1 /* Event loop machinery for GDB, the GNU debugger.
2 Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2008
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 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 /* If any exception escaped to here, we better enable
415 stdin. Otherwise, any command that calls async_disable_stdin,
416 and then throws, will leave stdin inoperable. */
417 async_enable_stdin ((void *) 0);
418 /* FIXME: this should really be a call to a hook that is
419 interface specific, because interfaces can display the
420 prompt in their own way. */
421 display_gdb_prompt (0);
422 /* This call looks bizarre, but it is required. If the user
423 entered a command that caused an error,
424 after_char_processing_hook won't be called from
425 rl_callback_read_char_wrapper. Using a cleanup there
426 won't work, since we want this function to be called
427 after a new prompt is printed. */
428 if (after_char_processing_hook)
429 (*after_char_processing_hook) ();
430 /* Maybe better to set a flag to be checked somewhere as to
431 whether display the prompt or not. */
435 /* We are done with the event loop. There are no more event sources
436 to listen to. So we exit GDB. */
441 /* Wrapper function for create_file_handler, so that the caller
442 doesn't have to know implementation details about the use of poll
445 add_file_handler (int fd, handler_func * proc, gdb_client_data client_data)
454 /* Check to see if poll () is usable. If not, we'll switch to
455 use select. This can happen on systems like
456 m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
457 On m68k-motorola-sysv, tty's are not stream-based and not
461 if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL))
464 internal_error (__FILE__, __LINE__,
465 _("use_poll without HAVE_POLL"));
466 #endif /* HAVE_POLL */
471 create_file_handler (fd, POLLIN, proc, client_data);
473 internal_error (__FILE__, __LINE__,
474 _("use_poll without HAVE_POLL"));
478 create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data);
481 /* Add a file handler/descriptor to the list of descriptors we are
483 FD is the file descriptor for the file/stream to be listened to.
484 For the poll case, MASK is a combination (OR) of
485 POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM,
486 POLLWRBAND: these are the events we are interested in. If any of them
487 occurs, proc should be called.
488 For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION.
489 PROC is the procedure that will be called when an event occurs for
490 FD. CLIENT_DATA is the argument to pass to PROC. */
492 create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data)
494 file_handler *file_ptr;
496 /* Do we already have a file handler for this file? (We may be
497 changing its associated procedure). */
498 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
499 file_ptr = file_ptr->next_file)
501 if (file_ptr->fd == fd)
505 /* It is a new file descriptor. Add it to the list. Otherwise, just
506 change the data associated with it. */
507 if (file_ptr == NULL)
509 file_ptr = (file_handler *) xmalloc (sizeof (file_handler));
511 file_ptr->ready_mask = 0;
512 file_ptr->next_file = gdb_notifier.first_file_handler;
513 gdb_notifier.first_file_handler = file_ptr;
518 gdb_notifier.num_fds++;
519 if (gdb_notifier.poll_fds)
520 gdb_notifier.poll_fds =
521 (struct pollfd *) xrealloc (gdb_notifier.poll_fds,
522 (gdb_notifier.num_fds
523 * sizeof (struct pollfd)));
525 gdb_notifier.poll_fds =
526 (struct pollfd *) xmalloc (sizeof (struct pollfd));
527 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd;
528 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask;
529 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
531 internal_error (__FILE__, __LINE__,
532 _("use_poll without HAVE_POLL"));
533 #endif /* HAVE_POLL */
537 if (mask & GDB_READABLE)
538 FD_SET (fd, &gdb_notifier.check_masks[0]);
540 FD_CLR (fd, &gdb_notifier.check_masks[0]);
542 if (mask & GDB_WRITABLE)
543 FD_SET (fd, &gdb_notifier.check_masks[1]);
545 FD_CLR (fd, &gdb_notifier.check_masks[1]);
547 if (mask & GDB_EXCEPTION)
548 FD_SET (fd, &gdb_notifier.check_masks[2]);
550 FD_CLR (fd, &gdb_notifier.check_masks[2]);
552 if (gdb_notifier.num_fds <= fd)
553 gdb_notifier.num_fds = fd + 1;
557 file_ptr->proc = proc;
558 file_ptr->client_data = client_data;
559 file_ptr->mask = mask;
