2 * This file is part of DisOrder.
3 * Copyright (C) 2004, 2005, 2007 Richard Kettlewell
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
21 * @brief DisOrder event loop
29 #include <sys/types.h>
30 #include <sys/resource.h>
39 #include <sys/socket.h>
40 #include <netinet/in.h>
51 /** @brief A timeout */
55 ev_timeout_callback
*callback
;
60 /** @brief A file descriptor in one mode */
63 ev_fd_callback
*callback
;
68 /** @brief All the file descriptors in a given mode */
70 /** @brief Mask of active file descriptors passed to @c select() */
73 /** @brief File descriptor mask returned from @c select() */
76 /** @brief Number of file descriptors in @p fds */
79 /** @brief Number of slots in @p fds */
82 /** @brief Array of all active file descriptors */
85 /** @brief Highest-numbered file descriptor or 0 */
89 /** @brief A signal handler */
91 struct sigaction oldsa
;
92 ev_signal_callback
*callback
;
96 /** @brief A child process */
100 ev_child_callback
*callback
;
104 /** @brief An event loop */
106 /** @brief File descriptors, per mode */
107 struct fdmode mode
[ev_nmodes
];
109 /** @brief Sorted linked list of timeouts
111 * We could use @ref HEAP_TYPE now, but there aren't many timeouts.
113 struct timeout
*timeouts
;
115 /** @brief Array of handled signals */
116 struct signal signals
[NSIG
];
118 /** @brief Mask of handled signals */
121 /** @brief Escape early from handling of @c select() results
123 * This is set if any of the file descriptor arrays are invalidated, since
124 * it's then not safe for processing of them to continue.
128 /** @brief Signal handling pipe
130 * The signal handle writes signal numbers down this pipe.
134 /** @brief Number of child processes in @p children */
137 /** @brief Number of slots in @p children */
140 /** @brief Array of child processes */
141 struct child
*children
;
144 /** @brief Names of file descriptor modes */
145 static const char *modenames
[] = { "read", "write", "except" };
147 /* utilities ******************************************************************/
149 /** @brief Great-than comparison for timevals
151 * Ought to be in @file lib/timeval.h
153 static inline int gt(const struct timeval
*a
, const struct timeval
*b
) {
154 if(a
->tv_sec
> b
->tv_sec
)
156 if(a
->tv_sec
== b
->tv_sec
157 && a
->tv_usec
> b
->tv_usec
)
162 /** @brief Greater-than-or-equal comparison for timevals
164 * Ought to be in @file lib/timeval.h
166 static inline int ge(const struct timeval
*a
, const struct timeval
*b
) {
170 /* creation *******************************************************************/
172 /** @brief Create a new event loop */
173 ev_source
*ev_new(void) {
174 ev_source
*ev
= xmalloc(sizeof *ev
);
177 memset(ev
, 0, sizeof *ev
);
178 for(n
= 0; n
< ev_nmodes
; ++n
)
179 FD_ZERO(&ev
->mode
[n
].enabled
);
180 ev
->sigpipe
[0] = ev
->sigpipe
[1] = -1;
181 sigemptyset(&ev
->sigmask
);
185 /* event loop *****************************************************************/
187 /** @brief Run the event loop
188 * @return -1 on error, non-0 if any callback returned non-0
190 int ev_run(ev_source
*ev
) {
193 struct timeval delta
;
197 struct timeout
*t
, **tt
;
200 xgettimeofday(&now
, 0);
201 /* Handle timeouts. We don't want to handle any timeouts that are added
202 * while we're handling them (otherwise we'd have to break out of infinite
203 * loops, preferrably without starving better-behaved subsystems). Hence
204 * the slightly complicated two-phase approach here. */
205 for(t
= ev
->timeouts
;
206 t
&& ge(&now
, &t
->when
);
209 D(("calling timeout for %ld.%ld callback %p %p",
210 (long)t
->when
.tv_sec
, (long)t
->when
.tv_usec
,
211 (void *)t
->callback
, t
->u
));
212 ret
= t
->callback(ev
, &now
, t
->u
);
224 for(mode
= 0; mode
< ev_nmodes
; ++mode
) {
225 ev
->mode
[mode
].tripped
= ev
->mode
[mode
].enabled
;
226 if(ev
