1 /* Event loop machinery for GDB, the GNU debugger.
2 Copyright (C) 1999-2015 Free Software Foundation, Inc.
3 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
5 This file is part of GDB.
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with this program. If not, see <http://www.gnu.org/licenses/>. */
21 #include "event-loop.h"
22 #include "event-top.h"
26 #if defined (HAVE_POLL_H)
28 #elif defined (HAVE_SYS_POLL_H)
33 #include <sys/types.h>
35 #include "gdb_select.h"
38 /* Tell create_file_handler what events we are interested in.
39 This is used by the select version of the event loop. */
41 #define GDB_READABLE (1<<1)
42 #define GDB_WRITABLE (1<<2)
43 #define GDB_EXCEPTION (1<<3)
45 /* Data point to pass to the event handler. */
46 typedef union event_data
52 typedef struct gdb_event gdb_event
;
53 typedef void (event_handler_func
) (event_data
);
55 /* Event for the GDB event system. Events are queued by calling
56 async_queue_event and serviced later on by gdb_do_one_event. An
57 event can be, for instance, a file descriptor becoming ready to be
58 read. Servicing an event simply means that the procedure PROC will
59 be called. We have 2 queues, one for file handlers that we listen
60 to in the event loop, and one for the file handlers+events that are
61 ready. The procedure PROC associated with each event is dependant
62 of the event source. In the case of monitored file descriptors, it
63 is always the same (handle_file_event). Its duty is to invoke the
64 handler associated with the file descriptor whose state change
65 generated the event, plus doing other cleanups and such. In the
66 case of async signal handlers, it is
67 invoke_async_signal_handler. */
69 typedef struct gdb_event
71 /* Procedure to call to service this event. */
72 event_handler_func
*proc
;
74 /* Data to pass to the event handler. */
78 /* Information about each file descriptor we register with the event
81 typedef struct file_handler
83 int fd
; /* File descriptor. */
84 int mask
; /* Events we want to monitor: POLLIN, etc. */
85 int ready_mask
; /* Events that have been seen since
87 handler_func
*proc
; /* Procedure to call when fd is ready. */
88 gdb_client_data client_data
; /* Argument to pass to proc. */
89 int error
; /* Was an error detected on this fd? */
90 struct file_handler
*next_file
; /* Next registered file descriptor. */
94 /* PROC is a function to be invoked when the READY flag is set. This
95 happens when there has been a signal and the corresponding signal
96 handler has 'triggered' this async_signal_handler for execution.
97 The actual work to be done in response to a signal will be carried
98 out by PROC at a later time, within process_event. This provides a
99 deferred execution of signal handlers.
101 Async_init_signals takes care of setting up such an
102 async_signal_handler for each interesting signal. */
104 typedef struct async_signal_handler
106 int ready
; /* If ready, call this handler
107 from the main event loop, using
108 invoke_async_handler. */
109 struct async_signal_handler
*next_handler
; /* Ptr to next handler. */
110 sig_handler_func
*proc
; /* Function to call to do the work. */
111 gdb_client_data client_data
; /* Argument to async_handler_func. */
113 async_signal_handler
;
115 /* PROC is a function to be invoked when the READY flag is set. This
116 happens when the event has been marked with
117 MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response
118 to an event will be carried out by PROC at a later time, within
119 process_event. This provides a deferred execution of event
121 typedef struct async_event_handler
123 /* If ready, call this handler from the main event loop, using
124 invoke_event_handler. */
127 /* Point to next handler. */
128 struct async_event_handler
*next_handler
;
130 /* Function to call to do the work. */
131 async_event_handler_func
*proc
;
133 /* Argument to PROC. */
134 gdb_client_data client_data
;
138 /* Gdb_notifier is just a list of file descriptors gdb is interested in.
139 These are the input file descriptor, and the target file
140 descriptor. We have two flavors of the notifier, one for platforms
141 that have the POLL function, the other for those that don't, and
142 only support SELECT. Each of the elements in the gdb_notifier list is
143 basically a description of what kind of events gdb is interested
146 /* As of 1999-04-30 only the input file descriptor is registered with the
149 /* Do we use poll or select ? */
154 #endif /* HAVE_POLL */
156 static unsigned char use_poll
= USE_POLL
;
165 /* Ptr to head of file handler list. */
166 file_handler
*first_file_handler
;
169 /* Ptr to array of pollfd structures. */
170 struct pollfd
*poll_fds
;
172 /* Timeout in milliseconds for calls to poll(). */
176 /* Masks to be used in the next call to select.
