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
333 result
= gdb_do_one_event ();
335 CATCH (ex
, RETURN_MASK_ALL
)
337 exception_print (gdb_stderr
, ex
);
339 /* If any exception escaped to here, we better enable
340 stdin. Otherwise, any command that calls async_disable_stdin,
341 and then throws, will leave stdin inoperable. */
342 async_enable_stdin ();
343 /* If we long-jumped out of do_one_event, we probably didn't
344 get around to resetting the prompt, which leaves readline
345 in a messed-up state. Reset it here. */
346 observer_notify_command_error ();
347 /* This call looks bizarre, but it is required. If the user
348 entered a command that caused an error,
349 after_char_processing_hook won't be called from
350 rl_callback_read_char_wrapper. Using a cleanup there
351 won't work, since we want this function to be called
352 after a new prompt is printed. */
353 if (after_char_processing_hook
)
354 (*after_char_processing_hook
) ();
355 /* Maybe better to set a flag to be checked somewhere as to
356 whether display the prompt or not. */
364 /* We are done with the event loop. There are no more event sources
365 to listen to. So we exit GDB. */
370 /* Wrapper function for create_file_handler, so that the caller
371 doesn't have to know implementation details about the use of poll
374 add_file_handler (int fd
, handler_func
* proc
, gdb_client_data client_data
)
383 /* Check to see if poll () is usable. If not, we'll switch to
384 use select. This can happen on systems like
385 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
386 On m68k-motorola-sysv, tty's are not stream-based and not
390 if (poll (&fds
, 1, 0) == 1 && (fds
.revents
& POLLNVAL
))
393 internal_error (__FILE__
, __LINE__
,
394 _("use_poll without HAVE_POLL"));
395 #endif /* HAVE_POLL */
400 create_file_handler (fd
, POLLIN
, proc
, client_data
);
402 internal_error (__FILE__
, __LINE__
,
403 _("use_poll without HAVE_POLL"));
407 create_file_handler (fd
, GDB_READABLE
| GDB_EXCEPTION
,
411 /* Add a file handler/descriptor to the list of descriptors we are
414 FD is the file descriptor for the file/stream to be listened to.
416 For the poll case, MASK is a combination (OR) of POLLIN,
417 POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND:
418 these are the events we are interested in. If any of them occurs,
419 proc should be called.
421 For the select case, MASK is a combination of READABLE, WRITABLE,
422 EXCEPTION. PROC is the procedure that will be called when an event
423 occurs for FD. CLIENT_DATA is the argument to pass to PROC. */
426 create_file_handler (int fd
, int mask
, handler_func
* proc
,
427 gdb_client_data client_data
)
429 file_handler
*file_ptr
;
431 /* Do we already have a file handler for this file? (We may be
432 changing its associated procedure). */
433 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
434 file_ptr
= file_ptr
->next_file
)
436 if (file_ptr
->fd
== fd
)
440 /* It is a new file descriptor. Add it to the list. Otherwise, just
441 change the data associated with it. */
442 if (file_ptr
== NULL
)
444 file_ptr
= (file_handler
*) xmalloc (sizeof (file_handler
));
446 file_ptr
->ready_mask
= 0;
447 file_ptr
->next_file
= gdb_notifier
.first_file_handler
;
448 gdb_notifier
.first_file_handler
= file_ptr
;
453 gdb_notifier
.num_fds
++;
454 if (gdb_notifier
.poll_fds
)
455 gdb_notifier
.poll_fds
=
456 (struct pollfd
*) xrealloc (gdb_notifier
.poll_fds
,
457 (gdb_notifier
.num_fds
458 * sizeof (struct pollfd
)));
460 gdb_notifier
.poll_fds
=
461 (struct pollfd
*) xmalloc (sizeof (struct pollfd
));
462 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->fd
= fd
;
463 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->events
= mask
;
464 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->revents
= 0;
466 internal_error (__FILE__
, __LINE__
,
467 _("use_poll without HAVE_POLL"));
468 #endif /* HAVE_POLL */
472 if (mask
& GDB_READABLE
)
473 FD_SET (fd
, &gdb_notifier
.check_masks
[0]);
475 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
477 if (mask
& GDB_WRITABLE
)
478 FD_SET (fd
, &gdb_notifier
.check_masks
[1]);
480 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
482 if (mask
& GDB_EXCEPTION
)
