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6f011d81 EZ |
1 | /* Filesystem notifications support for GNU Emacs on the Microsoft Windows API. |
2 | Copyright (C) 2012 Free Software Foundation, Inc. | |
3 | ||
4 | This file is part of GNU Emacs. | |
5 | ||
6 | GNU Emacs is free software: you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation, either version 3 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | GNU Emacs is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */ | |
18 | ||
c5c91b84 EZ |
19 | /* Design overview: |
20 | ||
21 | For each watch request, we launch a separate worker thread. The | |
22 | worker thread runs the watch_worker function, which issues an | |
23 | asynchronous call to ReadDirectoryChangesW, and then waits for that | |
24 | call to complete in SleepEx. Waiting in SleepEx puts the thread in | |
25 | an alertable state, so it wakes up when either (a) the call to | |
26 | ReadDirectoryChangesW completes, or (b) the main thread instructs | |
27 | the worker thread to terminate by sending it an APC, see below. | |
28 | ||
29 | When the ReadDirectoryChangesW call completes, its completion | |
30 | routine watch_completion is automatically called. watch_completion | |
31 | stashes the received file events in a buffer used to communicate | |
32 | them to the main thread (using a critical section, so that several | |
33 | threads could use the same buffer), posts a special message, | |
34 | WM_EMACS_FILENOTIFY, to the Emacs's message queue, and returns. | |
35 | That causes the SleepEx function call inside watch_worker to | |
36 | return, and watch_worker then issues another call to | |
37 | ReadDirectoryChangesW. (Except when it does not, see below.) | |
38 | ||
39 | The WM_EMACS_FILENOTIFY message, posted to the message queue gets | |
40 | dispatched to the main Emacs window procedure, which queues it for | |
41 | processing by w32_read_socket. When w32_read_socket sees this | |
42 | message, it accesses the buffer with file notifications (using a | |
43 | critical section), extracts the information, converts it to a | |
44 | series of FILE_NOTIFY_EVENT events, and stuffs them into the input | |
45 | event queue to be processed by keyboard.c input machinery | |
46 | (read_char via a call to kbd_buffer_get_event). When the | |
47 | FILE_NOTIFY_EVENT event is processed by kbd_buffer_get_event, it is | |
48 | converted to a Lispy event that can be bound to a command. The | |
49 | default binding is w32notify-handle-event, defined on subr.el. | |
50 | ||
51 | After w32_read_socket is done processing the notifications, it | |
52 | resets a flag signaling to all watch worker threads that the | |
53 | notifications buffer is available for more input. | |
54 | ||
55 | When the watch is removed by a call to w32notify-rm-watch, the main | |
56 | thread requests that the worker thread terminates by queuing an APC | |
57 | for the worker thread. The APC specifies the watch_end function to | |
58 | be called. watch_end calls CancelIo on the outstanding | |
59 | ReadDirectoryChangesW call and closes the handle on which the | |
60 | watched directory was open. When watch_end returns, the | |
61 | watch_completion function is called one last time with the | |
62 | ERROR_OPERATION_ABORTED status, which causes it to clean up and set | |
63 | a flag telling watch_worker to exit without issuing another | |
d6de1760 EZ |
