inotify: introduce debuginotify, which lists which paths are under watch

tests/test-inotify-debuginotify

@@ -0,0 +1,32 b''
+#!/bin/sh
+
+"$TESTDIR/hghave" inotify || exit 80
+
+hg init
+
+echo "[extensions]" >> $HGRCPATH
+echo "inotify=" >> $HGRCPATH
+
+echo % inserve
+hg inserve -d --pid-file=hg.pid
+cat hg.pid >> "$DAEMON_PIDS"
+
+# let the daemon finish its stuff
+sleep 1
+
+echo % empty
+hg debuginotify
+
+mkdir a
+sleep 1
+
+echo % only 'a'
+hg debuginotify
+
+rmdir a
+sleep 1
+
+echo % empty again
+hg debuginotify
+
+kill `cat hg.pid`

tests/test-inotify-debuginotify.out

@@ -0,0 +1,14 b''
+% inserve
+% empty
+directories being watched:
+  /
+  .hg/
+% only a
+directories being watched:
+  /
+  .hg/
+  a/
+% empty again
+directories being watched:
+  /
+  .hg/

hgext/inotify/__init__.py

@@ -1,92 +1,106 b''
 # __init__.py - inotify-based status acceleration for Linux
 #
 # Copyright 2006, 2007, 2008 Bryan O'Sullivan <[e-mail]>
 # Copyright 2007, 2008 Brendan Cully <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 '''inotify-based status acceleration for Linux systems
 '''
 
 # todo: socket permissions
 
 from mercurial.i18n import _
 from mercurial import cmdutil, util
 import os, server
 from weakref import proxy
 from client import client, QueryFailed
 
 def serve(ui, repo, **opts):
     '''start an inotify server for this repository'''
     timeout = opts.get('timeout')
     if timeout:
         timeout = float(timeout) * 1e3
 
     class service:
         def init(self):
             try:
                 self.master = server.master(ui, repo, timeout)
             except server.AlreadyStartedException, inst:
                 raise util.Abort(str(inst))
 
         def run(self):
             try:
                 self.master.run()
             finally:
                 self.master.shutdown()
 
     service = service()
     cmdutil.service(opts, initfn=service.init, runfn=service.run)
 
+def debuginotify(ui, repo, **opts):
+    '''debugging information for inotify extension
+
+    Prints the list of directories being watched by the inotify server.
+    '''
+    cli = client(ui, repo)
+    response = cli.debugquery()
+
+    ui.write(_('directories being watched:\n'))
+    for path in response:
+        ui.write(('  %s/\n') % path)
+
 def reposetup(ui, repo):
     if not hasattr(repo, 'dirstate'):
         return
 
     # XXX: weakref until hg stops relying on __del__
     repo = proxy(repo)
 
     class inotifydirstate(repo.dirstate.__class__):
         # Set to True if we're the inotify server, so we don't attempt
         # to recurse.
         inotifyserver = False
 
         def status(self, match, ignored, clean, unknown=True):
             files = match.files()
             if '.' in files:
                 files = []
             if not ignored and not self.inotifyserver:
                 cli = client(ui, repo)
                 try:
                     result = cli.statusquery(files, match, False,
                                             clean, unknown)
                 except QueryFailed, instr:
                     ui.debug(str(instr))
                     pass
                 else:
                     if ui.config('inotify', 'debug'):
                         r2 = super(inotifydirstate, self).status(
                             match, False, clean, unknown)
                         for c,a,b in zip('LMARDUIC', result, r2):
                             for f in a:
                                 if f not in b:
                                     ui.warn('*** inotify: %s +%s\n' % (c, f))
                             for f in b:
                                 if f not in a:
                                     ui.warn('*** inotify: %s -%s\n' % (c, f))
                         result = r2
                     return result
             return super(inotifydirstate, self).status(
                 match, ignored, clean, unknown)
 
     repo.dirstate.__class__ = inotifydirstate
 
 cmdtable = {
+    'debuginotify':
+        (debuginotify, [], ('hg debuginotify')),
     '^inserve':
-    (serve,
-     [('d', 'daemon', None, _('run server in background')),
-      ('', 'daemon-pipefds', '', _('used internally by daemon mode')),
-      ('t', 'idle-timeout', '', _('minutes to sit idle before exiting')),
-      ('', 'pid-file', '', _('name of file to write process ID to'))],
-     _('hg inserve [OPT]...')),
+        (serve,
+         [('d', 'daemon', None, _('run server in background')),
+          ('', 'daemon-pipefds', '', _('used internally by daemon mode')),
+          ('t', 'idle-timeout', '', _('minutes to sit idle before exiting')),
+          ('', 'pid-file', '', _('name of file to write process ID to'))],
+         _('hg inserve [OPT]...')),
     }

