1 /* Event loop machinery for GDB, the GNU debugger.
2 Copyright (C) 1999, 2000, 2001, 2002 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 2 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, write to the Free Software
19 Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
23 #include "event-loop.h"
24 #include "event-top.h"
27 #if defined (HAVE_POLL_H)
29 #elif defined (HAVE_SYS_POLL_H)
34 #include <sys/types.h>
35 #include "gdb_string.h"
38 #include "exceptions.h"
39 #include "gdb_assert.h"
41 typedef struct gdb_event gdb_event
;
42 typedef void (event_handler_func
) (int);
44 /* Event for the GDB event system. Events are queued by calling
45 async_queue_event and serviced later on by gdb_do_one_event. An
46 event can be, for instance, a file descriptor becoming ready to be
47 read. Servicing an event simply means that the procedure PROC will
48 be called. We have 2 queues, one for file handlers that we listen
49 to in the event loop, and one for the file handlers+events that are
50 ready. The procedure PROC associated with each event is always the
51 same (handle_file_event). Its duty is to invoke the handler
52 associated with the file descriptor whose state change generated
53 the event, plus doing other cleanups and such. */
57 event_handler_func
*proc
; /* Procedure to call to service this event. */
58 int fd
; /* File descriptor that is ready. */
59 struct gdb_event
*next_event
; /* Next in list of events or NULL. */
62 /* Information about each file descriptor we register with the event
65 typedef struct file_handler
67 int fd
; /* File descriptor. */
68 int mask
; /* Events we want to monitor: POLLIN, etc. */
69 int ready_mask
; /* Events that have been seen since
71 handler_func
*proc
; /* Procedure to call when fd is ready. */
72 gdb_client_data client_data
; /* Argument to pass to proc. */
73 int error
; /* Was an error detected on this fd? */
74 struct file_handler
*next_file
; /* Next registered file descriptor. */
78 /* PROC is a function to be invoked when the READY flag is set. This
79 happens when there has been a signal and the corresponding signal
80 handler has 'triggered' this async_signal_handler for
81 execution. The actual work to be done in response to a signal will
82 be carried out by PROC at a later time, within process_event. This
83 provides a deferred execution of signal handlers.
84 Async_init_signals takes care of setting up such an
85 asyn_signal_handler for each interesting signal. */
86 typedef struct async_signal_handler
88 int ready
; /* If ready, call this handler from the main event loop,
89 using invoke_async_handler. */
90 struct async_signal_handler
*next_handler
; /* Ptr to next handler */
91 sig_handler_func
*proc
; /* Function to call to do the work */
92 gdb_client_data client_data
; /* Argument to async_handler_func */
98 - the first event in the queue is the head of the queue.
99 It will be the next to be serviced.
100 - the last event in the queue
102 Events can be inserted at the front of the queue or at the end of
103 the queue. Events will be extracted from the queue for processing
104 starting from the head. Therefore, events inserted at the head of
105 the queue will be processed in a last in first out fashion, while
106 those inserted at the tail of the queue will be processed in a first
107 in first out manner. All the fields are NULL if the queue is
112 gdb_event
*first_event
; /* First pending event */
113 gdb_event
*last_event
; /* Last pending event */
117 /* Gdb_notifier is just a list of file descriptors gdb is interested in.
118 These are the input file descriptor, and the target file
119 descriptor. We have two flavors of the notifier, one for platforms
120 that have the POLL function, the other for those that don't, and
121 only support SELECT. Each of the elements in the gdb_notifier list is
122 basically a description of what kind of events gdb is interested
125 /* As of 1999-04-30 only the input file descriptor is registered with the
128 /* Do we use poll or select ? */
133 #endif /* HAVE_POLL */
135 static unsigned char use_poll
= USE_POLL
;
144 /* Ptr to head of file handler list. */
145 file_handler
*first_file_handler
;
148 /* Ptr to array of pollfd structures. */
149 struct pollfd
*poll_fds
;
151 /* Timeout in milliseconds for calls to poll(). */
155 /* Masks to be used in the next call to select.
