1 /* Event loop machinery for GDB, the GNU debugger.
2 Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009, 2010
3 Free Software Foundation, Inc.
4 Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
6 This file is part of GDB.
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>. */
22 #include "event-loop.h"
23 #include "event-top.h"
26 #if defined (HAVE_POLL_H)
28 #elif defined (HAVE_SYS_POLL_H)
33 #include <sys/types.h>
34 #include "gdb_string.h"
37 #include "exceptions.h"
38 #include "gdb_assert.h"
39 #include "gdb_select.h"
41 /* Data point to pass to the event handler. */
42 typedef union event_data
48 typedef struct gdb_event gdb_event;
49 typedef void (event_handler_func) (event_data);
51 /* Event for the GDB event system. Events are queued by calling
52 async_queue_event and serviced later on by gdb_do_one_event. An
53 event can be, for instance, a file descriptor becoming ready to be
54 read. Servicing an event simply means that the procedure PROC will
55 be called. We have 2 queues, one for file handlers that we listen
56 to in the event loop, and one for the file handlers+events that are
57 ready. The procedure PROC associated with each event is dependant
58 of the event source. In the case of monitored file descriptors, it
59 is always the same (handle_file_event). Its duty is to invoke the
60 handler associated with the file descriptor whose state change
61 generated the event, plus doing other cleanups and such. In the
62 case of async signal handlers, it is
63 invoke_async_signal_handler. */
67 /* Procedure to call to service this event. */
68 event_handler_func *proc;
70 /* Data to pass to the event handler. */
73 /* Next in list of events or NULL. */
74 struct gdb_event *next_event;
77 /* Information about each file descriptor we register with the event
80 typedef struct file_handler
82 int fd; /* File descriptor. */
83 int mask; /* Events we want to monitor: POLLIN, etc. */
84 int ready_mask; /* Events that have been seen since
86 handler_func *proc; /* Procedure to call when fd is ready. */
87 gdb_client_data client_data; /* Argument to pass to proc. */
88 int error; /* Was an error detected on this fd? */
89 struct file_handler *next_file; /* Next registered file descriptor. */
93 /* PROC is a function to be invoked when the READY flag is set. This
94 happens when there has been a signal and the corresponding signal
95 handler has 'triggered' this async_signal_handler for
96 execution. The actual work to be done in response to a signal will
97 be carried out by PROC at a later time, within process_event. This
98 provides a deferred execution of signal handlers.
99 Async_init_signals takes care of setting up such an
100 async_signal_handler for each interesting signal. */
101 typedef struct async_signal_handler
103 int ready; /* If ready, call this handler from the main event loop,
104 using invoke_async_handler. */
105 struct async_signal_handler *next_handler; /* Ptr to next handler */
106 sig_handler_func *proc; /* Function to call to do the work */
107 gdb_client_data client_data; /* Argument to async_handler_func */
109 async_signal_handler;
111 /* PROC is a function to be invoked when the READY flag is set. This
112 happens when the event has been marked with
113 MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response
114 to an event will be carried out by PROC at a later time, within
115 process_event. This provides a deferred execution of event
117 typedef struct async_event_handler
119 /* If ready, call this handler from the main event loop, using
120 invoke_event_handler. */
123 /* Point to next handler. */
124 struct async_event_handler *next_handler;
126 /* Function to call to do the work. */
127 async_event_handler_func *proc;
129 /* Argument to PROC. */
130 gdb_client_data client_data;
136 - the first event in the queue is the head of the queue.
137 It will be the next to be serviced.
138 - the last event in the queue
140 Events can be inserted at the front of the queue or at the end of
141 the queue. Events will be extracted from the queue for processing
142 starting from the head. Therefore, events inserted at the head of
143 the queue will be processed in a last in first out fashion, while
144 those inserted at the tail of the queue will be processed in a first
145 in first out manner. All the fields are NULL if the queue is
150 gdb_event *first_event; /* First pending event */
151 gdb_event *last_event; /* Last pending event */
155 /* Gdb_notifier is just a list of file descriptors gdb is interested in.
156 These are the input file descriptor, and the target file
157 descriptor. We have two flavors of the notifier, one for platforms
158 that have the POLL function, the other for those that don't, and
159 only support SELECT. Each of the elements in the gdb_notifier list is
160 basically a description of what kind of events gdb is interested
163 /* As of 1999-04-30 only the input file descriptor is registered with the
166 /* Do we use poll or select ? */
171 #endif /* HAVE_POLL */
173 static unsigned char use_poll = USE_POLL;
182 /* Ptr to head of file handler list. */
183 file_handler *first_file_handler;
186 /* Ptr to array of pollfd structures. */
187 struct pollfd *poll_fds;
189 /* Timeout in milliseconds for calls to poll(). */
193 /* Masks to be used in the next call to select.
