add hg and python

1 files changed, 874 insertions, 0 deletions

diff --git a/sys/src/cmd/hg/hgext/inotify/server.py b/sys/src/cmd/hg/hgext/inotify/server.py
new file mode 100644
index 000000000..75c00d632
--- /dev/null
+++ b/sys/src/cmd/hg/hgext/inotify/server.py
@@ -0,0 +1,874 @@
+# server.py - inotify status server
+#
+# Copyright 2006, 2007, 2008 Bryan O'Sullivan <bos@serpentine.com>
+# Copyright 2007, 2008 Brendan Cully <brendan@kublai.com>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2, incorporated herein by reference.
+
+from mercurial.i18n import _
+from mercurial import osutil, util
+import common
+import errno, os, select, socket, stat, struct, sys, tempfile, time
+
+try:
+    import linux as inotify
+    from linux import watcher
+except ImportError:
+    raise
+
+class AlreadyStartedException(Exception): pass
+
+def join(a, b):
+    if a:
+        if a[-1] == '/':
+            return a + b
+        return a + '/' + b
+    return b
+
+def split(path):
+    c = path.rfind('/')
+    if c == -1:
+        return '', path
+    return path[:c], path[c+1:]
+
+walk_ignored_errors = (errno.ENOENT, errno.ENAMETOOLONG)
+
+def walkrepodirs(dirstate, absroot):
+    '''Iterate over all subdirectories of this repo.
+    Exclude the .hg directory, any nested repos, and ignored dirs.'''
+    def walkit(dirname, top):
+        fullpath = join(absroot, dirname)
+        try:
+            for name, kind in osutil.listdir(fullpath):
+                if kind == stat.S_IFDIR:
+                    if name == '.hg':
+                        if not top:
+                            return
+                    else:
+                        d = join(dirname, name)
+                        if dirstate._ignore(d):
+                            continue
+                        for subdir in walkit(d, False):
+                            yield subdir
+        except OSError, err:
+            if err.errno not in walk_ignored_errors:
+                raise
+        yield fullpath
+
+    return walkit('', True)
+
+def walk(dirstate, absroot, root):
+    '''Like os.walk, but only yields regular files.'''
+
+    # This function is critical to performance during startup.
+
+    def walkit(root, reporoot):
+        files, dirs = [], []
+
+        try:
+            fullpath = join(absroot, root)
+            for name, kind in osutil.listdir(fullpath):
+                if kind == stat.S_IFDIR:
+                    if name == '.hg':
+                        if not reporoot:
+                            return
+                    else:
+                        dirs.append(name)
+                        path = join(root, name)
+                        if dirstate._ignore(path):
+                            continue
+                        for result in walkit(path, False):
+                            yield result
+                elif kind in (stat.S_IFREG, stat.S_IFLNK):
+                    files.append(name)
+            yield fullpath, dirs, files
+
+        except OSError, err:
+            if err.errno == errno.ENOTDIR:
+                # fullpath was a directory, but has since been replaced
+                # by a file.
+                yield fullpath, dirs, files
+            elif err.errno not in walk_ignored_errors:
+                raise
+
+    return walkit(root, root == '')
+
+def _explain_watch_limit(ui, dirstate, rootabs):
+    path = '/proc/sys/fs/inotify/max_user_watches'
+    try:
+        limit = int(file(path).read())
+    except IOError, err:
+        if err.errno != errno.ENOENT:
+            raise
+        raise util.Abort(_('this system does not seem to '
+                           'support inotify'))
+    ui.warn(_('*** the current per-user limit on the number '
+              'of inotify watches is %s\n') % limit)
+    ui.warn(_('*** this limit is too low to watch every '
+              'directory in this repository\n'))
+    ui.warn(_('*** counting directories: '))
+    ndirs = len(list(walkrepodirs(dirstate, rootabs)))
+    ui.warn(_('found %d\n') % ndirs)
+    newlimit = min(limit, 1024)
+    while newlimit < ((limit + ndirs) * 1.1):
+        newlimit *= 2
+    ui.warn(_('*** to raise the limit from %d to %d (run as root):\n') %
+            (limit, newlimit))
+    ui.warn(_('***  echo %d > %s\n') % (newlimit, path))
+    raise util.Abort(_('cannot watch %s until inotify watch limit is raised')
+                     % rootabs)
+
+class pollable(object):
+    """
+    Interface to support polling.
