Adding mozilla libraries required by Firefox interop test.

third_party/mozprocess/mozprocess/processhandler.py

+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this file,
+# You can obtain one at http://mozilla.org/MPL/2.0/.
+
+import logging
+import mozinfo
+import os
+import select
+import signal
+import subprocess
+import sys
+import threading
+import time
+import traceback
+from Queue import Queue
+from datetime import datetime, timedelta
+__all__ = ['ProcessHandlerMixin', 'ProcessHandler']
+
+# Set the MOZPROCESS_DEBUG environment variable to 1 to see some debugging output
+MOZPROCESS_DEBUG = os.getenv("MOZPROCESS_DEBUG")
+
+if mozinfo.isWin:
+    import ctypes, ctypes.wintypes, msvcrt
+    from ctypes import sizeof, addressof, c_ulong, byref, POINTER, WinError, c_longlong
+    import winprocess
+    from qijo import JobObjectAssociateCompletionPortInformation,\
+    JOBOBJECT_ASSOCIATE_COMPLETION_PORT, JobObjectExtendedLimitInformation,\
+    JOBOBJECT_BASIC_LIMIT_INFORMATION, JOBOBJECT_EXTENDED_LIMIT_INFORMATION, IO_COUNTERS
+
+class ProcessHandlerMixin(object):
+    """Class which represents a process to be executed."""
+
+    class Process(subprocess.Popen):
+        """
+        Represents our view of a subprocess.
+        It adds a kill() method which allows it to be stopped explicitly.
+        """
+
+        MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY = 180
+        MAX_PROCESS_KILL_DELAY = 30
+
+        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,
+                     ignore_children=False):
+
+            # Parameter for whether or not we should attempt to track child processes
+            self._ignore_children = ignore_children
+
+            if not self._ignore_children and not mozinfo.isWin:
+                # Set the process group id for linux systems
+                # Sets process group id to the pid of the parent process
+                # NOTE: This prevents you from using preexec_fn and managing
+                #       child processes, TODO: Ideally, find a way around this
+                def setpgidfn():
+                    os.setpgid(0, 0)
+                preexec_fn = setpgidfn
+
+            try:
+                subprocess.Popen.__init__(self, args, bufsize, executable,
+                                          stdin, stdout, stderr,
+                                          preexec_fn, close_fds,
+                                          shell, cwd, env,
+                                          universal_newlines, startupinfo, creationflags)
+            except OSError, e:
+                print >> sys.stderr, args
+                raise
+
+        def __del__(self, _maxint=sys.maxint):
+            if mozinfo.isWin:
+                if self._handle:
+                    if hasattr(self, '_internal_poll'):
+                        self._internal_poll(_deadstate=_maxint)
+                    else:
+                        self.poll(_deadstate=sys.maxint)
+                if self._handle or self._job or self._io_port:
+                    self._cleanup()
+            else:
+                subprocess.Popen.__del__(self)
+
+        def kill(self):
+            self.returncode = 0
+            if mozinfo.isWin:
+                if not self._ignore_children and self._handle and self._job:
+                    winprocess.TerminateJobObject(self._job, winprocess.ERROR_CONTROL_C_EXIT)
+                    self.returncode = winprocess.GetExitCodeProcess(self._handle)
+                elif self._handle:
+                    err = None
+                    try:
+                        winprocess.TerminateProcess(self._handle, winprocess.ERROR_CONTROL_C_EXIT)
+                    except:
+                        err = "Could not terminate process"
+                    self.returncode = winprocess.GetExitCodeProcess(self._handle)
+                    self._cleanup()
+                    if err is not None:
+                        raise OSError(err)
+                else:
+                    pass
+            else:
+                if not self._ignore_children:
+                    try:
+                        os.killpg(self.pid, signal.SIGKILL)
+                    except BaseException, e:
+                        if getattr(e, "errno", None) != 3:
+                            # Error 3 is "no such process", which is ok
+                            print >> sys.stdout, "Could not kill process, could not find pid: %s, assuming it's already dead" % self.pid
+                else:
+                    os.kill(self.pid, signal.SIGKILL)
+                if self.returncode is None:
+                    self.returncode = subprocess.Popen._internal_poll(self)
+
+            self._cleanup()
+            return self.returncode
+
+        def wait(self):
+            """ Popen.wait
+                Called to wait for a running process to shut down and return
+                its exit code
+                Returns the main process's exit code
+            """
+            # This call will be different for each OS
+            self.returncode = self._wait()
+            self._cleanup()
+            return self.returncode
+
+        """ Private Members of Process class """
+
+        if mozinfo.isWin:
+            # Redefine the execute child so that we can track process groups
+            def _execute_child(self, args, executable, preexec_fn, close_fds,
+                               cwd, env, universal_newlines, startupinfo,
+                               creationflags, shell,
+                               p2cread, p2cwrite,
+                               c2pread, c2pwrite,
+                               errread, errwrite):
+                if not isinstance(args, basestring):
+                    args = subprocess.list2cmdline(args)
+
+                # Always or in the create new process group