156 Bits are set in response to calls to create_file_handler. */
157 fd_set check_masks
[3];
159 /* What file descriptors were found ready by select. */
160 fd_set ready_masks
[3];
162 /* Number of file descriptors to monitor. (for poll) */
163 /* Number of valid bits (highest fd value + 1). (for select) */
166 /* Time structure for calls to select(). */
167 struct timeval select_timeout
;
169 /* Flag to tell whether the timeout should be used. */
174 /* Structure associated with a timer. PROC will be executed at the
175 first occasion after WHEN. */
180 struct gdb_timer
*next
;
181 timer_handler_func
*proc
; /* Function to call to do the work */
182 gdb_client_data client_data
; /* Argument to async_handler_func */
186 /* List of currently active timers. It is sorted in order of
187 increasing timers. */
190 /* Pointer to first in timer list. */
191 struct gdb_timer
*first_timer
;
193 /* Id of the last timer created. */
198 /* All the async_signal_handlers gdb is interested in are kept onto
202 /* Pointer to first in handler list. */
203 async_signal_handler
*first_handler
;
205 /* Pointer to last in handler list. */
206 async_signal_handler
*last_handler
;
210 /* Are any of the handlers ready? Check this variable using
211 check_async_ready. This is used by process_event, to determine
212 whether or not to invoke the invoke_async_signal_handler
214 static int async_handler_ready
= 0;
216 static void create_file_handler (int fd
, int mask
, handler_func
* proc
, gdb_client_data client_data
);
217 static void invoke_async_signal_handler (void);
218 static void handle_file_event (int event_file_desc
);
219 static int gdb_wait_for_event (void);
220 static int check_async_ready (void);
221 static void async_queue_event (gdb_event
* event_ptr
, queue_position position
);
222 static gdb_event
*create_file_event (int fd
);
223 static int process_event (void);
224 static void handle_timer_event (int dummy
);
225 static void poll_timers (void);
228 /* Insert an event object into the gdb event queue at
229 the specified position.
230 POSITION can be head or tail, with values TAIL, HEAD.
231 EVENT_PTR points to the event to be inserted into the queue.
232 The caller must allocate memory for the event. It is freed
233 after the event has ben handled.
234 Events in the queue will be processed head to tail, therefore,
235 events inserted at the head of the queue will be processed
236 as last in first out. Event appended at the tail of the queue
237 will be processed first in first out. */
239 async_queue_event (gdb_event
* event_ptr
, queue_position position
)
241 if (position
== TAIL
)
243 /* The event will become the new last_event. */
245 event_ptr
->next_event
= NULL
;
246 if (event_queue
.first_event
== NULL
)
247 event_queue
.first_event
= event_ptr
;
249 event_queue
.last_event
->next_event
= event_ptr
;
250 event_queue
.last_event
= event_ptr
;
252 else if (position
== HEAD
)
254 /* The event becomes the new first_event. */
256 event_ptr
->next_event
= event_queue
.first_event
;
257 if (event_queue
.first_event
== NULL
)
258 event_queue
.last_event
= event_ptr
;
259 event_queue
.first_event
= event_ptr
;
263 /* Create a file event, to be enqueued in the event queue for
264 processing. The procedure associated to this event is always
265 handle_file_event, which will in turn invoke the one that was
266 associated to FD when it was registered with the event loop. */
268 create_file_event (int fd
)
270 gdb_event
*file_event_ptr
;
272 file_event_ptr
= (gdb_event
*) xmalloc (sizeof (gdb_event
));
273 file_event_ptr
->proc
= handle_file_event
;
274 file_event_ptr
->fd
= fd
;
275 return (file_event_ptr
);
278 /* Process one event.
279 The event can be the next one to be serviced in the event queue,
280 or an asynchronous event handler can be invoked in response to
281 the reception of a signal.
282 If an event was processed (either way), 1 is returned otherwise
284 Scan the queue from head to tail, processing therefore the high
285 priority events first, by invoking the associated event handler
290 gdb_event
*event_ptr
, *prev_ptr
;
291 event_handler_func
*proc
;
294 /* First let's see if there are any asynchronous event handlers that
295 are ready. These would be the result of invoking any of the
298 if (check_async_ready ())
300 invoke_async_signal_handler ();
304 /* Look in the event queue to find an event that is ready
307 for (event_ptr
= event_queue
.first_event
; event_ptr
!= NULL
;
308 event_ptr
= event_ptr
->next_event
)
310 /* Call the handler for the event. */
312 proc
= event_ptr
->proc
;
315 /* Let's get rid of the event from the event queue. We need to