->mode
[mode
].maxfd
> maxfd
)
227 maxfd
= ev
->mode
[mode
].maxfd
;
229 xsigprocmask(SIG_UNBLOCK
, &ev
->sigmask
, 0);
232 xgettimeofday(&now
, 0);
233 delta
.tv_sec
= ev
->timeouts
->when
.tv_sec
- now
.tv_sec
;
234 delta
.tv_usec
= ev
->timeouts
->when
.tv_usec
- now
.tv_usec
;
235 if(delta
.tv_usec
< 0) {
236 delta
.tv_usec
+= 1000000;
240 delta
.tv_sec
= delta
.tv_usec
= 0;
241 n
= select(maxfd
+ 1,
242 &ev
->mode
[ev_read
].tripped
,
243 &ev
->mode
[ev_write
].tripped
,
244 &ev
->mode
[ev_except
].tripped
,
247 n
= select(maxfd
+ 1,
248 &ev
->mode
[ev_read
].tripped
,
249 &ev
->mode
[ev_write
].tripped
,
250 &ev
->mode
[ev_except
].tripped
,
253 } while(n
< 0 && errno
== EINTR
);
254 xsigprocmask(SIG_BLOCK
, &ev
->sigmask
, 0);
256 error(errno
, "error calling select");
258 /* If there's a bad FD in the mix then check them all and log what we
259 * find, to ease debugging */
260 for(mode
= 0; mode
< ev_nmodes
; ++mode
) {
261 for(n
= 0; n
< ev
->mode
[mode
].nfds
; ++n
) {
262 const int fd
= ev
->mode
[mode
].fds
[n
].fd
;
264 if(FD_ISSET(fd
, &ev
->mode
[mode
].enabled
)
265 && fstat(fd
, &sb
) < 0)
266 error(errno
, "mode %s fstat %d (%s)",
267 modenames
[mode
], fd
, ev
->mode
[mode
].fds
[n
].what
);
269 for(n
= 0; n
<= maxfd
; ++n
)
270 if(FD_ISSET(n
, &ev
->mode
[mode
].enabled
)
271 && fstat(n
, &sb
) < 0)
272 error(errno
, "mode %s fstat %d", modenames
[mode
], n
);
278 /* if anything deranges the meaning of an fd, or re-orders the
279 * fds[] tables, we'd better give up; such operations will
280 * therefore set @escape@. */
282 for(mode
= 0; mode
< ev_nmodes
&& !ev
->escape
; ++mode
)
283 for(n
= 0; n
< ev
->mode
[mode
].nfds
&& !ev
->escape
; ++n
) {
284 int fd
= ev
->mode
[mode
].fds
[n
].fd
;
285 if(FD_ISSET(fd
, &ev
->mode
[mode
].tripped
)) {
286 D(("calling %s fd %d callback %p %p", modenames
[mode
], fd
,
287 (void *)ev
->mode
[mode
].fds
[n
].callback
,
288 ev
->mode
[mode
].fds
[n
].u
));
289 ret
= ev
->mode
[mode
].fds
[n
].callback(ev
, fd
,
290 ev
->mode
[mode
].fds
[n
].u
);
296 /* we'll pick up timeouts back round the loop */
300 /* file descriptors ***********************************************************/
302 /** @brief Register a file descriptor
303 * @param ev Event loop
304 * @param mode @c ev_read or @c ev_write
305 * @param fd File descriptor
306 * @param callback Called when @p is readable/writable
307 * @param u Passed to @p callback
308 * @param what Text description
309 * @return 0 on success, non-0 on error
311 * Sets @ref ev_source::escape, so no further processing of file descriptors
312 * will occur this time round the event loop.
314 int ev_fd(ev_source
*ev
,
317 ev_fd_callback
*callback
,
322 D(("registering %s fd %d callback %p %p", modenames
[mode
], fd
,
323 (void *)callback
, u
));
324 assert(mode
< ev_nmodes
);
325 if(ev
->mode
[mode
].nfds
>= ev
->mode
[mode
].fdslots
) {
326 ev
->mode
[mode
].fdslots
= (ev
->mode
[mode
].fdslots
327 ?
2 * ev
->mode
[mode
].fdslots
: 16);
328 D(("expanding %s fd table to %d entries", modenames
[mode
],
329 ev
->mode
[mode
].fdslots
));
330 ev
->mode
[mode
].fds
= xrealloc(ev
->mode
[mode
].fds
,
331 ev
->mode
[mode
].fdslots
* sizeof (struct fd
));
333 n
= ev
->mode
[mode
].nfds
++;
334 FD_SET(fd
, &ev
->mode
[mode
].enabled
);
335 ev
->mode
[mode
].fds
[n
].fd
= fd
;
336 ev
->mode
[mode
].fds
[n
].callback
= callback
;
337 ev
->mode
[mode
].fds
[n
].u
= u
;
338 ev
->mode
[mode
].fds
[n
].what
= what
;
339 if(fd
> ev
->mode
[mode
].maxfd
)
340 ev
->mode
[mode
].maxfd
= fd
;
345 /** @brief Cancel a file descriptor
346 * @param ev Event loop
347 * @param mode @c ev_read or @c ev_write
348 * @param fd File descriptor
349 * @return 0 on success, non-0 on error
351 * Sets @ref ev_source::escape, so no further processing of file descriptors
352 * will occur this time round the event loop.
