/* Filesystem notifications support with kqueue API.
- Copyright (C) 2015 Free Software Foundation, Inc.
+
+Copyright (C) 2015-2016 Free Software Foundation, Inc.
This file is part of GNU Emacs.
GNU Emacs is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
-the Free Software Foundation, either version 3 of the License, or
-(at your option) any later version.
+the Free Software Foundation, either version 3 of the License, or (at
+your option) any later version.
GNU Emacs is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
#include "keyboard.h"
#include "process.h"
+#ifdef HAVE_SYS_RESOURCE_H
+#include <sys/resource.h>
+#endif /* HAVE_SYS_RESOURCE_H */
+
\f
/* File handle for kqueue. */
static int kqueuefd = -1;
/* Generate a file notification event. */
static void
-kqueue_generate_event
-(Lisp_Object ident, Lisp_Object actions, Lisp_Object file, Lisp_Object file1,
- Lisp_Object callback)
+kqueue_generate_event (Lisp_Object watch_object, Lisp_Object actions,
+ Lisp_Object file, Lisp_Object file1)
{
+ Lisp_Object flags, action, entry;
struct input_event event;
- EVENT_INIT (event);
- event.kind = FILE_NOTIFY_EVENT;
- event.frame_or_window = Qnil;
- event.arg = list2 (Fcons (ident, Fcons (actions,
- NILP (file1)
- ? Fcons (file, Qnil)
- : list2 (file, file1))),
- callback);
+
+ /* Check, whether all actions shall be monitored. */
+ flags = Fnth (make_number (2), watch_object);
+ action = actions;
+ do {
+ if (NILP (action))
+ break;
+ entry = XCAR (action);
+ if (NILP (Fmember (entry, flags))) {
+ action = XCDR (action);
+ actions = Fdelq (entry, actions);
+ } else
+ action = XCDR (action);
+ } while (1);
/* Store it into the input event queue. */
- kbd_buffer_store_event (&event);
+ if (! NILP (actions)) {
+ EVENT_INIT (event);
+ event.kind = FILE_NOTIFY_EVENT;
+ event.frame_or_window = Qnil;
+ event.arg = list2 (Fcons (XCAR (watch_object),
+ Fcons (actions,
+ NILP (file1)
+ ? Fcons (file, Qnil)
+ : list2 (file, file1))),
+ Fnth (make_number (3), watch_object));
+ kbd_buffer_store_event (&event);
+ }
}
/* This compares two directory listings in case of a `write' event for
replaced by the new directory listing at the end of this
function. */
static void
-kqueue_compare_dir_list
-(Lisp_Object watch_object)
+kqueue_compare_dir_list (Lisp_Object watch_object)
{
- Lisp_Object dir, callback;
+ Lisp_Object dir, pending_dl, deleted_dl;
Lisp_Object old_directory_files, old_dl, new_directory_files, new_dl, dl;
dir = XCAR (XCDR (watch_object));
- callback = Fnth (make_number (3), watch_object);
+ pending_dl = Qnil;
+ deleted_dl = Qnil;
old_directory_files = Fnth (make_number (4), watch_object);
old_dl = kqueue_directory_listing (old_directory_files);
/* When the directory is not accessible anymore, it has been deleted. */
if (NILP (Ffile_directory_p (dir))) {
- kqueue_generate_event
- (XCAR (watch_object), Fcons (Qdelete, Qnil), dir, Qnil, callback);
+ kqueue_generate_event (watch_object, Fcons (Qdelete, Qnil), dir, Qnil);
return;
}
new_directory_files =
/* Search for an entry with the same inode. */
old_entry = XCAR (dl);
- new_entry = Fassoc (XCAR (old_entry), new_dl);
+ new_entry = assq_no_quit (XCAR (old_entry), new_dl);
if (! NILP (Fequal (old_entry, new_entry))) {
/* Both entries are identical. Nothing to do. */
new_dl = Fdelq (new_entry, new_dl);
if (NILP (Fequal (Fnth (make_number (2), old_entry),
Fnth (make_number (2), new_entry))))
kqueue_generate_event
- (XCAR (watch_object), Fcons (Qwrite, Qnil),
- XCAR (XCDR (old_entry)), Qnil, callback);
