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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 | ||
977c6479 EZ |
39 | In a GUI session, The WM_EMACS_FILENOTIFY message, posted to the |
40 | message queue gets dispatched to the main Emacs window procedure, | |
41 | which queues it for processing by w32_read_socket. When | |
42 | w32_read_socket sees this message, it accesses the buffer with file | |
43 | notifications (using a critical section), extracts the information, | |
44 | converts it to a series of FILE_NOTIFY_EVENT events, and stuffs | |
45 | them into the input event queue to be processed by keyboard.c input | |
46 | machinery (read_char via a call to kbd_buffer_get_event). | |
47 | ||
48 | In a non-GUI session, we send the WM_EMACS_FILENOTIFY message to | |
49 | the main (a.k.a. "Lisp") thread instead, since there are no window | |
50 | procedures in console programs. That message wakes up | |
51 | MsgWaitForMultipleObjects inside sys_select, which then signals to | |
52 | its caller that some keyboard input is available. This causes | |
53 | w32_console_read_socket to be called, which accesses the buffer | |
54 | with file notifications and stuffs them into the input event queue | |
55 | for keyboard.c to process. | |
56 | ||
57 | When the FILE_NOTIFY_EVENT event is processed by keyboard.c's | |
58 | kbd_buffer_get_event, it is converted to a Lispy event that can be | |
59 | bound to a command. The default binding is w32notify-handle-event, | |
60 | defined on subr.el. | |
61 | ||
62 | After w32_read_socket or w32_console_read_socket is done processing | |
63 | the notifications, it resets a flag signaling to all watch worker | |
64 | threads that the notifications buffer is available for more input. | |
c5c91b84 EZ |
65 | |
66 | When the watch is removed by a call to w32notify-rm-watch, the main | |
67 | thread requests that the worker thread terminates by queuing an APC | |
68 | for the worker thread. The APC specifies the watch_end function to | |
69 | be called. watch_end calls CancelIo on the outstanding | |
70 | ReadDirectoryChangesW call and closes the handle on which the | |
71 | watched directory was open. When watch_end returns, the | |
72 | watch_completion function is called one last time with the | |
73 | ERROR_OPERATION_ABORTED status, which causes it to clean up and set | |
74 | a flag telling watch_worker to exit without issuing another | |
d6de1760 EZ |
75 | ReadDirectoryChangesW call. The main thread waits for some time |
76 | for the worker thread to exit, and if it doesn't, terminates it | |
77 | forcibly. */ | |
c5c91b84 | 78 | |
6f011d81 EZ |
79 | #include <stddef.h> |
80 | #include <errno.h> | |
81 | ||
82 | /* must include CRT headers *before* config.h */ | |
83 | #include <config.h> | |
84 | ||
85 | #include <windows.h> | |
86 | ||
87 | #include "lisp.h" | |
88 | #include "w32term.h" /* for enter_crit/leave_crit and WM_EMACS_FILENOTIFY */ | |
eb3abb61 | 89 | #include "w32common.h" /* for OS version data */ |
6f011d81 EZ |
90 | #include "w32.h" /* for w32_strerror */ |
91 | #include "coding.h" | |
92 | #include "keyboard.h" | |
93 | #include "frame.h" /* needed by termhooks.h */ | |
94 | #include "termhooks.h" /* for FILE_NOTIFY_EVENT */ | |