562 /* Remove the file descriptor FD from the list of monitored fd's:
563 i.e. we don't care anymore about events on the FD. */
565 delete_file_handler (int fd)
567 file_handler *file_ptr, *prev_ptr = NULL;
571 struct pollfd *new_poll_fds;
574 /* Find the entry for the given file. */
576 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
577 file_ptr = file_ptr->next_file)
579 if (file_ptr->fd == fd)
583 if (file_ptr == NULL)
589 /* Create a new poll_fds array by copying every fd's information but the
590 one we want to get rid of. */
593 (struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd));
595 for (i = 0, j = 0; i < gdb_notifier.num_fds; i++)
597 if ((gdb_notifier.poll_fds + i)->fd != fd)
599 (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd;
600 (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events;
601 (new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents;
605 xfree (gdb_notifier.poll_fds);
606 gdb_notifier.poll_fds = new_poll_fds;
607 gdb_notifier.num_fds--;
609 internal_error (__FILE__, __LINE__,
610 _("use_poll without HAVE_POLL"));
611 #endif /* HAVE_POLL */
615 if (file_ptr->mask & GDB_READABLE)
616 FD_CLR (fd, &gdb_notifier.check_masks[0]);
617 if (file_ptr->mask & GDB_WRITABLE)
618 FD_CLR (fd, &gdb_notifier.check_masks[1]);
619 if (file_ptr->mask & GDB_EXCEPTION)
620 FD_CLR (fd, &gdb_notifier.check_masks[2]);
622 /* Find current max fd. */
624 if ((fd + 1) == gdb_notifier.num_fds)
626 gdb_notifier.num_fds--;
627 for (i = gdb_notifier.num_fds; i; i--)
629 if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0])
630 || FD_ISSET (i - 1, &gdb_notifier.check_masks[1])
631 || FD_ISSET (i - 1, &gdb_notifier.check_masks[2]))
634 gdb_notifier.num_fds = i;
638 /* Deactivate the file descriptor, by clearing its mask,
639 so that it will not fire again. */
643 /* Get rid of the file handler in the file handler list. */
644 if (file_ptr == gdb_notifier.first_file_handler)
645 gdb_notifier.first_file_handler = file_ptr->next_file;
648 for (prev_ptr = gdb_notifier.first_file_handler;
649 prev_ptr->next_file != file_ptr;
650 prev_ptr = prev_ptr->next_file)
652 prev_ptr->next_file = file_ptr->next_file;
657 /* Handle the given event by calling the procedure associated to the
658 corresponding file handler. Called by process_event indirectly,
659 through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
660 event in the front of the event queue. */
662 handle_file_event (int event_file_desc)
664 file_handler *file_ptr;
668 int error_mask_returned;
671 /* Search the file handler list to find one that matches the fd in
673 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
674 file_ptr = file_ptr->next_file)
676 if (file_ptr->fd == event_file_desc)
678 /* With poll, the ready_mask could have any of three events
679 set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
680 be used in the requested event mask (events), but they
681 can be returned in the return mask (revents). We need to
682 check for those event too, and add them to the mask which
683 will be passed to the handler. */
685 /* See if the desired events (mask) match the received
686 events (ready_mask). */
691 error_mask = POLLHUP | POLLERR | POLLNVAL;
692 mask = (file_ptr->ready_mask & file_ptr->mask) |
693 (file_ptr->ready_mask & error_mask);
694 error_mask_returned = mask & error_mask;
696 if (error_mask_returned != 0)
698 /* Work in progress. We may need to tell somebody what
699 kind of error we had. */
700 if (error_mask_returned & POLLHUP)
701 printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr->fd);
702 if (error_mask_returned & POLLERR)
703 printf_unfiltered (_("Error detected on fd %d\n"), file_ptr->fd);
704 if (error_mask_returned & POLLNVAL)
705 printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr->fd);
711 internal_error (__FILE__, __LINE__,
712 _("use_poll without HAVE_POLL"));
713 #endif /* HAVE_POLL */
717 if (file_ptr->ready_mask & GDB_EXCEPTION)
719 printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr->fd);
724 mask = file_ptr->ready_mask & file_ptr->mask;
727 /* Clear the received events for next time around. */
728 file_ptr->ready_mask = 0;
730 /* If there was a match, then call the handler. */
732 (*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
738 /* Called by gdb_do_one_event to wait for new events on the
739 monitored file descriptors. Queue file events as they are
740 detected by the poll.
