-status", false);
user_pref("test.mousescroll", true);
user_pref("security.default_personal_cert", "Select Automatically"); // Need to client auth test be w/o any dialogs
user_pref("network.http.prompt-temp-redirect", false);
user_pref("media.cache_size", 100);
user_pref("security.warn_viewing_mixed", false);
user_pref("app.update.enabled", false);
user_pref("browser.panorama.experienced_first_run", true); // Assume experienced

// Only load extensions from the application and user profile
// AddonManager.SCOPE_PROFILE + AddonManager.SCOPE_APPLICATION
user_pref("extensions.enabledScopes", 5);
// Disable metadata caching for installed add-ons by default
user_pref("extensions.getAddons.cache.enabled", false);

user_pref("extensions.testpilot.runStudies", false);

user_pref("geo.wifi.uri", "http://%(server)s/tests/dom/tests/mochitest/geolocation/network_geolocation.sjs");
user_pref("geo.wifi.testing", true);
user_pref("geo.ignore.location_filter", true);

user_pref("camino.warn_when_closing", false); // Camino-only, harmless to others

// Make url-classifier updates so rare that they won't affect tests
user_pref("urlclassifier.updateinterval", 172800);
// Point the url-classifier to the local testing server for fast failures
user_pref("browser.safebrowsing.provider.0.gethashURL", "http://%(server)s/safebrowsing-dummy/gethash");
user_pref("browser.safebrowsing.provider.0.keyURL", "http://%(server)s/safebrowsing-dummy/newkey");
user_pref("browser.safebrowsing.provider.0.updateURL", "http://%(server)s/safebrowsing-dummy/update");
// Point update checks to the local testing server for fast failures
user_pref("extensions.update.url", "http://%(server)s/extensions-dummy/updateURL");
user_pref("extensions.blocklist.url", "http://%(server)s/extensions-dummy/blocklistURL");
// Make sure opening about:addons won't hit the network
user_pref("extensions.webservice.discoverURL", "http://%(server)s/extensions-dummy/discoveryURL");
""" % { "server" : self.webServer + ":" + str(self.httpPort) }
    prefs.append(part)

    if useServerLocations == False:
      part = """
user_pref("capability.principal.codebase.p1.granted",
          "UniversalXPConnect UniversalBrowserRead UniversalBrowserWrite \
           UniversalPreferencesRead UniversalPreferencesWrite \
           UniversalFileRead");
user_pref("capability.principal.codebase.p1.id", "%(origin)s");
user_pref("capability.principal.codebase.p1.subjectName", "");
"""  % { "origin": "http://" + self.webServer + ":" + str(self.httpPort) }
      prefs.append(part)
    else:
      # Grant God-power to all the privileged servers on which tests run.
      privileged = filter(lambda loc: "privileged" in loc.options, locations)
      for (i, l) in itertools.izip(itertools.count(1), privileged):
        part = """
user_pref("capability.principal.codebase.p%(i)d.granted",
          "UniversalXPConnect UniversalBrowserRead UniversalBrowserWrite \
           UniversalPreferencesRead UniversalPreferencesWrite \
           UniversalFileRead");
user_pref("capability.principal.codebase.p%(i)d.id", "%(origin)s");
user_pref("capability.principal.codebase.p%(i)d.subjectName", "");
"""  % { "i": i,
         "origin": (l.scheme + "://" + l.host + ":" + str(l.port)) }
        prefs.append(part)

      # We need to proxy every server but the primary one.
      origins = ["'%s://%s:%s'" % (l.scheme, l.host, l.port)
                for l in filter(lambda l: "primary" not in l.options, locations)]
      origins = ", ".join(origins)

      pacURL = """data:text/plain,
function FindProxyForURL(url, host)
{
  var origins = [%(origins)s];
  var regex = new RegExp('^([a-z][-a-z0-9+.]*)' +
                         '://' +
                         '(?:[^/@]*@)?' +
                         '(.*?)' +
                         '(?::(\\\\\\\\d+))?/');
  var matches = regex.exec(url);
  if (!matches)
    return 'DIRECT';
  var isHttp = matches[1] == 'http';
  var isHttps = matches[1] == 'https';
  var isWebSocket = matches[1] == 'ws';
  if (!matches[3])
  {
    if (isHttp | isWebSocket) matches[3] = '80';
    if (isHttps) matches[3] = '443';
  }
  if (isWebSocket)
    matches[1] = 'http';