64 | ReadDirectoryChangesW call. The main thread waits for some time |
65 | for the worker thread to exit, and if it doesn't, terminates it | |
66 | forcibly. */ | |
c5c91b84 | 67 | |
6f011d81 EZ |
68 | #include <stddef.h> |
69 | #include <errno.h> | |
70 | ||
71 | /* must include CRT headers *before* config.h */ | |
72 | #include <config.h> | |
73 | ||
74 | #include <windows.h> | |
75 | ||
76 | #include "lisp.h" | |
77 | #include "w32term.h" /* for enter_crit/leave_crit and WM_EMACS_FILENOTIFY */ | |
78 | #include "w32heap.h" /* for OS version data */ | |
79 | #include "w32.h" /* for w32_strerror */ | |
80 | #include "coding.h" | |
81 | #include "keyboard.h" | |
82 | #include "frame.h" /* needed by termhooks.h */ | |
83 | #include "termhooks.h" /* for FILE_NOTIFY_EVENT */ | |
84 | ||
85 | struct notification { | |
86 | BYTE *buf; /* buffer for ReadDirectoryChangesW */ | |
87 | OVERLAPPED *io_info; /* the OVERLAPPED structure for async I/O */ | |
88 | BOOL subtree; /* whether to watch subdirectories */ | |
89 | DWORD filter; /* bit mask for events to watch */ | |
90 | char *watchee; /* the file we are interested in */ | |
91 | HANDLE dir; /* handle to the watched directory */ | |
92 | HANDLE thr; /* handle to the thread that watches */ | |
93 | int terminate; /* if non-zero, request for the thread to terminate */ | |
94 | }; | |
95 | ||
96 | /* FIXME: this needs to be changed to support more that one request at | |
97 | a time. */ | |
98 | static struct notification dirwatch; | |
99 | ||
100 | /* Used for communicating notifications to the main thread. */ | |
101 | int notification_buffer_in_use; | |
102 | BYTE file_notifications[16384]; | |
103 | DWORD notifications_size; | |
104 | HANDLE notifications_desc; | |
105 | ||
106 | static Lisp_Object Qfile_name, Qdirectory_name, Qattributes, Qsize; | |
107 | static Lisp_Object Qlast_write_time, Qlast_access_time, Qcreation_time; | |
108 | static Lisp_Object Qsecurity_desc, Qsubtree, watch_list; | |
109 | ||
6f011d81 EZ |
110 | /* Signal to the main thread that we have file notifications for it to |
111 | process. */ | |
112 | static void | |
113 | send_notifications (BYTE *info, DWORD info_size, HANDLE hdir, int *terminate) | |
114 | { | |
115 | int done = 0; | |
116 | FRAME_PTR f = SELECTED_FRAME (); | |
117 | ||
118 | /* Too bad, but PostMessage will not work in non-GUI sessions. | |
119 | FIXME. */ | |
120 | if (!FRAME_W32_P (f)) | |
121 | return; | |
122 | ||
123 | /* A single buffer is used to communicate all notifications to the | |
124 | main thread. Since both the main thread and several watcher | |
125 | threads could be active at the same time, we use a critical area | |
126 | and an "in-use" flag to synchronize them. A watcher thread can | |
127 | only put its notifications in the buffer if it acquires the | |
128 | critical area and finds the "in-use" flag reset. The main thread | |
129 | resets the flag after it is done processing notifications. | |
130 | ||
131 | FIXME: is there a better way of dealing with this? */ | |
132 | while (!done && !*terminate) | |
133 | { | |
134 | enter_crit (); | |
135 | if (!notification_buffer_in_use) | |
136 | { | |
137 | if (info_size) | |
138 | memcpy (file_notifications, info, info_size); | |
139 | notifications_size = info_size; | |
140 | notifications_desc = hdir; | |
141 | /* If PostMessage fails, the message queue is full. If that | |
142 | happens, the last thing they will worry about is file | |