+                creationflags |= winprocess.CREATE_NEW_PROCESS_GROUP
+
+                if startupinfo is None:
+                    startupinfo = winprocess.STARTUPINFO()
+
+                if None not in (p2cread, c2pwrite, errwrite):
+                    startupinfo.dwFlags |= winprocess.STARTF_USESTDHANDLES
+                    startupinfo.hStdInput = int(p2cread)
+                    startupinfo.hStdOutput = int(c2pwrite)
+                    startupinfo.hStdError = int(errwrite)
+                if shell:
+                    startupinfo.dwFlags |= winprocess.STARTF_USESHOWWINDOW
+                    startupinfo.wShowWindow = winprocess.SW_HIDE
+                    comspec = os.environ.get("COMSPEC", "cmd.exe")
+                    args = comspec + " /c " + args
+
+                # determine if we can create create a job
+                canCreateJob = winprocess.CanCreateJobObject()
+
+                # Ensure we write a warning message if we are falling back
+                if not canCreateJob and not self._ignore_children:
+                    # We can't create job objects AND the user wanted us to
+                    # Warn the user about this.
+                    print >> sys.stderr, "ProcessManager UNABLE to use job objects to manage child processes"
+
+                # set process creation flags
+                creationflags |= winprocess.CREATE_SUSPENDED
+                creationflags |= winprocess.CREATE_UNICODE_ENVIRONMENT
+                if canCreateJob:
+                    creationflags |= winprocess.CREATE_BREAKAWAY_FROM_JOB
+                else:
+                    # Since we've warned, we just log info here to inform you
+                    # of the consequence of setting ignore_children = True
+                    print "ProcessManager NOT managing child processes"
+
+                # create the process
+                hp, ht, pid, tid = winprocess.CreateProcess(
+                    executable, args,
+                    None, None, # No special security
+                    1, # Must inherit handles!
+                    creationflags,
+                    winprocess.EnvironmentBlock(env),
+                    cwd, startupinfo)
+                self._child_created = True
+                self._handle = hp
+                self._thread = ht
+                self.pid = pid
+                self.tid = tid
+
+                if not self._ignore_children and canCreateJob:
+                    try:
+                        # We create a new job for this process, so that we can kill
+                        # the process and any sub-processes
+                        # Create the IO Completion Port
+                        self._io_port = winprocess.CreateIoCompletionPort()
+                        self._job = winprocess.CreateJobObject()
+
+                        # Now associate the io comp port and the job object
+                        joacp = JOBOBJECT_ASSOCIATE_COMPLETION_PORT(winprocess.COMPKEY_JOBOBJECT,
+                                                                    self._io_port)
+                        winprocess.SetInformationJobObject(self._job,
+                                                          JobObjectAssociateCompletionPortInformation,
+                                                          addressof(joacp),
+                                                          sizeof(joacp)
+                                                          )
+
+                        # Allow subprocesses to break away from us - necessary for
+                        # flash with protected mode
+                        jbli = JOBOBJECT_BASIC_LIMIT_INFORMATION(
+                                                c_longlong(0), # per process time limit (ignored)
+                                                c_longlong(0), # per job user time limit (ignored)
+                                                winprocess.JOB_OBJECT_LIMIT_BREAKAWAY_OK,
+                                                0, # min working set (ignored)
+                                                0, # max working set (ignored)
+                                                0, # active process limit (ignored)
+                                                None, # affinity (ignored)
+                                                0, # Priority class (ignored)
+                                                0, # Scheduling class (ignored)
+                                                )
+
+                        iocntr = IO_COUNTERS()
+                        jeli = JOBOBJECT_EXTENDED_LIMIT_INFORMATION(
+                                                jbli, # basic limit info struct
+                                                iocntr,    # io_counters (ignored)
+                                                0,    # process mem limit (ignored)
+                                                0,    # job mem limit (ignored)
+                                                0,    # peak process limit (ignored)
+                                                0)    # peak job limit (ignored)
+
+                        winprocess.SetInformationJobObject(self._job,
+                                                           JobObjectExtendedLimitInformation,
+                                                           addressof(jeli),
+                                                           sizeof(jeli)
+                                                           )
+
+                        # Assign the job object to the process
+                        winprocess.AssignProcessToJobObject(self._job, int(hp))
+
+                        # It's overkill, but we use Queue to signal between threads
+                        # because it handles errors more gracefully than event or condition.