177 Bits are set in response to calls to create_file_handler. */
178 fd_set check_masks
[3];
180 /* What file descriptors were found ready by select. */
181 fd_set ready_masks
[3];
183 /* Number of file descriptors to monitor (for poll). */
184 /* Number of valid bits (highest fd value + 1) (for select). */
187 /* Time structure for calls to select(). */
188 struct timeval select_timeout
;
190 /* Flag to tell whether the timeout should be used. */
195 /* Structure associated with a timer. PROC will be executed at the
196 first occasion after WHEN. */
201 struct gdb_timer
*next
;
202 timer_handler_func
*proc
; /* Function to call to do the work. */
203 gdb_client_data client_data
; /* Argument to async_handler_func. */
206 /* List of currently active timers. It is sorted in order of
207 increasing timers. */
210 /* Pointer to first in timer list. */
211 struct gdb_timer
*first_timer
;
213 /* Id of the last timer created. */
218 /* All the async_signal_handlers gdb is interested in are kept onto
222 /* Pointer to first in handler list. */
223 async_signal_handler
*first_handler
;
225 /* Pointer to last in handler list. */
226 async_signal_handler
*last_handler
;
230 /* All the async_event_handlers gdb is interested in are kept onto
234 /* Pointer to first in handler list. */
235 async_event_handler
*first_handler
;
237 /* Pointer to last in handler list. */
238 async_event_handler
*last_handler
;
240 async_event_handler_list
;
242 static int invoke_async_signal_handlers (void);
243 static void create_file_handler (int fd
, int mask
, handler_func
*proc
,
244 gdb_client_data client_data
);
245 static int check_async_event_handlers (void);
246 static int gdb_wait_for_event (int);
247 static int update_wait_timeout (void);
248 static int poll_timers (void);
251 /* Process one high level event. If nothing is ready at this time,
252 wait for something to happen (via gdb_wait_for_event), then process
253 it. Returns >0 if something was done otherwise returns <0 (this
254 can happen if there are no event sources to wait for). */
257 gdb_do_one_event (void)
259 static int event_source_head
= 0;
260 const int number_of_sources
= 3;
263 /* First let's see if there are any asynchronous signal handlers
264 that are ready. These would be the result of invoking any of the
266 if (invoke_async_signal_handlers ())
269 /* To level the fairness across event sources, we poll them in a
270 round-robin fashion. */
271 for (current
= 0; current
< number_of_sources
; current
++)
275 switch (event_source_head
)
278 /* Are any timers that are ready? */
279 res
= poll_timers ();
282 /* Are there events already waiting to be collected on the
283 monitored file descriptors? */
284 res
= gdb_wait_for_event (0);
287 /* Are there any asynchronous event handlers ready? */
288 res
= check_async_event_handlers ();
291 internal_error (__FILE__
, __LINE__
,
292 "unexpected event_source_head %d",
297 if (event_source_head
== number_of_sources
)
298 event_source_head
= 0;
304 /* Block waiting for a new event. If gdb_wait_for_event returns -1,
305 we should get out because this means that there are no event
306 sources left. This will make the event loop stop, and the
309 if (gdb_wait_for_event (1) < 0)
312 /* If gdb_wait_for_event has returned 1, it means that one event has
313 been handled. We break out of the loop. */
317 /* Start up the event loop. This is the entry point to the event loop
318 from the command loop. */
321 start_event_loop (void)
323 /* Loop until there is nothing to do. This is the entry point to
324 the event loop engine. gdb_do_one_event will process one event
325 for each invocation. It blocks waiting for an event and then
329 volatile struct gdb_exception ex
;
332 TRY_CATCH (ex
, RETURN_MASK_ALL
)
334 result
= gdb_do_one_event ();
338 exception_print (gdb_stderr
, ex
);
340 /* If any exception escaped to here, we better enable
341 stdin. Otherwise, any command that calls async_disable_stdin,
342 and then throws, will leave stdin inoperable. */
343 async_enable_stdin ();