143 | notifications. So we effectively discard the | |
144 | notification in that case. */ | |
145 | if (PostMessage (FRAME_W32_WINDOW (f), WM_EMACS_FILENOTIFY, 0, 0)) | |
146 | notification_buffer_in_use = 1; | |
147 | done = 1; | |
6f011d81 EZ |
148 | } |
149 | leave_crit (); | |
150 | if (!done) | |
151 | Sleep (5); | |
152 | } | |
153 | } | |
154 | ||
155 | /* An APC routine to cancel outstanding directory watch. Invoked by | |
156 | the main thread via QueueUserAPC. This is needed because only the | |
157 | thread that issued the ReadDirectoryChangesW call can call CancelIo | |
158 | to cancel that. (CancelIoEx is only available since Vista, so we | |
159 | cannot use it on XP.) */ | |
160 | VOID CALLBACK | |
161 | watch_end (ULONG_PTR arg) | |
162 | { | |
163 | HANDLE hdir = (HANDLE)arg; | |
164 | ||
165 | if (hdir && hdir != INVALID_HANDLE_VALUE) | |
166 | { | |
167 | CancelIo (hdir); | |
168 | CloseHandle (hdir); | |
169 | } | |
170 | } | |
171 | ||
172 | /* A completion routine (a.k.a. APC function) for handling events read | |
173 | by ReadDirectoryChangesW. Called by the OS when the thread which | |
174 | issued the asynchronous ReadDirectoryChangesW call is in the | |
175 | "alertable state", i.e. waiting inside SleepEx call. */ | |
176 | VOID CALLBACK | |
177 | watch_completion (DWORD status, DWORD bytes_ret, OVERLAPPED *io_info) | |
178 | { | |
179 | struct notification *dirwatch; | |
180 | ||
181 | /* Who knows what happened? Perhaps the OVERLAPPED structure was | |
182 | freed by someone already? In any case, we cannot do anything | |
183 | with this request, so just punt and skip it. FIXME: should we | |
184 | raise the 'terminate' flag in this case? */ | |
185 | if (!io_info) | |
186 | return; | |
187 | ||
188 | /* We have a pointer to our dirwatch structure conveniently stashed | |
189 | away in the hEvent member of the OVERLAPPED struct. According to | |
190 | MSDN documentation of ReadDirectoryChangesW: "The hEvent member | |
191 | of the OVERLAPPED structure is not used by the system, so you can | |
192 | use it yourself." */ | |
193 | dirwatch = (struct notification *)io_info->hEvent; | |
194 | if (status == ERROR_OPERATION_ABORTED) | |
195 | { | |
196 | /* We've been called because the main thread told us to issue | |
197 | CancelIo on the directory we watch, and watch_end did so. | |
198 | The directory handle is already closed. We should clean up | |
199 | and exit, signalling to the thread worker routine not to | |
200 | issue another call to ReadDirectoryChangesW. */ | |
201 | xfree (dirwatch->buf); | |
202 | dirwatch->buf = NULL; | |
203 | xfree (dirwatch->io_info); | |
204 | dirwatch->io_info = NULL; | |
205 | xfree (dirwatch->watchee); | |
206 | dirwatch->watchee = NULL; | |
7d605354 | 207 | dirwatch->dir = NULL; |
6f011d81 EZ |
208 | dirwatch->terminate = 1; |
209 | } | |
210 | else | |
211 | { | |
6f011d81 EZ |
212 | /* Tell the main thread we have notifications for it. */ |
213 | send_notifications (dirwatch->buf, bytes_ret, dirwatch->dir, | |
214 | &dirwatch->terminate); | |
215 | } | |
216 | } | |
217 | ||
218 | /* Worker routine for the watch thread. */ | |
219 | static DWORD WINAPI | |
220 | watch_worker (LPVOID arg) | |
221 | { | |
222 | struct notification *dirwatch = (struct notification *)arg; | |
223 | ||
224 | do { | |
225 | BOOL status; | |
226 | DWORD sleep_result; | |
227 | DWORD bytes_ret = 0; | |