+                        self._process_events = Queue()
+
+                        # Spin up our thread for managing the IO Completion Port
+                        self._procmgrthread = threading.Thread(target = self._procmgr)
+                    except:
+                        print >> sys.stderr, """Exception trying to use job objects;
+falling back to not using job objects for managing child processes"""
+                        tb = traceback.format_exc()
+                        print >> sys.stderr, tb
+                        # Ensure no dangling handles left behind
+                        self._cleanup_job_io_port()
+                else:
+                    self._job = None
+
+                winprocess.ResumeThread(int(ht))
+                if getattr(self, '_procmgrthread', None):
+                    self._procmgrthread.start()
+                ht.Close()
+
+                for i in (p2cread, c2pwrite, errwrite):
+                    if i is not None:
+                        i.Close()
+
+            # Windows Process Manager - watches the IO Completion Port and
+            # keeps track of child processes
+            def _procmgr(self):
+                if not (self._io_port) or not (self._job):
+                    return
+
+                try:
+                    self._poll_iocompletion_port()
+                except KeyboardInterrupt:
+                    raise KeyboardInterrupt
+
+            def _poll_iocompletion_port(self):
+                # Watch the IO Completion port for status
+                self._spawned_procs = {}
+                countdowntokill = 0
+
+                if MOZPROCESS_DEBUG:
+                    print "DBG::MOZPROC Self.pid value is: %s" % self.pid
+
+                while True:
+                    msgid = c_ulong(0)
+                    compkey = c_ulong(0)
+                    pid = c_ulong(0)
+                    portstatus = winprocess.GetQueuedCompletionStatus(self._io_port,
+                                                                      byref(msgid),
+                                                                      byref(compkey),
+                                                                      byref(pid),
+                                                                      5000)
+
+                    # If the countdowntokill has been activated, we need to check
+                    # if we should start killing the children or not.
+                    if countdowntokill != 0:
+                        diff = datetime.now() - countdowntokill
+                        # Arbitrarily wait 3 minutes for windows to get its act together
+                        # Windows sometimes takes a small nap between notifying the
+                        # IO Completion port and actually killing the children, and we
+                        # don't want to mistake that situation for the situation of an unexpected
+                        # parent abort (which is what we're looking for here).
+                        if diff.seconds > self.MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY:
+                            print >> sys.stderr, "Parent process %s exited with children alive:" % self.pid
+                            print >> sys.stderr, "PIDS: %s" %  ', '.join([str(i) for i in self._spawned_procs])
+                            print >> sys.stderr, "Attempting to kill them..."