+    The file descriptor returned by fileno() is registered to a polling
+    object.
+    Usage:
+        Every tick, check if an event has happened since the last tick:
+        * If yes, call handle_events
+        * If no, call handle_timeout
+    """
+    poll_events = select.POLLIN
+    instances = {}
+    poll = select.poll()
+
+    def fileno(self):
+        raise NotImplementedError
+
+    def handle_events(self, events):
+        raise NotImplementedError
+
+    def handle_timeout(self):
+        raise NotImplementedError
+
+    def shutdown(self):
+        raise NotImplementedError
+
+    def register(self, timeout):
+        fd = self.fileno()
+
+        pollable.poll.register(fd, pollable.poll_events)
+        pollable.instances[fd] = self
+
+        self.registered = True
+        self.timeout = timeout
+
+    def unregister(self):
+        pollable.poll.unregister(self)
+        self.registered = False
+
+    @classmethod
+    def run(cls):
+        while True:
+            timeout = None
+            timeobj = None
+            for obj in cls.instances.itervalues():
+                if obj.timeout is not None and (timeout is None or obj.timeout < timeout):
+                    timeout, timeobj = obj.timeout, obj
+            try:
+                events = cls.poll.poll(timeout)
+            except select.error, err:
+                if err[0] == errno.EINTR:
+                    continue
+                raise
+            if events:
+                by_fd = {}
+                for fd, event in events:
+                    by_fd.setdefault(fd, []).append(event)
+
+                for fd, events in by_fd.iteritems():
+                    cls.instances[fd].handle_pollevents(events)
+
+            elif timeobj:
+                timeobj.handle_timeout()
+
+def eventaction(code):
+    """
+    Decorator to help handle events in repowatcher
+    """
+    def decorator(f):
+        def wrapper(self, wpath):
+            if code == 'm' and wpath in self.lastevent and \
+                self.lastevent[wpath] in 'cm':
+                return
+            self.lastevent[wpath] = code
+            self.timeout = 250
+
+            f(self, wpath)
+
+        wrapper.func_name = f.func_name
+        return wrapper
+    return decorator
+
+class directory(object):
+    """
+    Representing a directory
+
+    * path is the relative path from repo root to this directory
+    * files is a dict listing the files in this directory
+        - keys are file names
+        - values are file status
+    * dirs is a dict listing the subdirectories
+        - key are subdirectories names
+        - values are directory objects
+    """
+    def __init__(self, relpath=''):
+        self.path = relpath
+        self.files = {}
+        self.dirs = {}
+
+    def dir(self, relpath):
+        """
+        Returns the directory contained at the relative path relpath.
+        Creates the intermediate directories if necessary.
+        """
+        if not relpath:
+            return self
+        l = relpath.split('/')
+        ret = self
+        while l:
+            next = l.pop(0)
+            try:
+                ret = ret.dirs[next]
+            except KeyError:
+                d = directory(join(ret.path, next))
+                ret.dirs[next] = d
+                ret = d
+        return ret
+
+    def walk(self, states):
+        """
+        yield (filename, status) pairs for items in the trees
+        that have status in states.
