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 ();
293 if (event_source_head
== number_of_sources
)
294 event_source_head
= 0;
300 /* Block waiting for a new event. If gdb_wait_for_event returns -1,
301 we should get out because this means that there are no event
302 sources left. This will make the event loop stop, and the
305 if (gdb_wait_for_event (1) < 0)
308 /* If gdb_wait_for_event has returned 1, it means that one event has
309 been handled. We break out of the loop. */
313 /* Start up the event loop. This is the entry point to the event loop
314 from the command loop. */
317 start_event_loop (void)
319 /* Loop until there is nothing to do. This is the entry point to
320 the event loop engine. gdb_do_one_event will process one event
321 for each invocation. It blocks waiting for an event and then
325 volatile struct gdb_exception ex
;
328 TRY_CATCH (ex
, RETURN_MASK_ALL
)
330 result
= gdb_do_one_event ();
334 exception_print (gdb_stderr
, ex
);
336 /* If any exception escaped to here, we better enable
337 stdin. Otherwise, any command that calls async_disable_stdin,
338 and then throws, will leave stdin inoperable. */
339 async_enable_stdin ();
340 /* If we long-jumped out of do_one_event, we probably didn't
341 get around to resetting the prompt, which leaves readline
342 in a messed-up state. Reset it here. */
343 observer_notify_command_error ();
344 /* This call looks bizarre, but it is required. If the user
345 entered a command that caused an error,
346 after_char_processing_hook won't be called from
347 rl_callback_read_char_wrapper. Using a cleanup there
348 won't work, since we want this function to be called
349 after a new prompt is printed. */
350 if (after_char_processing_hook
)
351 (*after_char_processing_hook
) ();
352 /* Maybe better to set a flag to be checked somewhere as to
353 whether display the prompt or not. */
359 /* We are done with the event loop. There are no more event sources
360 to listen to. So we exit GDB. */
365 /* Wrapper function for create_file_handler, so that the caller
366 doesn't have to know implementation details about the use of poll
369 add_file_handler (int fd
, handler_func
* proc
, gdb_client_data client_data
)
378 /* Check to see if poll () is usable. If not, we'll switch to
379 use select. This can happen on systems like
380 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
381 On m68k-motorola-sysv, tty's are not stream-based and not
385 if (poll (&fds
, 1, 0) == 1 && (fds
.revents
& POLLNVAL
))
388 internal_error (__FILE__
, __LINE__
,
389 _("use_poll without HAVE_POLL"));
390 #endif /* HAVE_POLL */
395 create_file_handler (fd
, POLLIN
, proc
, client_data
);
397 internal_error (__FILE__
, __LINE__
,
398 _("use_poll without HAVE_POLL"));
402 create_file_handler (fd
, GDB_READABLE
| GDB_EXCEPTION
,
406 /* Add a file handler/descriptor to the list of descriptors we are
409 FD is the file descriptor for the file/stream to be listened to.
411 For the poll case, MASK is a combination (OR) of POLLIN,
412 POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND:
413 these are the events we are interested in. If any of them occurs,
414 proc should be called.