  var origin = matches[1] + '://' + matches[2] + ':' + matches[3];
  if (origins.indexOf(origin) < 0)
    return 'DIRECT';
  if (isHttp)
    return 'PROXY %(remote)s:%(httpport)s';
  if (isHttps || isWebSocket)
    return 'PROXY %(remote)s:%(sslport)s';
  return 'DIRECT';
}""" % { "origins": origins,
         "remote":  self.webServer,
         "httpport":self.httpPort,
         "sslport": self.sslPort }
      pacURL = "".join(pacURL.splitlines())

      part += """
user_pref("network.proxy.type", 2);
user_pref("network.proxy.autoconfig_url", "%(pacURL)s");

user_pref("camino.use_system_proxy_settings", false); // Camino-only, harmless to others
""" % {"pacURL": pacURL}
      prefs.append(part)

    for v in extraPrefs:
      thispref = v.split("=")
      if len(thispref) < 2:
        print "Error: syntax error in --setpref=" + v
        sys.exit(1)
      part = 'user_pref("%s", %s);\n' % (thispref[0], thispref[1])
      prefs.append(part)

    # write the preferences
    prefsFile = open(profileDir + "/" + "user.js", "a")
    prefsFile.write("".join(prefs))
    prefsFile.close()

  def addCommonOptions(self, parser):
    "Adds command-line options which are common to mochitest and reftest."

    parser.add_option("--setpref",
                      action = "append", type = "string",
                      default = [],
                      dest = "extraPrefs", metavar = "PREF=VALUE",
                      help = "defines an extra user preference")  

  def fillCertificateDB(self, profileDir, certPath, utilityPath, xrePath):
    pwfilePath = os.path.join(profileDir, ".crtdbpw")
  
    pwfile = open(pwfilePath, "w")
    pwfile.write("\n")
    pwfile.close()

    # Create head of the ssltunnel configuration file
    sslTunnelConfigPath = os.path.join(profileDir, "ssltunnel.cfg")
    sslTunnelConfig = open(sslTunnelConfigPath, "w")
  
    sslTunnelConfig.write("httpproxy:1\n")
    sslTunnelConfig.write("certdbdir:%s\n" % certPath)
    sslTunnelConfig.write("forward:127.0.0.1:%s\n" % self.httpPort)
    sslTunnelConfig.write("websocketserver:%s:%s\n" % (self.webServer, self.webSocketPort))
    sslTunnelConfig.write("listen:*:%s:pgo server certificate\n" % self.sslPort)

    # Configure automatic certificate and bind custom certificates, client authentication
    locations = self.readLocations()
    locations.pop(0)
    for loc in locations:
      if loc.scheme == "https" and "nocert" not in loc.options:
        customCertRE = re.compile("^cert=(?P<nickname>[0-9a-zA-Z_ ]+)")
        clientAuthRE = re.compile("^clientauth=(?P<clientauth>[a-z]+)")
        for option in loc.options:
          match = customCertRE.match(option)
          if match:
            customcert = match.group("nickname");
            sslTunnelConfig.write("listen:%s:%s:%s:%s\n" %
                      (loc.host, loc.port, self.sslPort, customcert))

          match = clientAuthRE.match(option)
          if match:
            clientauth = match.group("clientauth");
            sslTunnelConfig.write("clientauth:%s:%s:%s:%s\n" %
                      (loc.host, loc.port, self.sslPort, clientauth))

    sslTunnelConfig.close()

    # Pre-create the certification database for the profile
    env = self.environment(xrePath = xrePath)
    certutil = os.path.join(utilityPath, "certutil" + self.BIN_SUFFIX)
    pk12util = os.path.join(utilityPath, "pk12util" + self.BIN_SUFFIX)

    status = self.Process([certutil, "-N", "-d", profileDir, "-f", pwfilePath], env = env).wait()
    if status != 0:
      return status