hgext/inotify/client.py

@@ -1,146 +1,153 b''
 # client.py - inotify status client
 #
 # Copyright 2006, 2007, 2008 Bryan O'Sullivan <[e-mail]>
 # Copyright 2007, 2008 Brendan Cully <[e-mail]>
 # Copyright 2009 Nicolas Dumazet <[e-mail]>
 #
 # 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 _
 import common, server
 import errno, os, socket, struct
 
 class QueryFailed(Exception): pass
 
 def start_server(function):
     """
     Decorator.
     Tries to call function, if it fails, try to (re)start inotify server.
     Raise QueryFailed if something went wrong
     """
     def decorated_function(self, *args):
         result = None
         try:
             return function(self, *args)
         except (OSError, socket.error), err:
             autostart = self.ui.configbool('inotify', 'autostart', True)
 
             if err[0] == errno.ECONNREFUSED:
                 self.ui.warn(_('(found dead inotify server socket; '
                                'removing it)\n'))
                 os.unlink(self.repo.join('inotify.sock'))
             if err[0] in (errno.ECONNREFUSED, errno.ENOENT) and autostart:
                 self.ui.debug(_('(starting inotify server)\n'))
                 try:
                     try:
                         server.start(self.ui, self.repo)
                     except server.AlreadyStartedException, inst:
                         # another process may have started its own
                         # inotify server while this one was starting.
                         self.ui.debug(str(inst))
                 except Exception, inst:
                     self.ui.warn(_('could not start inotify server: '
                                    '%s\n') % inst)
                 else:
                     try:
                         return function(self, *args)
                     except socket.error, err:
                         self.ui.warn(_('could not talk to new inotify '
                                        'server: %s\n') % err[-1])
             elif err[0] in (errno.ECONNREFUSED, errno.ENOENT):
                 # silently ignore normal errors if autostart is False
                 self.ui.debug(_('(inotify server not running)\n'))
             else:
                 self.ui.warn(_('failed to contact inotify server: %s\n')
                          % err[-1])
 
         self.ui.traceback()
         raise QueryFailed('inotify query failed')
 
     return decorated_function
 
 
 class client(object):
     def __init__(self, ui, repo):
         self.ui = ui
         self.repo = repo
         self.sock = socket.socket(socket.AF_UNIX)
 
     def _connect(self):
         sockpath = self.repo.join('inotify.sock')
         try:
             self.sock.connect(sockpath)
         except socket.error, err:
             if err[0] == "AF_UNIX path too long":
                 sockpath = os.readlink(sockpath)
                 self.sock.connect(sockpath)
             else:
                 raise
 
     def _send(self, type, data):
         """Sends protocol version number, and the data"""
         self.sock.sendall(chr(common.version) + type + data)
 
         self.sock.shutdown(socket.SHUT_WR)
 
     def _receive(self, type):
         """
         Read data, check version number, extract headers,
         and returns a tuple (data descriptor, header)
         Raises QueryFailed on error
         """
         cs = common.recvcs(self.sock)
         version = ord(cs.read(1))
         if version != common.version:
             self.ui.warn(_('(inotify: received response from incompatible '
                       'server version %d)\n') % version)
             raise QueryFailed('incompatible server version')
 
         readtype = cs.read(4)
         if readtype != type:
             self.ui.warn(_('(inotify: received \'%s\' response when expecting'
                        ' \'%s\')\n') % (readtype, type))
             raise QueryFailed('wrong response type')
 
         hdrfmt = common.resphdrfmts[type]
         hdrsize = common.resphdrsizes[type]
         try:
             resphdr = struct.unpack(hdrfmt, cs.read(hdrsize))
         except struct.error:
             raise QueryFailed('unable to retrieve query response headers')
 
         return cs, resphdr
 
     def query(self, type, req):
         self._connect()
 
         self._send(type, req)
 
         return self._receive(type)
 
     @start_server
     def statusquery(self, names, match, ignored, clean, unknown=True):
 
         def genquery():
             for n in names:
                 yield n
             states = 'almrx!'
             if ignored:
                 raise ValueError('this is insanity')
             if clean: states += 'c'
             if unknown: states += '?'
             yield states
 
         req = '\0'.join(genquery())
 
         cs, resphdr = self.query('STAT', req)
 
         def readnames(nbytes):
             if nbytes:
                 names = cs.read(nbytes)
                 if names:
                     return filter(match, names.split('\0'))
             return []
+        return map(readnames, resphdr)
 