+        filenames are relative to the repo root
+        """
+        for file, st in self.files.iteritems():
+            if st in states:
+                yield join(self.path, file), st
+        for dir in self.dirs.itervalues():
+            for e in dir.walk(states):
+                yield e
+
+    def lookup(self, states, path):
+        """
+        yield root-relative filenames that match path, and whose
+        status are in states:
+        * if path is a file, yield path
+        * if path is a directory, yield directory files
+        * if path is not tracked, yield nothing
+        """
+        if path[-1] == '/':
+            path = path[:-1]
+
+        paths = path.split('/')
+
+        # we need to check separately for last node
+        last = paths.pop()
+
+        tree = self
+        try:
+            for dir in paths:
+                tree = tree.dirs[dir]
+        except KeyError:
+            # path is not tracked
+            return
+
+        try:
+            # if path is a directory, walk it
+            for file, st in tree.dirs[last].walk(states):
+                yield file
+        except KeyError:
+            try:
+                if tree.files[last] in states:
+                    # path is a file
+                    yield path
+            except KeyError:
+                # path is not tracked
+                pass
+
+class repowatcher(pollable):
+    """
+    Watches inotify events
+    """
+    statuskeys = 'almr!?'
+    mask = (
+        inotify.IN_ATTRIB |
+        inotify.IN_CREATE |
+        inotify.IN_DELETE |
+        inotify.IN_DELETE_SELF |
+        inotify.IN_MODIFY |
+        inotify.IN_MOVED_FROM |
+        inotify.IN_MOVED_TO |
+        inotify.IN_MOVE_SELF |
+        inotify.IN_ONLYDIR |
+        inotify.IN_UNMOUNT |
+        0)
+
+    def __init__(self, ui, dirstate, root):
+        self.ui = ui
+        self.dirstate = dirstate
+
+        self.wprefix = join(root, '')
+        self.prefixlen = len(self.wprefix)
+        try:
+            self.watcher = watcher.watcher()
+        except OSError, err:
+            raise util.Abort(_('inotify service not available: %s') %
+                             err.strerror)
+        self.threshold = watcher.threshold(self.watcher)
+        self.fileno = self.watcher.fileno
+
+        self.tree = directory()
+        self.statcache = {}
+        self.statustrees = dict([(s, directory()) for s in self.statuskeys])
+
+        self.last_event = None
+
+        self.lastevent = {}
+
+        self.register(timeout=None)
+
+        self.ds_info = self.dirstate_info()
+        self.handle_timeout()
+        self.scan()
+
+    def event_time(self):
+        last = self.last_event
+        now = time.time()
+        self.last_event = now
+
+        if last is None:
+            return 'start'
+        delta = now - last
+        if delta < 5:
+            return '+%.3f' % delta
+        if delta < 50:
+            return '+%.2f' % delta
+        return '+%.1f' % delta
+
+    def dirstate_info(self):
+        try:
+            st = os.lstat(self.wprefix + '.hg/dirstate')
+            return st.st_mtime, st.st_ino
+        except OSError, err:
+            if err.errno != errno.ENOENT:
+                raise
+            return 0, 0
+
+    def add_watch(self, path, mask):
+        if not path:
+            return
+        if self.watcher.path(path) is None:
+            if self.ui.debugflag:
+                self.ui.note(_('watching %r\n') % path[self.prefixlen:])
+            try:
+                self.watcher.add(path, mask)
+            except OSError, err:
+                if err.errno in (errno.ENOENT, errno.ENOTDIR):
+                    return
+                if err.errno != errno.ENOSPC:
+                    raise
+                _explain_watch_limit(self.ui, self.dirstate, self.wprefix)
+
+    def setup(self):
+        self.ui.note(_('watching directories under %r\n') % self.wprefix)
+        self.add_watch(self.wprefix + '.hg', inotify.IN_DELETE)
+        self.check_dirstate()
+
+    def filestatus(self, fn, st):
+        try:
+            type_, mode, size, time = self.dirstate._map[fn][:4]
+        except KeyError:
+            type_ = '?'
+        if type_ == 'n':
+            st_mode, st_size, st_mtime = st
+            if size == -1:
+                return 'l'
+            if size and (size != st_size or (mode ^ st_mode) & 0100):
+                return 'm'
+            if time != int(st_mtime):
+                return 'l'
+            return 'n'
+        if type_ == '?' and self.dirstate._ignore(fn):
+            return 'i'
+        return type_
+
+    def updatefile(self, wfn, osstat):
+        '''
+        update the file entry of an existing file.