316 do this now because while processing the event, the proc
317 function could end up calling 'error' and therefore jump out
318 to the caller of this function, gdb_do_one_event. In that
319 case, we would have on the event queue an event wich has been
320 processed, but not deleted. */
322 if (event_queue
.first_event
== event_ptr
)
324 event_queue
.first_event
= event_ptr
->next_event
;
325 if (event_ptr
->next_event
== NULL
)
326 event_queue
.last_event
= NULL
;
330 prev_ptr
= event_queue
.first_event
;
331 while (prev_ptr
->next_event
!= event_ptr
)
332 prev_ptr
= prev_ptr
->next_event
;
334 prev_ptr
->next_event
= event_ptr
->next_event
;
335 if (event_ptr
->next_event
== NULL
)
336 event_queue
.last_event
= prev_ptr
;
340 /* Now call the procedure associated with the event. */
345 /* this is the case if there are no event on the event queue. */
349 /* Process one high level event. If nothing is ready at this time,
350 wait for something to happen (via gdb_wait_for_event), then process
351 it. Returns >0 if something was done otherwise returns <0 (this
352 can happen if there are no event sources to wait for). If an error
353 occurs catch_errors() which calls this function returns zero. */
356 gdb_do_one_event (void *data
)
358 /* Any events already waiting in the queue? */
359 if (process_event ())
364 /* Are any timers that are ready? If so, put an event on the queue. */
367 /* Wait for a new event. If gdb_wait_for_event returns -1,
368 we should get out because this means that there are no
369 event sources left. This will make the event loop stop,
370 and the application exit. */
372 if (gdb_wait_for_event () < 0)
377 /* Handle any new events occurred while waiting. */
378 if (process_event ())
383 /* If gdb_wait_for_event has returned 1, it means that one
384 event has been handled. We break out of the loop. */
388 /* Start up the event loop. This is the entry point to the event loop
389 from the command loop. */
392 start_event_loop (void)
394 /* Loop until there is nothing to do. This is the entry point to the
395 event loop engine. gdb_do_one_event, called via catch_errors()
396 will process one event for each invocation. It blocks waits for
397 an event and then processes it. >0 when an event is processed, 0
398 when catch_errors() caught an error and <0 when there are no
399 longer any event sources registered. */
404 gdb_result
= catch_errors (gdb_do_one_event
, 0, "", RETURN_MASK_ALL
);
408 /* If we long-jumped out of do_one_event, we probably
409 didn't get around to resetting the prompt, which leaves
410 readline in a messed-up state. Reset it here. */
414 /* FIXME: this should really be a call to a hook that is
415 interface specific, because interfaces can display the
416 prompt in their own way. */
417 display_gdb_prompt (0);
418 /* This call looks bizarre, but it is required. If the user
419 entered a command that caused an error,
420 after_char_processing_hook won't be called from
421 rl_callback_read_char_wrapper. Using a cleanup there
422 won't work, since we want this function to be called
423 after a new prompt is printed. */
424 if (after_char_processing_hook
)
425 (*after_char_processing_hook
) ();
426 /* Maybe better to set a flag to be checked somewhere as to
427 whether display the prompt or not. */
431 /* We are done with the event loop. There are no more event sources
432 to listen to. So we exit GDB. */
437 /* Wrapper function for create_file_handler, so that the caller
438 doesn't have to know implementation details about the use of poll
441 add_file_handler (int fd
, handler_func
* proc
, gdb_client_data client_data
)
450 /* Check to see if poll () is usable. If not, we'll switch to
451 use select. This can happen on systems like
452 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
453 On m68k-motorola-sysv, tty's are not stream-based and not
457 if (poll (&fds
, 1, 0) == 1 && (fds
.revents
& POLLNVAL
))
460 internal_error (__FILE__
, __LINE__
,
461 _("use_poll without HAVE_POLL"));
462 #endif /* HAVE_POLL */
467 create_file_handler (fd
, POLLIN
, proc
, client_data
);
469 internal_error (__FILE__
, __LINE__
,
470 _("use_poll without HAVE_POLL"));
474 create_file_handler (fd
, GDB_READABLE
| GDB_EXCEPTION
, proc
, client_data
);
477 /* Add a file handler/descriptor to the list of descriptors we are
479 FD is the file descriptor for the file/stream to be listened to.
480 For the poll case, MASK is a combination (OR) of
481 POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM,
482 POLLWRBAND: these are the events we are interested in. If any of them
483 occurs, proc should be called.
