2 * uloop - event loop implementation
4 * Copyright (C) 2010-2016 Felix Fietkau <nbd@openwrt.org>
6 * Permission to use, copy, modify, and/or distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 #include <sys/types.h>
34 #include <sys/event.h>
37 #include <sys/epoll.h>
41 struct uloop_fd_event
{
46 struct uloop_fd_stack
{
47 struct uloop_fd_stack
*next
;
52 static struct uloop_fd_stack
*fd_stack
= NULL
;
54 #define ULOOP_MAX_EVENTS 10
56 static struct list_head timeouts
= LIST_HEAD_INIT(timeouts
);
57 static struct list_head processes
= LIST_HEAD_INIT(processes
);
59 static int poll_fd
= -1;
60 bool uloop_cancelled
= false;
61 bool uloop_handle_sigchld
= true;
62 static int uloop_status
= 0;
63 static bool do_sigchld
= false;
65 static struct uloop_fd_event cur_fds
[ULOOP_MAX_EVENTS
];
66 static int cur_fd
, cur_nfds
;
67 static int uloop_run_depth
= 0;
69 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
);
72 #include "uloop-kqueue.c"
76 #include "uloop-epoll.c"
79 static void waker_consume(struct uloop_fd
*fd
, unsigned int events
)
83 while (read(fd
->fd
, buf
, 4) > 0)
87 static int waker_pipe
= -1;
88 static struct uloop_fd waker_fd
= {
93 static void waker_init_fd(int fd
)
95 fcntl(fd
, F_SETFD
, fcntl(fd
, F_GETFD
) | FD_CLOEXEC
);
96 fcntl(fd
, F_SETFL
, fcntl(fd
, F_GETFL
) | O_NONBLOCK
);
99 static int waker_init(void)
109 waker_init_fd(fds
[0]);
110 waker_init_fd(fds
[1]);
113 waker_fd
.fd
= fds
[0];
114 waker_fd
.cb
= waker_consume
;
115 uloop_fd_add(&waker_fd
, ULOOP_READ
);
120 static void uloop_setup_signals(bool add
);
124 if (uloop_init_pollfd() < 0)
127 if (waker_init() < 0) {
132 uloop_setup_signals(true);
137 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
139 struct uloop_fd_stack
*cur
;
142 * Do not buffer events for level-triggered fds, they will keep firing.
143 * Caller needs to take care of recursion issues.
145 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
148 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
155 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
163 static void uloop_run_events(int timeout
)
165 struct uloop_fd_event
*cur
;
170 cur_nfds
= uloop_fetch_events(timeout
);
175 while (cur_nfds
> 0) {
176 struct uloop_fd_stack stack_cur
;
179 cur
= &cur_fds
[cur_fd
++];
183 events
= cur
->events
;
190 if (uloop_fd_stack_event(fd
, cur
->events
))
193 stack_cur
.next
= fd_stack
;
195 fd_stack
= &stack_cur
;
197 stack_cur
.events
= 0;
199 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
200 } while (stack_cur
.fd
&& events
);
201 fd_stack
= stack_cur
.next
;
207 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
212 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
213 return uloop_fd_delete(sock
);
215 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
216 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
218 fcntl(sock
->fd
, F_SETFL
, fl
);
221 ret
= register_poll(sock
, flags
);
225 sock
->registered
= true;
233 int uloop_fd_delete(struct uloop_fd
*fd
)
237 for (i
= 0; i
< cur_nfds
; i
++) {
238 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
241 cur_fds
[cur_fd
+ i
].fd
= NULL
;
247 fd
->registered
= false;
248 uloop_fd_stack_event(fd
, -1);
249 return __uloop_fd_delete(fd
);
252 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
255 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
256 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
259 int uloop_timeout_add(struct uloop_timeout
*timeout
)
261 struct uloop_timeout
*tmp
;
262 struct list_head
*h
= &timeouts
;
264 if (timeout
->pending
)
267 list_for_each_entry(tmp
, &timeouts
, list
) {
268 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
274 list_add_tail(&timeout
->list
, h
);
275 timeout
->pending
= true;
280 static void uloop_gettime(struct timeval
*tv
)
284 clock_gettime(CLOCK_MONOTONIC
, &ts
);
285 tv
->tv_sec
= ts
.tv_sec
;
286 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