-        return map(readnames, resphdr)
+    @start_server
+    def debugquery(self):
+        cs, resphdr = self.query('DBUG', '')
+
+        nbytes = resphdr[0]
+        names = cs.read(nbytes)
+        return names.split('\0')

hgext/inotify/common.py

@@ -1,49 +1,51 b''
 # server.py - inotify common protocol code
 #
 # Copyright 2006, 2007, 2008 Bryan O'Sullivan <[e-mail]>
 # Copyright 2007, 2008 Brendan Cully <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2, incorporated herein by reference.
 
 import cStringIO, socket, struct
 
 """
   Protocol between inotify clients and server:
 
   Client sending query:
   1) send protocol version number
   2) send query type (string, 4 letters long)
   3) send query parameters:
      - For STAT, N+1 \0-separated strings:
         1) N different names that need checking
         2) 1 string containing all the status types to match
+     - No parameter needed for DBUG
 
   Server sending query answer:
   1) send protocol version number
   2) send query type
   3) send struct.pack'ed headers describing the length of the content:
       e.g. for STAT, receive 8 integers describing the length of the
       8 \0-separated string lists ( one list for each lmar!?ic status type )
 
 """
 
 version = 2
 
 resphdrfmts = {
-    'STAT': '>llllllll' # status requests
+    'STAT': '>llllllll', # status requests
+    'DBUG': '>l'         # debugging queries
 }
 resphdrsizes = dict((k, struct.calcsize(v))
                     for k, v in resphdrfmts.iteritems())
 
 def recvcs(sock):
     cs = cStringIO.StringIO()
     s = True
     try:
         while s:
             s = sock.recv(65536)
             cs.write(s)
     finally:
         sock.shutdown(socket.SHUT_RD)
     cs.seek(0)
     return cs

hgext/inotify/server.py

@@ -1,766 +1,778 b''
 # server.py - inotify status server
 #
 # Copyright 2006, 2007, 2008 Bryan O'Sullivan <[e-mail]>
 # Copyright 2007, 2008 Brendan Cully <[e-mail]>
 #
 # 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
 
 walk_ignored_errors = (errno.ENOENT, errno.ENAMETOOLONG)
 
 def walkrepodirs(repo):
     '''Iterate over all subdirectories of this repo.
     Exclude the .hg directory, any nested repos, and ignored dirs.'''
     rootslash = repo.root + os.sep
 
     def walkit(dirname, top):
         fullpath = rootslash + 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 repo.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(repo, root):
     '''Like os.walk, but only yields regular files.'''
 
     # This function is critical to performance during startup.
 
     rootslash = repo.root + os.sep
 
     def walkit(root, reporoot):
         files, dirs = [], []
 
         try:
             fullpath = rootslash + 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 repo.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 not in walk_ignored_errors:
                 raise
 
     return walkit(root, root == '')
 
 def _explain_watch_limit(ui, repo, count):
     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(repo)))
     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')
                      % repo.root)
 
 class repowatcher(object):
     poll_events = select.POLLIN
     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, repo, master):
         self.ui = ui
         self.repo = repo
         self.wprefix = self.repo.wjoin('')
         self.timeout = None
         self.master = master
         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.registered = True
         self.fileno = self.watcher.fileno
 
         self.repo.dirstate.__class__.inotifyserver = True
 
         self.tree = {}
         self.statcache = {}
         self.statustrees = dict([(s, {}) for s in self.statuskeys])
 
         self.watches = 0
         self.last_event = None
 
         self.eventq = {}
         self.deferred = 0
 
         self.ds_info = self.dirstate_info()
         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.repo.join('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[len(self.wprefix):])
             try:
                 self.watcher.add(path, mask)
                 self.watches += 1
             except OSError, err:
                 if err.errno in (errno.ENOENT, errno.ENOTDIR):
                     return
                 if err.errno != errno.ENOSPC:
                     raise
                 _explain_watch_limit(self.ui, self.repo, self.watches)
 
     def setup(self):
         self.ui.note(_('watching directories under %r\n') % self.repo.root)
         self.add_watch(self.repo.path, inotify.IN_DELETE)
         self.check_dirstate()
 