484 For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION.
485 PROC is the procedure that will be called when an event occurs for
486 FD. CLIENT_DATA is the argument to pass to PROC. */
488 create_file_handler (int fd
, int mask
, handler_func
* proc
, gdb_client_data client_data
)
490 file_handler
*file_ptr
;
492 /* Do we already have a file handler for this file? (We may be
493 changing its associated procedure). */
494 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
495 file_ptr
= file_ptr
->next_file
)
497 if (file_ptr
->fd
== fd
)
501 /* It is a new file descriptor. Add it to the list. Otherwise, just
502 change the data associated with it. */
503 if (file_ptr
== NULL
)
505 file_ptr
= (file_handler
*) xmalloc (sizeof (file_handler
));
507 file_ptr
->ready_mask
= 0;
508 file_ptr
->next_file
= gdb_notifier
.first_file_handler
;
509 gdb_notifier
.first_file_handler
= file_ptr
;
514 gdb_notifier
.num_fds
++;
515 if (gdb_notifier
.poll_fds
)
516 gdb_notifier
.poll_fds
=
517 (struct pollfd
*) xrealloc (gdb_notifier
.poll_fds
,
518 (gdb_notifier
.num_fds
519 * sizeof (struct pollfd
)));
521 gdb_notifier
.poll_fds
=
522 (struct pollfd
*) xmalloc (sizeof (struct pollfd
));
523 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->fd
= fd
;
524 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->events
= mask
;
525 (gdb_notifier
.poll_fds
+ gdb_notifier
.num_fds
- 1)->revents
= 0;
527 internal_error (__FILE__
, __LINE__
,
528 _("use_poll without HAVE_POLL"));
529 #endif /* HAVE_POLL */
533 if (mask
& GDB_READABLE
)
534 FD_SET (fd
, &gdb_notifier
.check_masks
[0]);
536 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
538 if (mask
& GDB_WRITABLE
)
539 FD_SET (fd
, &gdb_notifier
.check_masks
[1]);
541 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
543 if (mask
& GDB_EXCEPTION
)
544 FD_SET (fd
, &gdb_notifier
.check_masks
[2]);
546 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
548 if (gdb_notifier
.num_fds
<= fd
)
549 gdb_notifier
.num_fds
= fd
+ 1;
553 file_ptr
->proc
= proc
;
554 file_ptr
->client_data
= client_data
;
555 file_ptr
->mask
= mask
;
558 /* Remove the file descriptor FD from the list of monitored fd's:
559 i.e. we don't care anymore about events on the FD. */
561 delete_file_handler (int fd
)
563 file_handler
*file_ptr
, *prev_ptr
= NULL
;
567 struct pollfd
*new_poll_fds
;
570 /* Find the entry for the given file. */
572 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
573 file_ptr
= file_ptr
->next_file
)
575 if (file_ptr
->fd
== fd
)
579 if (file_ptr
== NULL
)
585 /* Create a new poll_fds array by copying every fd's information but the
586 one we want to get rid of. */
589 (struct pollfd
*) xmalloc ((gdb_notifier
.num_fds
- 1) * sizeof (struct pollfd
));
591 for (i
= 0, j
= 0; i
< gdb_notifier
.num_fds
; i
++)
593 if ((gdb_notifier
.poll_fds
+ i
)->fd
!= fd
)
595 (new_poll_fds
+ j
)->fd
= (gdb_notifier
.poll_fds
+ i
)->fd
;
596 (new_poll_fds
+ j
)->events
= (gdb_notifier
.poll_fds
+ i
)->events
;
597 (new_poll_fds
+ j
)->revents
= (gdb_notifier
.poll_fds
+ i
)->revents
;
601 xfree (gdb_notifier
.poll_fds
);
602 gdb_notifier
.poll_fds
= new_poll_fds
;
603 gdb_notifier
.num_fds
--;
605 internal_error (__FILE__
, __LINE__
,
606 _("use_poll without HAVE_POLL"));
607 #endif /* HAVE_POLL */
611 if (file_ptr
->mask
& GDB_READABLE
)
612 FD_CLR (fd
, &gdb_notifier
.check_masks
[0]);
613 if (file_ptr
->mask
& GDB_WRITABLE
)
614 FD_CLR (fd
, &gdb_notifier
.check_masks
[1]);
615 if (file_ptr
->mask
& GDB_EXCEPTION
)
616 FD_CLR (fd
, &gdb_notifier
.check_masks
[2]);
618 /* Find current max fd. */
620 if ((fd
+ 1) == gdb_notifier
.num_fds
)
622 gdb_notifier
.num_fds
--;
623 for (i
= gdb_notifier
.num_fds
; i
; i
--)
625 if (FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[0])
626 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[1])
627 || FD_ISSET (i
- 1, &gdb_notifier
.check_masks
[2]))
630 gdb_notifier
.num_fds
= i
;
634 /* Deactivate the file descriptor, by clearing its mask,
635 so that it will not fire again. */
639 /* Get rid of the file handler in the file handler list. */
640 if (file_ptr
== gdb_notifier
.first_file_handler
)
641 gdb_notifier
.first_file_handler
= file_ptr
->next_file
;
644 for (prev_ptr
= gdb_notifier
.first_file_handler
;
645 prev_ptr
->next_file
!= file_ptr
;
646 prev_ptr
= prev_ptr
->next_file
)
648 prev_ptr
->next_file
= file_ptr
->next_file
;
653 /* Handle the given event by calling the procedure associated to the
654 corresponding file handler. Called by process_event indirectly,