354 int ev_fd_cancel(ev_source
*ev
, ev_fdmode mode
, int fd
) {
358 D(("cancelling mode %s fd %d", modenames
[mode
], fd
));
359 /* find the right struct fd */
360 for(n
= 0; n
< ev
->mode
[mode
].nfds
&& fd
!= ev
->mode
[mode
].fds
[n
].fd
; ++n
)
362 assert(n
< ev
->mode
[mode
].nfds
);
363 /* swap in the last fd and reduce the count */
364 if(n
!= ev
->mode
[mode
].nfds
- 1)
365 ev
->mode
[mode
].fds
[n
] = ev
->mode
[mode
].fds
[ev
->mode
[mode
].nfds
- 1];
366 --ev
->mode
[mode
].nfds
;
367 /* if that was the biggest fd, find the new biggest one */
368 if(fd
== ev
->mode
[mode
].maxfd
) {
370 for(n
= 0; n
< ev
->mode
[mode
].nfds
; ++n
)
371 if(ev
->mode
[mode
].fds
[n
].fd
> maxfd
)
372 maxfd
= ev
->mode
[mode
].fds
[n
].fd
;
373 ev
->mode
[mode
].maxfd
= maxfd
;
375 /* don't tell select about this fd any more */
376 FD_CLR(fd
, &ev
->mode
[mode
].enabled
);
381 /** @brief Re-enable a file descriptor
382 * @param ev Event loop
383 * @param mode @c ev_read or @c ev_write
384 * @param fd File descriptor
385 * @return 0 on success, non-0 on error
387 * It is harmless if @p fd is currently disabled, but it must not have been
390 int ev_fd_enable(ev_source
*ev
, ev_fdmode mode
, int fd
) {
391 D(("enabling mode %s fd %d", modenames
[mode
], fd
));
392 FD_SET(fd
, &ev
->mode
[mode
].enabled
);
396 /** @brief Temporarily disable a file descriptor
397 * @param ev Event loop
398 * @param mode @c ev_read or @c ev_write
399 * @param fd File descriptor
400 * @return 0 on success, non-0 on error
402 * Re-enable with ev_fd_enable(). It is harmless if @p fd is already disabled,
403 * but it must not have been cancelled.
405 int ev_fd_disable(ev_source
*ev
, ev_fdmode mode
, int fd
) {
406 D(("disabling mode %s fd %d", modenames
[mode
], fd
));
407 FD_CLR(fd
, &ev
->mode
[mode
].enabled
);
408 FD_CLR(fd
, &ev
->mode
[mode
].tripped
);
412 /** @brief Log a report of file descriptor state */
413 void ev_report(ev_source
*ev
) {
420 for(mode
= 0; mode
< ev_nmodes
; ++mode
) {
421 info("mode %s maxfd %d", modenames
[mode
], ev
->mode
[mode
].maxfd
);
422 for(n
= 0; n
< ev
->mode
[mode
].nfds
; ++n
) {
423 fd
= ev
->mode
[mode
].fds
[n
].fd
;
424 info("fd %s %d%s%s (%s)", modenames
[mode
], fd
,
425 FD_ISSET(fd
, &ev
->mode
[mode
].enabled
) ?
" enabled" : "",
426 FD_ISSET(fd
, &ev
->mode
[mode
].tripped
) ?
" tripped" : "",
427 ev
->mode
[mode
].fds
[n
].what
);
430 for(fd
= 0; fd
<= ev
->mode
[mode
].maxfd
; ++fd
) {
431 if(!FD_ISSET(fd
, &ev
->mode
[mode
].enabled
))
433 for(n
= 0; n
< ev
->mode
[mode
].nfds
; ++n
) {
434 if(ev
->mode
[mode
].fds
[n
].fd
== fd
)
437 if(n
< ev
->mode
[mode
].nfds
)
438 snprintf(b
, sizeof b
, "%d(%s)", fd
, ev
->mode
[mode
].fds
[n
].what
);
440 snprintf(b
, sizeof b
, "%d", fd
);
441 dynstr_append(d
, ' ');
442 dynstr_append_string(d
, b
);
445 info("%s enabled:%s", modenames
[mode
], d
->vec
);
449 /* timeouts *******************************************************************/
451 /** @brief Register a timeout
452 * @param ev Event source
453 * @param handle Where to store timeout handle, or @c NULL
454 * @param when Earliest time to call @p callback, or @c NULL
455 * @param callback Function to call at or after @p when
456 * @param u Passed to @p callback
457 * @return 0 on success, non-0 on error
459 * If @p when is a null pointer then a time of 0 is assumed. The effect is to
460 * call the timeout handler from ev_run() next time around the event loop.