194 Bits are set in response to calls to create_file_handler. */
195 fd_set check_masks[3];
197 /* What file descriptors were found ready by select. */
198 fd_set ready_masks[3];
200 /* Number of file descriptors to monitor. (for poll) */
201 /* Number of valid bits (highest fd value + 1). (for select) */
204 /* Time structure for calls to select(). */
205 struct timeval select_timeout;
207 /* Flag to tell whether the timeout should be used. */
212 /* Structure associated with a timer. PROC will be executed at the
213 first occasion after WHEN. */
218 struct gdb_timer *next;
219 timer_handler_func *proc; /* Function to call to do the work */
220 gdb_client_data client_data; /* Argument to async_handler_func */
223 /* List of currently active timers. It is sorted in order of
224 increasing timers. */
227 /* Pointer to first in timer list. */
228 struct gdb_timer *first_timer;
230 /* Id of the last timer created. */
235 /* All the async_signal_handlers gdb is interested in are kept onto
239 /* Pointer to first in handler list. */
240 async_signal_handler *first_handler;
242 /* Pointer to last in handler list. */
243 async_signal_handler *last_handler;
247 /* All the async_event_handlers gdb is interested in are kept onto
251 /* Pointer to first in handler list. */
252 async_event_handler *first_handler;
254 /* Pointer to last in handler list. */
255 async_event_handler *last_handler;
257 async_event_handler_list;
259 static int invoke_async_signal_handlers (void);
260 static void create_file_handler (int fd, int mask, handler_func *proc,
261 gdb_client_data client_data);
262 static void handle_file_event (event_data data);
263 static void check_async_event_handlers (void);
264 static int gdb_wait_for_event (int);
265 static void poll_timers (void);
268 /* Insert an event object into the gdb event queue at
269 the specified position.
270 POSITION can be head or tail, with values TAIL, HEAD.
271 EVENT_PTR points to the event to be inserted into the queue.
272 The caller must allocate memory for the event. It is freed
273 after the event has ben handled.
274 Events in the queue will be processed head to tail, therefore,
275 events inserted at the head of the queue will be processed
276 as last in first out. Event appended at the tail of the queue
277 will be processed first in first out. */
279 async_queue_event (gdb_event * event_ptr, queue_position position)
281 if (position == TAIL)
283 /* The event will become the new last_event. */
285 event_ptr->next_event = NULL;
286 if (event_queue.first_event == NULL)
287 event_queue.first_event = event_ptr;
289 event_queue.last_event->next_event = event_ptr;
290 event_queue.last_event = event_ptr;
292 else if (position == HEAD)
294 /* The event becomes the new first_event. */
296 event_ptr->next_event = event_queue.first_event;
297 if (event_queue.first_event == NULL)
298 event_queue.last_event = event_ptr;
299 event_queue.first_event = event_ptr;
303 /* Create a generic event, to be enqueued in the event queue for
304 processing. PROC is the procedure associated to the event. DATA
305 is passed to PROC upon PROC invocation. */
308 create_event (event_handler_func proc, event_data data)
312 event = xmalloc (sizeof (*event));
319 /* Create a file event, to be enqueued in the event queue for
320 processing. The procedure associated to this event is always
321 handle_file_event, which will in turn invoke the one that was
322 associated to FD when it was registered with the event loop. */
324 create_file_event (int fd)
329 return create_event (handle_file_event, data);
332 /* Process one event.
333 The event can be the next one to be serviced in the event queue,
334 or an asynchronous event handler can be invoked in response to
335 the reception of a signal.