+
+        osstat: (mode, size, time) tuple, as returned by os.lstat(wfn)
+        '''
+
+        self._updatestatus(wfn, self.filestatus(wfn, osstat))
+
+    def deletefile(self, wfn, oldstatus):
+        '''
+        update the entry of a file which has been deleted.
+
+        oldstatus: char in statuskeys, status of the file before deletion
+        '''
+        if oldstatus == 'r':
+            newstatus = 'r'
+        elif oldstatus in 'almn':
+            newstatus = '!'
+        else:
+            newstatus = None
+
+        self.statcache.pop(wfn, None)
+        self._updatestatus(wfn, newstatus)
+
+    def _updatestatus(self, wfn, newstatus):
+        '''
+        Update the stored status of a file.
+
+        newstatus: - char in (statuskeys + 'ni'), new status to apply.
+                   - or None, to stop tracking wfn
+        '''
+        root, fn = split(wfn)
+        d = self.tree.dir(root)
+
+        oldstatus = d.files.get(fn)
+        # oldstatus can be either:
+        # - None : fn is new
+        # - a char in statuskeys: fn is a (tracked) file
+
+        if self.ui.debugflag and oldstatus != newstatus:
+            self.ui.note(_('status: %r %s -> %s\n') %
+                             (wfn, oldstatus, newstatus))
+
+        if oldstatus and oldstatus in self.statuskeys \
+            and oldstatus != newstatus:
+            del self.statustrees[oldstatus].dir(root).files[fn]
+
+        if newstatus in (None, 'i'):
+            d.files.pop(fn, None)
+        elif oldstatus != newstatus:
+            d.files[fn] = newstatus
+            if newstatus != 'n':
+                self.statustrees[newstatus].dir(root).files[fn] = newstatus
+
+
+    def check_deleted(self, key):
+        # Files that had been deleted but were present in the dirstate
+        # may have vanished from the dirstate; we must clean them up.
+        nuke = []
+        for wfn, ignore in self.statustrees[key].walk(key):
+            if wfn not in self.dirstate:
+                nuke.append(wfn)
+        for wfn in nuke:
+            root, fn = split(wfn)
+            del self.statustrees[key].dir(root).files[fn]
+            del self.tree.dir(root).files[fn]
+
+    def scan(self, topdir=''):
+        ds = self.dirstate._map.copy()
+        self.add_watch(join(self.wprefix, topdir), self.mask)
+        for root, dirs, files in walk(self.dirstate, self.wprefix, topdir):
+            for d in dirs:
+                self.add_watch(join(root, d), self.mask)
+            wroot = root[self.prefixlen:]
+            for fn in files:
+                wfn = join(wroot, fn)
+                self.updatefile(wfn, self.getstat(wfn))
+                ds.pop(wfn, None)
+        wtopdir = topdir
+        if wtopdir and wtopdir[-1] != '/':
+            wtopdir += '/'
+        for wfn, state in ds.iteritems():
+            if not wfn.startswith(wtopdir):
+                continue
+            try:
+                st = self.stat(wfn)
+            except OSError:
+                status = state[0]
+                self.deletefile(wfn, status)
+            else:
+                self.updatefile(wfn, st)
+        self.check_deleted('!')
+        self.check_deleted('r')
+
+    def check_dirstate(self):
+        ds_info = self.dirstate_info()
+        if ds_info == self.ds_info:
+            return
+        self.ds_info = ds_info
+        if not self.ui.debugflag:
+            self.last_event = None
+        self.ui.note(_('%s dirstate reload\n') % self.event_time())
+        self.dirstate.invalidate()
+        self.handle_timeout()
+        self.scan()
+        self.ui.note(_('%s end dirstate reload\n') % self.event_time())
+
+    def update_hgignore(self):
+        # An update of the ignore file can potentially change the
+        # states of all unknown and ignored files.