461 * This is used internally to schedule various operations if it is not
462 * convenient to call them from the current place in the call stack, or
463 * externally to ensure that other clients of the event loop get a look in when
464 * performing some lengthy operation.
466 int ev_timeout(ev_source
*ev
,
467 ev_timeout_handle
*handlep
,
468 const struct timeval
*when
,
469 ev_timeout_callback
*callback
,
471 struct timeout
*t
, *p
, **pp
;
473 D(("registering timeout at %ld.%ld callback %p %p",
474 when ?
(long)when
->tv_sec
: 0, when ?
(long)when
->tv_usec
: 0,
475 (void *)callback
, u
));
476 t
= xmalloc(sizeof *t
);
479 t
->callback
= callback
;
482 while((p
= *pp
) && gt(&t
->when
, &p
->when
))
491 /** @brief Cancel a timeout
492 * @param ev Event loop
493 * @param handle Handle returned from ev_timeout()
494 * @return 0 on success, non-0 on error
496 int ev_timeout_cancel(ev_source
*ev
,
497 ev_timeout_handle handle
) {
498 struct timeout
*t
= handle
, *p
, **pp
;
500 for(pp
= &ev
->timeouts
; (p
= *pp
) && p
!= t
; pp
= &p
->next
)
509 /* signals ********************************************************************/
511 /** @brief Mapping of signals to pipe write ends
513 * The pipes are per-event loop, it's possible in theory for there to be
514 * multiple event loops (e.g. in different threads), although in fact DisOrder
517 static int sigfd
[NSIG
];
519 /** @brief The signal handler
520 * @param s Signal number
522 * Writes to @c sigfd[s].
524 static void sighandler(int s
) {
525 unsigned char sc
= s
;
526 static const char errmsg
[] = "error writing to signal pipe";
528 /* probably the reader has stopped listening for some reason */
529 if(write(sigfd
[s
], &sc
, 1) < 0) {
530 write(2, errmsg
, sizeof errmsg
- 1);
535 /** @brief Read callback for signals */
536 static int signal_read(ev_source
*ev
,
537 int attribute((unused
)) fd
,
538 void attribute((unused
)) *u
) {
543 if((n
= read(ev
->sigpipe
[0], &s
, 1)) == 1)
544 if((ret
= ev
->signals
[s
].callback(ev
, s
, ev
->signals
[s
].u
)))
547 if(n
< 0 && (errno
!= EINTR
&& errno
!= EAGAIN
)) {
548 error(errno
, "error reading from signal pipe %d", ev
->sigpipe
[0]);
554 /** @brief Close the signal pipe */
555 static void close_sigpipe(ev_source
*ev
) {
556 int save_errno
= errno
;
558 xclose(ev
->sigpipe
[0]);
559 xclose(ev
->sigpipe
[1]);
560 ev
->sigpipe
[0] = ev
->sigpipe
[1] = -1;
564 /** @brief Register a signal handler
565 * @param ev Event loop
566 * @param sig Signal to handle
567 * @param callback Called when signal is delivered
568 * @param u Passed to @p callback
569 * @return 0 on success, non-0 on error
571 * Note that @p callback is called from inside ev_run(), not from inside the
572 * signal handler, so the usual restrictions on signal handlers do not apply.
574 int ev_signal(ev_source
*ev
,
576 ev_signal_callback
*callback
,
581 D(("registering signal %d handler callback %p %p", sig
, (void *)callback
, u
));
584 assert(sig
<= UCHAR_MAX
);
585 if(ev
->sigpipe
[0] == -1) {
586 D(("creating signal pipe"));
588 D(("signal pipe is %d, %d", ev
->sigpipe
[0], ev
->sigpipe
[1]));
589 for(n
= 0; n
< 2; ++n
) {
590 nonblock(ev
->sigpipe
[n
]);
591 cloexec(ev
->sigpipe
[n
]);
593 if(ev_fd(ev
, ev_read
, ev
->sigpipe
[0], signal_read
, 0, "sigpipe read")) {
598 sigaddset(&ev
->sigmask
, sig
);
599 xsigprocmask(SIG_BLOCK
, &ev
->sigmask
, 0);
600 sigfd
[sig
] = ev
->sigpipe
[1];
601 ev
->signals
[sig
].callback
= callback
;
602 ev
->signals
[sig
].u
= u
;
603 sa
.sa_handler
= sighandler
;
604 sigfillset(&sa
.sa_mask
);
605 sa
.sa_flags
= SA_RESTART
;
606 xsigaction(sig
, &sa
, &ev
->signals
[sig
].oldsa
);
611 /** @brief Cancel a signal handler
612 * @param ev Event loop
613 * @param sig Signal to cancel
614 * @return 0 on success, non-0 on error
616 int ev_signal_cancel(ev_source
*ev
,
620 xsigaction(sig
, &ev
->signals
[sig
].oldsa
, 0);
621 ev
->signals
[sig
].callback
= 0;
623 sigdelset(&ev
->sigmask
, sig
);
626 xsigprocmask(SIG_UNBLOCK
, &ss
, 0);
630 /** @brief Clean up signal handling
631 * @param ev Event loop
633 * This function can be called from inside a fork. It restores signal
634 * handlers, unblocks the signals, and closes the signal pipe for @p ev.