228 | ||
229 | if (dirwatch->dir) | |
230 | { | |
231 | status = ReadDirectoryChangesW (dirwatch->dir, dirwatch->buf, 16384, | |
232 | dirwatch->subtree, dirwatch->filter, | |
233 | &bytes_ret, | |
234 | dirwatch->io_info, watch_completion); | |
235 | if (!status) | |
236 | { | |
c5c91b84 | 237 | DebPrint (("watch_worker, abnormal exit: %lu\n", GetLastError ())); |
6f011d81 EZ |
238 | xfree (dirwatch->buf); |
239 | dirwatch->buf = NULL; | |
240 | xfree (dirwatch->io_info); | |
241 | dirwatch->io_info = NULL; | |
242 | CloseHandle (dirwatch->dir); | |
243 | dirwatch->dir = NULL; | |
244 | xfree (dirwatch->watchee); | |
245 | dirwatch->watchee = NULL; | |
246 | return 1; | |
247 | } | |
248 | } | |
249 | /* Sleep indefinitely until awoken by the I/O completion, which | |
250 | could be either a change notification or a cancellation of the | |
251 | watch. */ | |
252 | sleep_result = SleepEx (INFINITE, TRUE); | |
6f011d81 EZ |
253 | } while (!dirwatch->terminate); |
254 | ||
6f011d81 EZ |
255 | return 0; |
256 | } | |
257 | ||
258 | /* Launch a thread to watch changes to FILE in a directory open on | |
259 | handle HDIR. */ | |
260 | static int | |
261 | start_watching (const char *file, HANDLE hdir, BOOL subdirs, DWORD flags) | |
262 | { | |
263 | dirwatch.buf = xmalloc (16384); | |
264 | dirwatch.io_info = xzalloc (sizeof(OVERLAPPED)); | |
265 | /* Stash a pointer to dirwatch structure for use by the completion | |
266 | routine. According to MSDN documentation of ReadDirectoryChangesW: | |
267 | "The hEvent member of the OVERLAPPED structure is not used by the | |
268 | system, so you can use it yourself." */ | |
269 | dirwatch.io_info->hEvent = &dirwatch; | |
270 | dirwatch.subtree = subdirs; | |
271 | dirwatch.filter = flags; | |
272 | dirwatch.watchee = xstrdup (file); | |
273 | dirwatch.terminate = 0; | |
274 | dirwatch.dir = hdir; | |
275 | ||
276 | /* See w32proc.c where it calls CreateThread for the story behind | |
277 | the 2nd and 5th argument in the call to CreateThread. */ | |
278 | dirwatch.thr = CreateThread (NULL, 64 * 1024, watch_worker, | |
279 | (void *)&dirwatch, 0x00010000, NULL); | |
280 | ||
281 | if (!dirwatch.thr) | |
282 | { | |
283 | dirwatch.terminate = 1; | |
284 | xfree (dirwatch.buf); | |
285 | dirwatch.buf = NULL; | |
286 | xfree (dirwatch.io_info); | |
287 | dirwatch.io_info = NULL; | |
288 | xfree (dirwatch.watchee); | |
289 | dirwatch.watchee = NULL; | |
7d605354 | 290 | dirwatch.dir = NULL; |
6f011d81 EZ |
291 | return -1; |
292 | } | |
293 | return 0; | |
294 | } | |
295 | ||
296 | /* Called from the main thread to start watching FILE in PARENT_DIR, | |
297 | subject to FLAGS. If SUBDIRS is TRUE, watch the subdirectories of | |
298 | PARENT_DIR as well. Value is the handle on which the directory is | |
299 | open. */ | |
300 | static HANDLE * | |
301 | add_watch (const char *parent_dir, const char *file, BOOL subdirs, DWORD flags) | |
302 | { | |
303 | HANDLE hdir; | |
304 | ||
305 | if (!file || !*file) | |
306 | return NULL; | |
307 | ||
308 | hdir = CreateFile (parent_dir, | |
309 | FILE_LIST_DIRECTORY, | |
310 | /* FILE_SHARE_DELETE doesn't preclude other | |
311 | processes from deleting files inside | |
312 | parent_dir. */ | |
313 | FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, | |
314 | NULL, OPEN_EXISTING, | |
315 | FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, | |
316 | NULL); | |