336 If an event was processed (either way), 1 is returned otherwise
338 Scan the queue from head to tail, processing therefore the high
339 priority events first, by invoking the associated event handler
344 gdb_event *event_ptr, *prev_ptr;
345 event_handler_func *proc;
348 /* First let's see if there are any asynchronous event handlers that
349 are ready. These would be the result of invoking any of the
352 if (invoke_async_signal_handlers ())
355 /* Look in the event queue to find an event that is ready
358 for (event_ptr = event_queue.first_event; event_ptr != NULL;
359 event_ptr = event_ptr->next_event)
361 /* Call the handler for the event. */
363 proc = event_ptr->proc;
364 data = event_ptr->data;
366 /* Let's get rid of the event from the event queue. We need to
367 do this now because while processing the event, the proc
368 function could end up calling 'error' and therefore jump out
369 to the caller of this function, gdb_do_one_event. In that
370 case, we would have on the event queue an event wich has been
371 processed, but not deleted. */
373 if (event_queue.first_event == event_ptr)
375 event_queue.first_event = event_ptr->next_event;
376 if (event_ptr->next_event == NULL)
377 event_queue.last_event = NULL;
381 prev_ptr = event_queue.first_event;
382 while (prev_ptr->next_event != event_ptr)
383 prev_ptr = prev_ptr->next_event;
385 prev_ptr->next_event = event_ptr->next_event;
386 if (event_ptr->next_event == NULL)
387 event_queue.last_event = prev_ptr;
391 /* Now call the procedure associated with the event. */
396 /* this is the case if there are no event on the event queue. */
400 /* Process one high level event. If nothing is ready at this time,
401 wait for something to happen (via gdb_wait_for_event), then process
402 it. Returns >0 if something was done otherwise returns <0 (this
403 can happen if there are no event sources to wait for). If an error
404 occurs catch_errors() which calls this function returns zero. */
407 gdb_do_one_event (void *data)
409 static int event_source_head = 0;
410 const int number_of_sources = 3;
413 /* Any events already waiting in the queue? */
414 if (process_event ())
417 /* To level the fairness across event sources, we poll them in a
418 round-robin fashion. */
419 for (current = 0; current < number_of_sources; current++)
421 switch (event_source_head)
424 /* Are any timers that are ready? If so, put an event on the
429 /* Are there events already waiting to be collected on the
430 monitored file descriptors? */
431 gdb_wait_for_event (0);
434 /* Are there any asynchronous event handlers ready? */
435 check_async_event_handlers ();
440 if (event_source_head == number_of_sources)
441 event_source_head = 0;
444 /* Handle any new events collected. */
445 if (process_event ())
448 /* Block waiting for a new event. If gdb_wait_for_event returns -1,
449 we should get out because this means that there are no event
450 sources left. This will make the event loop stop, and the
453 if (gdb_wait_for_event (1) < 0)
456 /* Handle any new events occurred while waiting. */
457 if (process_event ())
460 /* If gdb_wait_for_event has returned 1, it means that one event has
461 been handled. We break out of the loop. */
465 /* Start up the event loop. This is the entry point to the event loop
466 from the command loop. */
469 start_event_loop (void)
471 /* Loop until there is nothing to do. This is the entry point to the
472 event loop engine. gdb_do_one_event, called via catch_errors()
473 will process one event for each invocation. It blocks waits for
474 an event and then processes it. >0 when an event is processed, 0
475 when catch_errors() caught an error and <0 when there are no
476 longer any event sources registered. */
481 gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
485 /* If we long-jumped out of do_one_event, we probably
486 didn't get around to resetting the prompt, which leaves
487 readline in a messed-up state. Reset it here. */
491 /* If any exception escaped to here, we better enable
492 stdin. Otherwise, any command that calls async_disable_stdin,
493 and then throws, will leave stdin inoperable. */
494 async_enable_stdin ();
495 /* FIXME: this should really be a call to a hook that is
496 interface specific, because interfaces can display the
497 prompt in their own way. */
498 display_gdb_prompt (0);
499 /* This call looks bizarre, but it is required. If the user
500 entered a command that caused an error,
501 after_char_processing_hook won't be called from
502 rl_callback_read_char_wrapper. Using a cleanup there
503 won't work, since we want this function to be called
504 after a new prompt is printed. */
505 if (after_char_processing_hook)
506 (*after_char_processing_hook) ();
507 /* Maybe better to set a flag to be checked somewhere as to
508 whether display the prompt or not. */
512 /* We are done with the event loop. There are no more event sources
513 to listen to. So we exit GDB. */
518 /* Wrapper function for create_file_handler, so that the caller
519 doesn't have to know implementation details about the use of poll
522 add_file_handler (int fd, handler_func * proc, gdb_client_data client_data)
531 /* Check to see if poll () is usable. If not, we'll switch to
532 use select. This can happen on systems like
533 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
534 On m68k-motorola-sysv, tty's are not stream-based and not
538 if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL))
541 internal_error (__FILE__, __LINE__,
542 _("use_poll without HAVE_POLL"));
543 #endif /* HAVE_POLL */
548 create_file_handler (fd, POLLIN, proc, client_data);
550 internal_error (__FILE__, __LINE__,
551 _("use_poll without HAVE_POLL"));
555 create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data);
558 /* Add a file handler/descriptor to the list of descriptors we are
560 FD is the file descriptor for the file/stream to be listened to.
561 For the poll case, MASK is a combination (OR) of
562 POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM,
563 POLLWRBAND: these are the events we are interested in. If any of them
564 occurs, proc should be called.