95 | ||
37a4dabe EZ |
96 | #define DIRWATCH_SIGNATURE 0x01233210 |
97 | ||
6f011d81 EZ |
98 | struct notification { |
99 | BYTE *buf; /* buffer for ReadDirectoryChangesW */ | |
100 | OVERLAPPED *io_info; /* the OVERLAPPED structure for async I/O */ | |
101 | BOOL subtree; /* whether to watch subdirectories */ | |
102 | DWORD filter; /* bit mask for events to watch */ | |
103 | char *watchee; /* the file we are interested in */ | |
104 | HANDLE dir; /* handle to the watched directory */ | |
105 | HANDLE thr; /* handle to the thread that watches */ | |
0b86d359 | 106 | volatile int terminate; /* if non-zero, request for the thread to terminate */ |
37a4dabe | 107 | unsigned signature; |
6f011d81 EZ |
108 | }; |
109 | ||
6f011d81 | 110 | /* Used for communicating notifications to the main thread. */ |
0b86d359 | 111 | volatile int notification_buffer_in_use; |
6f011d81 EZ |
112 | BYTE file_notifications[16384]; |
113 | DWORD notifications_size; | |
37a4dabe | 114 | void *notifications_desc; |
6f011d81 EZ |
115 | |
116 | static Lisp_Object Qfile_name, Qdirectory_name, Qattributes, Qsize; | |
117 | static Lisp_Object Qlast_write_time, Qlast_access_time, Qcreation_time; | |
118 | static Lisp_Object Qsecurity_desc, Qsubtree, watch_list; | |
119 | ||
6f011d81 EZ |
120 | /* Signal to the main thread that we have file notifications for it to |
121 | process. */ | |
122 | static void | |
0b86d359 EZ |
123 | send_notifications (BYTE *info, DWORD info_size, void *desc, |
124 | volatile int *terminate) | |
6f011d81 EZ |
125 | { |
126 | int done = 0; | |
127 | FRAME_PTR f = SELECTED_FRAME (); | |
128 | ||
6f011d81 EZ |
129 | /* A single buffer is used to communicate all notifications to the |
130 | main thread. Since both the main thread and several watcher | |
131 | threads could be active at the same time, we use a critical area | |
132 | and an "in-use" flag to synchronize them. A watcher thread can | |
133 | only put its notifications in the buffer if it acquires the | |
134 | critical area and finds the "in-use" flag reset. The main thread | |
135 | resets the flag after it is done processing notifications. | |
136 | ||
137 | FIXME: is there a better way of dealing with this? */ | |
138 | while (!done && !*terminate) | |
139 | { | |
140 | enter_crit (); | |
141 | if (!notification_buffer_in_use) | |
142 | { | |
143 | if (info_size) | |
144 | memcpy (file_notifications, info, info_size); | |
145 | notifications_size = info_size; | |
37a4dabe | 146 | notifications_desc = desc; |
977c6479 EZ |
147 | /* If PostMessage fails, the message queue is full. If that |
148 | happens, the last thing they will worry about is file | |
149 | notifications. So we effectively discard the | |
150 | notification in that case. */ | |
151 | if ((FRAME_TERMCAP_P (f) | |
152 | /* We send the message to the main (a.k.a. "Lisp") | |
153 | thread, where it will wake up MsgWaitForMultipleObjects | |
154 | inside sys_select, causing it to report that there's | |
155 | some keyboard input available. This will in turn cause | |
156 | w32_console_read_socket to be called, which will pick | |
157 | up the file notifications. */ | |
158 | && PostThreadMessage (dwMainThreadId, WM_EMACS_FILENOTIFY, 0, 0)) | |