655 through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
656 event in the front of the event queue. */
658 handle_file_event (int event_file_desc
)
660 file_handler
*file_ptr
;
664 int error_mask_returned
;
667 /* Search the file handler list to find one that matches the fd in
669 for (file_ptr
= gdb_notifier
.first_file_handler
; file_ptr
!= NULL
;
670 file_ptr
= file_ptr
->next_file
)
672 if (file_ptr
->fd
== event_file_desc
)
674 /* With poll, the ready_mask could have any of three events
675 set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
676 be used in the requested event mask (events), but they
677 can be returned in the return mask (revents). We need to
678 check for those event too, and add them to the mask which
679 will be passed to the handler. */
681 /* See if the desired events (mask) match the received
682 events (ready_mask). */
687 error_mask
= POLLHUP
| POLLERR
| POLLNVAL
;
688 mask
= (file_ptr
->ready_mask
& file_ptr
->mask
) |
689 (file_ptr
->ready_mask
& error_mask
);
690 error_mask_returned
= mask
& error_mask
;
692 if (error_mask_returned
!= 0)
694 /* Work in progress. We may need to tell somebody what
695 kind of error we had. */
696 if (error_mask_returned
& POLLHUP
)
697 printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr
->fd
);
698 if (error_mask_returned
& POLLERR
)
699 printf_unfiltered (_("Error detected on fd %d\n"), file_ptr
->fd
);
700 if (error_mask_returned
& POLLNVAL
)
701 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr
->fd
);
707 internal_error (__FILE__
, __LINE__
,
708 _("use_poll without HAVE_POLL"));
709 #endif /* HAVE_POLL */
713 if (file_ptr
->ready_mask
& GDB_EXCEPTION
)
715 printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr
->fd
);
720 mask
= file_ptr
->ready_mask
& file_ptr
->mask
;
723 /* Clear the received events for next time around. */
724 file_ptr
->ready_mask
= 0;
726 /* If there was a match, then call the handler. */
728 (*file_ptr
->proc
) (file_ptr
->error
, file_ptr
->client_data
);
734 /* Wrapper for select. This function is not yet exported from this
735 file because it is not sufficiently general. For example,
736 ser-base.c uses select to check for socket activity, and this
737 function does not support sockets under Windows, so we do not want
738 to use gdb_select in ser-base.c. */
741 gdb_select (int n
, fd_set
*readfds
, fd_set
*writefds
, fd_set
*exceptfds
,
742 struct timeval
*timeout
)
745 HANDLE handles
[MAXIMUM_WAIT_OBJECTS
];
754 for (fd
= 0; fd
< n
; ++fd
)
756 /* There is no support yet for WRITEFDS. At present, this isn't
757 used by GDB -- but we do not want to silently ignore WRITEFDS
758 if something starts using it. */
759 gdb_assert (!FD_ISSET (fd
, writefds
));
760 if (!FD_ISSET (fd
, readfds
)
761 && !FD_ISSET (fd
, exceptfds
))
763 h
= (HANDLE
) _get_osfhandle (fd
);
764 if (h
== INVALID_HANDLE_VALUE
)
766 /* If the underlying handle is INVALID_HANDLE_VALUE, then
767 this descriptor is no more. */
768 if (FD_ISSET (fd
, exceptfds
))
772 /* The only exceptional condition we recognize is a closed file
773 descriptor. Since we have already checked for that
774 condition, clear the exceptional bit for this descriptor. */
775 FD_CLR (fd
, exceptfds
);
776 if (FD_ISSET (fd
, readfds
))
778 gdb_assert (num_handles
< MAXIMUM_WAIT_OBJECTS
);
779 handles
[num_handles
++] = h
;
782 /* If we don't need to wait for any handles, we are done. */
785 event
= WaitForMultipleObjects (num_handles
,
789 ? (timeout
->tv_sec
* 1000 + timeout
->tv_usec
)
791 /* EVENT can only be a value in the WAIT_ABANDONED_0 range if the
792 HANDLES included an abandoned mutex. Since GDB doesn't use
793 mutexes, that should never occur. */
794 gdb_assert (!(WAIT_ABANDONED_0
<= event
795 && event
< WAIT_ABANDONED_0
+ num_handles
));
796 if (event
== WAIT_FAILED
)
798 if (event
== WAIT_TIMEOUT
)
800 /* Run through the READFDS, clearing bits corresponding to descriptors
801 for which input is unavailable. */
802 num_ready
+= num_handles
;
803 h
= handles
[event
- WAIT_OBJECT_0
];
804 for (fd
= 0; fd
< n
; ++fd
)
807 if (!FD_ISSET (fd
, readfds
))
809 fd_h
= (HANDLE
) _get_osfhandle (fd
);
810 /* This handle might be ready, even though it wasn't the handle
811 returned by WaitForMultipleObjects. */
812 if (fd_h
!= h
&& WaitForSingleObject (fd_h
, 0) != WAIT_OBJECT_0
)
814 FD_CLR (fd
, readfds
);
821 return select (n
, readfds
, writefds
, exceptfds
, timeout
);
825 /* Called by gdb_do_one_event to wait for new events on the
826 monitored file descriptors. Queue file events as they are
827 detected by the poll.