565 For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION.
566 PROC is the procedure that will be called when an event occurs for
567 FD. CLIENT_DATA is the argument to pass to PROC. */
569 create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data)
571 file_handler *file_ptr;
573 /* Do we already have a file handler for this file? (We may be
574 changing its associated procedure). */
575 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
576 file_ptr = file_ptr->next_file)
578 if (file_ptr->fd == fd)
582 /* It is a new file descriptor. Add it to the list. Otherwise, just
583 change the data associated with it. */
584 if (file_ptr == NULL)
586 file_ptr = (file_handler *) xmalloc (sizeof (file_handler));
588 file_ptr->ready_mask = 0;
589 file_ptr->next_file = gdb_notifier.first_file_handler;
590 gdb_notifier.first_file_handler = file_ptr;
595 gdb_notifier.num_fds++;
596 if (gdb_notifier.poll_fds)
597 gdb_notifier.poll_fds =
598 (struct pollfd *) xrealloc (gdb_notifier.poll_fds,
599 (gdb_notifier.num_fds
600 * sizeof (struct pollfd)));
602 gdb_notifier.poll_fds =
603 (struct pollfd *) xmalloc (sizeof (struct pollfd));
604 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd;
605 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask;
606 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
608 internal_error (__FILE__, __LINE__,
609 _("use_poll without HAVE_POLL"));
610 #endif /* HAVE_POLL */
614 if (mask & GDB_READABLE)
615 FD_SET (fd, &gdb_notifier.check_masks[0]);
617 FD_CLR (fd, &gdb_notifier.check_masks[0]);
619 if (mask & GDB_WRITABLE)
620 FD_SET (fd, &gdb_notifier.check_masks[1]);
622 FD_CLR (fd, &gdb_notifier.check_masks[1]);
624 if (mask & GDB_EXCEPTION)
625 FD_SET (fd, &gdb_notifier.check_masks[2]);
627 FD_CLR (fd, &gdb_notifier.check_masks[2]);
629 if (gdb_notifier.num_fds <= fd)
630 gdb_notifier.num_fds = fd + 1;
634 file_ptr->proc = proc;
635 file_ptr->client_data = client_data;
636 file_ptr->mask = mask;
639 /* Remove the file descriptor FD from the list of monitored fd's:
640 i.e. we don't care anymore about events on the FD. */
642 delete_file_handler (int fd)
644 file_handler *file_ptr, *prev_ptr = NULL;
648 struct pollfd *new_poll_fds;
651 /* Find the entry for the given file. */
653 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
654 file_ptr = file_ptr->next_file)
656 if (file_ptr->fd == fd)
660 if (file_ptr == NULL)
666 /* Create a new poll_fds array by copying every fd's information but the
667 one we want to get rid of. */
670 (struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd));
672 for (i = 0, j = 0; i < gdb_notifier.num_fds; i++)
674 if ((gdb_notifier.poll_fds + i)->fd != fd)
676 (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd;
677 (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events;
678 (new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents;
682 xfree (gdb_notifier.poll_fds);
683 gdb_notifier.poll_fds = new_poll_fds;
684 gdb_notifier.num_fds--;
686 internal_error (__FILE__, __LINE__,
687 _("use_poll without HAVE_POLL"));
688 #endif /* HAVE_POLL */
692 if (file_ptr->mask & GDB_READABLE)
693 FD_CLR (fd, &gdb_notifier.check_masks[0]);
694 if (file_ptr->mask & GDB_WRITABLE)
695 FD_CLR (fd, &gdb_notifier.check_masks[1]);
696 if (file_ptr->mask & GDB_EXCEPTION)
697 FD_CLR (fd, &gdb_notifier.check_masks[2]);
699 /* Find current max fd. */
701 if ((fd + 1) == gdb_notifier.num_fds)
703 gdb_notifier.num_fds--;
704 for (i = gdb_notifier.num_fds; i; i--)
706 if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0])
707 || FD_ISSET (i - 1, &gdb_notifier.check_masks[1])
708 || FD_ISSET (i - 1, &gdb_notifier.check_masks[2]))
711 gdb_notifier.num_fds = i;
715 /* Deactivate the file descriptor, by clearing its mask,
716 so that it will not fire again. */
720 /* Get rid of the file handler in the file handler list. */
721 if (file_ptr == gdb_notifier.first_file_handler)
722 gdb_notifier.first_file_handler = file_ptr->next_file;
725 for (prev_ptr = gdb_notifier.first_file_handler;
726 prev_ptr->next_file != file_ptr;
727 prev_ptr = prev_ptr->next_file)