+
+        # XXX If the user has other ignore files outside the repo, or
+        # changes their list of ignore files at run time, we'll
+        # potentially never see changes to them.  We could get the
+        # client to report to us what ignore data they're using.
+        # But it's easier to do nothing than to open that can of
+        # worms.
+
+        if '_ignore' in self.dirstate.__dict__:
+            delattr(self.dirstate, '_ignore')
+            self.ui.note(_('rescanning due to .hgignore change\n'))
+            self.handle_timeout()
+            self.scan()
+
+    def getstat(self, wpath):
+        try:
+            return self.statcache[wpath]
+        except KeyError:
+            try:
+                return self.stat(wpath)
+            except OSError, err:
+                if err.errno != errno.ENOENT:
+                    raise
+
+    def stat(self, wpath):
+        try:
+            st = os.lstat(join(self.wprefix, wpath))
+            ret = st.st_mode, st.st_size, st.st_mtime
+            self.statcache[wpath] = ret
+            return ret
+        except OSError:
+            self.statcache.pop(wpath, None)
+            raise
+
+    @eventaction('c')
+    def created(self, wpath):
+        if wpath == '.hgignore':
+            self.update_hgignore()
+        try:
+            st = self.stat(wpath)
+            if stat.S_ISREG(st[0]):
+                self.updatefile(wpath, st)
+        except OSError:
+            pass
+
+    @eventaction('m')
+    def modified(self, wpath):
+        if wpath == '.hgignore':
+            self.update_hgignore()
+        try:
+            st = self.stat(wpath)
+            if stat.S_ISREG(st[0]):
+                if self.dirstate[wpath] in 'lmn':
+                    self.updatefile(wpath, st)
+        except OSError:
+            pass
+
+    @eventaction('d')
+    def deleted(self, wpath):
+        if wpath == '.hgignore':
+            self.update_hgignore()
+        elif wpath.startswith('.hg/'):
+            if wpath == '.hg/wlock':
+                self.check_dirstate()
+            return
+
+        self.deletefile(wpath, self.dirstate[wpath])
+
+    def process_create(self, wpath, evt):
+        if self.ui.debugflag:
+            self.ui.note(_('%s event: created %s\n') %
+                         (self.event_time(), wpath))
+
+        if evt.mask & inotify.IN_ISDIR:
+            self.scan(wpath)
+        else:
+            self.created(wpath)
+
+    def process_delete(self, wpath, evt):
+        if self.ui.debugflag:
+            self.ui.note(_('%s event: deleted %s\n') %
+                         (self.event_time(), wpath))
+
+        if evt.mask & inotify.IN_ISDIR:
+            tree = self.tree.dir(wpath)
+            todelete = [wfn for wfn, ignore in tree.walk('?')]
+            for fn in todelete:
+                self.deletefile(fn, '?')
+            self.scan(wpath)
+        else:
+            self.deleted(wpath)
+
+    def process_modify(self, wpath, evt):
+        if self.ui.debugflag:
+            self.ui.note(_('%s event: modified %s\n') %
+                         (self.event_time(), wpath))
+
+        if not (evt.mask & inotify.IN_ISDIR):
+            self.modified(wpath)
+
+    def process_unmount(self, evt):
+        self.ui.warn(_('filesystem containing %s was unmounted\n') %
+                     evt.fullpath)
+        sys.exit(0)
+
+    def handle_pollevents(self, events):
+        if self.ui.debugflag:
+            self.ui.note(_('%s readable: %d bytes\n') %
+                         (self.event_time(), self.threshold.readable()))
+        if not self.threshold():
+            if self.registered:
+                if self.ui.debugflag:
+                    self.ui.note(_('%s below threshold - unhooking\n') %
+                                 (self.event_time()))
+                self.unregister()
+                self.timeout = 250
+        else:
+            self.read_events()
+
+    def read_events(self, bufsize=None):
+        events = self.watcher.read(bufsize)
+        if self.ui.debugflag:
+            self.ui.note(_('%s reading %d events\n') %
+                         (self.event_time(), len(events)))
+        for evt in events:
+            assert evt.fullpath.startswith(self.wprefix)
+            wpath = evt.fullpath[self.prefixlen:]
+
+            # paths have been normalized, wpath never ends with a '/'
+
+            if wpath.startswith('.hg/') and evt.mask & inotify.IN_ISDIR:
+                # ignore subdirectories of .hg/ (merge, patches...)