    # Walk the cert directory and add custom CAs and client certs
    files = os.listdir(certPath)
    for item in files:
      root, ext = os.path.splitext(item)
      if ext == ".ca":
        trustBits = "CT,,"
        if root.endswith("-object"):
          trustBits = "CT,,CT"
        self.Process([certutil, "-A", "-i", os.path.join(certPath, item),
                    "-d", profileDir, "-f", pwfilePath, "-n", root, "-t", trustBits],
                    env = env).wait()
      if ext == ".client":
        self.Process([pk12util, "-i", os.path.join(certPath, item), "-w",
                    pwfilePath, "-d", profileDir], 
                    env = env).wait()

    os.unlink(pwfilePath)
    return 0

  def environment(self, env = None, xrePath = None, crashreporter = True):
    if xrePath == None:
      xrePath = self.DIST_BIN
    if env == None:
      env = dict(os.environ)

    ldLibraryPath = os.path.abspath(os.path.join(SCRIPT_DIR, xrePath))
    if self.UNIXISH or self.IS_MAC:
      envVar = "LD_LIBRARY_PATH"
      if self.IS_MAC:
        envVar = "DYLD_LIBRARY_PATH"
      else: # unixish
        env['MOZILLA_FIVE_HOME'] = xrePath
      if envVar in env:
        ldLibraryPath = ldLibraryPath + ":" + env[envVar]
      env[envVar] = ldLibraryPath
    elif self.IS_WIN32:
      env["PATH"] = env["PATH"] + ";" + ldLibraryPath

    if crashreporter:
      env['MOZ_CRASHREPORTER_NO_REPORT'] = '1'
      env['MOZ_CRASHREPORTER'] = '1'
    else:
      env['MOZ_CRASHREPORTER_DISABLE'] = '1'

    env['GNOME_DISABLE_CRASH_DIALOG'] = '1'
    env['XRE_NO_WINDOWS_CRASH_DIALOG'] = '1'

    # Don't do this for Mac since it makes the Mac OS X 10.5 (32-bit)
    # trace-malloc leak test hang.  (It doesn't make the 10.6 (64-bit)
    # leak test hang, though.)
    if not self.IS_MAC:
      env['NS_TRACE_MALLOC_DISABLE_STACKS'] = '1'
    return env

  if IS_WIN32:
    PeekNamedPipe = ctypes.windll.kernel32.PeekNamedPipe
    GetLastError = ctypes.windll.kernel32.GetLastError

    def readWithTimeout(self, f, timeout):
      """Try to read a line of output from the file object |f|.
      |f| must be a  pipe, like the |stdout| member of a subprocess.Popen
      object created with stdout=PIPE. If no output
      is received within |timeout| seconds, return a blank line.
      Returns a tuple (line, did_timeout), where |did_timeout| is True
      if the read timed out, and False otherwise."""
      if timeout is None:
        # shortcut to allow callers to pass in "None" for no timeout.
        return (f.readline(), False)
      x = msvcrt.get_osfhandle(f.fileno())
      l = ctypes.c_long()
      done = time.time() + timeout
      while time.time() < done:
        if self.PeekNamedPipe(x, None, 0, None, ctypes.byref(l), None) == 0:
          err = self.GetLastError()
          if err == 38 or err == 109: # ERROR_HANDLE_EOF || ERROR_BROKEN_PIPE
            return ('', False)
          else:
            log.error("readWithTimeout got error: %d", err)
        if l.value > 0:
          # we're assuming that the output is line-buffered,
          # which is not unreasonable
          return (f.readline(), False)
        time.sleep(0.01)
      return ('', True)

    def isPidAlive(self, pid):
      STILL_ACTIVE = 259
      PROCESS_QUERY_LIMITED_INFORMATION = 0x1000
      pHandle = ctypes.windll.kernel32.OpenProcess(PROCESS_QUERY_LIMITED_INFORMATION, 0, pid)
      if not pHandle:
        return False
      pExitCode = ctypes.wintypes.DWORD()
      ctypes.windll.kernel32.GetExitCodeProcess(pHandle, ctypes.byref(pExitCode))
      ctypes.windll.kernel32.CloseHandle(pHandle)
      if (pExitCode.value == STILL_ACTIVE):
        return True
      else:
        return False

    def killPid(self, pid):
      PROCESS_TERMINATE = 0x0001
      pHandle = ctypes.windll.kernel32.OpenProcess(PROCESS_TERMINATE, 0, pid)
      if not pHandle:
        return
      success = ctypes.windll.kernel32.TerminateProcess(pHandle, 1)
      ctypes.windll.kernel32.CloseHandle(pHandle)

  else:

    def readWithTimeout(self, f, timeout):
      """Try to read a line of output from the file object |f|. If no output
      is received within |timeout| seconds, return a blank line.
      Returns a tuple (line, did_timeout), where |did_timeout| is True
      if the read timed out, and False otherwise."""
      (r, w, e) = select.select([f], [], [], timeout)
      if len(r) == 0:
        return ('', True)
      return (f.readline(), False)

    def isPidAlive(self, pid):
      try:
        # kill(pid, 0) checks for a valid PID without actually sending a signal
        # The method throws OSError if the PID is invalid, which we catch below.
        os.kill(pid, 0)

