1 /* Event loop machinery for GDB, the GNU debugger.
2 Copyright 1999 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., 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
24 #include "event-loop.h"
25 #include "event-top.h"
29 #include <sys/types.h>
36 /* Type of the mask arguments to select. */
40 /* All this stuff below is not required if select is used as God(tm)
41 intended, with the FD_* macros. Are there any implementations of
42 select which don't have FD_SET and other standard FD_* macros? I
43 don't think there are, but if I'm wrong, we need to catch them. */
44 #error FD_SET must be defined if select function is to be used!
50 #define SELECT_MASK void
52 #define SELECT_MASK int
55 /* Define "NBBY" (number of bits per byte) if it's not already defined. */
61 /* Define the number of fd_masks in an fd_set */
65 #define FD_SETSIZE OPEN_MAX
67 #define FD_SETSIZE 256
71 #define howmany(x, y) (((x)+((y)-1))/(y))
74 #define NFDBITS NBBY*sizeof(fd_mask)
76 #define MASK_SIZE howmany(FD_SETSIZE, NFDBITS)
78 #endif /* NO_FD_SET */
79 #endif /* !HAVE_POLL */
82 typedef struct gdb_event gdb_event;
83 typedef void (event_handler_func) (int);
85 /* Event for the GDB event system. Events are queued by calling
86 async_queue_event and serviced later on by gdb_do_one_event. An
87 event can be, for instance, a file descriptor becoming ready to be
88 read. Servicing an event simply means that the procedure PROC will
89 be called. We have 2 queues, one for file handlers that we listen
90 to in the event loop, and one for the file handlers+events that are
91 ready. The procedure PROC associated with each event is always the
92 same (handle_file_event). Its duty is to invoke the handler
93 associated with the file descriptor whose state change generated
94 the event, plus doing other cleanups adn such. */
98 event_handler_func *proc; /* Procedure to call to service this event. */
99 int fd; /* File descriptor that is ready. */
100 struct gdb_event *next_event; /* Next in list of events or NULL. */
103 /* Information about each file descriptor we register with the event
106 typedef struct file_handler
108 int fd; /* File descriptor. */
109 int mask; /* Events we want to monitor: POLLIN, etc. */
110 int ready_mask; /* Events that have been seen since
112 handler_func *proc; /* Procedure to call when fd is ready. */
113 gdb_client_data client_data; /* Argument to pass to proc. */
114 int error; /* Was an error detected on this fd? */
115 struct file_handler *next_file; /* Next registered file descriptor. */
119 /* PROC is a function to be invoked when the READY flag is set. This
120 happens when there has been a signal and the corresponding signal
121 handler has 'triggered' this async_signal_handler for
122 execution. The actual work to be done in response to a signal will
123 be carried out by PROC at a later time, within process_event. This
124 provides a deferred execution of signal handlers.
125 Async_init_signals takes care of setting up such an
126 asyn_signal_handler for each interesting signal. */
127 typedef struct async_signal_handler
129 int ready; /* If ready, call this handler from the main event loop,
130 using invoke_async_handler. */
131 struct async_signal_handler *next_handler; /* Ptr to next handler */
132 sig_handler_func *proc; /* Function to call to do the work */
133 gdb_client_data client_data; /* Argument to async_handler_func */
135 async_signal_handler;
139 - the first event in the queue is the head of the queue.
140 It will be the next to be serviced.
141 - the last event in the queue
143 Events can be inserted at the front of the queue or at the end of
144 the queue. Events will be extracted from the queue for processing
145 starting from the head. Therefore, events inserted at the head of
146 the queue will be processed in a last in first out fashion, while
147 those inserted at the tail of the queue will be processed in a first
148 in first out manner. All the fields are NULL if the queue is
153 gdb_event *first_event; /* First pending event */
154 gdb_event *last_event; /* Last pending event */
158 /* Gdb_notifier is just a list of file descriptors gdb is interested in.
