poky/bitbake/lib/bb/server/process.py

#
# BitBake Process based server.
#
# Copyright (C) 2010 Bob Foerster <robert@erafx.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

"""
    This module implements a multiprocessing.Process based server for bitbake.
"""

import bb
import bb.event
import itertools
import logging
import multiprocessing
import os
import signal
import sys
import time
from bb.cooker import BBCooker
from multiprocessing import Event, Process, util

logger = logging.getLogger('BitBake')

class ServerCommunicator():
    def __init__(self, connection):
        self.connection = connection

    def runCommand(self, command):
        # @todo try/except
        self.connection.send(command)

        while True:
            # don't let the user ctrl-c while we're waiting for a response
            try:
                if self.connection.poll(.5):
                    return self.connection.recv()
                else:
                    return None
            except KeyboardInterrupt:
                pass


class EventAdapter():
    """
    Adapter to wrap our event queue since the caller (bb.event) expects to
    call a send() method, but our actual queue only has put()
    """
    def __init__(self, queue):
        self.queue = queue

    def send(self, event):
        try:
            self.queue.put(event)
        except Exception, err:
            print("EventAdapter puked: %s" % str(err))


class ProcessServer(Process):
    profile_filename = "profile.log"
    profile_processed_filename = "profile.log.processed"

    def __init__(self, command_channel, event_queue, configuration):
        Process.__init__(self)
        self.command_channel = command_channel
        self.event_queue = event_queue
        self.event = EventAdapter(event_queue)
        self.configuration = configuration
        self.cooker = BBCooker(configuration, self.register_idle_function)
        self._idlefunctions = {}
        self.event_handle = bb.event.register_UIHhandler(self)
        self.quit = False

        self.keep_running = Event()
        self.keep_running.set()

        for event in bb.event.ui_queue:
            self.event_queue.put(event)

    def register_idle_function(self, function, data):
        """Register a function to be called while the server is idle"""
        assert hasattr(function, '__call__')
        self._idlefunctions[function] = data

    def run(self):
        if self.configuration.profile:
            return self.profile_main()
        else:
            return self.main()

    def profile_main(self):
        import cProfile
        profiler = cProfile.Profile()
        try:
            return profiler.runcall(self.main)
        finally:
            profiler.dump_stats(self.profile_filename)
            self.write_profile_stats()
            sys.__stderr__.write("Raw profiling information saved to %s and "
                                 "processed statistics to %s\n" %
                                 (self.profile_filename,
                                  self.profile_processed_filename))

    def write_profile_stats(self):
        import pstats
        with open(self.profile_processed_filename, 'w') as outfile:
            stats = pstats.Stats(self.profile_filename, stream=outfile)
            stats.sort_stats('time')
            stats.print_stats()
            stats.print_callers()
            stats.sort_stats('cumulative')
            stats.print_stats()

    def main(self):
        # Ignore SIGINT within the server, as all SIGINT handling is done by
        # the UI and communicated to us
        signal.signal(signal.SIGINT, signal.SIG_IGN)
        while self.keep_running.is_set():
            try:
                if self.command_channel.poll():
                    command = self.command_channel.recv()
                    self.runCommand(command)

                self.idle_commands(.1)
            except Exception:
                logger.exception('Running command %s', command)

        self.event_queue.cancel_join_thread()
        bb.event.unregister_UIHhandler(self.event_handle)
        self.command_channel.close()
        self.cooker.stop()
        self.idle_commands(.1)

    def idle_commands(self, delay):
        nextsleep = delay

        for function, data in self._idlefunctions.items():
            try:
                retval = function(self, data, False)
                if retval is False:
                    del self._idlefunctions[function]
                elif retval is True:
                    nextsleep = None
                elif nextsleep is None:
                    continue
                elif retval < nextsleep:
                    nextsleep = retval
            except SystemExit:
                raise
            except Exception:
                logger.exception('Running idle function')

        if nextsleep is not None:
            time.sleep(nextsleep)

    def runCommand(self, command):
        """
        Run a cooker command on the server
        """
        self.command_channel.send(self.cooker.command.runCommand(command))

    def stop(self):
        self.keep_running.clear()

    def bootstrap_2_6_6(self):
        """Pulled from python 2.6.6. Needed to ensure we have the fix from
        http://bugs.python.org/issue5313 when running on python version 2.6.2
        or lower."""

        try:
            self._children = set()
            self._counter = itertools.count(1)
            try:
                sys.stdin.close()
                sys.stdin = open(os.devnull)
            except (OSError, ValueError):
                pass
            multiprocessing._current_process = self
            util._finalizer_registry.clear()
            util._run_after_forkers()
            util.info('child process calling self.run()')
            try:
                self.run()
                exitcode = 0
            finally:
                util._exit_function()
        except SystemExit, e:
            if not e.args:
                exitcode = 1
            elif type(e.args[0]) is int:
                exitcode = e.args[0]
            else:
                sys.stderr.write(e.args[0] + '\n')
                sys.stderr.flush()
                exitcode = 1
        except:
            exitcode = 1
            import traceback
            sys.stderr.write('Process %s:\n' % self.name)
            sys.stderr.flush()
            traceback.print_exc()

        util.info('process exiting with exitcode %d' % exitcode)
        return exitcode

    # Python versions 2.6.0 through 2.6.2 suffer from a multiprocessing bug
    # which can result in a bitbake server hang during the parsing process
    if (2, 6, 0) <= sys.version_info < (2, 6, 3):
        _bootstrap = bootstrap_2_6_6