483 FD_SET (fd
, &gdb_notifier
.check_masks
[2]);
485 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
487 if (gdb_notifier
.num_fds
<= fd
)
488 gdb_notifier
.num_fds
= fd
+ 1;
492 file_ptr
->proc
= proc
;
493 file_ptr
->client_data
= client_data
;
494 file_ptr
->mask
= mask
;
497 /* Remove the file descriptor FD from the list of monitored fd's:
498 i.e. we don't care anymore about events on the FD. */
500 delete_file_handler (int fd
)
502 file_handler
*file_ptr
, *prev_ptr
= NULL
;
506 struct pollfd
*new_poll_fds
;
509 /* Find the entry for the given file. */
511 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
512 file_ptr
= file_ptr
->next_file
)
514 if (file_ptr
->fd
== fd
)
518 if (file_ptr
== NULL
)
524 /* Create a new poll_fds array by copying every fd's information
525 but the one we want to get rid of. */
527 new_poll_fds
= (struct pollfd
*)
528 xmalloc ((gdb_notifier
.num_fds
- 1) * sizeof (struct pollfd
));
530 for (i
= 0, j
= 0; i
< gdb_notifier
.num_fds
; i
++)
532 if ((gdb_notifier
.poll_fds
+ i
)->fd
!= fd
)
534 (new_poll_fds
+ j
)->fd
= (gdb_notifier
.poll_fds
+ i
)->fd
;
535 (new_poll_fds
+ j
)->events
= (gdb_notifier
.poll_fds
+ i
)->events
;
536 (new_poll_fds
+ j
)->revents
537 = (gdb_notifier
.poll_fds
+ i
)->revents
;
541 xfree (gdb_notifier
.poll_fds
);
542 gdb_notifier
.poll_fds
= new_poll_fds
;
543 gdb_notifier
.num_fds
--;
545 internal_error (__FILE__
, __LINE__
,
546 _("use_poll without HAVE_POLL"));
547 #endif /* HAVE_POLL */
551 if (file_ptr
->mask
& GDB_READABLE
)
552 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
553 if (file_ptr
->mask
& GDB_WRITABLE
)
554 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
555 if (file_ptr
->mask
& GDB_EXCEPTION
)
556 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
558 /* Find current max fd. */
560 if ((fd
+ 1) == gdb_notifier
.num_fds
)
562 gdb_notifier
.num_fds
--;
563 for (i
= gdb_notifier
.num_fds
; i
; i
--)
565 if (FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[0])
566 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[1])
567 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[2]))
570 gdb_notifier
.num_fds
= i
;
574 /* Deactivate the file descriptor, by clearing its mask,
575 so that it will not fire again. */
579 /* Get rid of the file handler in the file handler list. */
580 if (file_ptr
== gdb_notifier
.first_file_handler
)
581 gdb_notifier
.first_file_handler
= file_ptr
->next_file
;
584 for (prev_ptr
= gdb_notifier
.first_file_handler
;
585 prev_ptr
->next_file
!= file_ptr
;
586 prev_ptr
= prev_ptr
->next_file
)
588 prev_ptr
->next_file
= file_ptr
->next_file
;
593 /* Handle the given event by calling the procedure associated to the
594 corresponding file handler. */
597 handle_file_event (file_handler
*file_ptr
, int ready_mask
)
606 /* With poll, the ready_mask could have any of three events
607 set to 1: POLLHUP, POLLERR, POLLNVAL. These events
608 cannot be used in the requested event mask (events), but
609 they can be returned in the return mask (revents). We
610 need to check for those event too, and add them to the
611 mask which will be passed to the handler. */
613 /* See if the desired events (mask) match the received
614 events (ready_mask). */
619 /* POLLHUP means EOF, but can be combined with POLLIN to
620 signal more data to read. */
621 error_mask
= POLLHUP
| POLLERR
| POLLNVAL
;
622 mask
= ready_mask
& (file_ptr
->mask
| error_mask
);
624 if ((mask
& (POLLERR
| POLLNVAL
)) != 0)
626 /* Work in progress. We may need to tell somebody
627 what kind of error we had. */
629 printf_unfiltered (_("Error detected on fd %d\n"),
632 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"),
639 internal_error (__FILE__
, __LINE__
,
640 _("use_poll without HAVE_POLL"));
641 #endif /* HAVE_POLL */
645 if (ready_mask
& GDB_EXCEPTION
)
647 printf_unfiltered (_("Exception condition detected "
648 "on fd %d\n"), file_ptr
->fd
);
653 mask
= ready_mask
& file_ptr
->mask
;
656 /* If there was a match, then call the handler. */
658 (*file_ptr
->proc
) (file_ptr
->error
, file_ptr
->client_data
);
663 /* Wait for new events on the monitored file descriptors. Run the
664 event handler if the first descriptor that is detected by the poll.