159 These are the input file descriptor, and the target file
160 descriptor. We have two flavors of the notifier, one for platforms
161 that have the POLL function, the other for those that don't, and
162 only support SELECT. Each of the elements in the gdb_notifier list is
163 basically a description of what kind of events gdb is interested
166 /* As of 1999-04-30 only the input file descriptor is registered with the
170 /* Poll based implementation of the notifier. */
174 /* Ptr to head of file handler list. */
175 file_handler *first_file_handler;
177 /* Ptr to array of pollfd structures. */
178 struct pollfd *poll_fds;
180 /* Number of file descriptors to monitor. */
183 /* Timeout in milliseconds for calls to poll(). */
186 /* Flag to tell whether the timeout value shuld be used. */
191 #else /* ! HAVE_POLL */
193 /* Select based implementation of the notifier. */
197 /* Ptr to head of file handler list. */
198 file_handler *first_file_handler;
200 /* Masks to be used in the next call to select.
201 Bits are set in response to calls to create_file_handler. */
202 fd_set check_masks[3];
204 /* What file descriptors were found ready by select. */
205 fd_set ready_masks[3];
207 /* Number of valid bits (highest fd value + 1). */
210 /* Time structure for calls to select(). */
211 struct timeval timeout;
213 /* Flag to tell whether the timeout struct should be used. */
218 #endif /* HAVE_POLL */
220 /* Structure associated with a timer. PROC will be executed at the
221 first occasion after WHEN. */
226 struct gdb_timer *next;
227 timer_handler_func *proc; /* Function to call to do the work */
228 gdb_client_data client_data; /* Argument to async_handler_func */
232 /* List of currently active timers. It is sorted in order of
233 increasing timers. */
236 /* Pointer to first in timer list. */
237 struct gdb_timer *first_timer;
239 /* Id of the last timer created. */
244 /* All the async_signal_handlers gdb is interested in are kept onto
248 /* Pointer to first in handler list. */
249 async_signal_handler *first_handler;
251 /* Pointer to last in handler list. */
252 async_signal_handler *last_handler;
256 /* Is any of the handlers ready? Check this variable using
257 check_async_ready. This is used by process_event, to determine
258 whether or not to invoke the invoke_async_signal_handler
260 static int async_handler_ready = 0;
262 static void create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data);
263 static void invoke_async_signal_handler (void);
264 static void handle_file_event (int event_file_desc);
265 static int gdb_wait_for_event (void);
266 static int gdb_do_one_event (void *data);
267 static int check_async_ready (void);
268 static void async_queue_event (gdb_event * event_ptr, queue_position position);
269 static gdb_event *create_file_event (int fd);
270 static int process_event (void);
271 static void handle_timer_event (int dummy);
272 static void poll_timers (void);
275 /* Insert an event object into the gdb event queue at
276 the specified position.
277 POSITION can be head or tail, with values TAIL, HEAD.
278 EVENT_PTR points to the event to be inserted into the queue.
279 The caller must allocate memory for the event. It is freed
280 after the event has ben handled.
281 Events in the queue will be processed head to tail, therefore,
282 events inserted at the head of the queue will be processed
283 as last in first out. Event appended at the tail of the queue
284 will be processed first in first out. */
286 async_queue_event (gdb_event * event_ptr, queue_position position)
288 if (position == TAIL)
290 /* The event will become the new last_event. */
292 event_ptr->next_event = NULL;
293 if (event_queue.first_event == NULL)
294 event_queue.first_event = event_ptr;
296 event_queue.last_event->next_event = event_ptr;
297 event_queue.last_event = event_ptr;
299 else if (position == HEAD)
301 /* The event becomes the new first_event. */
303 event_ptr->next_event = event_queue.first_event;
304 if (event_queue.first_event == NULL)
305 event_queue.last_event = event_ptr;
306 event_queue.first_event = event_ptr;
310 /* Create a file event, to be enqueued in the event queue for
311 processing. The procedure associated to this event is always
312 handle_file_event, which will in turn invoke the one that was
313 associated to FD when it was registered with the event loop. */
315 create_file_event (int fd)
317 gdb_event *file_event_ptr;
319 file_event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
320 file_event_ptr->proc = handle_file_event;
321 file_event_ptr->fd = fd;
322 return (file_event_ptr);
325 /* Process one event.