344 /* If we long-jumped out of do_one_event, we probably didn't
345 get around to resetting the prompt, which leaves readline
346 in a messed-up state. Reset it here. */
347 observer_notify_command_error ();
348 /* This call looks bizarre, but it is required. If the user
349 entered a command that caused an error,
350 after_char_processing_hook won't be called from
351 rl_callback_read_char_wrapper. Using a cleanup there
352 won't work, since we want this function to be called
353 after a new prompt is printed. */
354 if (after_char_processing_hook
)
355 (*after_char_processing_hook
) ();
356 /* Maybe better to set a flag to be checked somewhere as to
357 whether display the prompt or not. */
363 /* We are done with the event loop. There are no more event sources
364 to listen to. So we exit GDB. */
369 /* Wrapper function for create_file_handler, so that the caller
370 doesn't have to know implementation details about the use of poll
373 add_file_handler (int fd
, handler_func
* proc
, gdb_client_data client_data
)
382 /* Check to see if poll () is usable. If not, we'll switch to
383 use select. This can happen on systems like
384 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
385 On m68k-motorola-sysv, tty's are not stream-based and not
389 if (poll (&fds
, 1, 0) == 1 && (fds
.revents
& POLLNVAL
))
392 internal_error (__FILE__
, __LINE__
,
393 _("use_poll without HAVE_POLL"));
394 #endif /* HAVE_POLL */
399 create_file_handler (fd
, POLLIN
, proc
, client_data
);
401 internal_error (__FILE__
, __LINE__
,
402 _("use_poll without HAVE_POLL"));
406 create_file_handler (fd
, GDB_READABLE
| GDB_EXCEPTION
,
410 /* Add a file handler/descriptor to the list of descriptors we are
413 FD is the file descriptor for the file/stream to be listened to.
415 For the poll case, MASK is a combination (OR) of POLLIN,
416 POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND:
417 these are the events we are interested in. If any of them occurs,
418 proc should be called.
420 For the select case, MASK is a combination of READABLE, WRITABLE,
421 EXCEPTION. PROC is the procedure that will be called when an event
422 occurs for FD. CLIENT_DATA is the argument to pass to PROC. */
425 create_file_handler (int fd
, int mask
, handler_func
* proc
,
426 gdb_client_data client_data
)
428 file_handler
*file_ptr
;
430 /* Do we already have a file handler for this file? (We may be
431 changing its associated procedure). */
432 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
433 file_ptr
= file_ptr
->next_file
)
435 if (file_ptr
->fd
== fd
)
439 /* It is a new file descriptor. Add it to the list. Otherwise, just
440 change the data associated with it. */
441 if (file_ptr
== NULL
)
443 file_ptr
= (file_handler
*) xmalloc (sizeof (file_handler
));
445 file_ptr
->ready_mask
= 0;
446 file_ptr
->next_file
= gdb_notifier
.first_file_handler
;
447 gdb_notifier
.first_file_handler
= file_ptr
;
452 gdb_notifier
.num_fds
++;
453 if (gdb_notifier
.poll_fds
)
454 gdb_notifier
.poll_fds
=
455 (struct pollfd
*) xrealloc (gdb_notifier
.poll_fds
,
456 (gdb_notifier
.num_fds
457 * sizeof (struct pollfd
)));
459 gdb_notifier
.poll_fds
=
460 (struct pollfd
*) xmalloc (sizeof (struct pollfd
));
461 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->fd
= fd
;
462 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->events
= mask
;
463 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->revents
= 0;
465 internal_error (__FILE__
, __LINE__
,
466 _("use_poll without HAVE_POLL"));
467 #endif /* HAVE_POLL */
471 if (mask
& GDB_READABLE
)
472 FD_SET (fd
, &gdb_notifier
.check_masks
[0]);
474 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
476 if (mask
& GDB_WRITABLE
)
477 FD_SET (fd
, &gdb_notifier
.check_masks
[1]);
479 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
481 if (mask
& GDB_EXCEPTION
)
482 FD_SET (fd
, &gdb_notifier
.check_masks
[2]);
484 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
486 if (gdb_notifier
.num_fds
<= fd
)
487 gdb_notifier
.num_fds
= fd
+ 1;
491 file_ptr