+                            self.kill()
+                            self._process_events.put({self.pid: 'FINISHED'})
+
+                    if not portstatus:
+                        # Check to see what happened
+                        errcode = winprocess.GetLastError()
+                        if errcode == winprocess.ERROR_ABANDONED_WAIT_0:
+                            # Then something has killed the port, break the loop
+                            print >> sys.stderr, "IO Completion Port unexpectedly closed"
+                            break
+                        elif errcode == winprocess.WAIT_TIMEOUT:
+                            # Timeouts are expected, just keep on polling
+                            continue
+                        else:
+                            print >> sys.stderr, "Error Code %s trying to query IO Completion Port, exiting" % errcode
+                            raise WinError(errcode)
+                            break
+
+                    if compkey.value == winprocess.COMPKEY_TERMINATE.value:
+                        if MOZPROCESS_DEBUG:
+                            print "DBG::MOZPROC compkeyterminate detected"
+                        # Then we're done
+                        break
+
+                    # Check the status of the IO Port and do things based on it
+                    if compkey.value == winprocess.COMPKEY_JOBOBJECT.value:
+                        if msgid.value == winprocess.JOB_OBJECT_MSG_ACTIVE_PROCESS_ZERO:
+                            # No processes left, time to shut down
+                            # Signal anyone waiting on us that it is safe to shut down
+                            if MOZPROCESS_DEBUG:
+                                print "DBG::MOZPROC job object msg active processes zero"
+                            self._process_events.put({self.pid: 'FINISHED'})
+                            break
+                        elif msgid.value == winprocess.JOB_OBJECT_MSG_NEW_PROCESS:
+                            # New Process started
+                            # Add the child proc to our list in case our parent flakes out on us
+                            # without killing everything.
+                            if pid.value != self.pid:
+                                self._spawned_procs[pid.value] = 1
+                                if MOZPROCESS_DEBUG:
+                                    print "DBG::MOZPROC new process detected with pid value: %s" % pid.value
+                        elif msgid.value == winprocess.JOB_OBJECT_MSG_EXIT_PROCESS:
+                            if MOZPROCESS_DEBUG:
+                                print "DBG::MOZPROC process id %s exited normally" % pid.value
+                            # One process exited normally
+                            if pid.value == self.pid and len(self._spawned_procs) > 0:
+                                # Parent process dying, start countdown timer
+                                countdowntokill = datetime.now()
+                            elif pid.value in self._spawned_procs:
+                                # Child Process died remove from list
+                                del(self._spawned_procs[pid.value])
+                        elif msgid.value == winprocess.JOB_OBJECT_MSG_ABNORMAL_EXIT_PROCESS:
+                            # One process existed abnormally
+                            if MOZPROCESS_DEBUG:
+                                print "DBG::MOZPROC process id %s existed abnormally" % pid.value
+                            if pid.value == self.pid and len(self._spawned_procs) > 0:
+                                # Parent process dying, start countdown timer
+                                countdowntokill = datetime.now()
+                            elif pid.value in self._spawned_procs:
+                                # Child Process died remove from list
+                                del self._spawned_procs[pid.value]
+                        else:
+                            # We don't care about anything else
+                            if MOZPROCESS_DEBUG:
+                                print "DBG::MOZPROC We got a message %s" % msgid.value
+                            pass
+
+            def _wait(self):
+
+                # First, check to see if the process is still running
+                if self._handle:
+                    self.returncode = winprocess.GetExitCodeProcess(self._handle)
+                else:
+                    # Dude, the process is like totally dead!
+                    return self.returncode
+
+                # Python 2.5 uses isAlive versus is_alive use the proper one
+                threadalive = False
+                if hasattr(self, "_procmgrthread"):
+                    if hasattr(self._procmgrthread, 'is_alive'):
+                        threadalive = self._procmgrthread.is_alive()
+                    else:
+                        threadalive = self._procmgrthread.isAlive()
+                if self._job and threadalive: 
+                    # Then we are managing with IO Completion Ports
+                    # wait on a signal so we know when we have seen the last
+                    # process come through.
+                    # We use queues to synchronize between the thread and this
+                    # function because events just didn't have robust enough error
+                    # handling on pre-2.7 versions
+                    err = None
+                    try:
+                        # timeout is the max amount of time the procmgr thread will wait for
+                        # child processes to shutdown before killing them with extreme prejudice.