665 If BLOCK and if there are no events, this function will block in
666 the call to poll. Return 1 if an event was handled. Return -1 if
667 there are no file descriptors to monitor. Return 1 if an event was
668 handled, otherwise returns 0. */
671 gdb_wait_for_event (int block
)
673 file_handler
*file_ptr
;
677 /* Make sure all output is done before getting another event. */
678 gdb_flush (gdb_stdout
);
679 gdb_flush (gdb_stderr
);
681 if (gdb_notifier
.num_fds
== 0)
685 update_wait_timeout ();
693 timeout
= gdb_notifier
.timeout_valid
? gdb_notifier
.poll_timeout
: -1;
697 num_found
= poll (gdb_notifier
.poll_fds
,
698 (unsigned long) gdb_notifier
.num_fds
, timeout
);
700 /* Don't print anything if we get out of poll because of a
702 if (num_found
== -1 && errno
!= EINTR
)
703 perror_with_name (("poll"));
705 internal_error (__FILE__
, __LINE__
,
706 _("use_poll without HAVE_POLL"));
707 #endif /* HAVE_POLL */
711 struct timeval select_timeout
;
712 struct timeval
*timeout_p
;
715 timeout_p
= gdb_notifier
.timeout_valid
716 ? &gdb_notifier
.select_timeout
: NULL
;
719 memset (&select_timeout
, 0, sizeof (select_timeout
));
720 timeout_p
= &select_timeout
;
723 gdb_notifier
.ready_masks
[0] = gdb_notifier
.check_masks
[0];
724 gdb_notifier
.ready_masks
[1] = gdb_notifier
.check_masks
[1];
725 gdb_notifier
.ready_masks
[2] = gdb_notifier
.check_masks
[2];
726 num_found
= gdb_select (gdb_notifier
.num_fds
,
727 &gdb_notifier
.ready_masks
[0],
728 &gdb_notifier
.ready_masks
[1],
729 &gdb_notifier
.ready_masks
[2],
732 /* Clear the masks after an error from select. */
735 FD_ZERO (&gdb_notifier
.ready_masks
[0]);
736 FD_ZERO (&gdb_notifier
.ready_masks
[1]);
737 FD_ZERO (&gdb_notifier
.ready_masks
[2]);
739 /* Dont print anything if we got a signal, let gdb handle
742 perror_with_name (("select"));
746 /* Run event handlers. We always run just one handler and go back
747 to polling, in case a handler changes the notifier list. Since
748 events for sources we haven't consumed yet wake poll/select
749 immediately, no event is lost. */
754 for (i
= 0; (i
< gdb_notifier
.num_fds
) && (num_found
> 0); i
++)
756 if ((gdb_notifier
.poll_fds
+ i
)->revents
)
761 for (file_ptr
= gdb_notifier
.first_file_handler
;
763 file_ptr
= file_ptr
->next_file
)
765 if (file_ptr
->fd
== (gdb_notifier
.poll_fds
+ i
)->fd
)
771 int mask
= (gdb_notifier
.poll_fds
+ i
)->revents
;
773 handle_file_event (file_ptr
, mask
);
778 internal_error (__FILE__
, __LINE__
,
779 _("use_poll without HAVE_POLL"));
780 #endif /* HAVE_POLL */
784 for (file_ptr
= gdb_notifier
.first_file_handler
;
785 (file_ptr
!= NULL
) && (num_found
> 0);
786 file_ptr
= file_ptr
->next_file
)
790 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[0]))
791 mask
|= GDB_READABLE
;
792 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[1]))
793 mask
|= GDB_WRITABLE
;
794 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[2]))
795 mask
|= GDB_EXCEPTION
;
802 handle_file_event (file_ptr
, mask
);
810 /* Create an asynchronous handler, allocating memory for it.
