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 static bool do_sigchld
= false;
63 static struct uloop_fd_event cur_fds
[ULOOP_MAX_EVENTS
];
64 static int cur_fd
, cur_nfds
;
66 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
);
69 #include "uloop-kqueue.c"
73 #include "uloop-epoll.c"
76 static void waker_consume(struct uloop_fd
*fd
, unsigned int events
)
80 while (read(fd
->fd
, buf
, 4) > 0)
84 static int waker_pipe
= -1;
85 static struct uloop_fd waker_fd
= {
90 static void waker_init_fd(int fd
)
92 fcntl(fd
, F_SETFD
, fcntl(fd
, F_GETFD
) | FD_CLOEXEC
);
93 fcntl(fd
, F_SETFL
, fcntl(fd
, F_GETFL
) | O_NONBLOCK
);
96 static int waker_init(void)
106 waker_init_fd(fds
[0]);
107 waker_init_fd(fds
[1]);
110 waker_fd
.fd
= fds
[0];
111 waker_fd
.cb
= waker_consume
;
112 uloop_fd_add(&waker_fd
, ULOOP_READ
);
119 if (uloop_init_pollfd() < 0)
122 if (waker_init() < 0) {
130 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
132 struct uloop_fd_stack
*cur
;
135 * Do not buffer events for level-triggered fds, they will keep firing.
136 * Caller needs to take care of recursion issues.
138 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
141 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
148 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
156 static void uloop_run_events(int timeout
)
158 struct uloop_fd_event
*cur
;
163 cur_nfds
= uloop_fetch_events(timeout
);
168 while (cur_nfds
> 0) {
169 struct uloop_fd_stack stack_cur
;
172 cur
= &cur_fds
[cur_fd
++];
176 events
= cur
->events
;
183 if (uloop_fd_stack_event(fd
, cur
->events
))
186 stack_cur
.next
= fd_stack
;
188 fd_stack
= &stack_cur
;
190 stack_cur
.events
= 0;
192 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
193 } while (stack_cur
.fd
&& events
);
194 fd_stack
= stack_cur
.next
;
200 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
205 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
206 return uloop_fd_delete(sock
);
208 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
209 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
211 fcntl(sock
->fd
, F_SETFL
, fl
);
214 ret
= register_poll(sock
, flags
);
218 sock
->registered
= true;
226 int uloop_fd_delete(struct uloop_fd
*fd
)
230 for (i
= 0; i
< cur_nfds
; i
++) {
231 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
234 cur_fds
[cur_fd
+ i
].fd
= NULL
;
240 fd
->registered
= false;
241 uloop_fd_stack_event(fd
, -1);
242 return __uloop_fd_delete(fd
);
245 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
248 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
249 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
252 int uloop_timeout_add(struct uloop_timeout
*timeout
)
254 struct uloop_timeout
*tmp
;
255 struct list_head
*h
= &timeouts
;
257 if (timeout
->pending
)
260 list_for_each_entry(tmp
, &timeouts
, list
) {
261 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
267 list_add_tail(&timeout
->list
, h
);
268 timeout
->pending
= true;
273 static void uloop_gettime(struct timeval
*tv
)
277 clock_gettime(CLOCK_MONOTONIC
, &ts
);
278 tv
->tv_sec
= ts
.tv_sec
;
279 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
282 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
284 struct timeval
*time
= &timeout
->time
;
286 if (timeout
->pending
)
287 uloop_timeout_cancel(timeout
);
291 time
->tv_sec
+= msecs
/ 1000;
292 time
->tv_usec
+= (msecs
% 1000) * 1000;
294 if (time
->tv_usec
> 1000000) {
296 time
->tv_usec
-= 1000000;
299 return uloop_timeout_add(timeout
);
302 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
304 if (!timeout
->pending
)
307 list_del(&timeout
->list
);
308 timeout
->pending
= false;
313 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
317 if (!timeout
->pending
)
322 return tv_diff(&timeout
->time
, &now
);
325 int uloop_process_add(struct uloop_process
*p
)
327 struct uloop_process
*tmp
;
328 struct list_head
*h
= &processes
;
333 list_for_each_entry(tmp
, &processes
, list
) {
334 if (tmp
->pid
> p
->pid
) {
340 list_add_tail(&p
->list
, h
);
346 int uloop_process_delete(struct uloop_process
*p
)
357 static void uloop_handle_processes(void)
359 struct uloop_process
*p
, *tmp
;
366 pid
= waitpid(-1, &ret
, WNOHANG
);
367 if (pid
< 0 && errno
== EINTR
)
373 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
380 uloop_process_delete(p
);
387 static void uloop_signal_wake(void)
389 write(waker_pipe
, "w", 1);
392 static void uloop_handle_sigint(int signo
)
394 uloop_cancelled
= true;
398 static void uloop_sigchld(int signo
)
404 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
407 struct sigaction
*act
;
410 sigaction(signum
, NULL
, &s
);
413 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
414 memcpy(old
, &s
, sizeof(struct sigaction
));
415 s
.sa_handler
= handler
;
420 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
425 sigaction(signum
, act
, NULL
);
428 static void uloop_ignore_signal(int signum
, bool ignore
)
431 void *new_handler
= NULL
;
433 sigaction(signum
, NULL
, &s
);
436 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
437 new_handler
= SIG_IGN
;
439 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
440 new_handler
= SIG_DFL
;
444 s
.sa_handler
= new_handler
;
446 sigaction(signum
, &s
, NULL
);
450 static void uloop_setup_signals(bool add
)
452 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
;
454 uloop_install_handler(SIGINT
, uloop_handle_sigint
, &old_sigint
, add
);
455 uloop_install_handler(SIGTERM
, uloop_handle_sigint
, &old_sigterm
, add
);
456 uloop_install_handler(SIGCHLD
, uloop_sigchld
, &old_sigchld
, add
);
458 uloop_ignore_signal(SIGPIPE
, add
);
461 static int uloop_get_next_timeout(struct timeval
*tv
)
463 struct uloop_timeout
*timeout
;
466 if (list_empty(&timeouts
))
469 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
470 diff
= tv_diff(&timeout
->time
, tv
);
477 static void uloop_process_timeouts(struct timeval
*tv
)
479 struct uloop_timeout
*t
;
481 while (!list_empty(&timeouts
)) {
482 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
484 if (tv_diff(&t
->time
, tv
) > 0)
487 uloop_timeout_cancel(t
);
493 static void uloop_clear_timeouts(void)
495 struct uloop_timeout
*t
, *tmp
;
497 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
498 uloop_timeout_cancel(t
);
501 static void uloop_clear_processes(void)
503 struct uloop_process
*p
, *tmp
;
505 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
506 uloop_process_delete(p
);
511 static int recursive_calls
= 0;
515 * Handlers are only updated for the first call to uloop_run() (and restored
516 * when this call is done).
518 if (!recursive_calls
++)
519 uloop_setup_signals(true);
521 uloop_cancelled
= false;
522 while(!uloop_cancelled
)
525 uloop_process_timeouts(&tv
);
528 uloop_handle_processes();
534 uloop_run_events(uloop_get_next_timeout(&tv
));
537 if (!--recursive_calls
)
538 uloop_setup_signals(false);
541 void uloop_done(void)
548 if (waker_pipe
>= 0) {
549 uloop_fd_delete(&waker_fd
);
555 uloop_clear_timeouts();
556 uloop_clear_processes();