636 void ev_signal_atfork(ev_source
*ev
) {
639 if(ev
->sigpipe
[0] != -1) {
640 /* revert any handled signals to their original state */
641 for(sig
= 1; sig
< NSIG
; ++sig
) {
642 if(ev
->signals
[sig
].callback
!= 0)
643 xsigaction(sig
, &ev
->signals
[sig
].oldsa
, 0);
645 /* and then unblock them */
646 xsigprocmask(SIG_UNBLOCK
, &ev
->sigmask
, 0);
647 /* don't want a copy of the signal pipe open inside the fork */
648 xclose(ev
->sigpipe
[0]);
649 xclose(ev
->sigpipe
[1]);
653 /* child processes ************************************************************/
655 /** @brief Called on SIGCHLD */
656 static int sigchld_callback(ev_source
*ev
,
657 int attribute((unused
)) sig
,
658 void attribute((unused
)) *u
) {
661 int status
, n
, ret
, revisit
;
665 for(n
= 0; n
< ev
->nchildren
; ++n
) {
666 r
= wait4(ev
->children
[n
].pid
,
668 ev
->children
[n
].options
| WNOHANG
,
671 ev_child_callback
*c
= ev
->children
[n
].callback
;
672 void *cu
= ev
->children
[n
].u
;
674 if(WIFEXITED(status
) || WIFSIGNALED(status
))
675 ev_child_cancel(ev
, r
);
677 if((ret
= c(ev
, r
, status
, &ru
, cu
)))
680 /* We should "never" get an ECHILD but it can in fact happen. For
681 * instance on Linux 2.4.31, and probably other versions, if someone
682 * straces a child process and then a different child process
683 * terminates, when we wait4() the trace process we will get ECHILD
684 * because it has been reparented to strace. Obviously this is a
685 * hopeless design flaw in the tracing infrastructure, but we don't
686 * want the disorder server to bomb out because of it. So we just log
687 * the problem and ignore it.
689 error(errno
, "error calling wait4 for PID %lu (broken ptrace?)",
690 (unsigned long)ev
->children
[n
].pid
);
699 /** @brief Configure event loop for child process handling
700 * @return 0 on success, non-0 on error
702 * Currently at most one event loop can handle child processes and it must be
703 * distinguished from others by calling this function on it. This could be
704 * fixed but since no process ever makes use of more than one event loop there
707 int ev_child_setup(ev_source
*ev
) {
708 D(("installing SIGCHLD handler"));
709 return ev_signal(ev
, SIGCHLD
, sigchld_callback
, 0);
712 /** @brief Wait for a child process to terminate
713 * @param ev Event loop
714 * @param pid Process ID of child
715 * @param options Options to pass to @c wait4()
716 * @param callback Called when child terminates (or possibly when it stops)
717 * @param u Passed to @p callback
718 * @return 0 on success, non-0 on error
720 * You must have called ev_child_setup() on @p ev once first.
722 int ev_child(ev_source
*ev
,
725 ev_child_callback
*callback
,
729 D(("registering child handling %ld options %d callback %p %p",
730 (long)pid
, options
, (void *)callback
, u
));
731 assert(ev
->signals
[SIGCHLD
].callback
== sigchld_callback
);
732 if(ev
->nchildren
>= ev
->nchildslots
) {
733 ev
->nchildslots
= ev
->nchildslots ?