182b170f | 159 | || (FRAME_W32_P (f) |
182b170f EZ |
160 | && PostMessage (FRAME_W32_WINDOW (f), |
161 | WM_EMACS_FILENOTIFY, 0, 0))) | |
6f011d81 EZ |
162 | notification_buffer_in_use = 1; |
163 | done = 1; | |
6f011d81 EZ |
164 | } |
165 | leave_crit (); | |
166 | if (!done) | |
167 | Sleep (5); | |
168 | } | |
169 | } | |
170 | ||
171 | /* An APC routine to cancel outstanding directory watch. Invoked by | |
172 | the main thread via QueueUserAPC. This is needed because only the | |
173 | thread that issued the ReadDirectoryChangesW call can call CancelIo | |
174 | to cancel that. (CancelIoEx is only available since Vista, so we | |
175 | cannot use it on XP.) */ | |
176 | VOID CALLBACK | |
177 | watch_end (ULONG_PTR arg) | |
178 | { | |
179 | HANDLE hdir = (HANDLE)arg; | |
180 | ||
181 | if (hdir && hdir != INVALID_HANDLE_VALUE) | |
182 | { | |
183 | CancelIo (hdir); | |
184 | CloseHandle (hdir); | |
185 | } | |
186 | } | |
187 | ||
188 | /* A completion routine (a.k.a. APC function) for handling events read | |
189 | by ReadDirectoryChangesW. Called by the OS when the thread which | |
190 | issued the asynchronous ReadDirectoryChangesW call is in the | |
191 | "alertable state", i.e. waiting inside SleepEx call. */ | |
192 | VOID CALLBACK | |
193 | watch_completion (DWORD status, DWORD bytes_ret, OVERLAPPED *io_info) | |
194 | { | |
195 | struct notification *dirwatch; | |
196 | ||
197 | /* Who knows what happened? Perhaps the OVERLAPPED structure was | |
198 | freed by someone already? In any case, we cannot do anything | |
199 | with this request, so just punt and skip it. FIXME: should we | |
200 | raise the 'terminate' flag in this case? */ | |
201 | if (!io_info) | |
202 | return; | |
203 | ||
204 | /* We have a pointer to our dirwatch structure conveniently stashed | |
205 | away in the hEvent member of the OVERLAPPED struct. According to | |
206 | MSDN documentation of ReadDirectoryChangesW: "The hEvent member | |
207 | of the OVERLAPPED structure is not used by the system, so you can | |
208 | use it yourself." */ | |
209 | dirwatch = (struct notification *)io_info->hEvent; | |
210 | if (status == ERROR_OPERATION_ABORTED) | |
211 | { | |
212 | /* We've been called because the main thread told us to issue | |
213 | CancelIo on the directory we watch, and watch_end did so. | |
214 | The directory handle is already closed. We should clean up | |
215 | and exit, signalling to the thread worker routine not to | |
37a4dabe EZ |
216 | issue another call to ReadDirectoryChangesW. Note that we |
217 | don't free the dirwatch object itself; this is done by the | |
218 | main thread in remove_watch. */ | |
6f011d81 EZ |
219 | xfree (dirwatch->buf); |
220 | dirwatch->buf = NULL; | |
221 | xfree (dirwatch->io_info); | |
222 | dirwatch->io_info = NULL; | |
223 | xfree (dirwatch->watchee); | |
224 | dirwatch->watchee = NULL; | |
7d605354 | 225 | dirwatch->dir = NULL; |
6f011d81 EZ |
226 | dirwatch->terminate = 1; |
227 | } | |
228 | else | |
229 | { | |
6f011d81 | 230 | /* Tell the main thread we have notifications for it. */ |
37a4dabe | 231 | send_notifications (dirwatch->buf, bytes_ret, dirwatch, |
6f011d81 EZ |
232 | &dirwatch->terminate); |
233 | } | |
234 | } | |