     def wpath(self, evt):
         path = evt.fullpath
         if path == self.repo.root:
             return ''
         if path.startswith(self.wprefix):
             return path[len(self.wprefix):]
         raise 'wtf? ' + path
 
     def dir(self, tree, path):
         if path:
             for name in path.split('/'):
                 tree = tree.setdefault(name, {})
         return tree
 
     def lookup(self, path, tree):
         if path:
             try:
                 for name in path.split('/'):
                     tree = tree[name]
             except KeyError:
                 return 'x'
             except TypeError:
                 return 'd'
         return tree
 
     def split(self, path):
         c = path.rfind('/')
         if c == -1:
             return '', path
         return path[:c], path[c+1:]
 
     def filestatus(self, fn, st):
         try:
             type_, mode, size, time = self.repo.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.repo.dirstate._ignore(fn):
             return 'i'
         return type_
 
     def updatestatus(self, wfn, osstat=None, newstatus=None):
         '''
         Update the stored status of a file or directory.
 
         osstat: (mode, size, time) tuple, as returned by os.lstat(wfn)
 
         newstatus: char in statuskeys, new status to apply.
         '''
         if osstat:
             newstatus = self.filestatus(wfn, osstat)
         else:
             self.statcache.pop(wfn, None)
         root, fn = self.split(wfn)
         d = self.dir(self.tree, root)
         oldstatus = d.get(fn)
         isdir = False
         if oldstatus:
             try:
                 if not newstatus:
                     if oldstatus in 'almn':
                         newstatus = '!'
                     elif oldstatus == 'r':
                         newstatus = 'r'
             except TypeError:
                 # oldstatus may be a dict left behind by a deleted
                 # directory
                 isdir = True
             else:
                 if oldstatus in self.statuskeys and oldstatus != newstatus:
                     del self.dir(self.statustrees[oldstatus], root)[fn]
         if self.ui.debugflag and oldstatus != newstatus:
             if isdir:
                 self.ui.note(_('status: %r dir(%d) -> %s\n') %
                              (wfn, len(oldstatus), newstatus))
             else:
                 self.ui.note(_('status: %r %s -> %s\n') %
                              (wfn, oldstatus, newstatus))
         if not isdir:
             if newstatus and newstatus != 'i':
                 d[fn] = newstatus
                 if newstatus in self.statuskeys:
                     dd = self.dir(self.statustrees[newstatus], root)
                     if oldstatus != newstatus or fn not in dd:
                         dd[fn] = newstatus
             else:
                 d.pop(fn, None)
         elif not newstatus:
             # a directory is being removed, check its contents
             for subfile, b in oldstatus.copy().iteritems():
                 self.updatestatus(wfn + '/' + subfile, None)
 
 
     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.walk(key, self.statustrees[key]):
             if wfn not in self.repo.dirstate:
                 nuke.append(wfn)
         for wfn in nuke:
             root, fn = self.split(wfn)
             del self.dir(self.statustrees[key], root)[fn]
             del self.dir(self.tree, root)[fn]
 
     def scan(self, topdir=''):
         self.handle_timeout()
         ds = self.repo.dirstate._map.copy()
         self.add_watch(join(self.repo.root, topdir), self.mask)
         for root, dirs, files in walk(self.repo, topdir):
             for d in dirs:
                 self.add_watch(join(root, d), self.mask)
             wroot = root[len(self.wprefix):]
             d = self.dir(self.tree, wroot)
             for fn in files:
                 wfn = join(wroot, fn)
                 self.updatestatus(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.updatestatus(wfn, None, newstatus=status)
             else:
                 self.updatestatus(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.repo.dirstate.invalidate()
         self.scan()
         self.ui.note(_('%s end dirstate reload\n') % self.event_time())
 
     def walk(self, states, tree, prefix=''):
         # This is the "inner loop" when talking to the client.
 
         for name, val in tree.iteritems():
             path = join(prefix, name)
             try:
                 if val in states:
                     yield path, val
             except TypeError:
                 for p in self.walk(states, val, path):
                     yield p
 