317 | if (hdir == INVALID_HANDLE_VALUE) | |
318 | return NULL; | |
319 | ||
320 | if (start_watching (file, hdir, subdirs, flags) == 0) | |
321 | return hdir; | |
322 | ||
323 | CloseHandle (hdir); | |
324 | return NULL; | |
325 | } | |
326 | ||
327 | /* Stop watching a directory specified by its handle HDIR. */ | |
328 | static int | |
329 | remove_watch (HANDLE hdir) | |
330 | { | |
331 | if (hdir == dirwatch.dir) | |
332 | { | |
333 | int i; | |
334 | BOOL status; | |
335 | DWORD exit_code, err; | |
336 | ||
337 | /* Only the thread that issued the outstanding I/O call can call | |
338 | CancelIo on it. (CancelIoEx is available only since Vista.) | |
339 | So we need to queue an APC for the worker thread telling it | |
340 | to terminate. */ | |
341 | if (!QueueUserAPC (watch_end, dirwatch.thr, (ULONG_PTR)dirwatch.dir)) | |
342 | DebPrint (("QueueUserAPC failed (%lu)!\n", GetLastError ())); | |
343 | /* We also set the terminate flag, for when the thread is | |
344 | waiting on the critical section that never gets acquired. | |
345 | FIXME: is there a cleaner method? Using SleepEx there is a | |
346 | no-no, as that will lead to recursive APC invocations and | |
347 | stack overflow. */ | |
348 | dirwatch.terminate = 1; | |
349 | /* Wait for the thread to exit. FIXME: is there a better method | |
350 | that is not overly complex? */ | |
351 | for (i = 0; i < 50; i++) | |
352 | { | |
353 | if (!((status = GetExitCodeThread (dirwatch.thr, &exit_code)) | |
354 | && exit_code == STILL_ACTIVE)) | |
355 | break; | |
356 | Sleep (10); | |
357 | } | |
358 | if ((status == FALSE && (err = GetLastError ()) == ERROR_INVALID_HANDLE) | |
359 | || exit_code == STILL_ACTIVE) | |
360 | { | |
361 | if (!(status == FALSE && err == ERROR_INVALID_HANDLE)) | |
362 | TerminateThread (dirwatch.thr, 0); | |
363 | } | |
364 | ||
365 | /* Clean up. */ | |
366 | if (dirwatch.thr) | |
367 | { | |
368 | CloseHandle (dirwatch.thr); | |
369 | dirwatch.thr = NULL; | |
370 | } | |
371 | return 0; | |
372 | } | |
373 | else if (!dirwatch.dir) | |
374 | { | |
375 | DebPrint (("Directory handle already closed!\n")); | |
376 | return 0; | |
377 | } | |
378 | else | |
379 | { | |
380 | DebPrint (("Unknown directory handle!\n")); | |
381 | return -1; | |
382 | } | |
383 | } | |
384 | ||
385 | static DWORD | |
386 | filter_list_to_flags (Lisp_Object filter_list) | |
387 | { | |
388 | DWORD flags = 0; | |
389 | ||
390 | if (NILP (filter_list)) | |
391 | return flags; | |
392 | ||
393 | if (!NILP (Fmember (Qfile_name, filter_list))) | |
394 | flags |= FILE_NOTIFY_CHANGE_FILE_NAME; | |
395 | if (!NILP (Fmember (Qdirectory_name, filter_list))) | |
396 | flags |= FILE_NOTIFY_CHANGE_DIR_NAME; | |
397 | if (!NILP (Fmember (Qattributes, filter_list))) | |
398 | flags |= FILE_NOTIFY_CHANGE_ATTRIBUTES; | |
399 | if (!NILP (Fmember (Qsize, filter_list))) | |
400 | flags |= FILE_NOTIFY_CHANGE_SIZE; | |
401 | if (!NILP (Fmember (Qlast_write_time, filter_list))) | |
402 | flags |= FILE_NOTIFY_CHANGE_LAST_WRITE; | |
403 | if (!NILP (Fmember (Qlast_access_time, filter_list))) | |
404 | flags |= FILE_NOTIFY_CHANGE_LAST_ACCESS; | |
405 | if (!NILP (Fmember (Qcreation_time, filter_list))) | |
406 | flags |= FILE_NOTIFY_CHANGE_CREATION; | |
407 | if (!NILP (Fmember (Qsecurity_desc, filter_list))) | |
408 | flags |= FILE_NOTIFY_CHANGE_SECURITY; | |
409 | ||
410 | return flags; | |
411 | } | |
412 | ||