->proc
= proc
;
492 file_ptr
->client_data
= client_data
;
493 file_ptr
->mask
= mask
;
496 /* Remove the file descriptor FD from the list of monitored fd's:
497 i.e. we don't care anymore about events on the FD. */
499 delete_file_handler (int fd
)
501 file_handler
*file_ptr
, *prev_ptr
= NULL
;
505 struct pollfd
*new_poll_fds
;
508 /* Find the entry for the given file. */
510 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
511 file_ptr
= file_ptr
->next_file
)
513 if (file_ptr
->fd
== fd
)
517 if (file_ptr
== NULL
)
523 /* Create a new poll_fds array by copying every fd's information
524 but the one we want to get rid of. */
526 new_poll_fds
= (struct pollfd
*)
527 xmalloc ((gdb_notifier
.num_fds
- 1) * sizeof (struct pollfd
));
529 for (i
= 0, j
= 0; i
< gdb_notifier
.num_fds
; i
++)
531 if ((gdb_notifier
.poll_fds
+ i
)->fd
!= fd
)
533 (new_poll_fds
+ j
)->fd
= (gdb_notifier
.poll_fds
+ i
)->fd
;
534 (new_poll_fds
+ j
)->events
= (gdb_notifier
.poll_fds
+ i
)->events
;
535 (new_poll_fds
+ j
)->revents
536 = (gdb_notifier
.poll_fds
+ i
)->revents
;
540 xfree (gdb_notifier
.poll_fds
);
541 gdb_notifier
.poll_fds
= new_poll_fds
;
542 gdb_notifier
.num_fds
--;
544 internal_error (__FILE__
, __LINE__
,
545 _("use_poll without HAVE_POLL"));
546 #endif /* HAVE_POLL */
550 if (file_ptr
->mask
& GDB_READABLE
)
551 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
552 if (file_ptr
->mask
& GDB_WRITABLE
)
553 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
554 if (file_ptr
->mask
& GDB_EXCEPTION
)
555 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
557 /* Find current max fd. */
559 if ((fd
+ 1) == gdb_notifier
.num_fds
)
561 gdb_notifier
.num_fds
--;
562 for (i
= gdb_notifier
.num_fds
; i
; i
--)
564 if (FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[0])
565 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[1])
566 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[2]))
569 gdb_notifier
.num_fds
= i
;
573 /* Deactivate the file descriptor, by clearing its mask,
574 so that it will not fire again. */
578 /* Get rid of the file handler in the file handler list. */
579 if (file_ptr
== gdb_notifier
.first_file_handler
)
580 gdb_notifier
.first_file_handler
= file_ptr
->next_file
;
583 for (prev_ptr
= gdb_notifier
.first_file_handler
;
584 prev_ptr
->next_file
!= file_ptr
;
585 prev_ptr
= prev_ptr
->next_file
)
587 prev_ptr
->next_file
= file_ptr
->next_file
;
592 /* Handle the given event by calling the procedure associated to the
593 corresponding file handler. */
596 handle_file_event (file_handler
*file_ptr
, int ready_mask
)
605 /* With poll, the ready_mask could have any of three events
606 set to 1: POLLHUP, POLLERR, POLLNVAL. These events
607 cannot be used in the requested event mask (events), but
608 they can be returned in the return mask (revents). We
609 need to check for those event too, and add them to the
610 mask which will be passed to the handler. */
612 /* See if the desired events (mask) match the received
613 events (ready_mask). */
618 /* POLLHUP means EOF, but can be combined with POLLIN to
619 signal more data to read. */
620 error_mask
= POLLHUP
| POLLERR
| POLLNVAL
;
621 mask
= ready_mask
& (file_ptr
->mask
| error_mask
);
623 if ((mask
& (POLLERR
| POLLNVAL
)) != 0)
625 /* Work in progress. We may need to tell somebody
626 what kind of error we had. */
628 printf_unfiltered (_("Error detected on fd %d\n"),
631 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"),
638 internal_error (__FILE__
, __LINE__
,
639 _("use_poll without HAVE_POLL"));
640 #endif /* HAVE_POLL */
644 if (ready_mask
& GDB_EXCEPTION
)
646 printf_unfiltered (_("Exception condition detected "
647 "on fd %d\n"), file_ptr
->fd
);
652 mask
= ready_mask
& file_ptr
->mask
;
655 /* If there was a match, then call the handler. */
657 (*file_ptr
->proc
) (file_ptr
->error
, file_ptr
->client_data
);
662 /* Wait for new events on the monitored file descriptors. Run the
663 event handler if the first descriptor that is detected by the poll.
