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
;
67 #include "uloop-kqueue.c"
73 * FIXME: uClibc < 0.9.30.3 does not define EPOLLRDHUP for Linux >= 2.6.17
76 #define EPOLLRDHUP 0x2000
84 poll_fd
= epoll_create(32);
88 fcntl(poll_fd
, F_SETFD
, fcntl(poll_fd
, F_GETFD
) | FD_CLOEXEC
);
92 static int register_poll(struct uloop_fd
*fd
, unsigned int flags
)
94 struct epoll_event ev
;
95 int op
= fd
->registered
? EPOLL_CTL_MOD
: EPOLL_CTL_ADD
;
97 memset(&ev
, 0, sizeof(struct epoll_event
));
99 if (flags
& ULOOP_READ
)
100 ev
.events
|= EPOLLIN
| EPOLLRDHUP
;
102 if (flags
& ULOOP_WRITE
)
103 ev
.events
|= EPOLLOUT
;
105 if (flags
& ULOOP_EDGE_TRIGGER
)
106 ev
.events
|= EPOLLET
;
112 return epoll_ctl(poll_fd
, op
, fd
->fd
, &ev
);
115 static struct epoll_event events
[ULOOP_MAX_EVENTS
];
117 static int __uloop_fd_delete(struct uloop_fd
*sock
)
120 return epoll_ctl(poll_fd
, EPOLL_CTL_DEL
, sock
->fd
, 0);
123 static int uloop_fetch_events(int timeout
)
127 nfds
= epoll_wait(poll_fd
, events
, ARRAY_SIZE(events
), timeout
);
128 for (n
= 0; n
< nfds
; ++n
) {
129 struct uloop_fd_event
*cur
= &cur_fds
[n
];
130 struct uloop_fd
*u
= events
[n
].data
.ptr
;
137 if (events
[n
].events
& (EPOLLERR
|EPOLLHUP
)) {
139 if (!(u
->flags
& ULOOP_ERROR_CB
))
143 if(!(events
[n
].events
& (EPOLLRDHUP
|EPOLLIN
|EPOLLOUT
|EPOLLERR
|EPOLLHUP
))) {
148 if(events
[n
].events
& EPOLLRDHUP
)
151 if(events
[n
].events
& EPOLLIN
)
154 if(events
[n
].events
& EPOLLOUT
)
165 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
167 struct uloop_fd_stack
*cur
;
170 * Do not buffer events for level-triggered fds, they will keep firing.
171 * Caller needs to take care of recursion issues.
173 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
176 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
183 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
191 static void uloop_run_events(int timeout
)
193 struct uloop_fd_event
*cur
;
198 cur_nfds
= uloop_fetch_events(timeout
);
203 while (cur_nfds
> 0) {
204 struct uloop_fd_stack stack_cur
;
207 cur
= &cur_fds
[cur_fd
++];
211 events
= cur
->events
;
218 if (uloop_fd_stack_event(fd
, cur
->events
))
221 stack_cur
.next
= fd_stack
;
223 fd_stack
= &stack_cur
;
225 stack_cur
.events
= 0;
227 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
228 } while (stack_cur
.fd
&& events
);
229 fd_stack
= stack_cur
.next
;
235 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
240 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
241 return uloop_fd_delete(sock
);
243 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
244 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
246 fcntl(sock
->fd
, F_SETFL
, fl
);
249 ret
= register_poll(sock
, flags
);
253 sock
->registered
= true;
261 int uloop_fd_delete(struct uloop_fd
*fd
)
265 for (i
= 0; i
< cur_nfds
; i
++) {
266 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
269 cur_fds
[cur_fd
+ i
].fd
= NULL
;
275 fd
->registered
= false;
276 uloop_fd_stack_event(fd
, -1);
277 return __uloop_fd_delete(fd
);
280 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
283 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
284 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
287 int uloop_timeout_add(struct uloop_timeout
*timeout
)
289 struct uloop_timeout
*tmp
;
290 struct list_head
*h
= &timeouts
;
292 if (timeout
->pending
)
295 list_for_each_entry(tmp
, &timeouts
, list
) {
296 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
302 list_add_tail(&timeout
->list
, h
);
303 timeout
->pending
= true;
308 static void uloop_gettime(struct timeval
*tv
)
312 clock_gettime(CLOCK_MONOTONIC
, &ts
);
313 tv
->tv_sec
= ts
.tv_sec
;
314 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