        # Wait on it to see if it's a zombie. This can throw OSError.ECHILD if
        # the process terminates before we get to this point.
        wpid, wstatus = os.waitpid(pid, os.WNOHANG)
        if wpid == 0:
          return True

        return False
      except OSError, err:
        # Catch the errors we might expect from os.kill/os.waitpid, 
        # and re-raise any others
        if err.errno == errno.ESRCH or err.errno == errno.ECHILD:
          return False
        raise

    def killPid(self, pid):
      os.kill(pid, signal.SIGKILL)

  if UNIXISH:
    def dumpScreen(self, utilityPath):
      self.haveDumpedScreen = True;

      screentopng = os.path.join(utilityPath, "screentopng")
      try:
        dumper = self.Process([screentopng], bufsize=-1,
                              stdout=subprocess.PIPE, close_fds=True)
      except OSError, err:
        self.log.info("Failed to start %s for screenshot: %s",
                      screentopng, err.strerror)
        return

      image = dumper.stdout.read()
      status = dumper.wait()
      if status != 0:
        self.log.info("screentopng exited with code %d", status)
        return

      import base64
      encoded = base64.b64encode(image)
      self.log.info("SCREENSHOT: data:image/png;base64,%s", encoded)

  def killAndGetStack(self, proc, utilityPath, debuggerInfo):
    """Kill the process, preferrably in a way that gets us a stack trace."""
    if self.UNIXISH and not debuggerInfo and not self.haveDumpedScreen:
      self.dumpScreen(utilityPath)

    if self.CRASHREPORTER and not debuggerInfo:
      if self.UNIXISH:
        # ABRT will get picked up by Breakpad's signal handler
        os.kill(proc.pid, signal.SIGABRT)
        return
      elif self.IS_WIN32:
        # We should have a "crashinject" program in our utility path
        crashinject = os.path.normpath(os.path.join(utilityPath, "crashinject.exe"))
        if os.path.exists(crashinject) and subprocess.Popen([crashinject, str(proc.pid)]).wait() == 0:
          return
      #TODO: kill the process such that it triggers Breakpad on OS X (bug 525296)
    self.log.info("Can't trigger Breakpad, just killing process")
    proc.kill()

  def waitForFinish(self, proc, utilityPath, timeout, maxTime, startTime, debuggerInfo, symbolsPath):
    """ Look for timeout or crashes and return the status after the process terminates """
    stackFixerProcess = None
    stackFixerFunction = None
    didTimeout = False
    if proc.stdout is None:
      self.log.info("TEST-INFO: Not logging stdout or stderr due to debugger connection")
    else:
      logsource = proc.stdout

      if self.IS_DEBUG_BUILD and (self.IS_MAC or self.IS_LINUX) and symbolsPath and os.path.exists(symbolsPath):
        # Run each line through a function in fix_stack_using_bpsyms.py (uses breakpad symbol files)
        # This method is preferred for Tinderbox builds, since native symbols may have been stripped.
        sys.path.insert(0, utilityPath)
        import fix_stack_using_bpsyms as stackFixerModule
        stackFixerFunction = lambda line: stackFixerModule.fixSymbols(line, symbolsPath)
        del sys.path[0]
      elif self.IS_DEBUG_BUILD and self.IS_MAC and False:
        # Run each line through a function in fix_macosx_stack.py (uses atos)
        sys.path.insert(0, utilityPath)
        import fix_macosx_stack as stackFixerModule
        stackFixerFunction = lambda line: stackFixerModule.fixSymbols(line)
        del sys.path[0]
      elif self.IS_DEBUG_BUILD and self.IS_LINUX:
        # Run logsource through fix-linux-stack.pl (uses addr2line)
        # This method is preferred for developer machines, so we don't have to run "make buildsymbols".
        stackFixerProcess = self.Process([self.PERL, os.path.join(utilityPath, "fix-linux-stack.pl")],
                                         stdin=logsource,
                                         stdout=subprocess.PIPE)
        logsource = stackFixerProcess.stdout