+                continue
+
+            if evt.mask & inotify.IN_UNMOUNT:
+                self.process_unmount(wpath, evt)
+            elif evt.mask & (inotify.IN_MODIFY | inotify.IN_ATTRIB):
+                self.process_modify(wpath, evt)
+            elif evt.mask & (inotify.IN_DELETE | inotify.IN_DELETE_SELF |
+                             inotify.IN_MOVED_FROM):
+                self.process_delete(wpath, evt)
+            elif evt.mask & (inotify.IN_CREATE | inotify.IN_MOVED_TO):
+                self.process_create(wpath, evt)
+
+        self.lastevent.clear()
+
+    def handle_timeout(self):
+        if not self.registered:
+            if self.ui.debugflag:
+                self.ui.note(_('%s hooking back up with %d bytes readable\n') %
+                             (self.event_time(), self.threshold.readable()))
+            self.read_events(0)
+            self.register(timeout=None)
+
+        self.timeout = None
+
+    def shutdown(self):
+        self.watcher.close()
+
+    def debug(self):
+        """
+        Returns a sorted list of relatives paths currently watched,
+        for debugging purposes.
+        """
+        return sorted(tuple[0][self.prefixlen:] for tuple in self.watcher)
+
+class server(pollable):
+    """
+    Listens for client queries on unix socket inotify.sock
+    """
+    def __init__(self, ui, root, repowatcher, timeout):
+        self.ui = ui
+        self.repowatcher = repowatcher
+        self.sock = socket.socket(socket.AF_UNIX)
+        self.sockpath = join(root, '.hg/inotify.sock')
+        self.realsockpath = None
+        try:
+            self.sock.bind(self.sockpath)
+        except socket.error, err:
+            if err[0] == errno.EADDRINUSE:
+                raise AlreadyStartedException(_('could not start server: %s')
+                                              % err[1])
+            if err[0] == "AF_UNIX path too long":
+                tempdir = tempfile.mkdtemp(prefix="hg-inotify-")
+                self.realsockpath = os.path.join(tempdir, "inotify.sock")
+                try:
+                    self.sock.bind(self.realsockpath)
+                    os.symlink(self.realsockpath, self.sockpath)
+                except (OSError, socket.error), inst:
+                    try:
+                        os.unlink(self.realsockpath)
+                    except:
+                        pass
+                    os.rmdir(tempdir)
+                    if inst.errno == errno.EEXIST:
+                        raise AlreadyStartedException(_('could not start server: %s')
+                                                      % inst.strerror)
+                    raise
+            else:
+                raise
+        self.sock.listen(5)
+        self.fileno = self.sock.fileno
+        self.register(timeout=timeout)
+
+    def handle_timeout(self):
+        pass
+
+    def answer_stat_query(self, cs):
+        names = cs.read().split('\0')
+
+        states = names.pop()
+
+        self.ui.note(_('answering query for %r\n') % states)
+
+        if self.repowatcher.timeout:
+            # We got a query while a rescan is pending.  Make sure we
+            # rescan before responding, or we could give back a wrong
+            # answer.
+            self.repowatcher.handle_timeout()
+
+        if not names:
+            def genresult(states, tree):
+                for fn, state in tree.walk(states):
+                    yield fn
+        else:
+            def genresult(states, tree):
+                for fn in names:
+                    for f in tree.lookup(states, fn):
+                        yield f
+
+        return ['\0'.join(r) for r in [
+            genresult('l', self.repowatcher.statustrees['l']),
+            genresult('m', self.repowatcher.statustrees['m']),
+            genresult('a', self.repowatcher.statustrees['a']),
+            genresult('r', self.repowatcher.statustrees['r']),
+            genresult('!', self.repowatcher.statustrees['!']),
+            '?' in states
+                and genresult('?', self.repowatcher.statustrees['?'])
