deps/libuv/src/unix/kqueue.c
/* 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 "internal.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/sysctl.h>
#include <sys/types.h>
#include <sys/event.h>
#include <sys/time.h>
#include <unistd.h>
#include <fcntl.h>
#include <time.h>
static void uv__fs_event(uv_loop_t* loop, uv__io_t* w, unsigned int fflags);
int uv__kqueue_init(uv_loop_t* loop) {
loop->backend_fd = kqueue();
if (loop->backend_fd == -1)
return -1;
uv__cloexec(loop->backend_fd, 1);
return 0;
}
void uv__io_poll(uv_loop_t* loop, int timeout) {
struct kevent events[1024];
struct kevent* ev;
struct timespec spec;
unsigned int nevents;
unsigned int revents;
ngx_queue_t* q;
uint64_t base;
uint64_t diff;
uv__io_t* w;
int filter;
int fflags;
int count;
int nfds;
int fd;
int op;
int i;
if (loop->nfds == 0) {
assert(ngx_queue_empty(&loop->watcher_queue));
return;
}
nevents = 0;
while (!ngx_queue_empty(&loop->watcher_queue)) {
q = ngx_queue_head(&loop->watcher_queue);
ngx_queue_remove(q);
ngx_queue_init(q);
w = ngx_queue_data(q, uv__io_t, watcher_queue);
assert(w->pevents != 0);
assert(w->fd >= 0);
assert(w->fd < (int) loop->nwatchers);
if ((w->events & UV__POLLIN) == 0 && (w->pevents & UV__POLLIN) != 0) {
filter = EVFILT_READ;
fflags = 0;
op = EV_ADD;
if (w->cb == uv__fs_event) {
filter = EVFILT_VNODE;
fflags = NOTE_ATTRIB | NOTE_WRITE | NOTE_RENAME
| NOTE_DELETE | NOTE_EXTEND | NOTE_REVOKE;
op = EV_ADD | EV_ONESHOT; /* Stop the event from firing repeatedly. */
}
EV_SET(events + nevents, w->fd, filter, op, fflags, 0, 0);
if (++nevents == ARRAY_SIZE(events)) {
if (kevent(loop->backend_fd, events, nevents, NULL, 0, NULL))
abort();
nevents = 0;
}
}
if ((w->events & UV__POLLOUT) == 0 && (w->pevents & UV__POLLOUT) != 0) {
EV_SET(events + nevents, w->fd, EVFILT_WRITE, EV_ADD, 0, 0, 0);
if (++nevents == ARRAY_SIZE(events)) {
if (kevent(loop->backend_fd, events, nevents, NULL, 0, NULL))
abort();
nevents = 0;
}
}
w->events = w->pevents;
}
assert(timeout >= -1);
base = loop->time;
count = 48; /* Benchmarks suggest this gives the best throughput. */
for (;; nevents = 0) {
if (timeout != -1) {
spec.tv_sec = timeout / 1000;
spec.tv_nsec = (timeout % 1000) * 1000000;
}
nfds = kevent(loop->backend_fd,
events,
nevents,
events,
ARRAY_SIZE(events),
timeout == -1 ? NULL : &spec);
/* Update loop->time unconditionally. It's tempting to skip the update when
* timeout == 0 (i.e. non-blocking poll) but there is no guarantee that the
* operating system didn't reschedule our process while in the syscall.