413 | DEFUN ("w32notify-add-watch", Fw32notify_add_watch, | |
414 | Sw32notify_add_watch, 3, 3, 0, | |
415 | doc: /* Add a watch for filesystem events pertaining to FILE. | |
416 | ||
417 | This arranges for filesystem events pertaining to FILE to be reported | |
418 | to Emacs. Use `w32notify-rm-watch' to cancel the watch. | |
419 | ||
420 | Value is a descriptor for the added watch, or nil if the file | |
421 | cannot be watched. | |
422 | ||
423 | FILTER is a list of conditions for reporting an event. It can include | |
424 | the following symbols: | |
425 | ||
426 | 'file-name' -- report file creation, deletion, or renaming | |
427 | 'directory-name' -- report directory creation, deletion, or renaming | |
428 | 'attributes' -- report changes in attributes | |
429 | 'size' -- report changes in file-size | |
430 | 'last-write-time' -- report changes in last-write time | |
431 | 'last-access-time' -- report changes in last-access time | |
432 | 'creation-time' -- report changes in creation time | |
433 | 'security-desc' -- report changes in security descriptor | |
434 | ||
435 | If FILE is a directory, and FILTER includes 'subtree', then all the | |
436 | subdirectories will also be watched and changes in them reported. | |
437 | ||
438 | When any event happens that satisfies the conditions specified by | |
439 | FILTER, Emacs will call the CALLBACK function passing it a single | |
440 | argument EVENT, which is of the form | |
441 | ||
442 | (DESCRIPTOR ACTION FILE) | |
443 | ||
444 | DESCRIPTOR is the same object as the one returned by this function. | |
445 | ACTION is the description of the event. It could be any one of the | |
446 | following: | |
447 | ||
448 | 'added' -- FILE was added | |
449 | 'removed' -- FILE was deleted | |
450 | 'modified' -- FILE's contents or its attributes were modified | |
451 | 'renamed-from' -- a file was renamed whose old name was FILE | |
452 | 'renamed-to' -- a file was renamed and its new name is FILE | |
453 | ||
454 | FILE is the name of the file whose event is being reported. */) | |
455 | (Lisp_Object file, Lisp_Object filter, Lisp_Object callback) | |
456 | { | |
457 | Lisp_Object encoded_file, watch_object, watch_descriptor; | |
458 | char parent_dir[MAX_PATH], *basename; | |
459 | size_t fn_len; | |
460 | HANDLE hdir; | |
461 | DWORD flags; | |
462 | BOOL subdirs = FALSE; | |
463 | Lisp_Object lisp_errstr; | |
464 | char *errstr; | |
465 | ||
466 | CHECK_LIST (filter); | |
467 | ||
468 | /* The underlying features are available only since XP. */ | |
469 | if (os_subtype == OS_9X | |
470 | || (w32_major_version == 5 && w32_major_version < 1)) | |
471 | { | |
472 | errno = ENOSYS; | |
473 | report_file_error ("Watching filesystem events is not supported", | |
474 | Qnil); | |
475 | } | |
476 | ||
7d605354 EZ |
477 | if (dirwatch.dir) |
478 | error ("File watch already active"); | |
479 | ||
6f011d81 EZ |
480 | /* We needa full absolute file name of FILE, and we need to remove |
481 | any trailing slashes from it, so that GetFullPathName below gets | |
482 | the basename part correctly. */ | |
483 | file = Fdirectory_file_name (Fexpand_file_name (file, Qnil)); | |
484 | encoded_file = ENCODE_FILE (file); | |
485 | ||
486 | fn_len = GetFullPathName (SDATA (encoded_file), MAX_PATH, parent_dir, | |
487 | &basename); | |
488 | if (!fn_len) | |
489 | { | |
490 | errstr = w32_strerror (0); | |
491 | errno = EINVAL; | |
492 | if (!NILP (Vlocale_coding_system)) | |