+                or [],
+            [],
+            'c' in states and genresult('n', self.repowatcher.tree) or [],
+            ]]
+
+    def answer_dbug_query(self):
+        return ['\0'.join(self.repowatcher.debug())]
+
+    def handle_pollevents(self, events):
+        for e in events:
+            self.handle_pollevent()
+
+    def handle_pollevent(self):
+        sock, addr = self.sock.accept()
+
+        cs = common.recvcs(sock)
+        version = ord(cs.read(1))
+
+        if version != common.version:
+            self.ui.warn(_('received query from incompatible client '
+                           'version %d\n') % version)
+            try:
+                # try to send back our version to the client
+                # this way, the client too is informed of the mismatch
+                sock.sendall(chr(common.version))
+            except:
+                pass
+            return
+
+        type = cs.read(4)
+
+        if type == 'STAT':
+            results = self.answer_stat_query(cs)
+        elif type == 'DBUG':
+            results = self.answer_dbug_query()
+        else:
+            self.ui.warn(_('unrecognized query type: %s\n') % type)
+            return
+
+        try:
+            try:
+                v = chr(common.version)
+
+                sock.sendall(v + type + struct.pack(common.resphdrfmts[type],
+                                            *map(len, results)))
+                sock.sendall(''.join(results))
+            finally:
+                sock.shutdown(socket.SHUT_WR)
+        except socket.error, err:
+            if err[0] != errno.EPIPE:
+                raise
+
+    def shutdown(self):
+        self.sock.close()
+        try:
+            os.unlink(self.sockpath)
+            if self.realsockpath:
+                os.unlink(self.realsockpath)
+                os.rmdir(os.path.dirname(self.realsockpath))
+        except OSError, err:
+            if err.errno != errno.ENOENT:
+                raise
+
+class master(object):
+    def __init__(self, ui, dirstate, root, timeout=None):
+        self.ui = ui
+        self.repowatcher = repowatcher(ui, dirstate, root)
+        self.server = server(ui, root, self.repowatcher, timeout)
+
+    def shutdown(self):
+        for obj in pollable.instances.itervalues():
+            obj.shutdown()
+
+    def run(self):
+        self.repowatcher.setup()
+        self.ui.note(_('finished setup\n'))
+        if os.getenv('TIME_STARTUP'):
+            sys.exit(0)
+        pollable.run()
+
+def start(ui, dirstate, root):
+    def closefds(ignore):
+        # (from python bug #1177468)
+        # close all inherited file descriptors
+        # Python 2.4.1 and later use /dev/urandom to seed the random module's RNG
+        # a file descriptor is kept internally as os._urandomfd (created on demand
+        # the first time os.urandom() is called), and should not be closed
+        try:
+            os.urandom(4)
+            urandom_fd = getattr(os, '_urandomfd', None)
+        except AttributeError:
+            urandom_fd = None
+        ignore.append(urandom_fd)
+        for fd in range(3, 256):
+            if fd in ignore:
+                continue
+            try:
+                os.close(fd)
+            except OSError:
+                pass
+
+    m = master(ui, dirstate, root)
+    sys.stdout.flush()
+    sys.stderr.flush()
+
+    pid = os.fork()
+    if pid:
+        return pid
+
+    closefds(pollable.instances.keys())
+    os.setsid()
+
+    fd = os.open('/dev/null', os.O_RDONLY)
+    os.dup2(fd, 0)
+    if fd > 0:
+        os.close(fd)
+
+    fd = os.open(ui.config('inotify', 'log', '/dev/null'),
+                 os.O_RDWR | os.O_CREAT | os.O_TRUNC)
+    os.dup2(fd, 1)
+    os.dup2(fd, 2)
+    if fd > 2:
+        os.close(fd)
+
+    try:
+        m.run()
+    finally:
+        m.shutdown()
+        os._exit(0)