811 Return a pointer to the newly created handler.
812 This pointer will be used to invoke the handler by
813 invoke_async_signal_handler.
814 PROC is the function to call with CLIENT_DATA argument
815 whenever the handler is invoked. */
816 async_signal_handler
*
817 create_async_signal_handler (sig_handler_func
* proc
,
818 gdb_client_data client_data
)
820 async_signal_handler
*async_handler_ptr
;
823 (async_signal_handler
*) xmalloc (sizeof (async_signal_handler
));
824 async_handler_ptr
->ready
= 0;
825 async_handler_ptr
->next_handler
= NULL
;
826 async_handler_ptr
->proc
= proc
;
827 async_handler_ptr
->client_data
= client_data
;
828 if (sighandler_list
.first_handler
== NULL
)
829 sighandler_list
.first_handler
= async_handler_ptr
;
831 sighandler_list
.last_handler
->next_handler
= async_handler_ptr
;
832 sighandler_list
.last_handler
= async_handler_ptr
;
833 return async_handler_ptr
;
836 /* Call the handler from HANDLER immediately. This function runs
837 signal handlers when returning to the event loop would be too
840 call_async_signal_handler (struct async_signal_handler
*handler
)
842 (*handler
->proc
) (handler
->client_data
);
845 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
846 will be used when the handlers are invoked, after we have waited
847 for some event. The caller of this function is the interrupt
848 handler associated with a signal. */
850 mark_async_signal_handler (async_signal_handler
* async_handler_ptr
)
852 async_handler_ptr
->ready
= 1;
855 /* Call all the handlers that are ready. Returns true if any was
858 invoke_async_signal_handlers (void)
860 async_signal_handler
*async_handler_ptr
;
863 /* Invoke ready handlers. */
867 for (async_handler_ptr
= sighandler_list
.first_handler
;
868 async_handler_ptr
!= NULL
;
869 async_handler_ptr
= async_handler_ptr
->next_handler
)
871 if (async_handler_ptr
->ready
)
874 if (async_handler_ptr
== NULL
)
877 async_handler_ptr
->ready
= 0;
878 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
884 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
885 Free the space allocated for it. */
887 delete_async_signal_handler (async_signal_handler
** async_handler_ptr
)
889 async_signal_handler
*prev_ptr
;
891 if (sighandler_list
.first_handler
== (*async_handler_ptr
))
893 sighandler_list
.first_handler
= (*async_handler_ptr
)->next_handler
;
894 if (sighandler_list
.first_handler
== NULL
)
895 sighandler_list
.last_handler
= NULL
;
899 prev_ptr
= sighandler_list
.first_handler
;
900 while (prev_ptr
&& prev_ptr
->next_handler
!= (*async_handler_ptr
))
901 prev_ptr
= prev_ptr
->next_handler
;
902 gdb_assert (prev_ptr
);
903 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
904 if (sighandler_list
.last_handler
== (*async_handler_ptr
))
905 sighandler_list
.last_handler
= prev_ptr
;
907 xfree ((*async_handler_ptr
));
908 (*async_handler_ptr
) = NULL
;
911 /* Create an asynchronous event handler, allocating memory for it.