+                        item = self._process_events.get(timeout=self.MAX_IOCOMPLETION_PORT_NOTIFICATION_DELAY +
+                                                                self.MAX_PROCESS_KILL_DELAY)
+                        if item[self.pid] == 'FINISHED':
+                            self._process_events.task_done()
+                    except:
+                        err = "IO Completion Port failed to signal process shutdown"
+                    # Either way, let's try to get this code
+                    if self._handle:
+                        self.returncode = winprocess.GetExitCodeProcess(self._handle)
+                    self._cleanup()
+
+                    if err is not None:
+                        raise OSError(err)
+
+
+                else:
+                    # Not managing with job objects, so all we can reasonably do
+                    # is call waitforsingleobject and hope for the best
+
+                    if MOZPROCESS_DEBUG and not self._ignore_children:
+                        print "DBG::MOZPROC NOT USING JOB OBJECTS!!!"
+                    # First, make sure we have not already ended
+                    if self.returncode != winprocess.STILL_ACTIVE:
+                        self._cleanup()
+                        return self.returncode
+
+                    rc = None
+                    if self._handle:
+                        rc = winprocess.WaitForSingleObject(self._handle, -1)
+
+                    if rc == winprocess.WAIT_TIMEOUT:
+                        # The process isn't dead, so kill it
+                        print "Timed out waiting for process to close, attempting TerminateProcess"
+                        self.kill()
+                    elif rc == winprocess.WAIT_OBJECT_0:
+                        # We caught WAIT_OBJECT_0, which indicates all is well
+                        print "Single process terminated successfully"
+                        self.returncode = winprocess.GetExitCodeProcess(self._handle)
+                    else:
+                        # An error occured we should probably throw
+                        rc = winprocess.GetLastError()
+                        if rc:
+                            raise WinError(rc)
+
+                    self._cleanup()
+
+                return self.returncode
+
+            def _cleanup_job_io_port(self):
+                """ Do the job and IO port cleanup separately because there are
+                    cases where we want to clean these without killing _handle
+                    (i.e. if we fail to create the job object in the first place)
+                """
+                if getattr(self, '_job') and self._job != winprocess.INVALID_HANDLE_VALUE:
+                    self._job.Close()
+                    self._job = None
+                else:
+                    # If windows already freed our handle just set it to none
+                    # (saw this intermittently while testing)
+                    self._job = None
+
+                if getattr(self, '_io_port', None) and self._io_port != winprocess.INVALID_HANDLE_VALUE:
+                    self._io_port.Close()
+                    self._io_port = None
+                else:
+                    self._io_port = None
+
+                if getattr(self, '_procmgrthread', None):
+                    self._procmgrthread = None
+
+            def _cleanup(self):
+                self._cleanup_job_io_port()
+                if self._thread and self._thread != winprocess.INVALID_HANDLE_VALUE:
+                    self._thread.Close()
+                    self._thread = None
+                else:
+                    self._thread = None
+
+                if self._handle and self._handle != winprocess.INVALID_HANDLE_VALUE:
+                    self._handle.Close()
+                    self._handle = None
+                else:
+                    self._handle = None
+
+        elif mozinfo.isMac or mozinfo.isUnix:
+
+            def _wait(self):
+                """ Haven't found any reason to differentiate between these platforms
+                    so they all use the same wait callback.  If it is necessary to
+                    craft different styles of wait, then a new _wait method
+                    could be easily implemented.
+                """
+
+                if not self._ignore_children:
+                    try:
+                        # os.waitpid returns a (pid, status) tuple
+                        return os.waitpid(self.pid, 0)[1]
+                    except OSError, e:
+                        if getattr(e, "errno", None) != 10:
+                            # Error 10 is "no child process", which could indicate normal
+                            # close
+                            print >> sys.stderr, "Encountered error waiting for pid to close: %s" % e
+                            raise
+                        return 0
+
+                else:
+                    # For non-group wait, call base class
+                    subprocess.Popen.wait(self)
+                    return self.returncode
+
+            def _cleanup(self):
+                pass
+
+        else:
+            # An unrecognized platform, we will call the base class for everything
+            print >> sys.stderr, "Unrecognized platform, process groups may not be managed properly"
+
+            def _wait(self):
+                self.returncode = subprocess.Popen.wait(self)
+                return self.returncode
+
+            def _cleanup(self):
+                pass
+
+    def __init__(self,
+                 cmd,
+                 args=None,
+                 cwd=None,
+                 env=None,
+                 ignore_children = False,
+                 processOutputLine=(),
+                 onTimeout=(),
+                 onFinish=(),
+                 **kwargs):
+        """
+        cmd = Command to run
+        args = array of arguments (defaults to None)
+        cwd = working directory for cmd (defaults to None)
+        env = environment to use for the process (defaults to os.environ)
+        ignore_children = when True, causes system to ignore child processes,
+        defaults to False (which tracks child processes)
+        processOutputLine = handlers to process the output line
+        onTimeout = handlers for timeout event
+        kwargs = keyword args to pass directly into Popen
+
+        NOTE: Child processes will be tracked by default.  If for any reason
+        we are unable to track child processes and ignore_children is set to False,
+        then we will fall back to only tracking the root process.  The fallback
+        will be logged.