     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.repo.dirstate.__dict__:
             delattr(self.repo.dirstate, '_ignore')
             self.ui.note(_('rescanning due to .hgignore change\n'))
             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
 
     def created(self, wpath):
         if wpath == '.hgignore':
             self.update_hgignore()
         try:
             st = self.stat(wpath)
             if stat.S_ISREG(st[0]):
                 self.updatestatus(wpath, st)
         except OSError:
             pass
 
     def modified(self, wpath):
         if wpath == '.hgignore':
             self.update_hgignore()
         try:
             st = self.stat(wpath)
             if stat.S_ISREG(st[0]):
                 if self.repo.dirstate[wpath] in 'lmn':
                     self.updatestatus(wpath, st)
         except OSError:
             pass
 
     def deleted(self, wpath):
         if wpath == '.hgignore':
             self.update_hgignore()
         elif wpath.startswith('.hg/'):
             if wpath == '.hg/wlock':
                 self.check_dirstate()
             return
 
         self.updatestatus(wpath, None)
 
     def schedule_work(self, wpath, evt):
         prev = self.eventq.setdefault(wpath, [])
         try:
             if prev and evt == 'm' and prev[-1] in 'cm':
                 return
             self.eventq[wpath].append(evt)
         finally:
             self.deferred += 1
             self.timeout = 250
 
     def deferred_event(self, wpath, evt):
         if evt == 'c':
             self.created(wpath)
         elif evt == 'm':
             self.modified(wpath)
         elif evt == 'd':
             self.deleted(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.schedule_work(wpath, 'c')
 
     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:
             self.scan(wpath)
         self.schedule_work(wpath, 'd')
 
     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.schedule_work(wpath, 'm')
 
     def process_unmount(self, evt):
         self.ui.warn(_('filesystem containing %s was unmounted\n') %
                      evt.fullpath)
         sys.exit(0)
 
     def handle_event(self, fd, event):
         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.master.poll.unregister(fd)
                 self.registered = False
                 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:
             wpath = self.wpath(evt)
             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)
 
     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.master.poll.register(self, select.POLLIN)
             self.registered = True
 
         if self.eventq:
             if self.ui.debugflag:
                 self.ui.note(_('%s processing %d deferred events as %d\n') %
                              (self.event_time(), self.deferred,
                               len(self.eventq)))
             for wpath, evts in sorted(self.eventq.iteritems()):
                 for evt in evts:
                     self.deferred_event(wpath, evt)
             self.eventq.clear()
             self.deferred = 0
         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][len(self.wprefix):] for tuple in self.watcher)
+
 class server(object):
     poll_events = select.POLLIN
 
     def __init__(self, ui, repo, repowatcher, timeout):
         self.ui = ui
         self.repo = repo
         self.repowatcher = repowatcher
         self.timeout = timeout
         self.sock = socket.socket(socket.AF_UNIX)
         self.sockpath = self.repo.join('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
 
     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 self.repowatcher.walk(states, tree):
                     yield fn
         else:
             def genresult(states, tree):
                 for fn in names:
                     l = self.repowatcher.lookup(fn, tree)
                     try:
                         if l in states:
                             yield fn
                     except TypeError:
                         for f, s in self.repowatcher.walk(states, l, 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_event(self, fd, event):
         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)
             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, repo, timeout=None):
         self.ui = ui
         self.repo = repo
         self.poll = select.poll()
         self.repowatcher = repowatcher(ui, repo, self)
         self.server = server(ui, repo, self.repowatcher, timeout)
         self.table = {}
         for obj in (self.repowatcher, self.server):
             fd = obj.fileno()
             self.table[fd] = obj
             self.poll.register(fd, obj.poll_events)
 
     def register(self, fd, mask):
         self.poll.register(fd, mask)
 
     def shutdown(self):
         for obj in self.table.itervalues():
             obj.shutdown()
 
     def run(self):
         self.repowatcher.setup()
         self.ui.note(_('finished setup\n'))
         if os.getenv('TIME_STARTUP'):
             sys.exit(0)
         while True:
             timeout = None
             timeobj = None
             for obj in self.table.itervalues():
                 if obj.timeout is not None and (timeout is None or obj.timeout < timeout):
                     timeout, timeobj = obj.timeout, obj
             try:
                 if self.ui.debugflag:
                     if timeout is None:
                         self.ui.note(_('polling: no timeout\n'))
                     else:
                         self.ui.note(_('polling: %sms timeout\n') % timeout)
                 events = self.poll.poll(timeout)
             except select.error, err:
                 if err[0] == errno.EINTR:
                     continue
                 raise
             if events:
                 for fd, event in events:
                     self.table[fd].handle_event(fd, event)
             elif timeobj:
                 timeobj.handle_timeout()
 
 def start(ui, repo):
     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, repo)
     sys.stdout.flush()
     sys.stderr.flush()
 
     pid = os.fork()
     if pid:
         return pid
 
     closefds([m.server.fileno(), m.repowatcher.fileno()])
     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)