729 prev_ptr->next_file = file_ptr->next_file;
734 /* Handle the given event by calling the procedure associated to the
735 corresponding file handler. Called by process_event indirectly,
736 through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
737 event in the front of the event queue. */
739 handle_file_event (event_data data)
741 file_handler *file_ptr;
745 int error_mask_returned;
747 int event_file_desc = data.integer;
749 /* Search the file handler list to find one that matches the fd in
751 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
752 file_ptr = file_ptr->next_file)
754 if (file_ptr->fd == event_file_desc)
756 /* With poll, the ready_mask could have any of three events
757 set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
758 be used in the requested event mask (events), but they
759 can be returned in the return mask (revents). We need to
760 check for those event too, and add them to the mask which
761 will be passed to the handler. */
763 /* See if the desired events (mask) match the received
764 events (ready_mask). */
769 error_mask = POLLHUP | POLLERR | POLLNVAL;
770 mask = (file_ptr->ready_mask & file_ptr->mask) |
771 (file_ptr->ready_mask & error_mask);
772 error_mask_returned = mask & error_mask;
774 if (error_mask_returned != 0)
776 /* Work in progress. We may need to tell somebody what
777 kind of error we had. */
778 if (error_mask_returned & POLLHUP)
779 printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr->fd);
780 if (error_mask_returned & POLLERR)
781 printf_unfiltered (_("Error detected on fd %d\n"), file_ptr->fd);
782 if (error_mask_returned & POLLNVAL)
783 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr->fd);
789 internal_error (__FILE__, __LINE__,
790 _("use_poll without HAVE_POLL"));
791 #endif /* HAVE_POLL */
795 if (file_ptr->ready_mask & GDB_EXCEPTION)
797 printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr->fd);
802 mask = file_ptr->ready_mask & file_ptr->mask;
805 /* Clear the received events for next time around. */
806 file_ptr->ready_mask = 0;
808 /* If there was a match, then call the handler. */
810 (*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
816 /* Called by gdb_do_one_event to wait for new events on the monitored
817 file descriptors. Queue file events as they are detected by the
818 poll. If BLOCK and if there are no events, this function will
819 block in the call to poll. Return -1 if there are no files
820 descriptors to monitor, otherwise return 0. */
822 gdb_wait_for_event (int block)
824 file_handler *file_ptr;
825 gdb_event *file_event_ptr;
829 /* Make sure all output is done before getting another event. */
830 gdb_flush (gdb_stdout);
831 gdb_flush (gdb_stderr);
833 if (gdb_notifier.num_fds == 0)
842 timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1;
846 num_found = poll (gdb_notifier.poll_fds,
847 (unsigned long) gdb_notifier.num_fds, timeout);
849 /* Don't print anything if we get out of poll because of a
851 if (num_found == -1 && errno != EINTR)
852 perror_with_name (("poll"));
854 internal_error (__FILE__, __LINE__,
855 _("use_poll without HAVE_POLL"));
856 #endif /* HAVE_POLL */
860 struct timeval select_timeout;
862 struct timeval *timeout_p;
864 timeout_p = gdb_notifier.timeout_valid
865 ? &gdb_notifier.select_timeout : NULL;
868 memset (&select_timeout, 0, sizeof (select_timeout));
869 timeout_p = &select_timeout;
872 gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0];
873 gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1];
874 gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2];
875 num_found = gdb_select (gdb_notifier.num_fds,
876 &gdb_notifier.ready_masks[0],
877 &gdb_notifier.ready_masks[1],
878 &gdb_notifier.ready_masks[2],
881 /* Clear the masks after an error from select. */
884 FD_ZERO (&gdb_notifier.ready_masks[0]);
885 FD_ZERO (&gdb_notifier.ready_masks[1]);
886 FD_ZERO (&gdb_notifier.ready_masks[2]);
888 /* Dont print anything if we got a signal, let gdb handle
891 perror_with_name (("select"));
895 /* Enqueue all detected file events. */
900 for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