326 The event can be the next one to be serviced in the event queue,
327 or an asynchronous event handler can be invoked in response to
328 the reception of a signal.
329 If an event was processed (either way), 1 is returned otherwise
331 Scan the queue from head to tail, processing therefore the high
332 priority events first, by invoking the associated event handler
337 gdb_event *event_ptr, *prev_ptr;
338 event_handler_func *proc;
341 /* First let's see if there are any asynchronous event handlers that
342 are ready. These would be the result of invoking any of the
345 if (check_async_ready ())
347 invoke_async_signal_handler ();
351 /* Look in the event queue to find an event that is ready
354 for (event_ptr = event_queue.first_event; event_ptr != NULL;
355 event_ptr = event_ptr->next_event)
357 /* Call the handler for the event. */
359 proc = event_ptr->proc;
362 /* Let's get rid of the event from the event queue. We need to
363 do this now because while processing the event, the proc
364 function could end up calling 'error' and therefore jump out
365 to the caller of this function, gdb_do_one_event. In that
366 case, we would have on the event queue an event wich has been
367 processed, but not deleted. */
369 if (event_queue.first_event == event_ptr)
371 event_queue.first_event = event_ptr->next_event;
372 if (event_ptr->next_event == NULL)
373 event_queue.last_event = NULL;
377 prev_ptr = event_queue.first_event;
378 while (prev_ptr->next_event != event_ptr)
379 prev_ptr = prev_ptr->next_event;
381 prev_ptr->next_event = event_ptr->next_event;
382 if (event_ptr->next_event == NULL)
383 event_queue.last_event = prev_ptr;
385 free ((char *) event_ptr);
387 /* Now call the procedure associted with the event. */
392 /* this is the case if there are no event on the event queue. */
396 /* Process one high level event. If nothing is ready at this time,
397 wait for something to happen (via gdb_wait_for_event), then process
398 it. Returns >0 if something was done otherwise returns <0 (this
399 can happen if there are no event sources to wait for). If an error
400 occures catch_errors() which calls this function returns zero. */
403 gdb_do_one_event (void *data)
405 /* Any events already waiting in the queue? */
406 if (process_event ())
411 /* Are any timers that are ready? If so, put an event on the queue. */
414 /* Wait for a new event. If gdb_wait_for_event returns -1,
415 we should get out because this means that there are no
416 event sources left. This will make the event loop stop,
417 and the application exit. */
419 if (gdb_wait_for_event () < 0)
424 /* Handle any new events occurred while waiting. */
425 if (process_event ())
430 /* If gdb_wait_for_event has returned 1, it means that one
431 event has been handled. We break out of the loop. */
435 /* Start up the event loop. This is the entry point to the event loop
436 from the command loop. */
439 start_event_loop (void)
441 /* Loop until there is nothing to do. This is the entry point to the
442 event loop engine. gdb_do_one_event, called via catch_errors()
443 will process one event for each invocation. It blocks waits for
444 an event and then processes it. >0 when an event is processed, 0
445 when catch_errors() caught an error and <0 when there are no
446 longer any event sources registered. */
449 int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
454 /* FIXME: this should really be a call to a hook that is
455 interface specific, because interfaces can display the
456 prompt in their own way. */
457 display_gdb_prompt (0);
458 /* Maybe better to set a flag to be checked somewhere as to
459 whether display the prompt or not. */
463 /* We are done with the event loop. There are no more event sources
464 to listen to. So we exit GDB. */
469 /* Wrapper function for create_file_handler, so that the caller
470 doesn't have to know implementation details about the use of poll
473 add_file_handler (int fd, handler_func * proc, gdb_client_data client_data)
476 create_file_handler (fd, POLLIN, proc, client_data);
478 create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data);
482 /* Add a file handler/descriptor to the list of descriptors we are
484 FD is the file descriptor for the file/stream to be listened to.
485 For the poll case, MASK is a combination (OR) of
486 POLLIN, POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM,
487 POLLWRBAND: these are the events we are interested in. If any of them
488 occurs, proc should be called.