+ (watch_object, Fcons (Qwrite, Qnil), XCAR (XCDR (old_entry)), Qnil);
/* Status change time has been changed, the file attributes
have changed. */
if (NILP (Fequal (Fnth (make_number (3), old_entry),
Fnth (make_number (3), new_entry))))
kqueue_generate_event
- (XCAR (watch_object), Fcons (Qattrib, Qnil),
- XCAR (XCDR (old_entry)), Qnil, callback);
+ (watch_object, Fcons (Qattrib, Qnil),
+ XCAR (XCDR (old_entry)), Qnil);
} else {
/* The file has been renamed. */
kqueue_generate_event
- (XCAR (watch_object), Fcons (Qrename, Qnil),
- XCAR (XCDR (old_entry)), XCAR (XCDR (new_entry)), callback);
+ (watch_object, Fcons (Qrename, Qnil),
+ XCAR (XCDR (old_entry)), XCAR (XCDR (new_entry)));
+ deleted_dl = Fcons (new_entry, deleted_dl);
}
new_dl = Fdelq (new_entry, new_dl);
goto the_end;
new_entry = XCAR (dl1);
if (strcmp (SSDATA (XCAR (XCDR (old_entry))),
SSDATA (XCAR (XCDR (new_entry)))) == 0) {
- kqueue_generate_event
- (XCAR (watch_object), Fcons (Qwrite, Qnil),
- XCAR (XCDR (old_entry)), Qnil, callback);
+ pending_dl = Fcons (new_entry, pending_dl);
new_dl = Fdelq (new_entry, new_dl);
goto the_end;
}
}
- /* The file has been deleted. */
- kqueue_generate_event
- (XCAR (watch_object), Fcons (Qdelete, Qnil),
- XCAR (XCDR (old_entry)), Qnil, callback);
+ /* Check, whether this a pending file. */
+ new_entry = assq_no_quit (XCAR (old_entry), pending_dl);
+
+ if (NILP (new_entry)) {
+ /* Check, whether this is an already deleted file (by rename). */
+ for (dl1 = deleted_dl; ! NILP (dl1); dl1 = XCDR (dl1)) {
+ new_entry = XCAR (dl1);
+ if (strcmp (SSDATA (XCAR (XCDR (old_entry))),
+ SSDATA (XCAR (XCDR (new_entry)))) == 0) {
+ deleted_dl = Fdelq (new_entry, deleted_dl);
+ goto the_end;
+ }
+ }
+ /* The file has been deleted. */
+ kqueue_generate_event
+ (watch_object, Fcons (Qdelete, Qnil), XCAR (XCDR (old_entry)), Qnil);
+
+ } else {
+ /* The file has been renamed. */
+ kqueue_generate_event
+ (watch_object, Fcons (Qrename, Qnil),
+ XCAR (XCDR (old_entry)), XCAR (XCDR (new_entry)));
+ pending_dl = Fdelq (new_entry, pending_dl);
+ }
the_end:
dl = XCDR (dl);
/* Parse through the resulting new list. */
dl = new_dl;
while (1) {
- Lisp_Object new_entry;
+ Lisp_Object entry;
if (NILP (dl))
break;
/* A new file has appeared. */
- new_entry = XCAR (dl);
+ entry = XCAR (dl);
kqueue_generate_event
- (XCAR (watch_object), Fcons (Qcreate, Qnil),
- XCAR (XCDR (new_entry)), Qnil, callback);
+ (watch_object, Fcons (Qcreate, Qnil), XCAR (XCDR (entry)), Qnil);
/* Check size of that file. */
- Lisp_Object size = Fnth (make_number (4), new_entry);
+ Lisp_Object size = Fnth (make_number (4), entry);
if (FLOATP (size) || (XINT (size) > 0))
kqueue_generate_event
- (XCAR (watch_object), Fcons (Qwrite, Qnil),
- XCAR (XCDR (new_entry)), Qnil, callback);
+ (watch_object, Fcons (Qwrite, Qnil), XCAR (XCDR (entry)), Qnil);
dl = XCDR (dl);
- new_dl = Fdelq (new_entry, new_dl);
+ new_dl = Fdelq (entry, new_dl);
}
- /* At this point, both old_dl and new_dl shall be empty. Let's make
- a check for this (might be removed once the code is stable). */
+ /* Parse through the resulting pending_dl list. */
+ dl = pending_dl;
+ while (1) {
+ Lisp_Object entry;
+ if (NILP (dl))
+ break;
+
+ /* A file is still pending. Assume it was a write. */
+ entry = XCAR (dl);
+ kqueue_generate_event
+ (watch_object, Fcons (Qwrite, Qnil), XCAR (XCDR (entry)), Qnil);
+
+ dl = XCDR (dl);
+ pending_dl = Fdelq (entry, pending_dl);
+ }
+
+ /* At this point, old_dl, new_dl and pending_dl shall be empty.