+        """
+        self.cmd = cmd
+        self.args = args
+        self.cwd = cwd
+        self.didTimeout = False
+        self._ignore_children = ignore_children
+        self.keywordargs = kwargs
+        self.outThread = None
+
+        if env is None:
+            env = os.environ.copy()
+        self.env = env
+
+        # handlers
+        self.processOutputLineHandlers = list(processOutputLine)
+        self.onTimeoutHandlers = list(onTimeout)
+        self.onFinishHandlers = list(onFinish)
+
+        # It is common for people to pass in the entire array with the cmd and
+        # the args together since this is how Popen uses it.  Allow for that.
+        if not isinstance(self.cmd, list):
+            self.cmd = [self.cmd]
+
+        if self.args:
+            self.cmd = self.cmd + self.args
+
+    @property
+    def timedOut(self):
+        """True if the process has timed out."""
+        return self.didTimeout
+
+    @property
+    def commandline(self):
+        """the string value of the command line"""
+        return subprocess.list2cmdline([self.cmd] + self.args)
+
+    def run(self, timeout=None, outputTimeout=None):
+        """
+        Starts the process.
+
+        If timeout is not None, the process will be allowed to continue for
+        that number of seconds before being killed.
+
+        If outputTimeout is not None, the process will be allowed to continue
+        for that number of seconds without producing any output before
+        being killed.
+        """
+        self.didTimeout = False
+        self.startTime = datetime.now()
+
+        # default arguments
+        args = dict(stdout=subprocess.PIPE,
+                    stderr=subprocess.STDOUT,
+                    cwd=self.cwd,
+                    env=self.env,
+                    ignore_children=self._ignore_children)
+
+        # build process arguments
+        args.update(self.keywordargs)
+
+        # launch the process
+        self.proc = self.Process(self.cmd, **args)
+
+        self.processOutput(timeout=timeout, outputTimeout=outputTimeout)
+
+    def kill(self):
+        """
+          Kills the managed process and if you created the process with
+          'ignore_children=False' (the default) then it will also
+          also kill all child processes spawned by it.
+          If you specified 'ignore_children=True' when creating the process,
+          only the root process will be killed.
+
+          Note that this does not manage any state, save any output etc,
+          it immediately kills the process.
+        """
+        return self.proc.kill()
+
+    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.
+
+          Calls a private member because this is a different function based on
+          the OS
+        """
+        return self._readWithTimeout(f, timeout)
+
+    def processOutputLine(self, line):
+        """Called for each line of output that a process sends to stdout/stderr.
+        """
+        for handler in self.processOutputLineHandlers:
+            handler(line)
+
+    def onTimeout(self):
+        """Called when a process times out."""
+        for handler in self.onTimeoutHandlers:
+            handler()
+
+    def onFinish(self):
+        """Called when a process finishes without a timeout."""
+        for handler in self.onFinishHandlers:
+            handler()
+
+    def processOutput(self, timeout=None, outputTimeout=None):
+        """
+        Handle process output until the process terminates or times out.
+
+        If timeout is not None, the process will be allowed to continue for
+        that number of seconds before being killed.
+
+        If outputTimeout is not None, the process will be allowed to continue
+        for that number of seconds without producing any output before
+        being killed.