416 For the select case, MASK is a combination of READABLE, WRITABLE,
417 EXCEPTION. PROC is the procedure that will be called when an event
418 occurs for FD. CLIENT_DATA is the argument to pass to PROC. */
421 create_file_handler (int fd
, int mask
, handler_func
* proc
,
422 gdb_client_data client_data
)
424 file_handler
*file_ptr
;
426 /* Do we already have a file handler for this file? (We may be
427 changing its associated procedure). */
428 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
429 file_ptr
= file_ptr
->next_file
)
431 if (file_ptr
->fd
== fd
)
435 /* It is a new file descriptor. Add it to the list. Otherwise, just
436 change the data associated with it. */
437 if (file_ptr
== NULL
)
439 file_ptr
= (file_handler
*) xmalloc (sizeof (file_handler
));
441 file_ptr
->ready_mask
= 0;
442 file_ptr
->next_file
= gdb_notifier
.first_file_handler
;
443 gdb_notifier
.first_file_handler
= file_ptr
;
448 gdb_notifier
.num_fds
++;
449 if (gdb_notifier
.poll_fds
)
450 gdb_notifier
.poll_fds
=
451 (struct pollfd
*) xrealloc (gdb_notifier
.poll_fds
,
452 (gdb_notifier
.num_fds
453 * sizeof (struct pollfd
)));
455 gdb_notifier
.poll_fds
=
456 (struct pollfd
*) xmalloc (sizeof (struct pollfd
));
457 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->fd
= fd
;
458 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->events
= mask
;
459 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->revents
= 0;
461 internal_error (__FILE__
, __LINE__
,
462 _("use_poll without HAVE_POLL"));
463 #endif /* HAVE_POLL */
467 if (mask
& GDB_READABLE
)
468 FD_SET (fd
, &gdb_notifier
.check_masks
[0]);
470 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
472 if (mask
& GDB_WRITABLE
)
473 FD_SET (fd
, &gdb_notifier
.check_masks
[1]);
475 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
477 if (mask
& GDB_EXCEPTION
)
478 FD_SET (fd
, &gdb_notifier
.check_masks
[2]);
480 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
482 if (gdb_notifier
.num_fds
<= fd
)
483 gdb_notifier
.num_fds
= fd
+ 1;
487 file_ptr
->proc
= proc
;
488 file_ptr
->client_data
= client_data
;
489 file_ptr
->mask
= mask
;
492 /* Remove the file descriptor FD from the list of monitored fd's:
493 i.e. we don't care anymore about events on the FD. */
495 delete_file_handler (int fd
)
497 file_handler
*file_ptr
, *prev_ptr
= NULL
;
501 struct pollfd
*new_poll_fds
;
504 /* Find the entry for the given file. */
506 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
507 file_ptr
= file_ptr
->next_file
)
509 if (file_ptr
->fd
== fd
)
513 if (file_ptr
== NULL
)
519 /* Create a new poll_fds array by copying every fd's information
520 but the one we want to get rid of. */
522 new_poll_fds
= (struct pollfd
*)
523 xmalloc ((gdb_notifier
.num_fds
- 1) * sizeof (struct pollfd
));
525 for (i
= 0, j
= 0; i
< gdb_notifier
.num_fds
; i
++)
527 if ((gdb_notifier
.poll_fds
+ i
)->fd
!= fd
)
529 (new_poll_fds
+ j
)->fd
= (gdb_notifier
.poll_fds
+ i
)->fd
;
530 (new_poll_fds
+ j
)->events
= (gdb_notifier
.poll_fds
+ i
)->events
;
531 (new_poll_fds
+ j
)->revents
532 = (gdb_notifier
.poll_fds
+ i
)->revents
;
536 xfree (gdb_notifier
.poll_fds
);
537 gdb_notifier
.poll_fds
= new_poll_fds
;
538 gdb_notifier
.num_fds
--;
540 internal_error (__FILE__
, __LINE__
,
541 _("use_poll without HAVE_POLL"));
542 #endif /* HAVE_POLL */
546 if (file_ptr
->mask
& GDB_READABLE
)
547 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
548 if (file_ptr
->mask
& GDB_WRITABLE
)
549 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
550 if (file_ptr
->mask
& GDB_EXCEPTION
)
551 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
553 /* Find current max fd. */
555 if ((fd
+ 1) == gdb_notifier
.num_fds
)
557 gdb_notifier
.num_fds
--;
558 for (i
= gdb_notifier
.num_fds
; i
; i
--)
560 if (FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[0])
561 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[1])
562 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[2]))
565 gdb_notifier
.num_fds
= i
;
569 /* Deactivate the file descriptor, by clearing its mask,
570 so that it will not fire again. */
574 /* Get rid of the file handler in the file handler list. */
575 if (file_ptr
== gdb_notifier
.first_file_handler
)
576 gdb_notifier
.first_file_handler
= file_ptr
->next_file
;
579 for (prev_ptr
= gdb_notifier
.first_file_handler
;
580 prev_ptr
->next_file
!= file_ptr
;
581 prev_ptr
= prev_ptr
->next_file
)
583 prev_ptr
->next_file
= file_ptr
->next_file
;
588 /* Handle the given event by calling the procedure associated to the
589 corresponding file handler. */