664 If BLOCK and if there are no events, this function will block in
665 the call to poll. Return 1 if an event was handled. Return -1 if
666 there are no file descriptors to monitor. Return 1 if an event was
667 handled, otherwise returns 0. */
670 gdb_wait_for_event (int block
)
672 file_handler
*file_ptr
;
676 /* Make sure all output is done before getting another event. */
677 gdb_flush (gdb_stdout
);
678 gdb_flush (gdb_stderr
);
680 if (gdb_notifier
.num_fds
== 0)
684 update_wait_timeout ();
692 timeout
= gdb_notifier
.timeout_valid
? gdb_notifier
.poll_timeout
: -1;
696 num_found
= poll (gdb_notifier
.poll_fds
,
697 (unsigned long) gdb_notifier
.num_fds
, timeout
);
699 /* Don't print anything if we get out of poll because of a
701 if (num_found
== -1 && errno
!= EINTR
)
702 perror_with_name (("poll"));
704 internal_error (__FILE__
, __LINE__
,
705 _("use_poll without HAVE_POLL"));
706 #endif /* HAVE_POLL */
710 struct timeval select_timeout
;
711 struct timeval
*timeout_p
;
714 timeout_p
= gdb_notifier
.timeout_valid
715 ? &gdb_notifier
.select_timeout
: NULL
;
718 memset (&select_timeout
, 0, sizeof (select_timeout
));
719 timeout_p
= &select_timeout
;
722 gdb_notifier
.ready_masks
[0] = gdb_notifier
.check_masks
[0];
723 gdb_notifier
.ready_masks
[1] = gdb_notifier
.check_masks
[1];
724 gdb_notifier
.ready_masks
[2] = gdb_notifier
.check_masks
[2];
725 num_found
= gdb_select (gdb_notifier
.num_fds
,
726 &gdb_notifier
.ready_masks
[0],
727 &gdb_notifier
.ready_masks
[1],
728 &gdb_notifier
.ready_masks
[2],
731 /* Clear the masks after an error from select. */
734 FD_ZERO (&gdb_notifier
.ready_masks
[0]);
735 FD_ZERO (&gdb_notifier
.ready_masks
[1]);
736 FD_ZERO (&gdb_notifier
.ready_masks
[2]);
738 /* Dont print anything if we got a signal, let gdb handle
741 perror_with_name (("select"));
745 /* Run event handlers. We always run just one handler and go back
746 to polling, in case a handler changes the notifier list. Since
747 events for sources we haven't consumed yet wake poll/select
748 immediately, no event is lost. */
753 for (i
= 0; (i
< gdb_notifier
.num_fds
) && (num_found
> 0); i
++)
755 if ((gdb_notifier
.poll_fds
+ i
)->revents
)
760 for (file_ptr
= gdb_notifier
.first_file_handler
;
762 file_ptr
= file_ptr
->next_file
)
764 if (file_ptr
->fd
== (gdb_notifier
.poll_fds
+ i
)->fd
)
770 int mask
= (gdb_notifier
.poll_fds
+ i
)->revents
;
772 handle_file_event (file_ptr
, mask
);
777 internal_error (__FILE__
, __LINE__
,
778 _("use_poll without HAVE_POLL"));
779 #endif /* HAVE_POLL */
783 for (file_ptr
= gdb_notifier
.first_file_handler
;
784 (file_ptr
!= NULL
) && (num_found
> 0);
785 file_ptr
= file_ptr
->next_file
)
789 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[0]))
790 mask
|= GDB_READABLE
;
791 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[1]))
792 mask
|= GDB_WRITABLE
;
793 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[2]))
794 mask
|= GDB_EXCEPTION
;
801 handle_file_event (file_ptr
, mask
);
809 /* Create an asynchronous handler, allocating memory for it.
