af84737c28ce6112337ee2362e23444885d7c57f
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 signal_fd
= -1;
60 static int poll_fd
= -1;
61 bool uloop_cancelled
= false;
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 static void uloop_handle_signal(int signo
);
70 #include "uloop-kqueue.c"
74 #include "uloop-epoll.c"
77 static bool uloop_fd_stack_event(struct uloop_fd
*fd
, int events
)
79 struct uloop_fd_stack
*cur
;
82 * Do not buffer events for level-triggered fds, they will keep firing.
83 * Caller needs to take care of recursion issues.
85 if (!(fd
->flags
& ULOOP_EDGE_TRIGGER
))
88 for (cur
= fd_stack
; cur
; cur
= cur
->next
) {
95 cur
->events
|= events
| ULOOP_EVENT_BUFFERED
;
103 static void uloop_run_events(int timeout
)
105 struct uloop_fd_event
*cur
;
110 cur_nfds
= uloop_fetch_events(timeout
);
115 while (cur_nfds
> 0) {
116 struct uloop_fd_stack stack_cur
;
119 cur
= &cur_fds
[cur_fd
++];
123 events
= cur
->events
;
130 if (uloop_fd_stack_event(fd
, cur
->events
))
133 stack_cur
.next
= fd_stack
;
135 fd_stack
= &stack_cur
;
137 stack_cur
.events
= 0;
139 events
= stack_cur
.events
& ULOOP_EVENT_MASK
;
140 } while (stack_cur
.fd
&& events
);
141 fd_stack
= stack_cur
.next
;
147 int uloop_fd_add(struct uloop_fd
*sock
, unsigned int flags
)
152 if (!(flags
& (ULOOP_READ
| ULOOP_WRITE
)))
153 return uloop_fd_delete(sock
);
155 if (!sock
->registered
&& !(flags
& ULOOP_BLOCKING
)) {
156 fl
= fcntl(sock
->fd
, F_GETFL
, 0);
158 fcntl(sock
->fd
, F_SETFL
, fl
);
161 ret
= register_poll(sock
, flags
);
165 sock
->registered
= true;
173 int uloop_fd_delete(struct uloop_fd
*fd
)
177 for (i
= 0; i
< cur_nfds
; i
++) {
178 if (cur_fds
[cur_fd
+ i
].fd
!= fd
)
181 cur_fds
[cur_fd
+ i
].fd
= NULL
;
187 fd
->registered
= false;
188 uloop_fd_stack_event(fd
, -1);
189 return __uloop_fd_delete(fd
);
192 static int tv_diff(struct timeval
*t1
, struct timeval
*t2
)
195 (t1
->tv_sec
- t2
->tv_sec
) * 1000 +
196 (t1
->tv_usec
- t2
->tv_usec
) / 1000;
199 int uloop_timeout_add(struct uloop_timeout
*timeout
)
201 struct uloop_timeout
*tmp
;
202 struct list_head
*h
= &timeouts
;
204 if (timeout
->pending
)
207 list_for_each_entry(tmp
, &timeouts
, list
) {
208 if (tv_diff(&tmp
->time
, &timeout
->time
) > 0) {
214 list_add_tail(&timeout
->list
, h
);
215 timeout
->pending
= true;
220 static void uloop_gettime(struct timeval
*tv
)
224 clock_gettime(CLOCK_MONOTONIC
, &ts
);
225 tv
->tv_sec
= ts
.tv_sec
;
226 tv
->tv_usec
= ts
.tv_nsec
/ 1000;
229 int uloop_timeout_set(struct uloop_timeout
*timeout
, int msecs
)
231 struct timeval
*time
= &timeout
->time
;
233 if (timeout
->pending
)
234 uloop_timeout_cancel(timeout
);
238 time
->tv_sec
+= msecs
/ 1000;
239 time
->tv_usec
+= (msecs
% 1000) * 1000;
241 if (time
->tv_usec
> 1000000) {
243 time
->tv_usec
-= 1000000;
246 return uloop_timeout_add(timeout
);
249 int uloop_timeout_cancel(struct uloop_timeout
*timeout
)
251 if (!timeout
->pending
)
254 list_del(&timeout
->list
);
255 timeout
->pending
= false;
260 int uloop_timeout_remaining(struct uloop_timeout
*timeout
)
264 if (!timeout
->pending
)
269 return tv_diff(&timeout
->time
, &now
);
272 int uloop_process_add(struct uloop_process
*p
)
274 struct uloop_process
*tmp
;
275 struct list_head
*h
= &processes
;
280 list_for_each_entry(tmp