489 For the select case, MASK is a combination of READABLE, WRITABLE, EXCEPTION.
490 PROC is the procedure that will be called when an event occurs for
491 FD. CLIENT_DATA is the argument to pass to PROC. */
493 create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data)
495 file_handler *file_ptr;
497 /* Do we already have a file handler for this file? (We may be
498 changing its associated procedure). */
499 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
500 file_ptr = file_ptr->next_file)
502 if (file_ptr->fd == fd)
506 /* It is a new file descriptor. Add it to the list. Otherwise, just
507 change the data associated with it. */
508 if (file_ptr == NULL)
510 file_ptr = (file_handler *) xmalloc (sizeof (file_handler));
512 file_ptr->ready_mask = 0;
513 file_ptr->next_file = gdb_notifier.first_file_handler;
514 gdb_notifier.first_file_handler = file_ptr;
516 gdb_notifier.num_fds++;
519 file_ptr->proc = proc;
520 file_ptr->client_data = client_data;
521 file_ptr->mask = mask;
525 if (gdb_notifier.poll_fds)
526 gdb_notifier.poll_fds =
527 (struct pollfd *) realloc (gdb_notifier.poll_fds,
528 (gdb_notifier.num_fds) * sizeof (struct pollfd));
530 gdb_notifier.poll_fds =
531 (struct pollfd *) xmalloc (sizeof (struct pollfd));
532 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd;
533 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask;
534 (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
536 #else /* ! HAVE_POLL */
538 if (mask & GDB_READABLE)
539 FD_SET (fd, &gdb_notifier.check_masks[0]);
541 FD_CLR (fd, &gdb_notifier.check_masks[0]);
543 if (mask & GDB_WRITABLE)
544 FD_SET (fd, &gdb_notifier.check_masks[1]);
546 FD_CLR (fd, &gdb_notifier.check_masks[1]);
548 if (mask & GDB_EXCEPTION)
549 FD_SET (fd, &gdb_notifier.check_masks[2]);
551 FD_CLR (fd, &gdb_notifier.check_masks[2]);
553 if (gdb_notifier.num_fds <= fd)
554 gdb_notifier.num_fds = fd + 1;
556 #endif /* HAVE_POLL */
559 /* Remove the file descriptor FD from the list of monitored fd's:
560 i.e. we don't care anymore about events on the FD. */
562 delete_file_handler (int fd)
564 file_handler *file_ptr, *prev_ptr = NULL;
568 struct pollfd *new_poll_fds;
571 /* Find the entry for the given file. */
573 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
574 file_ptr = file_ptr->next_file)
576 if (file_ptr->fd == fd)
580 if (file_ptr == NULL)
584 /* Create a new poll_fds array by copying every fd's information but the
585 one we want to get rid of. */
588 (struct pollfd *) xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd));
590 for (i = 0, j = 0; i < gdb_notifier.num_fds; i++)
592 if ((gdb_notifier.poll_fds + i)->fd != fd)
594 (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd;
595 (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events;
596 (new_poll_fds + j)->revents = (gdb_notifier.poll_fds + i)->revents;
600 free (gdb_notifier.poll_fds);
601 gdb_notifier.poll_fds = new_poll_fds;
602 gdb_notifier.num_fds--;
604 #else /* ! HAVE_POLL */
606 if (file_ptr->mask & GDB_READABLE)
607 FD_CLR (fd, &gdb_notifier.check_masks[0]);
608 if (file_ptr->mask & GDB_WRITABLE)
609 FD_CLR (fd, &gdb_notifier.check_masks[1]);
610 if (file_ptr->mask & GDB_EXCEPTION)
611 FD_CLR (fd, &gdb_notifier.check_masks[2]);
613 /* Find current max fd. */
615 if ((fd + 1) == gdb_notifier.num_fds)
617 gdb_notifier.num_fds--;
618 for (i = gdb_notifier.num_fds; i; i--)
620 if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0])
621 || FD_ISSET (i - 1, &gdb_notifier.check_masks[1])
622 || FD_ISSET (i - 1, &gdb_notifier.check_masks[2]))
625 gdb_notifier.num_fds = i;
627 #endif /* HAVE_POLL */
629 /* Deactivate the file descriptor, by clearing its mask,
630 so that it will not fire again. */
634 /* Get rid of the file handler in the file handler list. */
635 if (file_ptr == gdb_notifier.first_file_handler)
636 gdb_notifier.first_file_handler = file_ptr->next_file;