912 Return a pointer to the newly created handler. PROC is the
913 function to call with CLIENT_DATA argument whenever the handler is
915 async_event_handler
*
916 create_async_event_handler (async_event_handler_func
*proc
,
917 gdb_client_data client_data
)
919 async_event_handler
*h
;
921 h
= xmalloc (sizeof (*h
));
923 h
->next_handler
= NULL
;
925 h
->client_data
= client_data
;
926 if (async_event_handler_list
.first_handler
== NULL
)
927 async_event_handler_list
.first_handler
= h
;
929 async_event_handler_list
.last_handler
->next_handler
= h
;
930 async_event_handler_list
.last_handler
= h
;
934 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
935 will be used by gdb_do_one_event. The caller will be whoever
936 created the event source, and wants to signal that the event is
937 ready to be handled. */
939 mark_async_event_handler (async_event_handler
*async_handler_ptr
)
941 async_handler_ptr
->ready
= 1;
944 /* See event-loop.h. */
947 clear_async_event_handler (async_event_handler
*async_handler_ptr
)
949 async_handler_ptr
->ready
= 0;
952 /* Check if asynchronous event handlers are ready, and call the
953 handler function for one that is. */
956 check_async_event_handlers (void)
958 async_event_handler
*async_handler_ptr
;
960 for (async_handler_ptr
= async_event_handler_list
.first_handler
;
961 async_handler_ptr
!= NULL
;
962 async_handler_ptr
= async_handler_ptr
->next_handler
)
964 if (async_handler_ptr
->ready
)
966 async_handler_ptr
->ready
= 0;
967 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
975 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
976 Free the space allocated for it. */
978 delete_async_event_handler (async_event_handler
**async_handler_ptr
)
980 async_event_handler
*prev_ptr
;
982 if (async_event_handler_list
.first_handler
== *async_handler_ptr
)
984 async_event_handler_list
.first_handler
985 = (*async_handler_ptr
)->next_handler
;
986 if (async_event_handler_list
.first_handler
== NULL
)
987 async_event_handler_list
.last_handler
= NULL
;
991 prev_ptr
= async_event_handler_list
.first_handler
;
992 while (prev_ptr
&& prev_ptr
->next_handler
!= *async_handler_ptr
)
993 prev_ptr
= prev_ptr
->next_handler
;
994 gdb_assert (prev_ptr
);
995 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
996 if (async_event_handler_list
.last_handler
== (*async_handler_ptr
))
997 async_event_handler_list
.last_handler
= prev_ptr
;
999 xfree (*async_handler_ptr
);
1000 *async_handler_ptr
= NULL
;
1003 /* Create a timer that will expire in MILLISECONDS from now. When the
1004 timer is ready, PROC will be executed. At creation, the timer is
1005 aded to the timers queue. This queue is kept sorted in order of
1006 increasing timers. Return a handle to the timer struct. */
1008 create_timer (int milliseconds
, timer_handler_func
* proc
,
1009 gdb_client_data client_data
)
1011 struct gdb_timer
*timer_ptr
, *timer_index
, *prev_timer
;
1012 struct timeval time_now
, delta
;
1014 /* Compute seconds. */
1015 delta
.tv_sec
= milliseconds
/ 1000;
1016 /* Compute microseconds. */
1017 delta
.tv_usec
= (milliseconds
% 1000) * 1000;
1019 gettimeofday (&time_now
, NULL
);
1021 timer_ptr
= (struct gdb_timer
*) xmalloc (sizeof (*timer_ptr
));
1022 timer_ptr
->when
.tv_sec
= time_now
.tv_sec
+ delta
.tv_sec
;
1023 timer_ptr
->when
.tv_usec
= time_now
.tv_usec
+ delta
.tv_usec
;
1025 if (timer_ptr
->when
.tv_usec
>= 1000000)
1027 timer_ptr
->when
.tv_sec
+= 1;
1028 timer_ptr
->when
.tv_usec
-= 1000000;
1030 timer_ptr
->proc
= proc
;
1031 timer_ptr
->client_data
= client_data
;
1032 timer_list
.num_timers
++;
1033 timer_ptr
->timer_id
= timer_list
.num_timers
;
1035 /* Now add the timer to the timer queue, making sure it is sorted in