+        """
+        def _processOutput():
+            self.didTimeout = False
+            logsource = self.proc.stdout
+
+            lineReadTimeout = None
+            if timeout:
+                lineReadTimeout = timeout - (datetime.now() - self.startTime).seconds
+            elif outputTimeout:
+                lineReadTimeout = outputTimeout
+
+            (line, self.didTimeout) = self.readWithTimeout(logsource, lineReadTimeout)
+            while line != "" and not self.didTimeout:
+                self.processOutputLine(line.rstrip())
+                if timeout:
+                    lineReadTimeout = timeout - (datetime.now() - self.startTime).seconds
+                (line, self.didTimeout) = self.readWithTimeout(logsource, lineReadTimeout)
+
+            if self.didTimeout:
+                self.proc.kill()
+                self.onTimeout()
+            else:
+                self.onFinish()
+
+        if not hasattr(self, 'proc'):
+            self.run()
+
+        if not self.outThread:
+            self.outThread = threading.Thread(target=_processOutput)
+            self.outThread.daemon = True
+            self.outThread.start()
+
+
+    def wait(self, timeout=None):
+        """
+        Waits until all output has been read and the process is 
+        terminated.
+
+        If timeout is not None, will return after timeout seconds.
+        This timeout only causes the wait function to return and
+        does not kill the process.
+        """
+        if self.outThread:
+            # Thread.join() blocks the main thread until outThread is finished
+            # wake up once a second in case a keyboard interrupt is sent
+            count = 0
+            while self.outThread.isAlive():
+                self.outThread.join(timeout=1)
+                count += 1
+                if timeout and count > timeout:
+                    return
+
+        return self.proc.wait()
+
+    # TODO Remove this method when consumers have been fixed
+    def waitForFinish(self, timeout=None):
+        print >> sys.stderr, "MOZPROCESS WARNING: ProcessHandler.waitForFinish() is deprecated, " \
+                             "use ProcessHandler.wait() instead"
+        return self.wait(timeout=timeout)
+
+
+    ### Private methods from here on down. Thar be dragons.
+
+    if mozinfo.isWin:
+        # Windows Specific private functions are defined in this block
+        PeekNamedPipe = ctypes.windll.kernel32.PeekNamedPipe
+        GetLastError = ctypes.windll.kernel32.GetLastError
+
+        def _readWithTimeout(self, f, timeout):
+            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:
+                        raise OSError("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)
+
+    else:
+        # Generic
+        def _readWithTimeout(self, f, timeout):
+            try:
+                (r, w, e) = select.select([f], [], [], timeout)
+            except:
+                # return a blank line
+                return ('', True)
+
+            if len(r) == 0:
+                return ('', True)
+            return (f.readline(), False)
+
+    @property
+    def pid(self):
+        return self.proc.pid
+
+
+### default output handlers
+### these should be callables that take the output line
+
+def print_output(line):
+    print line
+
+class StoreOutput(object):
+    """accumulate stdout"""
+
+    def __init__(self):
+        self.output = []
+
+    def __call__(self, line):
+        self.output.append(line)
+
+class LogOutput(object):
+    """pass output to a file"""
+
+    def __init__(self, filename):
+        self.filename = filename
+        self.file = None
+
+    def __call__(self, line):
+        if self.file is None:
+            self.file = file(self.filename, 'a')
+        self.file.write(line + '\n')
+        self.file.flush()
+
+    def __del__(self):
+        if self.file is not None:
+            self.file.close()
+
+### front end class with the default handlers
+
+class ProcessHandler(ProcessHandlerMixin):
+
+    def __init__(self, cmd, logfile=None, storeOutput=True, **kwargs):
+        """
+        If storeOutput=True, the output produced by the process will be saved
+        as self.output.
+
+        If logfile is not None, the output produced by the process will be
+        appended to the given file.
+        """
+
+        kwargs.setdefault('processOutputLine', [])
+
+        # Print to standard output only if no outputline provided
+        if not kwargs['processOutputLine']:
+            kwargs['processOutputLine'].append(print_output)
+
+        if logfile:
+            logoutput = LogOutput(logfile)
+            kwargs['processOutputLine'].append(logoutput)
+
+        self.output = None
+        if storeOutput:
+            storeoutput = StoreOutput()
+            self.output = storeoutput.output
+            kwargs['processOutputLine'].append(storeoutput)
+
+        ProcessHandlerMixin.__init__(self, cmd, **kwargs)