*/
SAVE_ERRNO(uv__update_time(loop));
if (nfds == 0) {
assert(timeout != -1);
return;
}
if (nfds == -1) {
if (errno != EINTR)
abort();
if (timeout == 0)
return;
if (timeout == -1)
continue;
/* Interrupted by a signal. Update timeout and poll again. */
goto update_timeout;
}
nevents = 0;
for (i = 0; i < nfds; i++) {
ev = events + i;
fd = ev->ident;
w = loop->watchers[fd];
if (w == NULL) {
/* File descriptor that we've stopped watching, disarm it. */
/* TODO batch up */
struct kevent events[1];
EV_SET(events + 0, fd, ev->filter, EV_DELETE, 0, 0, 0);
if (kevent(loop->backend_fd, events, 1, NULL, 0, NULL))
if (errno != EBADF && errno != ENOENT)
abort();
continue;
}
if (ev->filter == EVFILT_VNODE) {
assert(w->events == UV__POLLIN);
assert(w->pevents == UV__POLLIN);
w->cb(loop, w, ev->fflags); /* XXX always uv__fs_event() */
nevents++;
continue;
}
revents = 0;
if (ev->filter == EVFILT_READ) {
if (w->events & UV__POLLIN) {
revents |= UV__POLLIN;
w->rcount = ev->data;
} else {
/* TODO batch up */
struct kevent events[1];
EV_SET(events + 0, fd, ev->filter, EV_DELETE, 0, 0, 0);
if (kevent(loop->backend_fd, events, 1, NULL, 0, NULL))
if (errno != ENOENT)
abort();
}
}
if (ev->filter == EVFILT_WRITE) {
if (w->events & UV__POLLOUT) {
revents |= UV__POLLOUT;
w->wcount = ev->data;
} else {
/* TODO batch up */
struct kevent events[1];
EV_SET(events + 0, fd, ev->filter, EV_DELETE, 0, 0, 0);
if (kevent(loop->backend_fd, events, 1, NULL, 0, NULL))
if (errno != ENOENT)
abort();
}
}
if (ev->flags & EV_ERROR)
revents |= UV__POLLERR;
if (revents == 0)
continue;
w->cb(loop, w, revents);
nevents++;
}
if (nevents != 0) {
if (nfds == ARRAY_SIZE(events) && --count != 0) {
/* Poll for more events but don't block this time. */
timeout = 0;
continue;
}
return;
}
if (timeout == 0)
return;
if (timeout == -1)
continue;
update_timeout:
assert(timeout > 0);
diff = loop->time - base;
if (diff >= (uint64_t) timeout)
return;
timeout -= diff;
}
}
static void uv__fs_event(uv_loop_t* loop, uv__io_t* w, unsigned int fflags) {
uv_fs_event_t* handle;
struct kevent ev;
int events;
handle = container_of(w, uv_fs_event_t, event_watcher);
if (fflags & (NOTE_ATTRIB | NOTE_EXTEND))
events = UV_CHANGE;
else
events = UV_RENAME;
handle->cb(handle, NULL, events, 0);
if (handle->event_watcher.fd == -1)
return;
/* Watcher operates in one-shot mode, re-arm it. */
fflags = NOTE_ATTRIB | NOTE_WRITE | NOTE_RENAME
| NOTE_DELETE | NOTE_EXTEND | NOTE_REVOKE;
EV_SET(&ev, w->fd, EVFILT_VNODE, EV_ADD | EV_ONESHOT, fflags, 0, 0);
if (kevent(loop->backend_fd, &ev, 1, NULL, 0, NULL))
abort();
}
int uv_fs_event_init(uv_loop_t* loop,
uv_fs_event_t* handle,
const char* filename,
uv_fs_event_cb cb,
int flags) {
#if defined(__APPLE__)
struct stat statbuf;
#endif /* defined(__APPLE__) */
int fd;
/* TODO open asynchronously - but how do we report back errors? */
if ((fd = open(filename, O_RDONLY)) == -1) {
uv__set_sys_error(loop, errno);
return -1;
}
uv__handle_init(loop, (uv_handle_t*)handle, UV_FS_EVENT);
uv__handle_start(handle); /* FIXME shouldn't start automatically */
uv__io_init(&handle->event_watcher, uv__fs_event, fd);
handle->filename = strdup(filename);
handle->cb = cb;
#if defined(__APPLE__)
/* Nullify field to perform checks later */
handle->cf_eventstream = NULL;
handle->realpath = NULL;
handle->realpath_len = 0;
handle->cf_flags = flags;
if (fstat(fd, &statbuf))
goto fallback;
/* FSEvents works only with directories */
if (!(statbuf.st_mode & S_IFDIR))
goto fallback;
return uv__fsevents_init(handle);
fallback:
#endif /* defined(__APPLE__) */
uv__io_start(loop, &handle->event_watcher, UV__POLLIN);
return 0;
}
void uv__fs_event_close(uv_fs_event_t* handle) {
#if defined(__APPLE__)
if (uv__fsevents_close(handle))
uv__io_stop(handle->loop, &handle->event_watcher, UV__POLLIN);
#else
uv__io_stop(handle->loop, &handle->event_watcher, UV__POLLIN);
#endif /* defined(__APPLE__) */
uv__handle_stop(handle);
free(handle->filename);
handle->filename = NULL;
close(handle->event_watcher.fd);
handle->event_watcher.fd = -1;
}