810 Return a pointer to the newly created handler.
811 This pointer will be used to invoke the handler by
812 invoke_async_signal_handler.
813 PROC is the function to call with CLIENT_DATA argument
814 whenever the handler is invoked. */
815 async_signal_handler
*
816 create_async_signal_handler (sig_handler_func
* proc
,
817 gdb_client_data client_data
)
819 async_signal_handler
*async_handler_ptr
;
822 (async_signal_handler
*) xmalloc (sizeof (async_signal_handler
));
823 async_handler_ptr
->ready
= 0;
824 async_handler_ptr
->next_handler
= NULL
;
825 async_handler_ptr
->proc
= proc
;
826 async_handler_ptr
->client_data
= client_data
;
827 if (sighandler_list
.first_handler
== NULL
)
828 sighandler_list
.first_handler
= async_handler_ptr
;
830 sighandler_list
.last_handler
->next_handler
= async_handler_ptr
;
831 sighandler_list
.last_handler
= async_handler_ptr
;
832 return async_handler_ptr
;
835 /* Call the handler from HANDLER immediately. This function runs
836 signal handlers when returning to the event loop would be too
839 call_async_signal_handler (struct async_signal_handler
*handler
)
841 (*handler
->proc
) (handler
->client_data
);
844 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
845 will be used when the handlers are invoked, after we have waited
846 for some event. The caller of this function is the interrupt
847 handler associated with a signal. */
849 mark_async_signal_handler (async_signal_handler
* async_handler_ptr
)
851 async_handler_ptr
->ready
= 1;
854 /* Call all the handlers that are ready. Returns true if any was
857 invoke_async_signal_handlers (void)
859 async_signal_handler
*async_handler_ptr
;
862 /* Invoke ready handlers. */
866 for (async_handler_ptr
= sighandler_list
.first_handler
;
867 async_handler_ptr
!= NULL
;
868 async_handler_ptr
= async_handler_ptr
->next_handler
)
870 if (async_handler_ptr
->ready
)
873 if (async_handler_ptr
== NULL
)
876 async_handler_ptr
->ready
= 0;
877 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
883 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
884 Free the space allocated for it. */
886 delete_async_signal_handler (async_signal_handler
** async_handler_ptr
)
888 async_signal_handler
*prev_ptr
;
890 if (sighandler_list
.first_handler
== (*async_handler_ptr
))
892 sighandler_list
.first_handler
= (*async_handler_ptr
)->next_handler
;
893 if (sighandler_list
.first_handler
== NULL
)
894 sighandler_list
.last_handler
= NULL
;
898 prev_ptr
= sighandler_list
.first_handler
;
899 while (prev_ptr
&& prev_ptr
->next_handler
!= (*async_handler_ptr
))
900 prev_ptr
= prev_ptr
->next_handler
;
901 gdb_assert (prev_ptr
);
902 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
903 if (sighandler_list
.last_handler
== (*async_handler_ptr
))
904 sighandler_list
.last_handler
= prev_ptr
;
906 xfree ((*async_handler_ptr
));
907 (*async_handler_ptr
) = NULL
;
910 /* Create an asynchronous event handler, allocating memory for it.