639 for (prev_ptr = gdb_notifier.first_file_handler;
640 prev_ptr->next_file != file_ptr;
641 prev_ptr = prev_ptr->next_file)
643 prev_ptr->next_file = file_ptr->next_file;
645 free ((char *) file_ptr);
648 /* Handle the given event by calling the procedure associated to the
649 corresponding file handler. Called by process_event indirectly,
650 through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
651 event in the front of the event queue. */
653 handle_file_event (int event_file_desc)
655 file_handler *file_ptr;
659 int error_mask_returned;
662 /* Search the file handler list to find one that matches the fd in
664 for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
665 file_ptr = file_ptr->next_file)
667 if (file_ptr->fd == event_file_desc)
669 /* With poll, the ready_mask could have any of three events
670 set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
671 be used in the requested event mask (events), but they
672 can be returned in the return mask (revents). We need to
673 check for those event too, and add them to the mask which
674 will be passed to the handler. */
676 /* See if the desired events (mask) match the received
677 events (ready_mask). */
680 error_mask = POLLHUP | POLLERR | POLLNVAL;
681 mask = (file_ptr->ready_mask & file_ptr->mask) |
682 (file_ptr->ready_mask & error_mask);
683 error_mask_returned = mask & error_mask;
685 if (error_mask_returned != 0)
687 /* Work in progress. We may need to tell somebody what
688 kind of error we had. */
689 if (error_mask_returned & POLLHUP)
690 printf_unfiltered ("Hangup detected on fd %d\n", file_ptr->fd);
691 if (error_mask_returned & POLLERR)
692 printf_unfiltered ("Error detected on fd %d\n", file_ptr->fd);
693 if (error_mask_returned & POLLNVAL)
694 printf_unfiltered ("Invalid or non-`poll'able fd %d\n", file_ptr->fd);
699 #else /* ! HAVE_POLL */
700 if (file_ptr->ready_mask & GDB_EXCEPTION)
702 printf_unfiltered ("Exception condition detected on fd %d\n", file_ptr->fd);
707 mask = file_ptr->ready_mask & file_ptr->mask;
708 #endif /* HAVE_POLL */
710 /* Clear the received events for next time around. */
711 file_ptr->ready_mask = 0;
713 /* If there was a match, then call the handler. */
715 (*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
721 /* Called by gdb_do_one_event to wait for new events on the
722 monitored file descriptors. Queue file events as they are
723 detected by the poll.
724 If there are no events, this function will block in the
726 Return -1 if there are no files descriptors to monitor,
727 otherwise return 0. */
729 gdb_wait_for_event (void)
731 file_handler *file_ptr;
732 gdb_event *file_event_ptr;
738 /* Make sure all output is done before getting another event. */
739 gdb_flush (gdb_stdout);
740 gdb_flush (gdb_stderr);
742 if (gdb_notifier.num_fds == 0)
747 poll (gdb_notifier.poll_fds,
748 (unsigned long) gdb_notifier.num_fds,
749 gdb_notifier.timeout_valid ? gdb_notifier.timeout : -1);
751 /* Don't print anything if we get out of poll because of a
753 if (num_found == -1 && errno != EINTR)
754 perror_with_name ("Poll");
756 #else /* ! HAVE_POLL */
758 gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0];
759 gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1];
760 gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2];
762 num_found = select (gdb_notifier.num_fds,
763 & gdb_notifier.ready_masks[0],
764 & gdb_notifier.ready_masks[1],
765 & gdb_notifier.ready_masks[2],
766 gdb_notifier.timeout_valid
767 ? &gdb_notifier.timeout : NULL);
769 /* Clear the masks after an error from select. */
772 FD_ZERO (&gdb_notifier.ready_masks[0]);
773 FD_ZERO (&gdb_notifier.ready_masks[1]);
774 FD_ZERO (&gdb_notifier.ready_masks[2]);
775 /* Dont print anything is we got a signal, let gdb handle it. */
777 perror_with_name ("Select");
779 #endif /* HAVE_POLL */