      (line, didTimeout) = self.readWithTimeout(logsource, timeout)
      hitMaxTime = False
      while line != "" and not didTimeout:
        if "TEST-START" in line and "|" in line:
          self.lastTestSeen = line.split("|")[1].strip()
        if stackFixerFunction:
          line = stackFixerFunction(line)
        self.log.info(line.rstrip())
        if self.UNIXISH and not debuggerInfo and not self.haveDumpedScreen and "TEST-UNEXPECTED-FAIL" in line and "Test timed out" in line:
          self.dumpScreen(utilityPath)

        (line, didTimeout) = self.readWithTimeout(logsource, timeout)
        if not hitMaxTime and maxTime and datetime.now() - startTime > timedelta(seconds = maxTime):
          # Kill the application, but continue reading from stack fixer so as not to deadlock on stackFixerProcess.wait().
          hitMaxTime = True
          self.log.info("TEST-UNEXPECTED-FAIL | %s | application ran for longer than allowed maximum time of %d seconds", self.lastTestSeen, int(maxTime))
          self.killAndGetStack(proc, utilityPath, debuggerInfo)
      if didTimeout:
        self.log.info("TEST-UNEXPECTED-FAIL | %s | application timed out after %d seconds with no output", self.lastTestSeen, int(timeout))
        self.killAndGetStack(proc, utilityPath, debuggerInfo)

    status = proc.wait()
    if status == 0:
      self.lastTestSeen = "Main app process exited normally"
    if status != 0 and not didTimeout and not hitMaxTime:
      self.log.info("TEST-UNEXPECTED-FAIL | %s | Exited with code %d during test run", self.lastTestSeen, status)
    if stackFixerProcess is not None:
      fixerStatus = stackFixerProcess.wait()
      if fixerStatus != 0 and not didTimeout and not hitMaxTime:
        self.log.info("TEST-UNEXPECTED-FAIL | automation.py | Stack fixer process exited with code %d during test run", fixerStatus)
    return status

  def buildCommandLine(self, app, debuggerInfo, profileDir, testURL, extraArgs):
    """ build the application command line """

    cmd = app
    if self.IS_MAC and not self.IS_CAMINO and not cmd.endswith("-bin"):
      cmd += "-bin"
    cmd = os.path.abspath(cmd)

    args = []

    if debuggerInfo:
      args.extend(debuggerInfo["args"])
      args.append(cmd)
      cmd = os.path.abspath(debuggerInfo["path"])

    if self.IS_MAC:
      args.append("-foreground")

    if self.IS_CYGWIN:
      profileDirectory = commands.getoutput("cygpath -w \"" + profileDir + "/\"")
    else:
      profileDirectory = profileDir + "/"

    args.extend(("-no-remote", "-profile", profileDirectory))
    if testURL is not None:
      if self.IS_CAMINO:
        args.extend(("-url", testURL))
      else:
        args.append((testURL))
    args.extend(extraArgs)
    return cmd, args

  def checkForZombies(self, processLog):
    """ Look for hung processes """
    if not os.path.exists(processLog):
      self.log.info('INFO | automation.py | PID log not found: %s', processLog)
    else:
      self.log.info('INFO | automation.py | Reading PID log: %s', processLog)
      processList = []
      pidRE = re.compile(r'launched child process (\d+)$')
      processLogFD = open(processLog)
      for line in processLogFD:
        self.log.info(line.rstrip())
        m = pidRE.search(line)
        if m:
          processList.append(int(m.group(1)))
      processLogFD.close()

      for processPID in processList:
        self.log.info("INFO | automation.py | Checking for orphan process with PID: %d", processPID)
        if self.isPidAlive(processPID):
          self.log.info("TEST-UNEXPECTED-FAIL | automation.py | child process %d still alive after shutdown", processPID)
          self.killPid(processPID)

  def runApp(self, testURL, env, app, profileDir, extraArgs,
             runSSLTunnel = False, utilityPath = None,
             xrePath = None, certPath = None,
             debuggerInfo = None, symbolsPath = None,
             timeout = -1, maxTime = None):
    """
    Run the app, log the duration it took to execute, return the status code.
    Kills the app if it runs for longer than |maxTime| seconds, or outputs nothing for |timeout| seconds.
    """

    if utilityPath == None:
      utilityPath = self.DIST_BIN
    if xrePath == None:
      xrePath = self.DIST_BIN
    if certPath == None:
      certPath = self.CERTS_SRC_DIR
    if timeout == -1:
      timeout = self.DEFAULT_TIMEOUT