902 if ((gdb_notifier.poll_fds + i)->revents)
907 for (file_ptr = gdb_notifier.first_file_handler;
909 file_ptr = file_ptr->next_file)
911 if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd)
917 /* Enqueue an event only if this is still a new event for
919 if (file_ptr->ready_mask == 0)
921 file_event_ptr = create_file_event (file_ptr->fd);
922 async_queue_event (file_event_ptr, TAIL);
924 file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
928 internal_error (__FILE__, __LINE__,
929 _("use_poll without HAVE_POLL"));
930 #endif /* HAVE_POLL */
934 for (file_ptr = gdb_notifier.first_file_handler;
935 (file_ptr != NULL) && (num_found > 0);
936 file_ptr = file_ptr->next_file)
940 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0]))
941 mask |= GDB_READABLE;
942 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1]))
943 mask |= GDB_WRITABLE;
944 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2]))
945 mask |= GDB_EXCEPTION;
952 /* Enqueue an event only if this is still a new event for
955 if (file_ptr->ready_mask == 0)
957 file_event_ptr = create_file_event (file_ptr->fd);
958 async_queue_event (file_event_ptr, TAIL);
960 file_ptr->ready_mask = mask;
967 /* Create an asynchronous handler, allocating memory for it.
968 Return a pointer to the newly created handler.
969 This pointer will be used to invoke the handler by
970 invoke_async_signal_handler.
971 PROC is the function to call with CLIENT_DATA argument
972 whenever the handler is invoked. */
973 async_signal_handler *
974 create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data)
976 async_signal_handler *async_handler_ptr;
979 (async_signal_handler *) xmalloc (sizeof (async_signal_handler));
980 async_handler_ptr->ready = 0;
981 async_handler_ptr->next_handler = NULL;
982 async_handler_ptr->proc = proc;
983 async_handler_ptr->client_data = client_data;
984 if (sighandler_list.first_handler == NULL)
985 sighandler_list.first_handler = async_handler_ptr;
987 sighandler_list.last_handler->next_handler = async_handler_ptr;
988 sighandler_list.last_handler = async_handler_ptr;
989 return async_handler_ptr;
992 /* Call the handler from HANDLER immediately. This function runs
993 signal handlers when returning to the event loop would be too
996 call_async_signal_handler (struct async_signal_handler *handler)
998 (*handler->proc) (handler->client_data);
1001 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
1002 be used when the handlers are invoked, after we have waited for
1003 some event. The caller of this function is the interrupt handler
1004 associated with a signal. */
1006 mark_async_signal_handler (async_signal_handler * async_handler_ptr)
1008 async_handler_ptr->ready = 1;
1011 /* Call all the handlers that are ready. Returns true if any was
1014 invoke_async_signal_handlers (void)
1016 async_signal_handler *async_handler_ptr;
1019 /* Invoke ready handlers. */
1023 for (async_handler_ptr = sighandler_list.first_handler;
1024 async_handler_ptr != NULL;
1025 async_handler_ptr = async_handler_ptr->next_handler)
1027 if (async_handler_ptr->ready)
1030 if (async_handler_ptr == NULL)
1033 async_handler_ptr->ready = 0;
1034 (*async_handler_ptr->proc) (async_handler_ptr->client_data);
1040 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
1041 Free the space allocated for it. */
1043 delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
1045 async_signal_handler *prev_ptr;
1047 if (sighandler_list.first_handler == (*async_handler_ptr))
1049 sighandler_list.first_handler = (*async_handler_ptr)->next_handler;
1050 if (sighandler_list.first_handler == NULL)
1051 sighandler_list.last_handler = NULL;
1055 prev_ptr = sighandler_list.first_handler;
1056 while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr))
1057 prev_ptr = prev_ptr->next_handler;
1058 prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
1059 if (sighandler_list.last_handler == (*async_handler_ptr))
1060 sighandler_list.last_handler = prev_ptr;
1062 xfree ((*async_handler_ptr));
1063 (*async_handler_ptr) = NULL;
1066 /* Create an asynchronous event handler, allocating memory for it.