, &processes
, list
) {
281 if (tmp
->pid
> p
->pid
) {
287 list_add_tail(&p
->list
, h
);
293 int uloop_process_delete(struct uloop_process
*p
)
304 static void uloop_handle_processes(void)
306 struct uloop_process
*p
, *tmp
;
313 pid
= waitpid(-1, &ret
, WNOHANG
);
314 if (pid
< 0 && errno
== EINTR
)
320 list_for_each_entry_safe(p
, tmp
, &processes
, list
) {
327 uloop_process_delete(p
);
334 static void uloop_handle_signal(int signo
)
340 uloop_cancelled
= true;
347 static void uloop_install_handler(int signum
, void (*handler
)(int), struct sigaction
* old
, bool add
)
350 struct sigaction
*act
;
353 sigaction(signum
, NULL
, &s
);
356 if (s
.sa_handler
== SIG_DFL
) { /* Do not override existing custom signal handlers */
357 memcpy(old
, &s
, sizeof(struct sigaction
));
358 s
.sa_handler
= handler
;
363 else if (s
.sa_handler
== handler
) { /* Do not restore if someone modified our handler */
368 sigaction(signum
, act
, NULL
);
371 static void uloop_ignore_signal(int signum
, bool ignore
)
374 void *new_handler
= NULL
;
376 sigaction(signum
, NULL
, &s
);
379 if (s
.sa_handler
== SIG_DFL
) /* Ignore only if there isn't any custom handler */
380 new_handler
= SIG_IGN
;
382 if (s
.sa_handler
== SIG_IGN
) /* Restore only if noone modified our SIG_IGN */
383 new_handler
= SIG_DFL
;
387 s
.sa_handler
= new_handler
;
389 sigaction(signum
, &s
, NULL
);
393 static void uloop_setup_signals(bool add
)
395 static struct sigaction old_sigint
, old_sigchld
, old_sigterm
, old_sigquit
;
397 uloop_setup_signalfd(add
);
399 uloop_install_handler(SIGINT
, uloop_handle_signal
, &old_sigint
, add
);
400 uloop_install_handler(SIGTERM
, uloop_handle_signal
, &old_sigterm
, add
);
401 uloop_install_handler(SIGQUIT
, uloop_handle_signal
, &old_sigquit
, add
);
402 uloop_install_handler(SIGCHLD
, uloop_handle_signal
, &old_sigchld
, add
);
404 uloop_ignore_signal(SIGPIPE
, add
);
407 static int uloop_get_next_timeout(struct timeval
*tv
)
409 struct uloop_timeout
*timeout
;
412 if (list_empty(&timeouts
))
415 timeout
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
416 diff
= tv_diff(&timeout
->time
, tv
);
423 static void uloop_process_timeouts(struct timeval
*tv
)
425 struct uloop_timeout
*t
;
427 while (!list_empty(&timeouts
)) {
428 t
= list_first_entry(&timeouts
, struct uloop_timeout
, list
);
430 if (tv_diff(&t
->time
, tv
) > 0)
433 uloop_timeout_cancel(t
);
439 static void uloop_clear_timeouts(void)
441 struct uloop_timeout
*t
, *tmp
;
443 list_for_each_entry_safe(t
, tmp
, &timeouts
, list
)
444 uloop_timeout_cancel(t
);
447 static void uloop_clear_processes(void)
449 struct uloop_process
*p
, *tmp
;
451 list_for_each_entry_safe(p
, tmp
, &processes
, list
)
452 uloop_process_delete(p
);
457 static int recursive_calls
= 0;
461 * Handlers are only updated for the first call to uloop_run() (and restored
462 * when this call is done).
464 if (!recursive_calls
++)
465 uloop_setup_signals(true);
467 uloop_cancelled
= false;
468 while(!uloop_cancelled
)
471 uloop_process_timeouts(&tv
);
474 uloop_handle_processes();
480 uloop_run_events(uloop_get_next_timeout(&tv
));
483 if (!--recursive_calls
)
484 uloop_setup_signals(false);
487 void uloop_done(void)
489 if (signal_fd
>= 0) {
500 uloop_clear_timeouts();
501 uloop_clear_processes();