235 | ||
236 | /* Worker routine for the watch thread. */ | |
237 | static DWORD WINAPI | |
238 | watch_worker (LPVOID arg) | |
239 | { | |
240 | struct notification *dirwatch = (struct notification *)arg; | |
241 | ||
242 | do { | |
243 | BOOL status; | |
244 | DWORD sleep_result; | |
245 | DWORD bytes_ret = 0; | |
246 | ||
247 | if (dirwatch->dir) | |
248 | { | |
249 | status = ReadDirectoryChangesW (dirwatch->dir, dirwatch->buf, 16384, | |
250 | dirwatch->subtree, dirwatch->filter, | |
251 | &bytes_ret, | |
252 | dirwatch->io_info, watch_completion); | |
253 | if (!status) | |
254 | { | |
c5c91b84 | 255 | DebPrint (("watch_worker, abnormal exit: %lu\n", GetLastError ())); |
37a4dabe EZ |
256 | /* We cannot remove the dirwatch object from watch_list, |
257 | because we are in a separate thread. So we free and | |
258 | zero out all the pointers in the object, but do not | |
259 | free the object itself. We also don't touch the | |
260 | signature. This way, remove_watch can still identify | |
261 | the object, remove it, and free its memory. */ | |
6f011d81 EZ |
262 | xfree (dirwatch->buf); |
263 | dirwatch->buf = NULL; | |
264 | xfree (dirwatch->io_info); | |
265 | dirwatch->io_info = NULL; | |
266 | CloseHandle (dirwatch->dir); | |
267 | dirwatch->dir = NULL; | |
268 | xfree (dirwatch->watchee); | |
269 | dirwatch->watchee = NULL; | |
270 | return 1; | |
271 | } | |
272 | } | |
273 | /* Sleep indefinitely until awoken by the I/O completion, which | |
274 | could be either a change notification or a cancellation of the | |
275 | watch. */ | |
276 | sleep_result = SleepEx (INFINITE, TRUE); | |
6f011d81 EZ |
277 | } while (!dirwatch->terminate); |
278 | ||
6f011d81 EZ |
279 | return 0; |
280 | } | |
281 | ||
282 | /* Launch a thread to watch changes to FILE in a directory open on | |
283 | handle HDIR. */ | |
37a4dabe | 284 | static struct notification * |
6f011d81 EZ |
285 | start_watching (const char *file, HANDLE hdir, BOOL subdirs, DWORD flags) |
286 | { | |
37a4dabe EZ |
287 | struct notification *dirwatch = xzalloc (sizeof (struct notification)); |
288 | HANDLE thr; | |
289 | ||
290 | dirwatch->signature = DIRWATCH_SIGNATURE; | |
291 | dirwatch->buf = xmalloc (16384); | |
292 | dirwatch->io_info = xzalloc (sizeof(OVERLAPPED)); | |
6f011d81 EZ |
293 | /* Stash a pointer to dirwatch structure for use by the completion |
294 | routine. According to MSDN documentation of ReadDirectoryChangesW: | |
295 | "The hEvent member of the OVERLAPPED structure is not used by the | |
296 | system, so you can use it yourself." */ | |
37a4dabe EZ |
297 | dirwatch->io_info->hEvent = dirwatch; |
298 | dirwatch->subtree = subdirs; | |
299 | dirwatch->filter = flags; | |
300 | dirwatch->watchee = xstrdup (file); | |
301 | dirwatch->terminate = 0; | |
302 | dirwatch->dir = hdir; | |
6f011d81 EZ |
303 | |
304 | /* See w32proc.c where it calls CreateThread for the story behind | |
305 | the 2nd and 5th argument in the call to CreateThread. */ | |
37a4dabe EZ |
306 | dirwatch->thr = CreateThread (NULL, 64 * 1024, watch_worker, (void *)dirwatch, |
307 | 0x00010000, NULL); | |
6f011d81 | 308 | |
37a4dabe | 309 | if (!dirwatch->thr) |
6f011d81 | 310 | { |
37a4dabe EZ |
311 | xfree (dirwatch->buf); |