317 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
319 struct timeval
*time
= &timeout
->time
;
321 if (timeout
->pending
)
322 uloop_timeout_cancel(timeout
);
326 time
->tv_sec
+= msecs
/ 1000;
327 time
->tv_usec
+= (msecs
% 1000) * 1000;
329 if (time
->tv_usec
> 1000000) {
331 time
->tv_usec
-= 1000000;
334 return uloop_timeout_add(timeout
);
337 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
339 if (!timeout
->pending
)
342 list_del(&timeout
->list
);
343 timeout
->pending
= false;
348 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
352 if (!timeout
->pending
)
357 return tv_diff(&timeout
->time
, &now
);
360 int uloop_process_add(struct uloop_process
*p
)
362 struct uloop_process
*tmp
;
363 struct list_head
*h
= &processes
;
368 list_for_each_entry(tmp
, &processes
, list
) {
369 if (tmp
->pid
> p
->pid
) {
375 list_add_tail(&p
->list
, h
);
381 int uloop_process_delete(struct uloop_process
*p
)
392 static void uloop_handle_processes(void)
394 struct uloop_process
*p
, *tmp
;
401 pid
= waitpid(-1, &ret
, WNOHANG
);
405 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
412 uloop_process_delete(p
);
419 static void uloop_handle_sigint(int signo
)
421 uloop_cancelled
= true;
424 static void uloop_sigchld(int signo
)
429 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
432 struct sigaction
*act
;
435 sigaction(signum
, NULL
, &s
);
438 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
439 memcpy(old
, &s
, sizeof(struct sigaction
));
440 s
.sa_handler
= handler
;
445 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
450 sigaction(signum
, act
, NULL
);
453 static void uloop_ignore_signal(int signum
, bool ignore
)
456 void *new_handler
= NULL
;
458 sigaction(signum
, NULL
, &s
);
461 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
462 new_handler
= SIG_IGN
;
464 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
465 new_handler
= SIG_DFL
;
469 s
.sa_handler
= new_handler
;
471 sigaction(signum
, &s
, NULL
);
475 static void uloop_setup_signals(bool add
)
477 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
;
479 uloop_install_handler(SIGINT
, uloop_handle_sigint
, &old_sigint
, add
);
480 uloop_install_handler(SIGTERM
, uloop_handle_sigint
, &old_sigterm
, add
);
481 uloop_install_handler(SIGCHLD
, uloop_sigchld
, &old_sigchld
, add
);
483 uloop_ignore_signal(SIGPIPE
, add
);
486 static int uloop_get_next_timeout(struct timeval
*tv
)
488 struct uloop_timeout
*timeout
;
491 if (list_empty(&timeouts
))
494 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
495 diff
= tv_diff(&timeout
->time
, tv
);
502 static void uloop_process_timeouts(struct timeval
*tv
)
504 struct uloop_timeout
*t
;
506 while (!list_empty(&timeouts
)) {
507 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
509 if (tv_diff(&t
->time
, tv
) > 0)
512 uloop_timeout_cancel(t
);
518 static void uloop_clear_timeouts(void)
520 struct uloop_timeout
*t
, *tmp
;
522 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
523 uloop_timeout_cancel(t
);
526 static void uloop_clear_processes(void)
528 struct uloop_process
*p
, *tmp
;
530 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
531 uloop_process_delete(p
);
536 static int recursive_calls
= 0;
540 * Handlers are only updated for the first call to uloop_run() (and restored
541 * when this call is done).
543 if (!recursive_calls
++)
544 uloop_setup_signals(true);
546 uloop_cancelled
= false;
547 while(!uloop_cancelled
)
550 uloop_process_timeouts(&tv
);
553 uloop_handle_processes();
559 uloop_run_events(uloop_get_next_timeout(&tv
));
562 if (!--recursive_calls
)
563 uloop_setup_signals(false);
566 void uloop_done(void)
574 uloop_clear_timeouts();
575 uloop_clear_processes();