592 handle_file_event (file_handler
*file_ptr
, int ready_mask
)
601 /* With poll, the ready_mask could have any of three events
602 set to 1: POLLHUP, POLLERR, POLLNVAL. These events
603 cannot be used in the requested event mask (events), but
604 they can be returned in the return mask (revents). We
605 need to check for those event too, and add them to the
606 mask which will be passed to the handler. */
608 /* See if the desired events (mask) match the received
609 events (ready_mask). */
614 /* POLLHUP means EOF, but can be combined with POLLIN to
615 signal more data to read. */
616 error_mask
= POLLHUP
| POLLERR
| POLLNVAL
;
617 mask
= ready_mask
& (file_ptr
->mask
| error_mask
);
619 if ((mask
& (POLLERR
| POLLNVAL
)) != 0)
621 /* Work in progress. We may need to tell somebody
622 what kind of error we had. */
624 printf_unfiltered (_("Error detected on fd %d\n"),
627 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"),
634 internal_error (__FILE__
, __LINE__
,
635 _("use_poll without HAVE_POLL"));
636 #endif /* HAVE_POLL */
640 if (ready_mask
& GDB_EXCEPTION
)
642 printf_unfiltered (_("Exception condition detected "
643 "on fd %d\n"), file_ptr
->fd
);
648 mask
= ready_mask
& file_ptr
->mask
;
651 /* If there was a match, then call the handler. */
653 (*file_ptr
->proc
) (file_ptr
->error
, file_ptr
->client_data
);
658 /* Wait for new events on the monitored file descriptors. Run the
659 event handler if the first descriptor that is detected by the poll.
660 If BLOCK and if there are no events, this function will block in
661 the call to poll. Return 1 if an event was handled. Return -1 if
662 there are no file descriptors to monitor. Return 1 if an event was
663 handled, otherwise returns 0. */
666 gdb_wait_for_event (int block
)
668 file_handler
*file_ptr
;
672 /* Make sure all output is done before getting another event. */
673 gdb_flush (gdb_stdout
);
674 gdb_flush (gdb_stderr
);
676 if (gdb_notifier
.num_fds
== 0)
680 update_wait_timeout ();
688 timeout
= gdb_notifier
.timeout_valid
? gdb_notifier
.poll_timeout
: -1;
692 num_found
= poll (gdb_notifier
.poll_fds
,
693 (unsigned long) gdb_notifier
.num_fds
, timeout
);
695 /* Don't print anything if we get out of poll because of a
697 if (num_found
== -1 && errno
!= EINTR
)
698 perror_with_name (("poll"));
700 internal_error (__FILE__
, __LINE__
,
701 _("use_poll without HAVE_POLL"));
702 #endif /* HAVE_POLL */
706 struct timeval select_timeout
;
707 struct timeval
*timeout_p
;
710 timeout_p
= gdb_notifier
.timeout_valid
711 ? &gdb_notifier
.select_timeout
: NULL
;
714 memset (&select_timeout
, 0, sizeof (select_timeout
));
715 timeout_p
= &select_timeout
;
718 gdb_notifier
.ready_masks
[0] = gdb_notifier
.check_masks
[0];
719 gdb_notifier
.ready_masks
[1] = gdb_notifier
.check_masks
[1];
720 gdb_notifier
.ready_masks
[2] = gdb_notifier
.check_masks
[2];
721 num_found
= gdb_select (gdb_notifier
.num_fds
,
722 &gdb_notifier
.ready_masks
[0],
723 &gdb_notifier
.ready_masks
[1],
724 &gdb_notifier
.ready_masks
[2],
727 /* Clear the masks after an error from select. */
730 FD_ZERO (&gdb_notifier
.ready_masks
[0]);
731 FD_ZERO (&gdb_notifier
.ready_masks
[1]);
732 FD_ZERO (&gdb_notifier
.ready_masks
[2]);
734 /* Dont print anything if we got a signal, let gdb handle
737 perror_with_name (("select"));
741 /* Run event handlers. We always run just one handler and go back
742 to polling, in case a handler changes the notifier list. Since
743 events for sources we haven't consumed yet wake poll/select
744 immediately, no event is lost. */
749 for (i
= 0; (i
< gdb_notifier
.num_fds
) && (num_found
> 0); i
++)
751 if ((gdb_notifier
.poll_fds
+ i
)->revents
)
756 for (file_ptr
= gdb_notifier
.first_file_handler
;
758 file_ptr
= file_ptr
->next_file
)
760 if (file_ptr
->fd
== (gdb_notifier
.poll_fds
+ i
)->fd
)
766 int mask
= (gdb_notifier
.poll_fds
+ i
)->revents
;
768 handle_file_event (file_ptr
, mask
);
773 internal_error (__FILE__
, __LINE__
,
774 _("use_poll without HAVE_POLL"));
775 #endif /* HAVE_POLL */
779 for (file_ptr
= gdb_notifier
.first_file_handler
;
780 (file_ptr
!= NULL
) && (num_found
> 0);
781 file_ptr
= file_ptr
->next_file
)
785 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[0]))
786 mask
|= GDB_READABLE
;
787 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[1]))
788 mask
|= GDB_WRITABLE
;
789 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[2]))
790 mask
|= GDB_EXCEPTION
;
797 handle_file_event (file_ptr
, mask
);
805 /* Create an asynchronous handler, allocating memory for it.