741 If there are no events, this function will block in the
743 Return -1 if there are no files descriptors to monitor,
744 otherwise return 0. */
746 gdb_wait_for_event (void)
748 file_handler *file_ptr;
749 gdb_event *file_event_ptr;
753 /* Make sure all output is done before getting another event. */
754 gdb_flush (gdb_stdout);
755 gdb_flush (gdb_stderr);
757 if (gdb_notifier.num_fds == 0)
764 poll (gdb_notifier.poll_fds,
765 (unsigned long) gdb_notifier.num_fds,
766 gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1);
768 /* Don't print anything if we get out of poll because of a
770 if (num_found == -1 && errno != EINTR)
771 perror_with_name (("poll"));
773 internal_error (__FILE__, __LINE__,
774 _("use_poll without HAVE_POLL"));
775 #endif /* HAVE_POLL */
779 gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0];
780 gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1];
781 gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2];
782 num_found = gdb_select (gdb_notifier.num_fds,
783 &gdb_notifier.ready_masks[0],
784 &gdb_notifier.ready_masks[1],
785 &gdb_notifier.ready_masks[2],
786 gdb_notifier.timeout_valid
787 ? &gdb_notifier.select_timeout : NULL);
789 /* Clear the masks after an error from select. */
792 FD_ZERO (&gdb_notifier.ready_masks[0]);
793 FD_ZERO (&gdb_notifier.ready_masks[1]);
794 FD_ZERO (&gdb_notifier.ready_masks[2]);
795 /* Dont print anything is we got a signal, let gdb handle it. */
797 perror_with_name (("select"));
801 /* Enqueue all detected file events. */
806 for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
808 if ((gdb_notifier.poll_fds + i)->revents)
813 for (file_ptr = gdb_notifier.first_file_handler;
815 file_ptr = file_ptr->next_file)
817 if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd)
823 /* Enqueue an event only if this is still a new event for
825 if (file_ptr->ready_mask == 0)
827 file_event_ptr = create_file_event (file_ptr->fd);
828 async_queue_event (file_event_ptr, TAIL);
830 file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
834 internal_error (__FILE__, __LINE__,
835 _("use_poll without HAVE_POLL"));
836 #endif /* HAVE_POLL */
840 for (file_ptr = gdb_notifier.first_file_handler;
841 (file_ptr != NULL) && (num_found > 0);
842 file_ptr = file_ptr->next_file)
846 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0]))
847 mask |= GDB_READABLE;
848 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1]))
849 mask |= GDB_WRITABLE;
850 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2]))
851 mask |= GDB_EXCEPTION;
858 /* Enqueue an event only if this is still a new event for
861 if (file_ptr->ready_mask == 0)
863 file_event_ptr = create_file_event (file_ptr->fd);
864 async_queue_event (file_event_ptr, TAIL);
866 file_ptr->ready_mask = mask;
873 /* Create an asynchronous handler, allocating memory for it.
874 Return a pointer to the newly created handler.
875 This pointer will be used to invoke the handler by
876 invoke_async_signal_handler.