1036 increasing order of expiration. */
1038 for (timer_index
= timer_list
.first_timer
;
1039 timer_index
!= NULL
;
1040 timer_index
= timer_index
->next
)
1042 /* If the seconds field is greater or if it is the same, but the
1043 microsecond field is greater. */
1044 if ((timer_index
->when
.tv_sec
> timer_ptr
->when
.tv_sec
)
1045 || ((timer_index
->when
.tv_sec
== timer_ptr
->when
.tv_sec
)
1046 && (timer_index
->when
.tv_usec
> timer_ptr
->when
.tv_usec
)))
1050 if (timer_index
== timer_list
.first_timer
)
1052 timer_ptr
->next
= timer_list
.first_timer
;
1053 timer_list
.first_timer
= timer_ptr
;
1058 for (prev_timer
= timer_list
.first_timer
;
1059 prev_timer
->next
!= timer_index
;
1060 prev_timer
= prev_timer
->next
)
1063 prev_timer
->next
= timer_ptr
;
1064 timer_ptr
->next
= timer_index
;
1067 gdb_notifier
.timeout_valid
= 0;
1068 return timer_ptr
->timer_id
;
1071 /* There is a chance that the creator of the timer wants to get rid of
1072 it before it expires. */
1074 delete_timer (int id
)
1076 struct gdb_timer
*timer_ptr
, *prev_timer
= NULL
;
1078 /* Find the entry for the given timer. */
1080 for (timer_ptr
= timer_list
.first_timer
; timer_ptr
!= NULL
;
1081 timer_ptr
= timer_ptr
->next
)
1083 if (timer_ptr
->timer_id
== id
)
1087 if (timer_ptr
== NULL
)
1089 /* Get rid of the timer in the timer list. */
1090 if (timer_ptr
== timer_list
.first_timer
)
1091 timer_list
.first_timer
= timer_ptr
->next
;
1094 for (prev_timer
= timer_list
.first_timer
;
1095 prev_timer
->next
!= timer_ptr
;
1096 prev_timer
= prev_timer
->next
)
1098 prev_timer
->next
= timer_ptr
->next
;
1102 gdb_notifier
.timeout_valid
= 0;
1105 /* Update the timeout for the select() or poll(). Returns true if the
1106 timer has already expired, false otherwise. */
1109 update_wait_timeout (void)
1111 struct timeval time_now
, delta
;
1113 if (timer_list
.first_timer
!= NULL
)
1115 gettimeofday (&time_now
, NULL
);
1116 delta
.tv_sec
= timer_list
.first_timer
->when
.tv_sec
- time_now
.tv_sec
;
1117 delta
.tv_usec
= timer_list
.first_timer
->when
.tv_usec
- time_now
.tv_usec
;
1119 if (delta
.tv_usec
< 0)
1122 delta
.tv_usec
+= 1000000;
1125 /* Cannot simply test if delta.tv_sec is negative because time_t
1126 might be unsigned. */
1127 if (timer_list
.first_timer
->when
.tv_sec
< time_now
.tv_sec
1128 || (timer_list
.first_timer
->when
.tv_sec
== time_now
.tv_sec
1129 && timer_list
.first_timer
->when
.tv_usec
< time_now
.tv_usec
))
1131 /* It expired already. */
1136 /* Update the timeout for select/ poll. */
1140 gdb_notifier
.poll_timeout
= delta
.tv_sec
* 1000;
1142 internal_error (__FILE__
, __LINE__
,
1143 _("use_poll without HAVE_POLL"));
1144 #endif /* HAVE_POLL */
1148 gdb_notifier
.select_timeout
.tv_sec
= delta
.tv_sec
;
1149 gdb_notifier
.select_timeout
.tv_usec
= delta
.tv_usec
;
1151 gdb_notifier
.timeout_valid
= 1;
1153 if (delta
.tv_sec
== 0 && delta
.tv_usec
== 0)
1157 gdb_notifier
.timeout_valid
= 0;
1162 /* Check whether a timer in the timers queue is ready. If a timer is
1163 ready, call its handler and return. Update the timeout for the
1164 select() or poll() as well. Return 1 if an event was handled,
1165 otherwise returns 0.*/
1170 if (update_wait_timeout ())
1172 struct gdb_timer
*timer_ptr
= timer_list
.first_timer
;
1173 timer_handler_func
*proc
= timer_ptr
->proc
;
1174 gdb_client_data client_data
= timer_ptr
->client_data
;
1176 /* Get rid of the timer from the beginning of the list. */
1177 timer_list
.first_timer
= timer_ptr
->next
;
1179 /* Delete the timer before calling the callback, not after, in
1180 case the callback itself decides to try deleting the timer
1184 /* Call the procedure associated with that timer. */
1185 (proc
) (client_data
);