1067 Return a pointer to the newly created handler. PROC is the
1068 function to call with CLIENT_DATA argument whenever the handler is
1070 async_event_handler *
1071 create_async_event_handler (async_event_handler_func *proc,
1072 gdb_client_data client_data)
1074 async_event_handler *h;
1076 h = xmalloc (sizeof (*h));
1078 h->next_handler = NULL;
1080 h->client_data = client_data;
1081 if (async_event_handler_list.first_handler == NULL)
1082 async_event_handler_list.first_handler = h;
1084 async_event_handler_list.last_handler->next_handler = h;
1085 async_event_handler_list.last_handler = h;
1089 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
1090 will be used by gdb_do_one_event. The caller will be whoever
1091 created the event source, and wants to signal that the event is
1092 ready to be handled. */
1094 mark_async_event_handler (async_event_handler *async_handler_ptr)
1096 async_handler_ptr->ready = 1;
1099 struct async_event_handler_data
1101 async_event_handler_func* proc;
1102 gdb_client_data client_data;
1106 invoke_async_event_handler (event_data data)
1108 struct async_event_handler_data *hdata = data.ptr;
1109 async_event_handler_func* proc = hdata->proc;
1110 gdb_client_data client_data = hdata->client_data;
1113 (*proc) (client_data);
1116 /* Check if any asynchronous event handlers are ready, and queue
1117 events in the ready queue for any that are. */
1119 check_async_event_handlers (void)
1121 async_event_handler *async_handler_ptr;
1122 struct async_event_handler_data *hdata;
1123 struct gdb_event *event_ptr;
1126 for (async_handler_ptr = async_event_handler_list.first_handler;
1127 async_handler_ptr != NULL;
1128 async_handler_ptr = async_handler_ptr->next_handler)
1130 if (async_handler_ptr->ready)
1132 async_handler_ptr->ready = 0;
1134 hdata = xmalloc (sizeof (*hdata));
1136 hdata->proc = async_handler_ptr->proc;
1137 hdata->client_data = async_handler_ptr->client_data;
1141 event_ptr = create_event (invoke_async_event_handler, data);
1142 async_queue_event (event_ptr, TAIL);
1147 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
1148 Free the space allocated for it. */
1150 delete_async_event_handler (async_event_handler **async_handler_ptr)
1152 async_event_handler *prev_ptr;
1154 if (async_event_handler_list.first_handler == *async_handler_ptr)
1156 async_event_handler_list.first_handler = (*async_handler_ptr)->next_handler;
1157 if (async_event_handler_list.first_handler == NULL)
1158 async_event_handler_list.last_handler = NULL;
1162 prev_ptr = async_event_handler_list.first_handler;
1163 while (prev_ptr && prev_ptr->next_handler != *async_handler_ptr)
1164 prev_ptr = prev_ptr->next_handler;
1165 prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
1166 if (async_event_handler_list.last_handler == (*async_handler_ptr))
1167 async_event_handler_list.last_handler = prev_ptr;
1169 xfree (*async_handler_ptr);
1170 *async_handler_ptr = NULL;
1173 /* Create a timer that will expire in MILLISECONDS from now. When the
1174 timer is ready, PROC will be executed. At creation, the timer is
1175 aded to the timers queue. This queue is kept sorted in order of
1176 increasing timers. Return a handle to the timer struct. */
1178 create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data)
1180 struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
1181 struct timeval time_now, delta;
1183 /* compute seconds */
1184 delta.tv_sec = milliseconds / 1000;
1185 /* compute microseconds */
1186 delta.tv_usec = (milliseconds % 1000) * 1000;
1188 gettimeofday (&time_now, NULL);
1190 timer_ptr = (struct gdb_timer *) xmalloc (sizeof (*timer_ptr));
1191 timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec;
1192 timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec;
1194 if (timer_ptr->when.tv_usec >= 1000000)
1196 timer_ptr->when.tv_sec += 1;
1197 timer_ptr->when.tv_usec -= 1000000;
1199 timer_ptr->proc = proc;
1200 timer_ptr->client_data = client_data;
1201 timer_list.num_timers++;
1202 timer_ptr->timer_id = timer_list.num_timers;
1204 /* Now add the timer to the timer queue, making sure it is sorted in
1205 increasing order of expiration. */
1207 for (timer_index = timer_list.first_timer;
1208 timer_index != NULL;
1209 timer_index = timer_index->next)