312 | xfree (dirwatch->io_info); | |
313 | xfree (dirwatch->watchee); | |
314 | xfree (dirwatch); | |
315 | dirwatch = NULL; | |
6f011d81 | 316 | } |
37a4dabe | 317 | return dirwatch; |
6f011d81 EZ |
318 | } |
319 | ||
320 | /* Called from the main thread to start watching FILE in PARENT_DIR, | |
321 | subject to FLAGS. If SUBDIRS is TRUE, watch the subdirectories of | |
37a4dabe EZ |
322 | PARENT_DIR as well. Value is a pointer to 'struct notification' |
323 | used by the thread that watches the changes. */ | |
324 | static struct notification * | |
6f011d81 EZ |
325 | add_watch (const char *parent_dir, const char *file, BOOL subdirs, DWORD flags) |
326 | { | |
327 | HANDLE hdir; | |
37a4dabe | 328 | struct notification *dirwatch = NULL; |
6f011d81 EZ |
329 | |
330 | if (!file || !*file) | |
331 | return NULL; | |
332 | ||
333 | hdir = CreateFile (parent_dir, | |
334 | FILE_LIST_DIRECTORY, | |
335 | /* FILE_SHARE_DELETE doesn't preclude other | |
336 | processes from deleting files inside | |
337 | parent_dir. */ | |
338 | FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, | |
339 | NULL, OPEN_EXISTING, | |
340 | FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OVERLAPPED, | |
341 | NULL); | |
342 | if (hdir == INVALID_HANDLE_VALUE) | |
343 | return NULL; | |
344 | ||
37a4dabe EZ |
345 | if ((dirwatch = start_watching (file, hdir, subdirs, flags)) == NULL) |
346 | CloseHandle (hdir); | |
6f011d81 | 347 | |
37a4dabe | 348 | return dirwatch; |
6f011d81 EZ |
349 | } |
350 | ||
37a4dabe | 351 | /* Stop watching a directory specified by a pointer to its dirwatch object. */ |
6f011d81 | 352 | static int |
37a4dabe | 353 | remove_watch (struct notification *dirwatch) |
6f011d81 | 354 | { |
37a4dabe | 355 | if (dirwatch && dirwatch->signature == DIRWATCH_SIGNATURE) |
6f011d81 EZ |
356 | { |
357 | int i; | |
358 | BOOL status; | |
359 | DWORD exit_code, err; | |
360 | ||
361 | /* Only the thread that issued the outstanding I/O call can call | |
362 | CancelIo on it. (CancelIoEx is available only since Vista.) | |
363 | So we need to queue an APC for the worker thread telling it | |
364 | to terminate. */ | |
37a4dabe | 365 | if (!QueueUserAPC (watch_end, dirwatch->thr, (ULONG_PTR)dirwatch->dir)) |
6f011d81 EZ |
366 | DebPrint (("QueueUserAPC failed (%lu)!\n", GetLastError ())); |
367 | /* We also set the terminate flag, for when the thread is | |
368 | waiting on the critical section that never gets acquired. | |
369 | FIXME: is there a cleaner method? Using SleepEx there is a | |
370 | no-no, as that will lead to recursive APC invocations and | |
371 | stack overflow. */ | |
37a4dabe | 372 | dirwatch->terminate = 1; |
6f011d81 EZ |
373 | /* Wait for the thread to exit. FIXME: is there a better method |
374 | that is not overly complex? */ | |
375 | for (i = 0; i < 50; i++) | |
376 | { | |
37a4dabe | 377 | if (!((status = GetExitCodeThread (dirwatch->thr, &exit_code)) |
6f011d81 EZ |
378 | && exit_code == STILL_ACTIVE)) |
379 | break; | |
380 | Sleep (10); | |
381 | } | |
382 | if ((status == FALSE && (err = GetLastError ()) == ERROR_INVALID_HANDLE) | |
383 | || exit_code == STILL_ACTIVE) | |
384 | { | |
385 | if (!(status == FALSE && err == ERROR_INVALID_HANDLE)) | |
