0b75d4b3f4bd72f2d7fc33a918b09782c204d9a6
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 int uloop_status
= 0;
62 static bool do_sigchld
= false;
64 static struct uloop_fd_event cur_fds
[ULOOP_MAX_EVENTS
];
65 static int cur_fd
, cur_nfds
;
67 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
);
70 #include "uloop-kqueue.c"
74 #include "uloop-epoll.c"
77 static void waker_consume(struct uloop_fd
*fd
, unsigned int events
)
81 while (read(fd
->fd
, buf
, 4) > 0)
85 static int waker_pipe
= -1;
86 static struct uloop_fd waker_fd
= {
91 static void waker_init_fd(int fd
)
93 fcntl(fd
, F_SETFD
, fcntl(fd
, F_GETFD
) | FD_CLOEXEC
);
94 fcntl(fd
, F_SETFL
, fcntl(fd
, F_GETFL
) | O_NONBLOCK
);
97 static int waker_init(void)
107 waker_init_fd(fds
[0]);
108 waker_init_fd(fds
[1]);
111 waker_fd
.fd
= fds
[0];
112 waker_fd
.cb
= waker_consume
;
113 uloop_fd_add(&waker_fd
, ULOOP_READ
);
120 if (uloop_init_pollfd() < 0)
123 if (waker_init() < 0) {
131 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
133 struct uloop_fd_stack
*cur
;
136 * Do not buffer events for level-triggered fds, they will keep firing.
137 * Caller needs to take care of recursion issues.
139 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
142 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
149 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
157 static void uloop_run_events(int timeout
)
159 struct uloop_fd_event
*cur
;
164 cur_nfds
= uloop_fetch_events(timeout
);
169 while (cur_nfds
> 0) {
170 struct uloop_fd_stack stack_cur
;
173 cur
= &cur_fds
[cur_fd
++];
177 events
= cur
->events
;
184 if (uloop_fd_stack_event(fd
, cur
->events
))
187 stack_cur
.next
= fd_stack
;
189 fd_stack
= &stack_cur
;
191 stack_cur
.events
= 0;
193 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
194 } while (stack_cur
.fd
&& events
);
195 fd_stack
= stack_cur
.next
;
201 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
206 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
207 return uloop_fd_delete(sock
);
209 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
210 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
212 fcntl(sock
->fd
, F_SETFL
, fl
);
215 ret
= register_poll(sock
, flags
);
219 sock
->registered
= true;
227 int uloop_fd_delete(struct uloop_fd
*fd
)
231 for (i
= 0; i
< cur_nfds
; i
++) {
232 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
235 cur_fds
[cur_fd
+ i
].fd
= NULL
;
241 fd
->registered
= false;
242 uloop_fd_stack_event(fd
, -1);
243 return __uloop_fd_delete(fd
);
246 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
249 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
250 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
253 int uloop_timeout_add(struct uloop_timeout
*timeout
)
255 struct uloop_timeout
*tmp
;
256 struct list_head
*h
= &timeouts
;
258 if (timeout
->pending
)
261 list_for_each_entry(tmp
, &timeouts
, list
) {
262 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
268 list_add_tail(&timeout
->list
, h
);
269 timeout
->pending
= true;
274 static void uloop_gettime(struct timeval
*tv
)
278 clock_gettime(CLOCK_MONOTONIC
, &ts
);
279 tv
->tv_sec
= ts
.tv_sec
;
280 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
283 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
285 struct timeval
*time
= &timeout
->time
;
287 if (timeout
->pending
)
288 uloop_timeout_cancel(timeout
);
292 time
->tv_sec
+= msecs
/ 1000;
293 time
->tv_usec
+= (msecs
% 1000) * 1000;
295 if (time
->tv_usec
> 1000000) {
297 time
->tv_usec
-= 1000000;
300 return uloop_timeout_add(timeout
);
303 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
305 if (!timeout
->pending
)
308 list_del(&timeout
->list
);
309 timeout
->pending
= false;
314 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
318 if (!timeout
->pending
)
323 return tv_diff(&timeout
->time
, &now
);
326 int uloop_process_add(struct uloop_process
*p
)
328 struct uloop_process
*tmp
;
329 struct list_head
*h
= &processes
;
334 list_for_each_entry(tmp
, &processes
, list
) {
335 if (tmp
->pid
> p
->pid
) {
341 list_add_tail(&p
->list
, h
);
347 int uloop_process_delete(struct uloop_process
*p
)
358 static void uloop_handle_processes(void)
360 struct uloop_process
*p
, *tmp
;
367 pid
= waitpid(-1, &ret
, WNOHANG
);
368 if (pid
< 0 && errno
== EINTR
)
374 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
381 uloop_process_delete(p
);
388 static void uloop_signal_wake(void)
390 write(waker_pipe
, "w", 1);
393 static void uloop_handle_sigint(int signo
)
395 uloop_status
= signo
;
396 uloop_cancelled
= true;
400 static void uloop_sigchld(int signo
)
406 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
409 struct sigaction
*act
;
412 sigaction(signum
, NULL
, &s
);
415 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
416 memcpy(old
, &s
, sizeof(struct sigaction
));
417 s
.sa_handler
= handler
;
422 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
427 sigaction(signum
, act
, NULL
);
430 static void uloop_ignore_signal(int signum
, bool ignore
)
433 void *new_handler
= NULL
;
435 sigaction(signum
, NULL
, &s
);
438 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
439 new_handler
= SIG_IGN
;
441 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
442 new_handler
= SIG_DFL
;
446 s
.sa_handler
= new_handler
;
448 sigaction(signum
, &s
, NULL
);
452 static void uloop_setup_signals(bool add
)
454 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
;
456 uloop_install_handler(SIGINT
, uloop_handle_sigint
, &old_sigint
, add
);
457 uloop_install_handler(SIGTERM
, uloop_handle_sigint
, &old_sigterm
, add
);
458 uloop_install_handler(SIGCHLD
, uloop_sigchld
, &old_sigchld
, add
);
460 uloop_ignore_signal(SIGPIPE
, add
);
463 static int uloop_get_next_timeout(struct timeval
*tv
)
465 struct uloop_timeout
*timeout
;
468 if (list_empty(&timeouts
))
471 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
472 diff
= tv_diff(&timeout
->time
, tv
);
479 static void uloop_process_timeouts(struct timeval
*tv
)
481 struct uloop_timeout
*t
;
483 while (!list_empty(&timeouts
)) {
484 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
486 if (tv_diff(&t
->time
, tv
) > 0)
489 uloop_timeout_cancel(t
);
495 static void uloop_clear_timeouts(void)
497 struct uloop_timeout
*t
, *tmp
;
499 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
500 uloop_timeout_cancel(t
);
503 static void uloop_clear_processes(void)
505 struct uloop_process
*p
, *tmp
;
507 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
508 uloop_process_delete(p
);
513 static int recursive_calls
= 0;
517 * Handlers are only updated for the first call to uloop_run() (and restored
518 * when this call is done).
520 if (!recursive_calls
++)
521 uloop_setup_signals(true);
524 uloop_cancelled
= false;
525 while (!uloop_cancelled
)
528 uloop_process_timeouts(&tv
);
531 uloop_handle_processes();
537 uloop_run_events(uloop_get_next_timeout(&tv
));
540 if (!--recursive_calls
)
541 uloop_setup_signals(false);
546 void uloop_done(void)
553 if (waker_pipe
>= 0) {
554 uloop_fd_delete(&waker_fd
);
560 uloop_clear_timeouts();
561 uloop_clear_processes();