911 Return a pointer to the newly created handler. PROC is the
912 function to call with CLIENT_DATA argument whenever the handler is
914 async_event_handler
*
915 create_async_event_handler (async_event_handler_func
*proc
,
916 gdb_client_data client_data
)
918 async_event_handler
*h
;
920 h
= xmalloc (sizeof (*h
));
922 h
->next_handler
= NULL
;
924 h
->client_data
= client_data
;
925 if (async_event_handler_list
.first_handler
== NULL
)
926 async_event_handler_list
.first_handler
= h
;
928 async_event_handler_list
.last_handler
->next_handler
= h
;
929 async_event_handler_list
.last_handler
= h
;
933 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
934 will be used by gdb_do_one_event. The caller will be whoever
935 created the event source, and wants to signal that the event is
936 ready to be handled. */
938 mark_async_event_handler (async_event_handler
*async_handler_ptr
)
940 async_handler_ptr
->ready
= 1;
943 /* See event-loop.h. */
946 clear_async_event_handler (async_event_handler
*async_handler_ptr
)
948 async_handler_ptr
->ready
= 0;
951 /* Check if asynchronous event handlers are ready, and call the
952 handler function for one that is. */
955 check_async_event_handlers (void)
957 async_event_handler
*async_handler_ptr
;
959 for (async_handler_ptr
= async_event_handler_list
.first_handler
;
960 async_handler_ptr
!= NULL
;
961 async_handler_ptr
= async_handler_ptr
->next_handler
)
963 if (async_handler_ptr
->ready
)
965 async_handler_ptr
->ready
= 0;
966 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
974 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
975 Free the space allocated for it. */
977 delete_async_event_handler (async_event_handler
**async_handler_ptr
)
979 async_event_handler
*prev_ptr
;
981 if (async_event_handler_list
.first_handler
== *async_handler_ptr
)
983 async_event_handler_list
.first_handler
984 = (*async_handler_ptr
)->next_handler
;
985 if (async_event_handler_list
.first_handler
== NULL
)
986 async_event_handler_list
.last_handler
= NULL
;
990 prev_ptr
= async_event_handler_list
.first_handler
;
991 while (prev_ptr
&& prev_ptr
->next_handler
!= *async_handler_ptr
)
992 prev_ptr
= prev_ptr
->next_handler
;
993 gdb_assert (prev_ptr
);
994 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
995 if (async_event_handler_list
.last_handler
== (*async_handler_ptr
))
996 async_event_handler_list
.last_handler
= prev_ptr
;
998 xfree (*async_handler_ptr
);
999 *async_handler_ptr
= NULL
;
1002 /* Create a timer that will expire in MILLISECONDS from now. When the
1003 timer is ready, PROC will be executed. At creation, the timer is
1004 aded to the timers queue. This queue is kept sorted in order of
1005 increasing timers. Return a handle to the timer struct. */
1007 create_timer (int milliseconds
, timer_handler_func
* proc
,
1008 gdb_client_data client_data
)
1010 struct gdb_timer
*timer_ptr
, *timer_index
, *prev_timer
;
1011 struct timeval time_now
, delta
;
1013 /* Compute seconds. */
1014 delta
.tv_sec
= milliseconds
/ 1000;
1015 /* Compute microseconds. */
1016 delta
.tv_usec
= (milliseconds
% 1000) * 1000;
1018 gettimeofday (&time_now
, NULL
);
1020 timer_ptr
= (struct gdb_timer
*) xmalloc (sizeof (*timer_ptr
));
1021 timer_ptr
->when
.tv_sec
= time_now
.tv_sec
+ delta
.tv_sec
;
1022 timer_ptr
->when
.tv_usec
= time_now
.tv_usec
+ delta
.tv_usec
;
1024 if (timer_ptr
->when
.tv_usec
>= 1000000)
1026 timer_ptr
->when
.tv_sec
+= 1;
1027 timer_ptr
->when
.tv_usec
-= 1000000;
1029 timer_ptr
->proc
= proc
;
1030 timer_ptr
->client_data
= client_data
;
1031 timer_list
.num_timers
++;
1032 timer_ptr
->timer_id
= timer_list
.num_timers
;
1034 /* Now add the timer to the timer queue, making sure it is sorted in
