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"
71 #include "uloop-epoll.c"
74 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
76 struct uloop_fd_stack
*cur
;
79 * Do not buffer events for level-triggered fds, they will keep firing.
80 * Caller needs to take care of recursion issues.
82 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
85 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
92 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
100 static void uloop_run_events(int timeout
)
102 struct uloop_fd_event
*cur
;
107 cur_nfds
= uloop_fetch_events(timeout
);
112 while (cur_nfds
> 0) {
113 struct uloop_fd_stack stack_cur
;
116 cur
= &cur_fds
[cur_fd
++];
120 events
= cur
->events
;
127 if (uloop_fd_stack_event(fd
, cur
->events
))
130 stack_cur
.next
= fd_stack
;
132 fd_stack
= &stack_cur
;
134 stack_cur
.events
= 0;
136 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
137 } while (stack_cur
.fd
&& events
);
138 fd_stack
= stack_cur
.next
;
144 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
149 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
150 return uloop_fd_delete(sock
);
152 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
153 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
155 fcntl(sock
->fd
, F_SETFL
, fl
);
158 ret
= register_poll(sock
, flags
);
162 sock
->registered
= true;
170 int uloop_fd_delete(struct uloop_fd
*fd
)
174 for (i
= 0; i
< cur_nfds
; i
++) {
175 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
178 cur_fds
[cur_fd
+ i
].fd
= NULL
;
184 fd
->registered
= false;
185 uloop_fd_stack_event(fd
, -1);
186 return __uloop_fd_delete(fd
);
189 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
192 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
193 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
196 int uloop_timeout_add(struct uloop_timeout
*timeout
)
198 struct uloop_timeout
*tmp
;
199 struct list_head
*h
= &timeouts
;
201 if (timeout
->pending
)
204 list_for_each_entry(tmp
, &timeouts
, list
) {
205 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
211 list_add_tail(&timeout
->list
, h
);
212 timeout
->pending
= true;
217 static void uloop_gettime(struct timeval
*tv
)
221 clock_gettime(CLOCK_MONOTONIC
, &ts
);
222 tv
->tv_sec
= ts
.tv_sec
;
223 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
226 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
228 struct timeval
*time
= &timeout
->time
;
230 if (timeout
->pending
)
231 uloop_timeout_cancel(timeout
);
235 time
->tv_sec
+= msecs
/ 1000;
236 time
->tv_usec
+= (msecs
% 1000) * 1000;
238 if (time
->tv_usec
> 1000000) {
240 time
->tv_usec
-= 1000000;
243 return uloop_timeout_add(timeout
);
246 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
248 if (!timeout
->pending
)
251 list_del(&timeout
->list
);
252 timeout
->pending
= false;
257 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
261 if (!timeout
->pending
)
266 return tv_diff(&timeout
->time
, &now
);
269 int uloop_process_add(struct uloop_process
*p
)
271 struct uloop_process
*tmp
;
272 struct list_head
*h
= &processes
;
277 list_for_each_entry(tmp
, &processes
, list
) {
278 if (tmp
->pid
> p
->pid
) {
284 list_add_tail(&p
->list
, h
);
290 int uloop_process_delete(struct uloop_process
*p
)
301 static void uloop_handle_processes(void)
303 struct uloop_process
*p
, *tmp
;
310 pid
= waitpid(-1, &ret
, WNOHANG
);
311 if (pid
< 0 && errno
== EINTR
)
317 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
324 uloop_process_delete(p
);
331 static void uloop_handle_sigint(int signo
)
333 uloop_cancelled
= true;
336 static void uloop_sigchld(int signo
)
341 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
344 struct sigaction
*act
;
347 sigaction(signum
, NULL
, &s
);
350 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
351 memcpy(old
, &s
, sizeof(struct sigaction
));
352 s
.sa_handler
= handler
;
357 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
362 sigaction(signum
, act
, NULL
);
365 static void uloop_ignore_signal(int signum
, bool ignore
)
368 void *new_handler
= NULL
;
370 sigaction(signum
, NULL
, &s
);
373 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
374 new_handler
= SIG_IGN
;
376 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
377 new_handler
= SIG_DFL
;
381 s
.sa_handler
= new_handler
;
383 sigaction(signum
, &s
, NULL
);
387 static void uloop_setup_signals(bool add
)
389 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
;
391 uloop_install_handler(SIGINT
, uloop_handle_sigint
, &old_sigint
, add
);
392 uloop_install_handler(SIGTERM
, uloop_handle_sigint
, &old_sigterm
, add
);
393 uloop_install_handler(SIGCHLD
, uloop_sigchld
, &old_sigchld
, add
);
395 uloop_ignore_signal(SIGPIPE
, add
);
398 static int uloop_get_next_timeout(struct timeval
*tv
)
400 struct uloop_timeout
*timeout
;
403 if (list_empty(&timeouts
))
406 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
407 diff
= tv_diff(&timeout
->time
, tv
);
414 static void uloop_process_timeouts(struct timeval
*tv
)
416 struct uloop_timeout
*t
;
418 while (!list_empty(&timeouts
)) {
419 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
421 if (tv_diff(&t
->time
, tv
) > 0)
424 uloop_timeout_cancel(t
);
430 static void uloop_clear_timeouts(void)
432 struct uloop_timeout
*t
, *tmp
;
434 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
435 uloop_timeout_cancel(t
);
438 static void uloop_clear_processes(void)
440 struct uloop_process
*p
, *tmp
;
442 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
443 uloop_process_delete(p
);
448 static int recursive_calls
= 0;
452 * Handlers are only updated for the first call to uloop_run() (and restored
453 * when this call is done).
455 if (!recursive_calls
++)
456 uloop_setup_signals(true);
458 uloop_cancelled
= false;
459 while(!uloop_cancelled
)
462 uloop_process_timeouts(&tv
);
465 uloop_handle_processes();
471 uloop_run_events(uloop_get_next_timeout(&tv
));
474 if (!--recursive_calls
)
475 uloop_setup_signals(false);
478 void uloop_done(void)
486 uloop_clear_timeouts();
487 uloop_clear_processes();