    # copy env so we don't munge the caller's environment
    env = dict(env);
    env["NO_EM_RESTART"] = "1"
    tmpfd, processLog = tempfile.mkstemp(suffix='pidlog')
    os.close(tmpfd)
    env["MOZ_PROCESS_LOG"] = processLog

    if self.IS_TEST_BUILD and runSSLTunnel:
      # create certificate database for the profile
      certificateStatus = self.fillCertificateDB(profileDir, certPath, utilityPath, xrePath)
      if certificateStatus != 0:
        self.log.info("TEST-UNEXPECTED FAIL | automation.py | Certificate integration failed")
        return certificateStatus

      # start ssltunnel to provide https:// URLs capability
      ssltunnel = os.path.join(utilityPath, "ssltunnel" + self.BIN_SUFFIX)
      ssltunnelProcess = self.Process([ssltunnel, 
                               os.path.join(profileDir, "ssltunnel.cfg")], 
                               env = self.environment(xrePath = xrePath))
      self.log.info("INFO | automation.py | SSL tunnel pid: %d", ssltunnelProcess.pid)

    cmd, args = self.buildCommandLine(app, debuggerInfo, profileDir, testURL, extraArgs)
    startTime = datetime.now()

    if debuggerInfo and debuggerInfo["interactive"]:
      # If an interactive debugger is attached, don't redirect output,
      # don't use timeouts, and don't capture ctrl-c.
      timeout = None
      maxTime = None
      outputPipe = None
      signal.signal(signal.SIGINT, lambda sigid, frame: None)
    else:
      outputPipe = subprocess.PIPE

    self.lastTestSeen = "automation.py"
    proc = self.Process([cmd] + args,
                 env = self.environment(env, xrePath = xrePath,
                                   crashreporter = not debuggerInfo),
                 stdout = outputPipe,
                 stderr = subprocess.STDOUT)
    self.log.info("INFO | automation.py | Application pid: %d", proc.pid)

    status = self.waitForFinish(proc, utilityPath, timeout, maxTime, startTime, debuggerInfo, symbolsPath)
    self.log.info("INFO | automation.py | Application ran for: %s", str(datetime.now() - startTime))

    # Do a final check for zombie child processes.
    self.checkForZombies(processLog)
    automationutils.checkForCrashes(os.path.join(profileDir, "minidumps"), symbolsPath, self.lastTestSeen)

    if os.path.exists(processLog):
      os.unlink(processLog)

    if self.IS_TEST_BUILD and runSSLTunnel:
      ssltunnelProcess.kill()

    return status

  """ 
   Copies an "installed" extension into the extensions directory of the given profile
   extensionSource - the source location of the extension files.  This can be either 
                     a directory or a path to an xpi file.
   profileDir      - the profile directory we are copying into.  We will create the
                     "extensions" directory there if it doesn't exist
   extensionID     - the id of the extension to be used as the containing directory for the
                     extension, i.e.
                 this is the name of the folder in the <profileDir>/extensions/<extensionID>
  """
  def installExtension(self, extensionSource, profileDir, extensionID):
    if (not os.path.exists(extensionSource)):
      self.log.info("INFO | automation.py | Cannot install extension no source at: %s", extensionSource) 
      
    if (not os.path.exists(profileDir)):
      self.log.info("INFO | automation.py | Cannot install extension invalid profileDir at: %s", profileDir)

    # See if we have an XPI or a directory
    if (os.path.isfile(extensionSource)):
      tmpd = tempfile.mkdtemp()
      extrootdir = self.extractZip(extensionSource, tmpd)
    else:
      extrootdir = extensionSource 
    extnsdir = os.path.join(profileDir, "extensions")
    extnshome = os.path.join(extnsdir, extensionID)

    # Now we copy the extension source into the extnshome
    shutil.copytree(extrootdir, extnshome)

  def extractZip(self, filename, dest):
    z = zipfile.ZipFile(filename, 'r')
    for n in z.namelist():
      fullpath = os.path.join(dest, n)
      parentdir = os.path.dirname(fullpath)
      if not os.path.isdir(parentdir):
        os.makedirs(parentdir)
      if (not n.endswith(os.sep)):
        data = z.read(n)
        f = open(fullpath, 'w')
        f.write(data)
        f.close()
    z.close()
    return dest