2 * ev
->nchildslots
: 16;
734 ev
->children
= xrealloc(ev
->children
,
735 ev
->nchildslots
* sizeof (struct child
));
738 ev
->children
[n
].pid
= pid
;
739 ev
->children
[n
].options
= options
;
740 ev
->children
[n
].callback
= callback
;
741 ev
->children
[n
].u
= u
;
745 /** @brief Stop waiting for a child process
746 * @param ev Event loop
747 * @param pid Child process ID
748 * @return 0 on success, non-0 on error
750 int ev_child_cancel(ev_source
*ev
,
754 for(n
= 0; n
< ev
->nchildren
&& ev
->children
[n
].pid
!= pid
; ++n
)
756 assert(n
< ev
->nchildren
);
757 if(n
!= ev
->nchildren
- 1)
758 ev
->children
[n
] = ev
->children
[ev
->nchildren
- 1];
763 /* socket listeners ***********************************************************/
765 /** @brief State for a socket listener */
766 struct listen_state
{
767 ev_listen_callback
*callback
;
771 /** @brief Called when a listenign socket is readable */
772 static int listen_callback(ev_source
*ev
, int fd
, void *u
) {
773 const struct listen_state
*l
= u
;
776 struct sockaddr_in in
;
777 #if HAVE_STRUCT_SOCKADDR_IN6
778 struct sockaddr_in6 in6
;
780 struct sockaddr_un un
;
786 D(("callback for listener fd %d", fd
));
787 while((addrlen
= sizeof addr
),
788 (newfd
= accept(fd
, &addr
.sa
, &addrlen
)) >= 0) {
789 if((ret
= l
->callback(ev
, newfd
, &addr
.sa
, addrlen
, l
->u
)))
798 error(errno
, "error calling accept");
803 /* XXX on some systems EPROTO should be fatal, but we don't know if
804 * we're running on one of them */
805 error(errno
, "error calling accept");
809 fatal(errno
, "error calling accept");
812 if(errno
!= EINTR
&& errno
!= EAGAIN
)
813 error(errno
, "error calling accept");
817 /** @brief Listen on a socket for inbound stream connections
818 * @param ev Event source
819 * @param fd File descriptor of socket
820 * @param callback Called when a new connection arrives
821 * @param u Passed to @p callback
822 * @param what Text description of socket
823 * @return 0 on success, non-0 on error
825 int ev_listen(ev_source
*ev
,
827 ev_listen_callback
*callback
,
830 struct listen_state
*l
= xmalloc(sizeof *l
);
832 D(("registering listener fd %d callback %p %p", fd
, (void *)callback
, u
));
833 l
->callback
= callback
;
835 return ev_fd(ev
, ev_read
, fd
, listen_callback
, l
, what
);
838 /** @brief Stop listening on a socket
839 * @param ev Event loop
840 * @param fd File descriptor of socket
841 * @return 0 on success, non-0 on error
843 int ev_listen_cancel(ev_source
*ev
, int fd
) {
844 D(("cancelling listener fd %d", fd
));
845 return ev_fd_cancel(ev
, ev_read
, fd
);
848 /* buffer *********************************************************************/
850 /** @brief Buffer structure */
852 char *base
, *start
, *end
, *top
;
855 /* @brief Make sure there is @p bytes available at @c b->end */
856 static void buffer_space(struct buffer
*b
, size_t bytes
) {
857 D(("buffer_space %p %p %p %p want %lu",
858 (void *)b
->base
, (void *)b
->start
, (void *)b
->end
, (void *)b
->top
,
859 (unsigned long)bytes
));
860 if(b
->start
== b
->end
)
861 b
->start
= b
->end
= b
->base
;
862 if((size_t)(b
->top
- b
->end
) < bytes
) {
863 if((size_t)((b
->top
- b
->end
) + (b
->start
- b
->base
)) < bytes
) {
864 size_t newspace
= b
->end
- b
->start
+ bytes
, n
;
867 for(n
= 16; n
< newspace
; n
*= 2)
869 newbase
= xmalloc_noptr(n
);
870 memcpy(newbase
, b
->start
, b
->end
- b
->start
);
872 b
->end
= newbase
+ (b
->end
- b
->start
);
873 b
->top
= newbase
+ n
;
874 b
->start
= newbase
; /* must be last */
876 memmove(b
->base
, b
->start
, b
->end
- b
->start
);
877 b
->end
= b
->base
+ (b
->end
- b
->start
);
881 D(("result %p %p %p %p",
882 (void *)b
->base
, (void *)b
->start
, (void *)b
->end
, (void *)b
->top
));
885 /* buffered writer ************************************************************/
887 /** @brief State structure for a buffered writer */
893 ev_error_callback
*callback
;
898 /** @brief Called when a writer's file descriptor is writable */
899 static int writer_callback(ev_source
*ev
, int fd
, void *u
) {
903 n
= write(fd
, w
->b
.start
, w
->b
.end
- w
->b
.start
);
904 D(("callback for writer fd %d, %ld bytes, n=%d, errno=%d",
905 fd
, (long)(w
->b
.end
- w
->b
.start
), n
, errno
));
908 if(w
->b
.start
== w
->b
.end
) {
910 ev_fd_cancel(ev
, ev_write
, fd
);
911 return w
->callback(ev
, fd
, 0, w
->u
);
913 ev_fd_disable(ev
, ev_write
, fd
);
921 ev_fd_cancel(ev
, ev_write
, fd
);
922 return w
->callback(ev
, fd
, errno
, w
->u
);
928 /** @brief Write bytes to a writer's buffer
930 * This is the sink write callback.