+ deleted_dl might not be empty when there was a rename to a
+ nonexistent file. Let's make a check for this (might be removed
+ once the code is stable). */
if (! NILP (old_dl))
report_file_error ("Old list not empty", old_dl);
if (! NILP (new_dl))
report_file_error ("New list not empty", new_dl);
+ if (! NILP (pending_dl))
+ report_file_error ("Pending events list not empty", pending_dl);
+ // if (! NILP (deleted_dl))
+ // report_file_error ("Deleted events list not empty", deleted_dl);
/* Replace old directory listing with the new one. */
XSETCDR (Fnthcdr (make_number (3), watch_object),
for (;;) {
struct kevent kev;
static const struct timespec nullts = { 0, 0 };
- Lisp_Object descriptor, watch_object, file, callback, actions;
+ Lisp_Object descriptor, watch_object, file, actions;
/* Read one event. */
int ret = kevent (kqueuefd, NULL, 0, &kev, 1, &nullts);
return;
}
- /* Determine descriptor, file name and callback function. */
+ /* Determine descriptor and file name. */
descriptor = make_number (kev.ident);
watch_object = assq_no_quit (descriptor, watch_list);
-
- if (CONSP (watch_object)) {
+ if (CONSP (watch_object))
file = XCAR (XCDR (watch_object));
- callback = Fnth (make_number (3), watch_object);
- }
else
continue;
/* Create the event. */
if (! NILP (actions))
- kqueue_generate_event (descriptor, actions, file, Qnil, callback);
+ kqueue_generate_event (watch_object, actions, file, Qnil);
/* Cancel monitor if file or directory is deleted or renamed. */
if (kev.fflags & (NOTE_DELETE | NOTE_RENAME))
(Lisp_Object file, Lisp_Object flags, Lisp_Object callback)
{
Lisp_Object watch_object, dir_list;
- int fd, oflags;
+ int maxfd, fd, oflags;
u_short fflags = 0;
struct kevent kev;
+#ifdef HAVE_GETRLIMIT
+ struct rlimit rlim;
+#endif /* HAVE_GETRLIMIT */
/* Check parameters. */
CHECK_STRING (file);
if (! FUNCTIONP (callback))
wrong_type_argument (Qinvalid_function, callback);
+ /* Check available file descriptors. */
+#ifdef HAVE_GETRLIMIT
+ if (! getrlimit (RLIMIT_NOFILE, &rlim))
+ maxfd = rlim.rlim_cur;
+ else
+#endif /* HAVE_GETRLIMIT */
+ maxfd = 256;
+
+ /* We assume 50 file descriptors are sufficient for the rest of Emacs. */
+ if ((maxfd - 50) < XINT (Flength (watch_list)))
+ xsignal2
+ (Qfile_notify_error,
+ build_string ("File watching not possible, no file descriptor left"),
+ Flength (watch_list));
+
if (kqueuefd < 0)
{
/* Create kqueue descriptor. */