828 If there are no events, this function will block in the
830 Return -1 if there are no files descriptors to monitor,
831 otherwise return 0. */
833 gdb_wait_for_event (void)
835 file_handler
*file_ptr
;
836 gdb_event
*file_event_ptr
;
840 /* Make sure all output is done before getting another event. */
841 gdb_flush (gdb_stdout
);
842 gdb_flush (gdb_stderr
);
844 if (gdb_notifier
.num_fds
== 0)
851 poll (gdb_notifier
.poll_fds
,
852 (unsigned long) gdb_notifier
.num_fds
,
853 gdb_notifier
.timeout_valid
? gdb_notifier
.poll_timeout
: -1);
855 /* Don't print anything if we get out of poll because of a
857 if (num_found
== -1 && errno
!= EINTR
)
858 perror_with_name (("poll"));
860 internal_error (__FILE__
, __LINE__
,
861 _("use_poll without HAVE_POLL"));
862 #endif /* HAVE_POLL */
866 gdb_notifier
.ready_masks
[0] = gdb_notifier
.check_masks
[0];
867 gdb_notifier
.ready_masks
[1] = gdb_notifier
.check_masks
[1];
868 gdb_notifier
.ready_masks
[2] = gdb_notifier
.check_masks
[2];
869 num_found
= gdb_select (gdb_notifier
.num_fds
,
870 &gdb_notifier
.ready_masks
[0],
871 &gdb_notifier
.ready_masks
[1],
872 &gdb_notifier
.ready_masks
[2],
873 gdb_notifier
.timeout_valid
874 ? &gdb_notifier
.select_timeout
: NULL
);
876 /* Clear the masks after an error from select. */
879 FD_ZERO (&gdb_notifier
.ready_masks
[0]);
880 FD_ZERO (&gdb_notifier
.ready_masks
[1]);
881 FD_ZERO (&gdb_notifier
.ready_masks
[2]);
882 /* Dont print anything is we got a signal, let gdb handle it. */
884 perror_with_name (("select"));
888 /* Enqueue all detected file events. */
893 for (i
= 0; (i
< gdb_notifier
.num_fds
) && (num_found
> 0); i
++)
895 if ((gdb_notifier
.poll_fds
+ i
)->revents
)
900 for (file_ptr
= gdb_notifier
.first_file_handler
;
902 file_ptr
= file_ptr
->next_file
)
904 if (file_ptr
->fd
== (gdb_notifier
.poll_fds
+ i
)->fd
)
910 /* Enqueue an event only if this is still a new event for
912 if (file_ptr
->ready_mask
== 0)
914 file_event_ptr
= create_file_event (file_ptr
->fd
);
915 async_queue_event (file_event_ptr
, TAIL
);
919 file_ptr
->ready_mask
= (gdb_notifier
.poll_fds
+ i
)->revents
;
922 internal_error (__FILE__
, __LINE__
,
923 _("use_poll without HAVE_POLL"));
924 #endif /* HAVE_POLL */
928 for (file_ptr
= gdb_notifier
.first_file_handler
;
929 (file_ptr
!= NULL
) && (num_found
> 0);
930 file_ptr
= file_ptr
->next_file
)
934 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[0]))
935 mask
|= GDB_READABLE
;
936 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[1]))
937 mask
|= GDB_WRITABLE
;
938 if (FD_ISSET (file_ptr
->fd
, &gdb_notifier
.ready_masks
[2]))
939 mask
|= GDB_EXCEPTION
;
946 /* Enqueue an event only if this is still a new event for
949 if (file_ptr
->ready_mask
== 0)
951 file_event_ptr
= create_file_event (file_ptr
->fd
);
952 async_queue_event (file_event_ptr
, TAIL
);
954 file_ptr
->ready_mask
= mask
;
961 /* Create an asynchronous handler, allocating memory for it.
962 Return a pointer to the newly created handler.
963 This pointer will be used to invoke the handler by
964 invoke_async_signal_handler.