806 Return a pointer to the newly created handler.
807 This pointer will be used to invoke the handler by
808 invoke_async_signal_handler.
809 PROC is the function to call with CLIENT_DATA argument
810 whenever the handler is invoked. */
811 async_signal_handler
*
812 create_async_signal_handler (sig_handler_func
* proc
,
813 gdb_client_data client_data
)
815 async_signal_handler
*async_handler_ptr
;
818 (async_signal_handler
*) xmalloc (sizeof (async_signal_handler
));
819 async_handler_ptr
->ready
= 0;
820 async_handler_ptr
->next_handler
= NULL
;
821 async_handler_ptr
->proc
= proc
;
822 async_handler_ptr
->client_data
= client_data
;
823 if (sighandler_list
.first_handler
== NULL
)
824 sighandler_list
.first_handler
= async_handler_ptr
;
826 sighandler_list
.last_handler
->next_handler
= async_handler_ptr
;
827 sighandler_list
.last_handler
= async_handler_ptr
;
828 return async_handler_ptr
;
831 /* Call the handler from HANDLER immediately. This function runs
832 signal handlers when returning to the event loop would be too
835 call_async_signal_handler (struct async_signal_handler
*handler
)
837 (*handler
->proc
) (handler
->client_data
);
840 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
841 will be used when the handlers are invoked, after we have waited
842 for some event. The caller of this function is the interrupt
843 handler associated with a signal. */
845 mark_async_signal_handler (async_signal_handler
* async_handler_ptr
)
847 async_handler_ptr
->ready
= 1;
850 /* Call all the handlers that are ready. Returns true if any was
853 invoke_async_signal_handlers (void)
855 async_signal_handler
*async_handler_ptr
;
858 /* Invoke ready handlers. */
862 for (async_handler_ptr
= sighandler_list
.first_handler
;
863 async_handler_ptr
!= NULL
;
864 async_handler_ptr
= async_handler_ptr
->next_handler
)
866 if (async_handler_ptr
->ready
)
869 if (async_handler_ptr
== NULL
)
872 async_handler_ptr
->ready
= 0;
873 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
879 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
880 Free the space allocated for it. */
882 delete_async_signal_handler (async_signal_handler
** async_handler_ptr
)
884 async_signal_handler
*prev_ptr
;
886 if (sighandler_list
.first_handler
== (*async_handler_ptr
))
888 sighandler_list
.first_handler
= (*async_handler_ptr
)->next_handler
;
889 if (sighandler_list
.first_handler
== NULL
)
890 sighandler_list
.last_handler
= NULL
;
894 prev_ptr
= sighandler_list
.first_handler
;
895 while (prev_ptr
&& prev_ptr
->next_handler
!= (*async_handler_ptr
))
896 prev_ptr
= prev_ptr
->next_handler
;
897 gdb_assert (prev_ptr
);
898 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
899 if (sighandler_list
.last_handler
== (*async_handler_ptr
))
900 sighandler_list
.last_handler
= prev_ptr
;
902 xfree ((*async_handler_ptr
));
903 (*async_handler_ptr
) = NULL
;
906 /* Create an asynchronous event handler, allocating memory for it.