37a4dabe EZ |
386 | { |
387 | TerminateThread (dirwatch->thr, 0); | |
388 | if (dirwatch->dir) | |
389 | CloseHandle (dirwatch->dir); | |
390 | } | |
6f011d81 EZ |
391 | } |
392 | ||
393 | /* Clean up. */ | |
37a4dabe | 394 | if (dirwatch->thr) |
6f011d81 | 395 | { |
37a4dabe EZ |
396 | CloseHandle (dirwatch->thr); |
397 | dirwatch->thr = NULL; | |
6f011d81 | 398 | } |
37a4dabe EZ |
399 | xfree (dirwatch->buf); |
400 | xfree (dirwatch->io_info); | |
401 | xfree (dirwatch->watchee); | |
402 | xfree (dirwatch); | |
403 | ||
6f011d81 EZ |
404 | return 0; |
405 | } | |
406 | else | |
407 | { | |
37a4dabe | 408 | DebPrint (("Unknown dirwatch object!\n")); |
6f011d81 EZ |
409 | return -1; |
410 | } | |
411 | } | |
412 | ||
413 | static DWORD | |
414 | filter_list_to_flags (Lisp_Object filter_list) | |
415 | { | |
416 | DWORD flags = 0; | |
417 | ||
418 | if (NILP (filter_list)) | |
419 | return flags; | |
420 | ||
421 | if (!NILP (Fmember (Qfile_name, filter_list))) | |
422 | flags |= FILE_NOTIFY_CHANGE_FILE_NAME; | |
423 | if (!NILP (Fmember (Qdirectory_name, filter_list))) | |
424 | flags |= FILE_NOTIFY_CHANGE_DIR_NAME; | |
425 | if (!NILP (Fmember (Qattributes, filter_list))) | |
426 | flags |= FILE_NOTIFY_CHANGE_ATTRIBUTES; | |
427 | if (!NILP (Fmember (Qsize, filter_list))) | |
428 | flags |= FILE_NOTIFY_CHANGE_SIZE; | |
429 | if (!NILP (Fmember (Qlast_write_time, filter_list))) | |
430 | flags |= FILE_NOTIFY_CHANGE_LAST_WRITE; | |
431 | if (!NILP (Fmember (Qlast_access_time, filter_list))) | |
432 | flags |= FILE_NOTIFY_CHANGE_LAST_ACCESS; | |
433 | if (!NILP (Fmember (Qcreation_time, filter_list))) | |
434 | flags |= FILE_NOTIFY_CHANGE_CREATION; | |
435 | if (!NILP (Fmember (Qsecurity_desc, filter_list))) | |
436 | flags |= FILE_NOTIFY_CHANGE_SECURITY; | |
437 | ||
438 | return flags; | |
439 | } | |
440 | ||
441 | DEFUN ("w32notify-add-watch", Fw32notify_add_watch, | |
442 | Sw32notify_add_watch, 3, 3, 0, | |
443 | doc: /* Add a watch for filesystem events pertaining to FILE. | |
444 | ||
445 | This arranges for filesystem events pertaining to FILE to be reported | |
446 | to Emacs. Use `w32notify-rm-watch' to cancel the watch. | |
447 | ||
448 | Value is a descriptor for the added watch, or nil if the file | |
449 | cannot be watched. | |
450 | ||
451 | FILTER is a list of conditions for reporting an event. It can include | |
452 | the following symbols: | |
453 | ||
454 | 'file-name' -- report file creation, deletion, or renaming | |
455 | 'directory-name' -- report directory creation, deletion, or renaming | |
456 | 'attributes' -- report changes in attributes | |
457 | 'size' -- report changes in file-size | |
458 | 'last-write-time' -- report changes in last-write time | |
459 | 'last-access-time' -- report changes in last-access time | |
460 | 'creation-time' -- report changes in creation time | |
461 | 'security-desc' -- report changes in security descriptor | |
462 | ||
463 | If FILE is a directory, and FILTER includes 'subtree', then all the | |
464 | subdirectories will also be watched and changes in them reported. | |
465 | ||
466 | When any event happens that satisfies the conditions specified by | |
467 | FILTER, Emacs will call the CALLBACK function passing it a single | |