932 * Calls ev_fd_enable() if necessary (i.e. if the buffer was empty but
935 static int ev_writer_write(struct sink
*sk
, const void *s
, int n
) {
936 ev_writer
*w
= (ev_writer
*)sk
;
938 buffer_space(&w
->b
, n
);
939 if(w
->b
.start
== w
->b
.end
)
940 ev_fd_enable(w
->ev
, ev_write
, w
->fd
);
941 memcpy(w
->b
.end
, s
, n
);
946 /** @brief Create a new buffered writer
947 * @param ev Event loop
948 * @param fd File descriptor to write to
949 * @param callback Called if an error occurs and when finished
950 * @param u Passed to @p callback
951 * @param what Text description
952 * @return New writer or @c NULL
954 ev_writer
*ev_writer_new(ev_source
*ev
,
956 ev_error_callback
*callback
,
959 ev_writer
*w
= xmalloc(sizeof *w
);
961 D(("registering writer fd %d callback %p %p", fd
, (void *)callback
, u
));
962 w
->s
.write
= ev_writer_write
;
964 w
->callback
= callback
;
967 if(ev_fd(ev
, ev_write
, fd
, writer_callback
, w
, what
))
969 ev_fd_disable(ev
, ev_write
, fd
);
973 /** @brief Return the sink associated with a writer
975 * @return Pointer to sink
977 * Writing to the sink will arrange for those bytes to be written to the file
978 * descriptor as and when it is writable.
980 struct sink
*ev_writer_sink(ev_writer
*w
) {
984 /** @brief Shutdown callback
986 * See ev_writer_close().
988 static int writer_shutdown(ev_source
*ev
,
989 const attribute((unused
)) struct timeval
*now
,
993 return w
->callback(ev
, w
->fd
, 0, w
->u
);
996 /** @brief Close a writer
997 * @param w Writer to close
998 * @return 0 on success, non-0 on error
1000 * Close a writer. No more bytes should be written to its sink.
1002 * When the last byte has been written the callback will be called with an
1003 * error code of 0. It is guaranteed that this will NOT happen before
1004 * ev_writer_close() returns (although the file descriptor for the writer might
1005 * be cancelled by the time it returns).
1007 int ev_writer_close(ev_writer
*w
) {
1008 D(("close writer fd %d", w
->fd
));
1010 if(w
->b
.start
== w
->b
.end
) {
1011 /* we're already finished */
1012 ev_fd_cancel(w
->ev
, ev_write
, w
->fd
);
1013 return ev_timeout(w
->ev
, 0, 0, writer_shutdown
, w
);
1018 /** @brief Cancel a writer discarding any buffered data
1019 * @param w Writer to close
1020 * @return 0 on success, non-0 on error
1022 * This cancels a writer immediately. Any unwritten buffered data is discarded
1023 * and the error callback is never called. This is appropriate to call if (for
1024 * instance) the read half of a TCP connection is known to have failed and the
1025 * writer is therefore obsolete.
1027 int ev_writer_cancel(ev_writer
*w
) {
1028 D(("cancel writer fd %d", w
->fd
));
1029 return ev_fd_cancel(w
->ev
, ev_write
, w
->fd
);
1032 /** @brief Attempt to flush a writer
1033 * @param w Writer to flush
1034 * @return 0 on success, non-0 on error
1036 * Does a speculative write of any buffered data. Does not block if it cannot
1039 int ev_writer_flush(ev_writer
*w
) {
1040 return writer_callback(w
->ev
, w
->fd
, w
);
1043 /* buffered reader ************************************************************/
1045 /** @brief State structure for a buffered reader */
1049 ev_reader_callback
*callback
;
1050 ev_error_callback
*error_callback
;
1056 /** @brief Called when a reader's @p fd is readable */
1057 static int reader_callback(ev_source
*ev
, int fd
, void *u
) {
1061 buffer_space(&r
->b
, 1);
1062 n
= read(fd
, r
->b
.end
, r
->b
.top
- r
->b
.end
);
1063 D(("read fd %d buffer %d returned %d errno %d",
1064 fd
, (int)(r
->b
.top
- r
->b
.end
), n
, errno
));
1067 return r
->callback(ev
, r
, fd
, r
->b
.start
, r
->b
.end
- r
->b
.start
, 0, r
->u
);
1070 ev_fd_cancel(ev
, ev_read
, fd
);
1071 return r
->callback(ev
, r
, fd
, r
->b
.start
, r
->b
.end
- r
->b
.start
, 1, r
->u
);
1078 ev_fd_cancel(ev
, ev_read
, fd
);
1079 return r