907 Return a pointer to the newly created handler. PROC is the
908 function to call with CLIENT_DATA argument whenever the handler is
910 async_event_handler
*
911 create_async_event_handler (async_event_handler_func
*proc
,
912 gdb_client_data client_data
)
914 async_event_handler
*h
;
916 h
= xmalloc (sizeof (*h
));
918 h
->next_handler
= NULL
;
920 h
->client_data
= client_data
;
921 if (async_event_handler_list
.first_handler
== NULL
)
922 async_event_handler_list
.first_handler
= h
;
924 async_event_handler_list
.last_handler
->next_handler
= h
;
925 async_event_handler_list
.last_handler
= h
;
929 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
930 will be used by gdb_do_one_event. The caller will be whoever
931 created the event source, and wants to signal that the event is
932 ready to be handled. */
934 mark_async_event_handler (async_event_handler
*async_handler_ptr
)
936 async_handler_ptr
->ready
= 1;
939 /* See event-loop.h. */
942 clear_async_event_handler (async_event_handler
*async_handler_ptr
)
944 async_handler_ptr
->ready
= 0;
947 /* Check if asynchronous event handlers are ready, and call the
948 handler function for one that is. */
951 check_async_event_handlers (void)
953 async_event_handler
*async_handler_ptr
;
955 for (async_handler_ptr
= async_event_handler_list
.first_handler
;
956 async_handler_ptr
!= NULL
;
957 async_handler_ptr
= async_handler_ptr
->next_handler
)
959 if (async_handler_ptr
->ready
)
961 async_handler_ptr
->ready
= 0;
962 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
970 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
971 Free the space allocated for it. */
973 delete_async_event_handler (async_event_handler
**async_handler_ptr
)
975 async_event_handler
*prev_ptr
;
977 if (async_event_handler_list
.first_handler
== *async_handler_ptr
)
979 async_event_handler_list
.first_handler
980 = (*async_handler_ptr
)->next_handler
;
981 if (async_event_handler_list
.first_handler
== NULL
)
982 async_event_handler_list
.last_handler
= NULL
;
986 prev_ptr
= async_event_handler_list
.first_handler
;
987 while (prev_ptr
&& prev_ptr
->next_handler
!= *async_handler_ptr
)
988 prev_ptr
= prev_ptr
->next_handler
;
989 gdb_assert (prev_ptr
);
990 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
991 if (async_event_handler_list
.last_handler
== (*async_handler_ptr
))
992 async_event_handler_list
.last_handler
= prev_ptr
;
994 xfree (*async_handler_ptr
);
995 *async_handler_ptr
= NULL
;
998 /* Create a timer that will expire in MILLISECONDS from now. When the
999 timer is ready, PROC will be executed. At creation, the timer is
1000 aded to the timers queue. This queue is kept sorted in order of
1001 increasing timers. Return a handle to the timer struct. */
1003 create_timer (int milliseconds
, timer_handler_func
* proc
,
1004 gdb_client_data client_data
)
1006 struct gdb_timer
*timer_ptr
, *timer_index
, *prev_timer
;
1007 struct timeval time_now
, delta
;
1009 /* Compute seconds. */
1010 delta
.tv_sec
= milliseconds
/ 1000;
1011 /* Compute microseconds. */
1012 delta
.tv_usec
= (milliseconds
% 1000) * 1000;
1014 gettimeofday (&time_now
, NULL
);
1016 timer_ptr
= (struct gdb_timer
*) xmalloc (sizeof (*timer_ptr
));
1017 timer_ptr
->when
.tv_sec
= time_now
.tv_sec
+ delta
.tv_sec
;
1018 timer_ptr
->when
.tv_usec
= time_now
.tv_usec
+ delta
.tv_usec
;
1020 if (timer_ptr
->when
.tv_usec
>= 1000000)
1022 timer_ptr
->when
.tv_sec
+= 1;
1023 timer_ptr
->when
.tv_usec
-= 1000000;
1025 timer_ptr
->proc
= proc
;
1026 timer_ptr
->client_data
= client_data
;
1027 timer_list
.num_timers
++;
1028 timer_ptr
->timer_id
= timer_list
.num_timers
;
1030 /* Now add the timer to the timer queue, making sure it is sorted in