877 PROC is the function to call with CLIENT_DATA argument
878 whenever the handler is invoked. */
879 async_signal_handler *
880 create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data)
882 async_signal_handler *async_handler_ptr;
885 (async_signal_handler *) xmalloc (sizeof (async_signal_handler));
886 async_handler_ptr->ready = 0;
887 async_handler_ptr->next_handler = NULL;
888 async_handler_ptr->proc = proc;
889 async_handler_ptr->client_data = client_data;
890 if (sighandler_list.first_handler == NULL)
891 sighandler_list.first_handler = async_handler_ptr;
893 sighandler_list.last_handler->next_handler = async_handler_ptr;
894 sighandler_list.last_handler = async_handler_ptr;
895 return async_handler_ptr;
898 /* Call the handler from HANDLER immediately. This function runs
899 signal handlers when returning to the event loop would be too
902 call_async_signal_handler (struct async_signal_handler *handler)
904 (*handler->proc) (handler->client_data);
907 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
908 be used when the handlers are invoked, after we have waited for
909 some event. The caller of this function is the interrupt handler
910 associated with a signal. */
912 mark_async_signal_handler (async_signal_handler * async_handler_ptr)
914 ((async_signal_handler *) async_handler_ptr)->ready = 1;
915 async_handler_ready = 1;
918 /* Call all the handlers that are ready. */
920 invoke_async_signal_handler (void)
922 async_signal_handler *async_handler_ptr;
924 if (async_handler_ready == 0)
926 async_handler_ready = 0;
928 /* Invoke ready handlers. */
932 for (async_handler_ptr = sighandler_list.first_handler;
933 async_handler_ptr != NULL;
934 async_handler_ptr = async_handler_ptr->next_handler)
936 if (async_handler_ptr->ready)
939 if (async_handler_ptr == NULL)
941 async_handler_ptr->ready = 0;
942 (*async_handler_ptr->proc) (async_handler_ptr->client_data);
948 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
949 Free the space allocated for it. */
951 delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
953 async_signal_handler *prev_ptr;
955 if (sighandler_list.first_handler == (*async_handler_ptr))
957 sighandler_list.first_handler = (*async_handler_ptr)->next_handler;
958 if (sighandler_list.first_handler == NULL)
959 sighandler_list.last_handler = NULL;
963 prev_ptr = sighandler_list.first_handler;
964 while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr))
965 prev_ptr = prev_ptr->next_handler;
966 prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
967 if (sighandler_list.last_handler == (*async_handler_ptr))
968 sighandler_list.last_handler = prev_ptr;
970 xfree ((*async_handler_ptr));
971 (*async_handler_ptr) = NULL;
974 /* Is it necessary to call invoke_async_signal_handler? */
976 check_async_ready (void)
978 return async_handler_ready;
981 /* Create a timer that will expire in MILLISECONDS from now. When the
982 timer is ready, PROC will be executed. At creation, the timer is
983 aded to the timers queue. This queue is kept sorted in order of
984 increasing timers. Return a handle to the timer struct. */
986 create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data)
988 struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
989 struct timeval time_now, delta;
991 /* compute seconds */
992 delta.tv_sec = milliseconds / 1000;
993 /* compute microseconds */
994 delta.tv_usec = (milliseconds % 1000) * 1000;
996 gettimeofday (&time_now, NULL);
998 timer_ptr = (struct gdb_timer *) xmalloc (sizeof (gdb_timer));
999 timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec;
1000 timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec;
1002 if (timer_ptr->when.tv_usec >= 1000000)
1004 timer_ptr->when.tv_sec += 1;
1005 timer_ptr->when.tv_usec -= 1000000;
1007 timer_ptr->proc = proc;
1008 timer_ptr->client_data = client_data;
1009 timer_list.num_timers++;
1010 timer_ptr->timer_id = timer_list.num_timers;
1012 /* Now add the timer to the timer queue, making sure it is sorted in
1013 increasing order of expiration. */
1015 for (timer_index = timer_list.first_timer;
1016 timer_index != NULL;
1017 timer_index = timer_index->next)