965 PROC is the function to call with CLIENT_DATA argument
966 whenever the handler is invoked. */
967 async_signal_handler
*
968 create_async_signal_handler (sig_handler_func
* proc
, gdb_client_data client_data
)
970 async_signal_handler
*async_handler_ptr
;
973 (async_signal_handler
*) xmalloc (sizeof (async_signal_handler
));
974 async_handler_ptr
->ready
= 0;
975 async_handler_ptr
->next_handler
= NULL
;
976 async_handler_ptr
->proc
= proc
;
977 async_handler_ptr
->client_data
= client_data
;
978 if (sighandler_list
.first_handler
== NULL
)
979 sighandler_list
.first_handler
= async_handler_ptr
;
981 sighandler_list
.last_handler
->next_handler
= async_handler_ptr
;
982 sighandler_list
.last_handler
= async_handler_ptr
;
983 return async_handler_ptr
;
986 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
987 be used when the handlers are invoked, after we have waited for
988 some event. The caller of this function is the interrupt handler
989 associated with a signal. */
991 mark_async_signal_handler (async_signal_handler
* async_handler_ptr
)
993 ((async_signal_handler
*) async_handler_ptr
)->ready
= 1;
994 async_handler_ready
= 1;
997 /* Call all the handlers that are ready. */
999 invoke_async_signal_handler (void)
1001 async_signal_handler
*async_handler_ptr
;
1003 if (async_handler_ready
== 0)
1005 async_handler_ready
= 0;
1007 /* Invoke ready handlers. */
1011 for (async_handler_ptr
= sighandler_list
.first_handler
;
1012 async_handler_ptr
!= NULL
;
1013 async_handler_ptr
= async_handler_ptr
->next_handler
)
1015 if (async_handler_ptr
->ready
)
1018 if (async_handler_ptr
== NULL
)
1020 async_handler_ptr
->ready
= 0;
1021 (*async_handler_ptr
->proc
) (async_handler_ptr
->client_data
);
1027 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
1028 Free the space allocated for it. */
1030 delete_async_signal_handler (async_signal_handler
** async_handler_ptr
)
1032 async_signal_handler
*prev_ptr
;
1034 if (sighandler_list
.first_handler
== (*async_handler_ptr
))
1036 sighandler_list
.first_handler
= (*async_handler_ptr
)->next_handler
;
1037 if (sighandler_list
.first_handler
== NULL
)
1038 sighandler_list
.last_handler
= NULL
;
1042 prev_ptr
= sighandler_list
.first_handler
;
1043 while (prev_ptr
->next_handler
!= (*async_handler_ptr
) && prev_ptr
)
1044 prev_ptr
= prev_ptr
->next_handler
;
1045 prev_ptr
->next_handler
= (*async_handler_ptr
)->next_handler
;
1046 if (sighandler_list
.last_handler
== (*async_handler_ptr
))
1047 sighandler_list
.last_handler
= prev_ptr
;
1049 xfree ((*async_handler_ptr
));
1050 (*async_handler_ptr
) = NULL
;
1053 /* Is it necessary to call invoke_async_signal_handler? */
1055 check_async_ready (void)
1057 return async_handler_ready
;
1060 /* Create a timer that will expire in MILLISECONDS from now. When the
1061 timer is ready, PROC will be executed. At creation, the timer is
1062 aded to the timers queue. This queue is kept sorted in order of
1063 increasing timers. Return a handle to the timer struct. */
1065 create_timer (int milliseconds
, timer_handler_func
* proc
, gdb_client_data client_data
)
1067 struct gdb_timer
*timer_ptr
, *timer_index
, *prev_timer
;
1068 struct timeval time_now
, delta
;
1070 /* compute seconds */
1071 delta
.tv_sec
= milliseconds
/ 1000;
1072 /* compute microseconds */
1073 delta
.tv_usec
= (milliseconds
% 1000) * 1000;
1075 gettimeofday (&time_now
, NULL
);
1077 timer_ptr
= (struct gdb_timer
*) xmalloc (sizeof (gdb_timer
));
1078 timer_ptr
->when
.tv_sec
= time_now
.tv_sec
+ delta
.tv_sec
;
1079 timer_ptr
->when
.tv_usec
= time_now
.tv_usec
+ delta
.tv_usec
;
1081 if (timer_ptr
->when
.tv_usec
>= 1000000)
1083 timer_ptr
->when
.tv_sec
+= 1;
1084 timer_ptr
->when
.tv_usec
-= 1000000;
1086 timer_ptr
->proc
= proc
;
1087 timer_ptr
->client_data
= client_data
;
1088 timer_list
.num_timers
++;
1089 timer_ptr
->timer_id
= timer_list
.num_timers
;
1091 /* Now add the timer to the timer queue, making sure it is sorted in
1092 increasing order of expiration. */
1094 for (timer_index
= timer_list
.first_timer
;
1095 timer_index
!= NULL
;
1096 timer_index
= timer_index
->next
)
1098 /* If the seconds field is greater or if it is the same, but the
1099 microsecond field is greater. */
1100 if ((timer_index
->when