468 | argument EVENT, which is of the form | |
469 | ||
470 | (DESCRIPTOR ACTION FILE) | |
471 | ||
472 | DESCRIPTOR is the same object as the one returned by this function. | |
473 | ACTION is the description of the event. It could be any one of the | |
474 | following: | |
475 | ||
476 | 'added' -- FILE was added | |
477 | 'removed' -- FILE was deleted | |
478 | 'modified' -- FILE's contents or its attributes were modified | |
479 | 'renamed-from' -- a file was renamed whose old name was FILE | |
480 | 'renamed-to' -- a file was renamed and its new name is FILE | |
481 | ||
482 | FILE is the name of the file whose event is being reported. */) | |
483 | (Lisp_Object file, Lisp_Object filter, Lisp_Object callback) | |
484 | { | |
485 | Lisp_Object encoded_file, watch_object, watch_descriptor; | |
486 | char parent_dir[MAX_PATH], *basename; | |
487 | size_t fn_len; | |
6f011d81 EZ |
488 | DWORD flags; |
489 | BOOL subdirs = FALSE; | |
37a4dabe | 490 | struct notification *dirwatch = NULL; |
6f011d81 EZ |
491 | Lisp_Object lisp_errstr; |
492 | char *errstr; | |
493 | ||
494 | CHECK_LIST (filter); | |
495 | ||
496 | /* The underlying features are available only since XP. */ | |
497 | if (os_subtype == OS_9X | |
498 | || (w32_major_version == 5 && w32_major_version < 1)) | |
499 | { | |
500 | errno = ENOSYS; | |
501 | report_file_error ("Watching filesystem events is not supported", | |
502 | Qnil); | |
503 | } | |
504 | ||
37a4dabe | 505 | /* We need a full absolute file name of FILE, and we need to remove |
6f011d81 EZ |
506 | any trailing slashes from it, so that GetFullPathName below gets |
507 | the basename part correctly. */ | |
508 | file = Fdirectory_file_name (Fexpand_file_name (file, Qnil)); | |
509 | encoded_file = ENCODE_FILE (file); | |
510 | ||
511 | fn_len = GetFullPathName (SDATA (encoded_file), MAX_PATH, parent_dir, | |
512 | &basename); | |
513 | if (!fn_len) | |
514 | { | |
515 | errstr = w32_strerror (0); | |
516 | errno = EINVAL; | |
517 | if (!NILP (Vlocale_coding_system)) | |
518 | lisp_errstr | |
519 | = code_convert_string_norecord (build_unibyte_string (errstr), | |
520 | Vlocale_coding_system, 0); | |
521 | else | |
522 | lisp_errstr = build_string (errstr); | |
523 | report_file_error ("GetFullPathName failed", | |
524 | Fcons (lisp_errstr, Fcons (file, Qnil))); | |
525 | } | |
526 | /* We need the parent directory without the slash that follows it. | |
527 | If BASENAME is NULL, the argument was the root directory on its | |
528 | drive. */ | |
529 | if (basename) | |
530 | basename[-1] = '\0'; | |
531 | else | |
532 | subdirs = TRUE; | |
533 | ||
534 | if (!NILP (Fmember (Qsubtree, filter))) | |
535 | subdirs = TRUE; | |
536 | ||
537 | flags = filter_list_to_flags (filter); | |
538 | ||
37a4dabe EZ |
539 | dirwatch = add_watch (parent_dir, basename, subdirs, flags); |
540 | if (!dirwatch) | |
6f011d81 EZ |
541 | { |
542 | DWORD err = GetLastError (); | |
543 | ||
544 | errno = EINVAL; | |
545 | if (err) | |
546 | { | |
547 | errstr = w32_strerror (err); | |
548 | if (!NILP (Vlocale_coding_system)) | |
549 | lisp_errstr | |
550 | = code_convert_string_norecord (build_unibyte_string (errstr), | |
551 | Vlocale_coding_system, 0); | |