1211 /* If the seconds field is greater or if it is the same, but the
1212 microsecond field is greater. */
1213 if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec)
1214 || ((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
1215 && (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
1219 if (timer_index == timer_list.first_timer)
1221 timer_ptr->next = timer_list.first_timer;
1222 timer_list.first_timer = timer_ptr;
1227 for (prev_timer = timer_list.first_timer;
1228 prev_timer->next != timer_index;
1229 prev_timer = prev_timer->next)
1232 prev_timer->next = timer_ptr;
1233 timer_ptr->next = timer_index;
1236 gdb_notifier.timeout_valid = 0;
1237 return timer_ptr->timer_id;
1240 /* There is a chance that the creator of the timer wants to get rid of
1241 it before it expires. */
1243 delete_timer (int id)
1245 struct gdb_timer *timer_ptr, *prev_timer = NULL;
1247 /* Find the entry for the given timer. */
1249 for (timer_ptr = timer_list.first_timer; timer_ptr != NULL;
1250 timer_ptr = timer_ptr->next)
1252 if (timer_ptr->timer_id == id)
1256 if (timer_ptr == NULL)
1258 /* Get rid of the timer in the timer list. */
1259 if (timer_ptr == timer_list.first_timer)
1260 timer_list.first_timer = timer_ptr->next;
1263 for (prev_timer = timer_list.first_timer;
1264 prev_timer->next != timer_ptr;
1265 prev_timer = prev_timer->next)
1267 prev_timer->next = timer_ptr->next;
1271 gdb_notifier.timeout_valid = 0;
1274 /* When a timer event is put on the event queue, it will be handled by
1275 this function. Just call the associated procedure and delete the
1276 timer event from the event queue. Repeat this for each timer that
1279 handle_timer_event (event_data dummy)
1281 struct timeval time_now;
1282 struct gdb_timer *timer_ptr, *saved_timer;
1284 gettimeofday (&time_now, NULL);
1285 timer_ptr = timer_list.first_timer;
1287 while (timer_ptr != NULL)
1289 if ((timer_ptr->when.tv_sec > time_now.tv_sec)
1290 || ((timer_ptr->when.tv_sec == time_now.tv_sec)
1291 && (timer_ptr->when.tv_usec > time_now.tv_usec)))
1294 /* Get rid of the timer from the beginning of the list. */
1295 timer_list.first_timer = timer_ptr->next;
1296 saved_timer = timer_ptr;
1297 timer_ptr = timer_ptr->next;
1298 /* Call the procedure associated with that timer. */
1299 (*saved_timer->proc) (saved_timer->client_data);
1300 xfree (saved_timer);
1303 gdb_notifier.timeout_valid = 0;
1306 /* Check whether any timers in the timers queue are ready. If at least
1307 one timer is ready, stick an event onto the event queue. Even in
1308 case more than one timer is ready, one event is enough, because the
1309 handle_timer_event() will go through the timers list and call the
1310 procedures associated with all that have expired. Update the
1311 timeout for the select() or poll() as well. */
1315 struct timeval time_now, delta;
1316 gdb_event *event_ptr;
1318 if (timer_list.first_timer != NULL)
1320 gettimeofday (&time_now, NULL);
1321 delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec;
1322 delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec;
1324 if (delta.tv_usec < 0)
1327 delta.tv_usec += 1000000;
1330 /* Oops it expired already. Tell select / poll to return
1331 immediately. (Cannot simply test if delta.tv_sec is negative
1332 because time_t might be unsigned.) */
1333 if (timer_list.first_timer->when.tv_sec < time_now.tv_sec
1334 || (timer_list.first_timer->when.tv_sec == time_now.tv_sec
1335 && timer_list.first_timer->when.tv_usec < time_now.tv_usec))
1341 if (delta.tv_sec == 0 && delta.tv_usec == 0)
1343 event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
1344 event_ptr->proc = handle_timer_event;
1345 event_ptr->data.integer = timer_list.first_timer->timer_id;
1346 async_queue_event (event_ptr, TAIL);
1349 /* Now we need to update the timeout for select/ poll, because we
1350 don't want to sit there while this timer is expiring. */
1354 gdb_notifier.poll_timeout = delta.tv_sec * 1000;
1356 internal_error (__FILE__, __LINE__,
1357 _("use_poll without HAVE_POLL"));
1358 #endif /* HAVE_POLL */
1362 gdb_notifier.select_timeout.tv_sec = delta.tv_sec;
1363 gdb_notifier.select_timeout.tv_usec = delta.tv_usec;
1365 gdb_notifier.timeout_valid = 1;
1368 gdb_notifier.timeout_valid = 0;