->error_callback(ev
, fd
, errno
, r
->u
);
1085 /** @brief Create a new buffered reader
1086 * @param ev Event loop
1087 * @param fd File descriptor to read from
1088 * @param callback Called when new data is available
1089 * @param error_callback Called if an error occurs
1090 * @param u Passed to callbacks
1091 * @param what Text description
1092 * @return New reader or @c NULL
1094 ev_reader
*ev_reader_new(ev_source
*ev
,
1096 ev_reader_callback
*callback
,
1097 ev_error_callback
*error_callback
,
1100 ev_reader
*r
= xmalloc(sizeof *r
);
1102 D(("registering reader fd %d callback %p %p %p",
1103 fd
, (void *)callback
, (void *)error_callback
, u
));
1105 r
->callback
= callback
;
1106 r
->error_callback
= error_callback
;
1109 if(ev_fd(ev
, ev_read
, fd
, reader_callback
, r
, what
))
1114 void ev_reader_buffer(ev_reader
*r
, size_t nbytes
) {
1115 buffer_space(&r
->b
, nbytes
- (r
->b
.end
- r
->b
.start
));
1118 /** @brief Consume @p n bytes from the reader's buffer
1120 * @param n Number of bytes to consume
1122 * Tells the reader than the next @p n bytes have been dealt with and can now
1125 void ev_reader_consume(ev_reader
*r
, size_t n
) {
1129 /** @brief Cancel a reader
1131 * @return 0 on success, non-0 on error
1133 int ev_reader_cancel(ev_reader
*r
) {
1134 D(("cancel reader fd %d", r
->fd
));
1135 return ev_fd_cancel(r
->ev
, ev_read
, r
->fd
);
1138 /** @brief Temporarily disable a reader
1140 * @return 0 on success, non-0 on error
1142 * No further callbacks for this reader will be made. Re-enable with
1143 * ev_reader_enable().
1145 int ev_reader_disable(ev_reader
*r
) {
1146 D(("disable reader fd %d", r
->fd
));
1147 return r
->eof ?
0 : ev_fd_disable(r
->ev
, ev_read
, r
->fd
);
1150 /** @brief Called from ev_run() for ev_reader_incomplete() */
1151 static int reader_continuation(ev_source
attribute((unused
)) *ev
,
1152 const attribute((unused
)) struct timeval
*now
,
1156 D(("reader continuation callback fd %d", r
->fd
));
1157 if(ev_fd_enable(r
->ev
, ev_read
, r
->fd
)) return -1;
1158 return r
->callback(ev
, r
, r
->fd
, r
->b
.start
, r
->b
.end
- r
->b
.start
, r
->eof
, r
->u
);
1161 /** @brief Arrange another callback
1163 * @return 0 on success, non-0 on error
1165 * Indicates that the reader can process more input but would like to yield to
1166 * other clients of the event loop. Input will be disabled but it will be
1167 * re-enabled on the next iteration of the event loop and the read callback
1168 * will be called again (even if no further bytes are available).
1170 int ev_reader_incomplete(ev_reader
*r
) {
1171 if(ev_fd_disable(r
->ev
, ev_read
, r
->fd
)) return -1;
1172 return ev_timeout(r
->ev
, 0, 0, reader_continuation
, r
);
1175 static int reader_enabled(ev_source
*ev
,
1176 const attribute((unused
)) struct timeval
*now
,
1180 D(("reader enabled callback fd %d", r
->fd
));
1181 return r
->callback(ev
, r
, r
->fd
, r
->b
.start
, r
->b
.end
- r
->b
.start
, r
->eof
, r
->u
);
1184 /** @brief Re-enable reading
1186 * @return 0 on success, non-0 on error
1188 * If there is unconsumed data then you get a callback next time round the
1189 * event loop even if nothing new has been read.
1191 * The idea is in your read callback you come across a line (or whatever) that
1192 * can't be processed immediately. So you set up processing and disable
1193 * reading with ev_reader_disable(). Later when you finish processing you
1194 * re-enable. You'll automatically get another callback directly from the
1195 * event loop (i.e. not from inside ev_reader_enable()) so you can handle the
1196 * next line (or whatever) if the whole thing has in fact already arrived.
1198 int ev_reader_enable(ev_reader
*r
) {
1199 D(("enable reader fd %d", r
->fd
));
1200 return ((r
->eof ?
0 : ev_fd_enable(r
->ev
, ev_read
, r
->fd
))
1201 || ev_timeout(r
->ev
, 0, 0, reader_enabled
, r
)) ?
-1 : 0;