552 | else | |
553 | lisp_errstr = build_string (errstr); | |
554 | report_file_error ("Cannot watch file", | |
555 | Fcons (lisp_errstr, Fcons (file, Qnil))); | |
556 | } | |
557 | else | |
558 | report_file_error ("Cannot watch file", Fcons (file, Qnil)); | |
559 | } | |
560 | /* Store watch object in watch list. */ | |
0b86d359 | 561 | watch_descriptor = XIL ((EMACS_INT)dirwatch); |
6f011d81 EZ |
562 | watch_object = Fcons (watch_descriptor, callback); |
563 | watch_list = Fcons (watch_object, watch_list); | |
564 | ||
565 | return watch_descriptor; | |
566 | } | |
567 | ||
568 | DEFUN ("w32notify-rm-watch", Fw32notify_rm_watch, | |
569 | Sw32notify_rm_watch, 1, 1, 0, | |
570 | doc: /* Remove an existing watch specified by its WATCH-DESCRIPTOR. | |
571 | ||
572 | WATCH-DESCRIPTOR should be an object returned by `w32notify-add-watch'. */) | |
573 | (Lisp_Object watch_descriptor) | |
574 | { | |
575 | Lisp_Object watch_object; | |
0b86d359 EZ |
576 | struct notification *dirwatch; |
577 | int status = -1; | |
6f011d81 | 578 | |
37a4dabe EZ |
579 | /* Remove the watch object from watch list. Do this before freeing |
580 | the object, do that even if we fail to free it, watch_list is | |
581 | kept free of junk. */ | |
6f011d81 EZ |
582 | watch_object = Fassoc (watch_descriptor, watch_list); |
583 | if (!NILP (watch_object)) | |
0b86d359 EZ |
584 | { |
585 | watch_list = Fdelete (watch_object, watch_list); | |
586 | dirwatch = (struct notification *)XLI (watch_descriptor); | |
587 | if (w32_valid_pointer_p (dirwatch, sizeof(struct notification))) | |
588 | status = remove_watch (dirwatch); | |
589 | } | |
6f011d81 | 590 | |
0b86d359 | 591 | if (status == -1) |
37a4dabe EZ |
592 | report_file_error ("Invalid watch descriptor", Fcons (watch_descriptor, |
593 | Qnil)); | |
594 | ||
6f011d81 EZ |
595 | return Qnil; |
596 | } | |
597 | ||
598 | Lisp_Object | |
0b86d359 | 599 | w32_get_watch_object (void *desc) |
37a4dabe | 600 | { |
0b86d359 EZ |
601 | Lisp_Object descriptor = XIL ((EMACS_INT)desc); |
602 | ||
d884121b EZ |
603 | /* This is called from the input queue handling code, inside a |
604 | critical section, so we cannot possibly QUIT if watch_list is not | |
605 | in the right condition. */ | |
0b86d359 | 606 | return NILP (watch_list) ? Qnil : assoc_no_quit (descriptor, watch_list); |
37a4dabe EZ |
607 | } |
608 | ||
609 | void | |
610 | globals_of_w32notify (void) | |
6f011d81 | 611 | { |
37a4dabe | 612 | watch_list = Qnil; |
6f011d81 EZ |
613 | } |
614 | ||
615 | void | |
616 | syms_of_w32notify (void) | |
617 | { | |
618 | DEFSYM (Qfile_name, "file-name"); | |
619 | DEFSYM (Qdirectory_name, "directory-name"); | |
620 | DEFSYM (Qattributes, "attributes"); | |
621 | DEFSYM (Qsize, "size"); | |
622 | DEFSYM (Qlast_write_time, "last-write-time"); | |
623 | DEFSYM (Qlast_access_time, "last-access-time"); | |
624 | DEFSYM (Qcreation_time, "creation-time"); | |
625 | DEFSYM (Qsecurity_desc, "security-desc"); | |
626 | DEFSYM (Qsubtree, "subtree"); | |
627 | ||
628 | defsubr (&Sw32notify_add_watch); | |
629 | defsubr (&Sw32notify_rm_watch); | |
630 | ||
631 | staticpro (&watch_list); | |
632 | ||
633 | Fprovide (intern_c_string ("w32notify"), Qnil); | |
634 | } |