.tv_sec
> timer_ptr
->when
.tv_sec
) ||
1101 ((timer_index
->when
.tv_sec
== timer_ptr
->when
.tv_sec
)
1102 && (timer_index
->when
.tv_usec
> timer_ptr
->when
.tv_usec
)))
1106 if (timer_index
== timer_list
.first_timer
)
1108 timer_ptr
->next
= timer_list
.first_timer
;
1109 timer_list
.first_timer
= timer_ptr
;
1114 for (prev_timer
= timer_list
.first_timer
;
1115 prev_timer
->next
!= timer_index
;
1116 prev_timer
= prev_timer
->next
)
1119 prev_timer
->next
= timer_ptr
;
1120 timer_ptr
->next
= timer_index
;
1123 gdb_notifier
.timeout_valid
= 0;
1124 return timer_ptr
->timer_id
;
1127 /* There is a chance that the creator of the timer wants to get rid of
1128 it before it expires. */
1130 delete_timer (int id
)
1132 struct gdb_timer
*timer_ptr
, *prev_timer
= NULL
;
1134 /* Find the entry for the given timer. */
1136 for (timer_ptr
= timer_list
.first_timer
; timer_ptr
!= NULL
;
1137 timer_ptr
= timer_ptr
->next
)
1139 if (timer_ptr
->timer_id
== id
)
1143 if (timer_ptr
== NULL
)
1145 /* Get rid of the timer in the timer list. */
1146 if (timer_ptr
== timer_list
.first_timer
)
1147 timer_list
.first_timer
= timer_ptr
->next
;
1150 for (prev_timer
= timer_list
.first_timer
;
1151 prev_timer
->next
!= timer_ptr
;
1152 prev_timer
= prev_timer
->next
)
1154 prev_timer
->next
= timer_ptr
->next
;
1158 gdb_notifier
.timeout_valid
= 0;
1161 /* When a timer event is put on the event queue, it will be handled by
1162 this function. Just call the assiciated procedure and delete the
1163 timer event from the event queue. Repeat this for each timer that
1166 handle_timer_event (int dummy
)
1168 struct timeval time_now
;
1169 struct gdb_timer
*timer_ptr
, *saved_timer
;
1171 gettimeofday (&time_now
, NULL
);
1172 timer_ptr
= timer_list
.first_timer
;
1174 while (timer_ptr
!= NULL
)
1176 if ((timer_ptr
->when
.tv_sec
> time_now
.tv_sec
) ||
1177 ((timer_ptr
->when
.tv_sec
== time_now
.tv_sec
) &&
1178 (timer_ptr
->when
.tv_usec
> time_now
.tv_usec
)))
1181 /* Get rid of the timer from the beginning of the list. */
1182 timer_list
.first_timer
= timer_ptr
->next
;
1183 saved_timer
= timer_ptr
;
1184 timer_ptr
= timer_ptr
->next
;
1185 /* Call the procedure associated with that timer. */
1186 (*saved_timer
->proc
) (saved_timer
->client_data
);
1187 xfree (saved_timer
);
1190 gdb_notifier
.timeout_valid
= 0;
1193 /* Check whether any timers in the timers queue are ready. If at least
1194 one timer is ready, stick an event onto the event queue. Even in
1195 case more than one timer is ready, one event is enough, because the
1196 handle_timer_event() will go through the timers list and call the
1197 procedures associated with all that have expired. Update the
1198 timeout for the select() or poll() as well. */
1202 struct timeval time_now
, delta
;
1203 gdb_event
*event_ptr
;
1205 if (timer_list
.first_timer
!= NULL
)
1207 gettimeofday (&time_now
, NULL
);
1208 delta
.tv_sec
= timer_list
.first_timer
->when
.tv_sec
- time_now
.tv_sec
;
1209 delta
.tv_usec
= timer_list
.first_timer
->when
.tv_usec
- time_now
.tv_usec
;
1211 if (delta
.tv_usec
< 0)
1214 delta
.tv_usec
+= 1000000;
1217 /* Oops it expired already. Tell select / poll to return
1218 immediately. (Cannot simply test if delta.tv_sec is negative
1219 because time_t might be unsigned.) */
1220 if (timer_list
.first_timer
->when
.tv_sec
< time_now
.tv_sec
1221 || (timer_list
.first_timer
->when
.tv_sec
== time_now
.tv_sec
1222 && timer_list
.first_timer
->when
.tv_usec
< time_now
.tv_usec
))
1228 if (delta
.tv_sec
== 0 && delta
.tv_usec
== 0)
1230 event_ptr
= (gdb_event
*) xmalloc (sizeof (gdb_event
));
1231 event_ptr
->proc
= handle_timer_event
;
1232 event_ptr
->fd
= timer_list
.first_timer
->timer_id
;
1233 async_queue_event (event_ptr
, TAIL
);
1236 /* Now we need to update the timeout for select/ poll, because we
1237 don't want to sit there while this timer is expiring. */
1241 gdb_notifier
.poll_timeout
= delta
.tv_sec
* 1000;
1243 internal_error (__FILE__
, __LINE__
,
1244 _("use_poll without HAVE_POLL"));
1245 #endif /* HAVE_POLL */
1249 gdb_notifier
.select_timeout
.tv_sec
= delta
.tv_sec
;
1250 gdb_notifier
.select_timeout
.tv_usec
= delta
.tv_usec
;
1252 gdb_notifier
.timeout_valid
= 1;
1255 gdb_notifier
.timeout_valid
= 0;