1031 increasing order of expiration. */
1033 for (timer_index
= timer_list
.first_timer
;
1034 timer_index
!= NULL
;
1035 timer_index
= timer_index
->next
)
1037 /* If the seconds field is greater or if it is the same, but the
1038 microsecond field is greater. */
1039 if ((timer_index
->when
.tv_sec
> timer_ptr
->when
.tv_sec
)
1040 || ((timer_index
->when
.tv_sec
== timer_ptr
->when
.tv_sec
)
1041 && (timer_index
->when
.tv_usec
> timer_ptr
->when
.tv_usec
)))
1045 if (timer_index
== timer_list
.first_timer
)
1047 timer_ptr
->next
= timer_list
.first_timer
;
1048 timer_list
.first_timer
= timer_ptr
;
1053 for (prev_timer
= timer_list
.first_timer
;
1054 prev_timer
->next
!= timer_index
;
1055 prev_timer
= prev_timer
->next
)
1058 prev_timer
->next
= timer_ptr
;
1059 timer_ptr
->next
= timer_index
;
1062 gdb_notifier
.timeout_valid
= 0;
1063 return timer_ptr
->timer_id
;
1066 /* There is a chance that the creator of the timer wants to get rid of
1067 it before it expires. */
1069 delete_timer (int id
)
1071 struct gdb_timer
*timer_ptr
, *prev_timer
= NULL
;
1073 /* Find the entry for the given timer. */
1075 for (timer_ptr
= timer_list
.first_timer
; timer_ptr
!= NULL
;
1076 timer_ptr
= timer_ptr
->next
)
1078 if (timer_ptr
->timer_id
== id
)
1082 if (timer_ptr
== NULL
)
1084 /* Get rid of the timer in the timer list. */
1085 if (timer_ptr
== timer_list
.first_timer
)
1086 timer_list
.first_timer
= timer_ptr
->next
;
1089 for (prev_timer
= timer_list
.first_timer
;
1090 prev_timer
->next
!= timer_ptr
;
1091 prev_timer
= prev_timer
->next
)
1093 prev_timer
->next
= timer_ptr
->next
;
1097 gdb_notifier
.timeout_valid
= 0;
1100 /* Update the timeout for the select() or poll(). Returns true if the
1101 timer has already expired, false otherwise. */
1104 update_wait_timeout (void)
1106 struct timeval time_now
, delta
;
1108 if (timer_list
.first_timer
!= NULL
)
1110 gettimeofday (&time_now
, NULL
);
1111 delta
.tv_sec
= timer_list
.first_timer
->when
.tv_sec
- time_now
.tv_sec
;
1112 delta
.tv_usec
= timer_list
.first_timer
->when
.tv_usec
- time_now
.tv_usec
;
1114 if (delta
.tv_usec
< 0)
1117 delta
.tv_usec
+= 1000000;
1120 /* Cannot simply test if delta.tv_sec is negative because time_t
1121 might be unsigned. */
1122 if (timer_list
.first_timer
->when
.tv_sec
< time_now
.tv_sec
1123 || (timer_list
.first_timer
->when
.tv_sec
== time_now
.tv_sec
1124 && timer_list
.first_timer
->when
.tv_usec
< time_now
.tv_usec
))
1126 /* It expired already. */
1131 /* Update the timeout for select/ poll. */
1135 gdb_notifier
.poll_timeout
= delta
.tv_sec
* 1000;
1137 internal_error (__FILE__
, __LINE__
,
1138 _("use_poll without HAVE_POLL"));
1139 #endif /* HAVE_POLL */
1143 gdb_notifier
.select_timeout
.tv_sec
= delta
.tv_sec
;
1144 gdb_notifier
.select_timeout
.tv_usec
= delta
.tv_usec
;
1146 gdb_notifier
.timeout_valid
= 1;
1148 if (delta
.tv_sec
== 0 && delta
.tv_usec
== 0)
1152 gdb_notifier
.timeout_valid
= 0;
1157 /* Check whether a timer in the timers queue is ready. If a timer is
1158 ready, call its handler and return. Update the timeout for the
1159 select() or poll() as well. Return 1 if an event was handled,
1160 otherwise returns 0.*/
1165 if (update_wait_timeout ())
1167 struct gdb_timer
*timer_ptr
= timer_list
.first_timer
;
1168 timer_handler_func
*proc
= timer_ptr
->proc
;
1169 gdb_client_data client_data
= timer_ptr
->client_data
;
1171 /* Get rid of the timer from the beginning of the list. */
1172 timer_list
.first_timer
= timer_ptr
->next
;
1174 /* Delete the timer before calling the callback, not after, in
1175 case the callback itself decides to try deleting the timer
1179 /* Call the procedure associated with that timer. */
1180 (proc
) (client_data
);