1019 /* If the seconds field is greater or if it is the same, but the
1020 microsecond field is greater. */
1021 if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) ||
1022 ((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
1023 && (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
1027 if (timer_index == timer_list.first_timer)
1029 timer_ptr->next = timer_list.first_timer;
1030 timer_list.first_timer = timer_ptr;
1035 for (prev_timer = timer_list.first_timer;
1036 prev_timer->next != timer_index;
1037 prev_timer = prev_timer->next)
1040 prev_timer->next = timer_ptr;
1041 timer_ptr->next = timer_index;
1044 gdb_notifier.timeout_valid = 0;
1045 return timer_ptr->timer_id;
1048 /* There is a chance that the creator of the timer wants to get rid of
1049 it before it expires. */
1051 delete_timer (int id)
1053 struct gdb_timer *timer_ptr, *prev_timer = NULL;
1055 /* Find the entry for the given timer. */
1057 for (timer_ptr = timer_list.first_timer; timer_ptr != NULL;
1058 timer_ptr = timer_ptr->next)
1060 if (timer_ptr->timer_id == id)
1064 if (timer_ptr == NULL)
1066 /* Get rid of the timer in the timer list. */
1067 if (timer_ptr == timer_list.first_timer)
1068 timer_list.first_timer = timer_ptr->next;
1071 for (prev_timer = timer_list.first_timer;
1072 prev_timer->next != timer_ptr;
1073 prev_timer = prev_timer->next)
1075 prev_timer->next = timer_ptr->next;
1079 gdb_notifier.timeout_valid = 0;
1082 /* When a timer event is put on the event queue, it will be handled by
1083 this function. Just call the assiciated procedure and delete the
1084 timer event from the event queue. Repeat this for each timer that
1087 handle_timer_event (int dummy)
1089 struct timeval time_now;
1090 struct gdb_timer *timer_ptr, *saved_timer;
1092 gettimeofday (&time_now, NULL);
1093 timer_ptr = timer_list.first_timer;
1095 while (timer_ptr != NULL)
1097 if ((timer_ptr->when.tv_sec > time_now.tv_sec) ||
1098 ((timer_ptr->when.tv_sec == time_now.tv_sec) &&
1099 (timer_ptr->when.tv_usec > time_now.tv_usec)))
1102 /* Get rid of the timer from the beginning of the list. */
1103 timer_list.first_timer = timer_ptr->next;
1104 saved_timer = timer_ptr;
1105 timer_ptr = timer_ptr->next;
1106 /* Call the procedure associated with that timer. */
1107 (*saved_timer->proc) (saved_timer->client_data);
1108 xfree (saved_timer);
1111 gdb_notifier.timeout_valid = 0;
1114 /* Check whether any timers in the timers queue are ready. If at least
1115 one timer is ready, stick an event onto the event queue. Even in
1116 case more than one timer is ready, one event is enough, because the
1117 handle_timer_event() will go through the timers list and call the
1118 procedures associated with all that have expired. Update the
1119 timeout for the select() or poll() as well. */
1123 struct timeval time_now, delta;
1124 gdb_event *event_ptr;
1126 if (timer_list.first_timer != NULL)
1128 gettimeofday (&time_now, NULL);
1129 delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec;
1130 delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec;
1132 if (delta.tv_usec < 0)
1135 delta.tv_usec += 1000000;
1138 /* Oops it expired already. Tell select / poll to return
1139 immediately. (Cannot simply test if delta.tv_sec is negative
1140 because time_t might be unsigned.) */
1141 if (timer_list.first_timer->when.tv_sec < time_now.tv_sec
1142 || (timer_list.first_timer->when.tv_sec == time_now.tv_sec
1143 && timer_list.first_timer->when.tv_usec < time_now.tv_usec))
1149 if (delta.tv_sec == 0 && delta.tv_usec == 0)
1151 event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
1152 event_ptr->proc = handle_timer_event;
1153 event_ptr->fd = timer_list.first_timer->timer_id;
1154 async_queue_event (event_ptr, TAIL);
1157 /* Now we need to update the timeout for select/ poll, because we
1158 don't want to sit there while this timer is expiring. */
1162 gdb_notifier.poll_timeout = delta.tv_sec * 1000;
1164 internal_error (__FILE__, __LINE__,
1165 _("use_poll without HAVE_POLL"));
1166 #endif /* HAVE_POLL */
1170 gdb_notifier.select_timeout.tv_sec = delta.tv_sec;
1171 gdb_notifier.select_timeout.tv_usec = delta.tv_usec;
1173 gdb_notifier.timeout_valid = 1;
1176 gdb_notifier.timeout_valid = 0;