493 | lisp_errstr | |
494 | = code_convert_string_norecord (build_unibyte_string (errstr), | |
495 | Vlocale_coding_system, 0); | |
496 | else | |
497 | lisp_errstr = build_string (errstr); | |
498 | report_file_error ("GetFullPathName failed", | |
499 | Fcons (lisp_errstr, Fcons (file, Qnil))); | |
500 | } | |
501 | /* We need the parent directory without the slash that follows it. | |
502 | If BASENAME is NULL, the argument was the root directory on its | |
503 | drive. */ | |
504 | if (basename) | |
505 | basename[-1] = '\0'; | |
506 | else | |
507 | subdirs = TRUE; | |
508 | ||
509 | if (!NILP (Fmember (Qsubtree, filter))) | |
510 | subdirs = TRUE; | |
511 | ||
512 | flags = filter_list_to_flags (filter); | |
513 | ||
514 | hdir = add_watch (parent_dir, basename, subdirs, flags); | |
515 | if (!hdir) | |
516 | { | |
517 | DWORD err = GetLastError (); | |
518 | ||
519 | errno = EINVAL; | |
520 | if (err) | |
521 | { | |
522 | errstr = w32_strerror (err); | |
523 | if (!NILP (Vlocale_coding_system)) | |
524 | lisp_errstr | |
525 | = code_convert_string_norecord (build_unibyte_string (errstr), | |
526 | Vlocale_coding_system, 0); | |
527 | else | |
528 | lisp_errstr = build_string (errstr); | |
529 | report_file_error ("Cannot watch file", | |
530 | Fcons (lisp_errstr, Fcons (file, Qnil))); | |
531 | } | |
532 | else | |
533 | report_file_error ("Cannot watch file", Fcons (file, Qnil)); | |
534 | } | |
535 | /* Store watch object in watch list. */ | |
536 | watch_descriptor = make_number (hdir); | |
537 | watch_object = Fcons (watch_descriptor, callback); | |
538 | watch_list = Fcons (watch_object, watch_list); | |
539 | ||
540 | return watch_descriptor; | |
541 | } | |
542 | ||
543 | DEFUN ("w32notify-rm-watch", Fw32notify_rm_watch, | |
544 | Sw32notify_rm_watch, 1, 1, 0, | |
545 | doc: /* Remove an existing watch specified by its WATCH-DESCRIPTOR. | |
546 | ||
547 | WATCH-DESCRIPTOR should be an object returned by `w32notify-add-watch'. */) | |
548 | (Lisp_Object watch_descriptor) | |
549 | { | |
550 | Lisp_Object watch_object; | |
551 | HANDLE hdir = (HANDLE)XINT (watch_descriptor); | |
552 | ||
553 | if (remove_watch (hdir) == -1) | |
554 | report_file_error ("Could not remove watch", Fcons (watch_descriptor, | |
555 | Qnil)); | |
556 | ||
557 | /* Remove watch descriptor from watch list. */ | |
558 | watch_object = Fassoc (watch_descriptor, watch_list); | |
559 | if (!NILP (watch_object)) | |
560 | watch_list = Fdelete (watch_object, watch_list); | |
561 | ||
562 | return Qnil; | |
563 | } | |
564 | ||
565 | Lisp_Object | |
566 | get_watch_object (Lisp_Object desc) | |
567 | { | |
568 | return Fassoc (desc, watch_list); | |
569 | } | |
570 | ||
571 | void | |
572 | syms_of_w32notify (void) | |
573 | { | |
574 | DEFSYM (Qfile_name, "file-name"); | |
575 | DEFSYM (Qdirectory_name, "directory-name"); | |
576 | DEFSYM (Qattributes, "attributes"); | |
577 | DEFSYM (Qsize, "size"); | |
578 | DEFSYM (Qlast_write_time, "last-write-time"); | |
579 | DEFSYM (Qlast_access_time, "last-access-time"); | |
580 | DEFSYM (Qcreation_time, "creation-time"); | |
581 | DEFSYM (Qsecurity_desc, "security-desc"); | |
582 | DEFSYM (Qsubtree, "subtree"); | |
583 | ||
584 | defsubr (&Sw32notify_add_watch); | |
585 | defsubr (&Sw32notify_rm_watch); | |
586 | ||
587 | staticpro (&watch_list); | |
588 | ||
589 | Fprovide (intern_c_string ("w32notify"), Qnil); | |
590 | } |