Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
kqueue: don't immediately remove watches for all files in a directory…
… on Delete event (#526) The problem was that that on Delete events for directories it would call Watcher.Remove() for all files in that directory too. This is fine if you call w.Remove() from the application, but if you rm -rf a directory the directory itself tends to be the first remove event (on FreeBSD at least): DELETE WRITE /tmp/xxx DELETE /tmp/xxx/a DELETE /tmp/xxx/b DELETE /tmp/xxx/c DELETE /tmp/xxx/d DELETE /tmp/xxx/e DELETE /tmp/xxx/f DELETE /tmp/xxx/g So what would happen is that the internal state for /tmp/xxx/a etc. would get removed, and when the event gets processed we no longer have access to it. Move Remove() to remove() with a flag to control removing files. If a watched directory is removed then the files will emit their own delete event, so we don't really need to do this. Fixes #514 Also: - Don't send Remove|Write events; that's never really useful: if it's gone, then it's gone. No other backends do this. - Save a stat call by checking the readdir error instead. - Don't stat every directory; this isn't really needed, and getting a write event before a delete is fine (and this didn't suppress the write even anyway). - Add test/kqueue.c; just a simple implementation to test things.
- Loading branch information
Showing
3 changed files
with
201 additions
and
58 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,123 @@ | ||
| // This is an example kqueue program which watches a directory and all paths in | ||
| // it with the same flags as those fsnotify uses. This is useful sometimes to | ||
| // test what events kqueue sends with as little abstraction as possible. | ||
| // | ||
| // Note this does *not* set up monitoring on new files as they're created. | ||
| // | ||
| // Usage: | ||
| // cc kqueue.c -o kqueue | ||
| // ./kqueue /path/to/dir | ||
|
|
||
| #include <sys/event.h> | ||
| #include <sys/time.h> | ||
| #include <dirent.h> | ||
| #include <fcntl.h> | ||
| #include <stdarg.h> | ||
| #include <stdio.h> | ||
| #include <stdlib.h> | ||
| #include <string.h> | ||
| #include <unistd.h> | ||
|
|
||
| void die(const char *fmt, ...) { | ||
| va_list ap; | ||
| va_start(ap, fmt); | ||
| vfprintf(stderr, fmt, ap); | ||
| va_end(ap); | ||
|
|
||
| if (fmt[0] && fmt[strlen(fmt)-1] == ':') { | ||
| fputc(' ', stderr); | ||
| perror(NULL); | ||
| } | ||
| else | ||
| fputc('\n', stderr); | ||
|
|
||
| exit(1); | ||
| } | ||
|
|
||
| int main(int argc, char* argv[]) { | ||
| if (argc < 2) { | ||
| fprintf(stderr, "usage: %s path/to/dir\n", argv[0]); | ||
| return 1; | ||
| } | ||
| char *dir = argv[1]; | ||
|
|
||
| int kq = kqueue(); | ||
| if (kq == -1) | ||
| die("kqueue:"); | ||
|
|
||
| int fp = open(dir, O_RDONLY); | ||
| if (fp == -1) | ||
| die("open: %s:", dir); | ||
| DIR *dp = fdopendir(fp); | ||
| if (dp == NULL) | ||
| die("fdopendir:"); | ||
|
|
||
| int fds[1024] = {fp}; | ||
| char *names[1024] = {dir}; | ||
| int n_fds = 0; | ||
| struct dirent *ls; | ||
| while ((ls = readdir(dp)) != NULL) { | ||
| if (ls->d_name[0] == '.') | ||
| continue; | ||
|
|
||
| char *path = malloc(strlen(dir) + strlen(ls->d_name) + 2); | ||
| sprintf(path, "%s/%s", dir, ls->d_name); | ||
|
|
||
| int fp = open(path, O_RDONLY); | ||
| if (fp == -1) | ||
| die("open: %s:", path); | ||
| fds[++n_fds] = fp; | ||
| names[n_fds] = path; | ||
| } | ||
|
|
||
| for (int i=0; i<=n_fds; i++) { | ||
| struct kevent changes; | ||
| EV_SET(&changes, fds[i], EVFILT_VNODE, | ||
| EV_ADD | EV_CLEAR | EV_ENABLE, | ||
| NOTE_DELETE | NOTE_WRITE | NOTE_ATTRIB | NOTE_RENAME, | ||
| 0, 0); | ||
|
|
||
| int n = kevent(kq, &changes, 1, NULL, 0, NULL); | ||
| if (n == -1) | ||
| die("register kevent changes:"); | ||
| } | ||
|
|
||
| printf("Ready; press ^C to exit\n"); | ||
| for (;;) { | ||
| struct kevent event; | ||
| int n = kevent(kq, NULL, 0, &event, 1, NULL); | ||
| if (n == -1) | ||
| die("kevent:"); | ||
| if (n == 0) | ||
| continue; | ||
|
|
||
| char *ev_name = malloc(128); | ||
| if (event.fflags & NOTE_WRITE) | ||
| strncat(ev_name, "WRITE ", 6); | ||
| if (event.fflags & NOTE_RENAME) | ||
| strncat(ev_name, "RENAME ", 6); | ||
| if (event.fflags & NOTE_ATTRIB) | ||
| strncat(ev_name, "CHMOD ", 5); | ||
| if (event.fflags & NOTE_DELETE) { | ||
| strncat(ev_name, "DELETE ", 7); | ||
| struct kevent changes; | ||
| EV_SET(&changes, event.ident, EVFILT_VNODE, | ||
| EV_DELETE, | ||
| NOTE_DELETE | NOTE_WRITE | NOTE_ATTRIB | NOTE_RENAME, | ||
| 0, 0); | ||
| int n = kevent(kq, &changes, 1, NULL, 0, NULL); | ||
| if (n == -1) | ||
| die("remove kevent on delete:"); | ||
| } | ||
|
|
||
| char *name; | ||
| for (int i=0; i<=n_fds; i++) | ||
| if (fds[i] == event.ident) { | ||
| name = names[i]; | ||
| break; | ||
| } | ||
|
|
||
| printf("%-13s %s\n", ev_name, name); | ||
| } | ||
| return 0; | ||
| } |