Commit Graph

7 Commits

Author SHA1 Message Date
Philip Withnall
e4e88688a0 kqueue: Fix unlocked access to shared variable
And drop the `volatile` qualifier because it doesn’t help.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>

Helps: #600
2020-11-20 14:40:19 +00:00
Ting-Wei Lan
e714e1e951 kqueue: Use the worker context to schedule rescanning of missing files
This makes it consistent with the file monitor itself, which already
attaches kqueue event sources to the worker context.
2018-06-17 11:26:32 +08:00
Ting-Wei Lan
09c019a4f0 kqueue: Make it possible to pass file monitor tests
Previously, kqueue file monitor only add event sources for directories
regardless of the type of the file being monitored. Doing so may be
possible on inotify, but it is not sufficient on kqueue. Watching a
directory on kqueue doesn't report changes made to files under it, and
we must watch files themselves to get notified. This problem is fixed
by adding a second watch for non-directory file monitors, and the result
is that we are now able to receive 'CHANGED' and 'ATTRIBUTE_CHANGED'
events for non-directory files.

Since having two watches on one file monitor requires many code changes
to work properly, this commit also changes the following things:

 - NOTE_ALL macro is now replaced by note_all inline function. Since the
   kqueue backend is shared by all BSD operating systems, there are a
   few difference between these systems. It is easier to do '#ifdef'
   check in a function than in a macro.

 - Both g_kqueue_file_monitor_callback and g_kqueue_file_monitor_cancel
   now holds a lock before accessing kqueue_sub structs. This fixes a
   crash when these two functions are called from different threads,
   causing g_kqueue_file_monitor_callback to access freed memory.

 - 'mask' variable in g_kqueue_file_monitor_callback is now removed.
   The usage of 'mask' was wrong because of the 'mask > 0' check.
   'CHANGED' event has value 0 so the 'mask > 0' check made it
   impossible to emit 'CHANGED' events.

 - kqueue-missing scans can now be triggered from the kqueue event
   callback instead of always waiting for 4 seconds.

 - Don't remove a file from kqueue on unlink unless its hard link count
   has dropped to zero.

 - Don't use 'else if' in the check of 'fflags'. It is possible for a
   kevent to have multiple flags set.

 - Don't use g_file_monitor_emit_event directly. Always use
   g_file_monitor_source_handle_event to report events.
   Events submitted to g_file_monitor_emit_event are delivered
   immediately, but events sent to g_file_monitor_source_handle_event
   are scheduled by GLocalFileMonitor. If we mix the two, the order of
   events will be wrong and tests will fail.

 - Report 'CHANGES_DONE_HINT' immediately after 'CREATED' if the file
   created is not a regular file. This is copied from ih_event_callback.
2018-06-17 11:26:32 +08:00
Martin Pieuchot
aa39a0557c kqueue: Multiple fixes and simplifications
- Stop using a custom thread for listening to kqueue(2) events.  Instead
   call kevent(2) in non blocking mode in a monitor callback.  Under the
   hood poll(2) is used to figure out if new events are available.

 - Do not use a socketpair with a custom protocol requiring 2 supplementary
   context switches per event to commicate between multiple threads.  Calling
   kevent(2), in non blocking mode, to add/remove events is fine from any
   context.

 - Add kqueue(2) events without the EV_ONESHOT flag.  This removes a race
   where some notifications were lost because events had to be re-added for
   every new notification.

 - Get rid of the global hash table and its associated lock and races.  Use
   the 'cookie' argument of kevent(2) to pass the associated descriptor when
   registering an event.

 - Fix _kh_file_appeared_cb() by properly passing a monitor instead of a
   source to g_file_monitor_emit_event().

 - Properly refcount sources.

 - Remove a lot of abstraction making it harder to fix the remaining issues.

https://bugzilla.gnome.org/show_bug.cgi?id=739424
2018-03-13 12:23:10 +00:00
Antoine Jacoutot
fb21c8eaab kqueue: fix a potential deadlock
In case an object is already monitored, we lock then return without
unlocking it which can then result in a self deadlock. So properly
unlock before returning.

https://bugzilla.gnome.org/show_bug.cgi?id=721074
2013-12-26 19:57:44 +01:00
Ryan Lortie
59e46c4928 kqueue: Reduce G_GNUC_INTERNAL + G_LOCK abuse
The kqueue file monitoring backend was misusing G_GNUC_INTERNAL for want
of 'static' in a couple of places and also using it to declare a lock
that was never used at all.

Fix those up.
2013-01-13 23:48:23 -05:00
Antoine Jacoutot
a335fd1de8 GFileMonitor: Add kqueue(3) support to GIO
Written by Dmitry Matveev as part of GSoC 2011:
http://netbsd-soc.sourceforge.net/projects/kqueue4gio/

This brings native file monitoring support on systems supporting kqueue(3)
(all BSDs) and remove the need to rely on the unmaintained gamin software.
The backend adds GKqueueDirectoryMonitor and GKqueueFileMonitor.

Some parts rewritten by myself (to prevent needing a configuration file).
Helpful inputs from Colin Walters and Simon McVittie.

https://bugzilla.gnome.org/show_bug.cgi?id=679793
2012-11-15 08:13:30 +01:00