289 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
291 struct timeval
*time
= &timeout
->time
;
293 if (timeout
->pending
)
294 uloop_timeout_cancel(timeout
);
298 time
->tv_sec
+= msecs
/ 1000;
299 time
->tv_usec
+= (msecs
% 1000) * 1000;
301 if (time
->tv_usec
> 1000000) {
303 time
->tv_usec
-= 1000000;
306 return uloop_timeout_add(timeout
);
309 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
311 if (!timeout
->pending
)
314 list_del(&timeout
->list
);
315 timeout
->pending
= false;
320 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
324 if (!timeout
->pending
)
329 return tv_diff(&timeout
->time
, &now
);
332 int uloop_process_add(struct uloop_process
*p
)
334 struct uloop_process
*tmp
;
335 struct list_head
*h
= &processes
;
340 list_for_each_entry(tmp
, &processes
, list
) {
341 if (tmp
->pid
> p
->pid
) {
347 list_add_tail(&p
->list
, h
);
353 int uloop_process_delete(struct uloop_process
*p
)
364 static void uloop_handle_processes(void)
366 struct uloop_process
*p
, *tmp
;
373 pid
= waitpid(-1, &ret
, WNOHANG
);
374 if (pid
< 0 && errno
== EINTR
)
380 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
387 uloop_process_delete(p
);
394 static void uloop_signal_wake(void)
397 if (write(waker_pipe
, "w", 1) < 0) {
405 static void uloop_handle_sigint(int signo
)
407 uloop_status
= signo
;
408 uloop_cancelled
= true;
412 static void uloop_sigchld(int signo
)
418 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
421 struct sigaction
*act
;
424 sigaction(signum
, NULL
, &s
);
427 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
428 memcpy(old
, &s
, sizeof(struct sigaction
));
429 s
.sa_handler
= handler
;
434 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
439 sigaction(signum
, act
, NULL
);
442 static void uloop_ignore_signal(int signum
, bool ignore
)
445 void *new_handler
= NULL
;
447 sigaction(signum
, NULL
, &s
);
450 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
451 new_handler
= SIG_IGN
;
453 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
454 new_handler
= SIG_DFL
;
458 s
.sa_handler
= new_handler
;
460 sigaction(signum
, &s
, NULL
);
464 static void uloop_setup_signals(bool add
)
466 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
;
468 uloop_install_handler(SIGINT
, uloop_handle_sigint
, &old_sigint
, add
);
469 uloop_install_handler(SIGTERM
, uloop_handle_sigint
, &old_sigterm
, add
);
471 if (uloop_handle_sigchld
)
472 uloop_install_handler(SIGCHLD
, uloop_sigchld
, &old_sigchld
, add
);
474 uloop_ignore_signal(SIGPIPE
, add
);
477 static int uloop_get_next_timeout(struct timeval
*tv
)
479 struct uloop_timeout
*timeout
;
482 if (list_empty(&timeouts
))
485 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
486 diff
= tv_diff(&timeout
->time
, tv
);
493 static void uloop_process_timeouts(struct timeval
*tv
)
495 struct uloop_timeout
*t
;
497 while (!list_empty(&timeouts
)) {
498 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
500 if (tv_diff(&t
->time
, tv
) > 0)
503 uloop_timeout_cancel(t
);
509 static void uloop_clear_timeouts(void)
511 struct uloop_timeout
*t
, *tmp
;
513 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
514 uloop_timeout_cancel(t
);
517 static void uloop_clear_processes(void)
519 struct uloop_process
*p
, *tmp
;
521 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
522 uloop_process_delete(p
);
525 bool uloop_cancelling(void)
527 return uloop_run_depth
> 0 && uloop_cancelled
;
530 int uloop_run_timeout(int timeout
)
538 uloop_cancelled
= false;
539 while (!uloop_cancelled
)
542 uloop_process_timeouts(&tv
);
545 uloop_handle_processes();
552 next_time
= uloop_get_next_timeout(&tv
);
553 if (timeout
>= 0 && timeout
< next_time
)
555 uloop_run_events(next_time
);
563 void uloop_done(void)
565 uloop_setup_signals(false);
572 if (waker_pipe
>= 0) {
573 uloop_fd_delete(&waker_fd
);
579 uloop_clear_timeouts();
580 uloop_clear_processes();