1035 increasing order of expiration. */
1037 for (timer_index
= timer_list
.first_timer
;
1038 timer_index
!= NULL
;
1039 timer_index
= timer_index
->next
)
1041 /* If the seconds field is greater or if it is the same, but the
1042 microsecond field is greater. */
1043 if ((timer_index
->when
.tv_sec
> timer_ptr
->when
.tv_sec
)
1044 || ((timer_index
->when
.tv_sec
== timer_ptr
->when
.tv_sec
)
1045 && (timer_index
->when
.tv_usec
> timer_ptr
->when
.tv_usec
)))
1049 if (timer_index
== timer_list
.first_timer
)
1051 timer_ptr
->next
= timer_list
.first_timer
;
1052 timer_list
.first_timer
= timer_ptr
;
1057 for (prev_timer
= timer_list
.first_timer
;
1058 prev_timer
->next
!= timer_index
;
1059 prev_timer
= prev_timer
->next
)
1062 prev_timer
->next
= timer_ptr
;
1063 timer_ptr
->next
= timer_index
;
1066 gdb_notifier
.timeout_valid
= 0;
1067 return timer_ptr
->timer_id
;
1070 /* There is a chance that the creator of the timer wants to get rid of
1071 it before it expires. */
1073 delete_timer (int id
)
1075 struct gdb_timer
*timer_ptr
, *prev_timer
= NULL
;
1077 /* Find the entry for the given timer. */
1079 for (timer_ptr
= timer_list
.first_timer
; timer_ptr
!= NULL
;
1080 timer_ptr
= timer_ptr
->next
)
1082 if (timer_ptr
->timer_id
== id
)
1086 if (timer_ptr
== NULL
)
1088 /* Get rid of the timer in the timer list. */
1089 if (timer_ptr
== timer_list
.first_timer
)
1090 timer_list
.first_timer
= timer_ptr
->next
;
1093 for (prev_timer
= timer_list
.first_timer
;
1094 prev_timer
->next
!= timer_ptr
;
1095 prev_timer
= prev_timer
->next
)
1097 prev_timer
->next
= timer_ptr
->next
;
1101 gdb_notifier
.timeout_valid
= 0;
1104 /* Update the timeout for the select() or poll(). Returns true if the
1105 timer has already expired, false otherwise. */
1108 update_wait_timeout (void)
1110 struct timeval time_now
, delta
;
1112 if (timer_list
.first_timer
!= NULL
)
1114 gettimeofday (&time_now
, NULL
);
1115 delta
.tv_sec
= timer_list
.first_timer
->when
.tv_sec
- time_now
.tv_sec
;
1116 delta
.tv_usec
= timer_list
.first_timer
->when
.tv_usec
- time_now
.tv_usec
;
1118 if (delta
.tv_usec
< 0)
1121 delta
.tv_usec
+= 1000000;
1124 /* Cannot simply test if delta.tv_sec is negative because time_t
1125 might be unsigned. */
1126 if (timer_list
.first_timer
->when
.tv_sec
< time_now
.tv_sec
1127 || (timer_list
.first_timer
->when
.tv_sec
== time_now
.tv_sec
1128 && timer_list
.first_timer
->when
.tv_usec
< time_now
.tv_usec
))
1130 /* It expired already. */
1135 /* Update the timeout for select/ poll. */
1139 gdb_notifier
.poll_timeout
= delta
.tv_sec
* 1000;
1141 internal_error (__FILE__
, __LINE__
,
1142 _("use_poll without HAVE_POLL"));
1143 #endif /* HAVE_POLL */
1147 gdb_notifier
.select_timeout
.tv_sec
= delta
.tv_sec
;
1148 gdb_notifier
.select_timeout
.tv_usec
= delta
.tv_usec
;
1150 gdb_notifier
.timeout_valid
= 1;
1152 if (delta
.tv_sec
== 0 && delta
.tv_usec
== 0)
1156 gdb_notifier
.timeout_valid
= 0;
1161 /* Check whether a timer in the timers queue is ready. If a timer is
1162 ready, call its handler and return. Update the timeout for the
1163 select() or poll() as well. Return 1 if an event was handled,
1164 otherwise returns 0.*/
1169 if (update_wait_timeout ())
1171 struct gdb_timer
*timer_ptr
= timer_list
.first_timer
;
1172 timer_handler_func
*proc
= timer_ptr
->proc
;
1173 gdb_client_data client_data
= timer_ptr
->client_data
;
1175 /* Get rid of the timer from the beginning of the list. */
1176 timer_list
.first_timer
= timer_ptr
->next
;
1178 /* Delete the timer before calling the callback, not after, in
1179 case the callback itself decides to try deleting the timer
1183 /* Call the procedure associated with that timer. */
1184 (proc
) (client_data
);