diff options
Diffstat (limited to 'Utilities/cmlibuv/src/unix/linux-inotify.c')
-rw-r--r-- | Utilities/cmlibuv/src/unix/linux-inotify.c | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/Utilities/cmlibuv/src/unix/linux-inotify.c b/Utilities/cmlibuv/src/unix/linux-inotify.c new file mode 100644 index 0000000..4708c05 --- /dev/null +++ b/Utilities/cmlibuv/src/unix/linux-inotify.c @@ -0,0 +1,285 @@ +/* Copyright Joyent, Inc. and other Node contributors. All rights reserved. + * Permission is hereby granted, free of charge, to any person obtaining a copy + * of this software and associated documentation files (the "Software"), to + * deal in the Software without restriction, including without limitation the + * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or + * sell copies of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be included in + * all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE + * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS + * IN THE SOFTWARE. + */ + +#include "uv.h" +#include "tree.h" +#include "internal.h" + +#include <stdint.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <errno.h> + +#include <sys/types.h> +#include <unistd.h> + +struct watcher_list { + RB_ENTRY(watcher_list) entry; + QUEUE watchers; + int iterating; + char* path; + int wd; +}; + +struct watcher_root { + struct watcher_list* rbh_root; +}; +#define CAST(p) ((struct watcher_root*)(p)) + + +static int compare_watchers(const struct watcher_list* a, + const struct watcher_list* b) { + if (a->wd < b->wd) return -1; + if (a->wd > b->wd) return 1; + return 0; +} + + +RB_GENERATE_STATIC(watcher_root, watcher_list, entry, compare_watchers) + + +static void uv__inotify_read(uv_loop_t* loop, + uv__io_t* w, + unsigned int revents); + + +static int new_inotify_fd(void) { + int err; + int fd; + + fd = uv__inotify_init1(UV__IN_NONBLOCK | UV__IN_CLOEXEC); + if (fd != -1) + return fd; + + if (errno != ENOSYS) + return -errno; + + fd = uv__inotify_init(); + if (fd == -1) + return -errno; + + err = uv__cloexec(fd, 1); + if (err == 0) + err = uv__nonblock(fd, 1); + + if (err) { + uv__close(fd); + return err; + } + + return fd; +} + + +static int init_inotify(uv_loop_t* loop) { + int err; + + if (loop->inotify_fd != -1) + return 0; + + err = new_inotify_fd(); + if (err < 0) + return err; + + loop->inotify_fd = err; + uv__io_init(&loop->inotify_read_watcher, uv__inotify_read, loop->inotify_fd); + uv__io_start(loop, &loop->inotify_read_watcher, POLLIN); + + return 0; +} + + +static struct watcher_list* find_watcher(uv_loop_t* loop, int wd) { + struct watcher_list w; + w.wd = wd; + return RB_FIND(watcher_root, CAST(&loop->inotify_watchers), &w); +} + +static void maybe_free_watcher_list(struct watcher_list* w, uv_loop_t* loop) { + /* if the watcher_list->watchers is being iterated over, we can't free it. */ + if ((!w->iterating) && QUEUE_EMPTY(&w->watchers)) { + /* No watchers left for this path. Clean up. */ + RB_REMOVE(watcher_root, CAST(&loop->inotify_watchers), w); + uv__inotify_rm_watch(loop->inotify_fd, w->wd); + uv__free(w); + } +} + +static void uv__inotify_read(uv_loop_t* loop, + uv__io_t* dummy, + unsigned int events) { + const struct uv__inotify_event* e; + struct watcher_list* w; + uv_fs_event_t* h; + QUEUE queue; + QUEUE* q; + const char* path; + ssize_t size; + const char *p; + /* needs to be large enough for sizeof(inotify_event) + strlen(path) */ + char buf[4096]; + + while (1) { + do + size = read(loop->inotify_fd, buf, sizeof(buf)); + while (size == -1 && errno == EINTR); + + if (size == -1) { + assert(errno == EAGAIN || errno == EWOULDBLOCK); + break; + } + + assert(size > 0); /* pre-2.6.21 thing, size=0 == read buffer too small */ + + /* Now we have one or more inotify_event structs. */ + for (p = buf; p < buf + size; p += sizeof(*e) + e->len) { + e = (const struct uv__inotify_event*)p; + + events = 0; + if (e->mask & (UV__IN_ATTRIB|UV__IN_MODIFY)) + events |= UV_CHANGE; + if (e->mask & ~(UV__IN_ATTRIB|UV__IN_MODIFY)) + events |= UV_RENAME; + + w = find_watcher(loop, e->wd); + if (w == NULL) + continue; /* Stale event, no watchers left. */ + + /* inotify does not return the filename when monitoring a single file + * for modifications. Repurpose the filename for API compatibility. + * I'm not convinced this is a good thing, maybe it should go. + */ + path = e->len ? (const char*) (e + 1) : uv__basename_r(w->path); + + /* We're about to iterate over the queue and call user's callbacks. + * What can go wrong? + * A callback could call uv_fs_event_stop() + * and the queue can change under our feet. + * So, we use QUEUE_MOVE() trick to safely iterate over the queue. + * And we don't free the watcher_list until we're done iterating. + * + * First, + * tell uv_fs_event_stop() (that could be called from a user's callback) + * not to free watcher_list. + */ + w->iterating = 1; + QUEUE_MOVE(&w->watchers, &queue); + while (!QUEUE_EMPTY(&queue)) { + q = QUEUE_HEAD(&queue); + h = QUEUE_DATA(q, uv_fs_event_t, watchers); + + QUEUE_REMOVE(q); + QUEUE_INSERT_TAIL(&w->watchers, q); + + h->cb(h, path, events, 0); + } + /* done iterating, time to (maybe) free empty watcher_list */ + w->iterating = 0; + maybe_free_watcher_list(w, loop); + } + } +} + + +int uv_fs_event_init(uv_loop_t* loop, uv_fs_event_t* handle) { + uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_EVENT); + return 0; +} + + +int uv_fs_event_start(uv_fs_event_t* handle, + uv_fs_event_cb cb, + const char* path, + unsigned int flags) { + struct watcher_list* w; + int events; + int err; + int wd; + + if (uv__is_active(handle)) + return -EINVAL; + + err = init_inotify(handle->loop); + if (err) + return err; + + events = UV__IN_ATTRIB + | UV__IN_CREATE + | UV__IN_MODIFY + | UV__IN_DELETE + | UV__IN_DELETE_SELF + | UV__IN_MOVE_SELF + | UV__IN_MOVED_FROM + | UV__IN_MOVED_TO; + + wd = uv__inotify_add_watch(handle->loop->inotify_fd, path, events); + if (wd == -1) + return -errno; + + w = find_watcher(handle->loop, wd); + if (w) + goto no_insert; + + w = uv__malloc(sizeof(*w) + strlen(path) + 1); + if (w == NULL) + return -ENOMEM; + + w->wd = wd; + w->path = strcpy((char*)(w + 1), path); + QUEUE_INIT(&w->watchers); + w->iterating = 0; + RB_INSERT(watcher_root, CAST(&handle->loop->inotify_watchers), w); + +no_insert: + uv__handle_start(handle); + QUEUE_INSERT_TAIL(&w->watchers, &handle->watchers); + handle->path = w->path; + handle->cb = cb; + handle->wd = wd; + + return 0; +} + + +int uv_fs_event_stop(uv_fs_event_t* handle) { + struct watcher_list* w; + + if (!uv__is_active(handle)) + return 0; + + w = find_watcher(handle->loop, handle->wd); + assert(w != NULL); + + handle->wd = -1; + handle->path = NULL; + uv__handle_stop(handle); + QUEUE_REMOVE(&handle->watchers); + + maybe_free_watcher_list(w, handle->loop); + + return 0; +} + + +void uv__fs_event_close(uv_fs_event_t* handle) { + uv_fs_event_stop(handle); +} |