781 /* Enqueue all detected file events. */
785 for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
787 if ((gdb_notifier.poll_fds + i)->revents)
792 for (file_ptr = gdb_notifier.first_file_handler;
794 file_ptr = file_ptr->next_file)
796 if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd)
802 /* Enqueue an event only if this is still a new event for
804 if (file_ptr->ready_mask == 0)
806 file_event_ptr = create_file_event (file_ptr->fd);
807 async_queue_event (file_event_ptr, TAIL);
811 file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
814 #else /* ! HAVE_POLL */
816 for (file_ptr = gdb_notifier.first_file_handler;
817 (file_ptr != NULL) && (num_found > 0);
818 file_ptr = file_ptr->next_file)
822 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0]))
823 mask |= GDB_READABLE;
824 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1]))
825 mask |= GDB_WRITABLE;
826 if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2]))
827 mask |= GDB_EXCEPTION;
834 /* Enqueue an event only if this is still a new event for
837 if (file_ptr->ready_mask == 0)
839 file_event_ptr = create_file_event (file_ptr->fd);
840 async_queue_event (file_event_ptr, TAIL);
842 file_ptr->ready_mask = mask;
845 #endif /* HAVE_POLL */
851 /* Create an asynchronous handler, allocating memory for it.
852 Return a pointer to the newly created handler.
853 This pointer will be used to invoke the handler by
854 invoke_async_signal_handler.
855 PROC is the function to call with CLIENT_DATA argument
856 whenever the handler is invoked. */
857 async_signal_handler *
858 create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data)
860 async_signal_handler *async_handler_ptr;
863 (async_signal_handler *) xmalloc (sizeof (async_signal_handler));
864 async_handler_ptr->ready = 0;
865 async_handler_ptr->next_handler = NULL;
866 async_handler_ptr->proc = proc;
867 async_handler_ptr->client_data = client_data;
868 if (sighandler_list.first_handler == NULL)
869 sighandler_list.first_handler = async_handler_ptr;
871 sighandler_list.last_handler->next_handler = async_handler_ptr;
872 sighandler_list.last_handler = async_handler_ptr;
873 return async_handler_ptr;
876 /* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
877 be used when the handlers are invoked, after we have waited for
878 some event. The caller of this function is the interrupt handler
879 associated with a signal. */
881 mark_async_signal_handler (async_signal_handler * async_handler_ptr)
883 ((async_signal_handler *) async_handler_ptr)->ready = 1;
884 async_handler_ready = 1;
887 /* Call all the handlers that are ready. */
889 invoke_async_signal_handler (void)
891 async_signal_handler *async_handler_ptr;
893 if (async_handler_ready == 0)
895 async_handler_ready = 0;
897 /* Invoke ready handlers. */
901 for (async_handler_ptr = sighandler_list.first_handler;
902 async_handler_ptr != NULL;
903 async_handler_ptr = async_handler_ptr->next_handler)
905 if (async_handler_ptr->ready)
908 if (async_handler_ptr == NULL)
910 async_handler_ptr->ready = 0;
911 (*async_handler_ptr->proc) (async_handler_ptr->client_data);
917 /* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
918 Free the space allocated for it. */
920 delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
922 async_signal_handler *prev_ptr;
924 if (sighandler_list.first_handler == (*async_handler_ptr))
926 sighandler_list.first_handler = (*async_handler_ptr)->next_handler;
927 if (sighandler_list.first_handler == NULL)
928 sighandler_list.last_handler = NULL;
932 prev_ptr = sighandler_list.first_handler;
933 while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr)
934 prev_ptr = prev_ptr->next_handler;
935 prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
936 if (sighandler_list.last_handler == (*async_handler_ptr))
937 sighandler_list.last_handler = prev_ptr;
939 free ((char *) (*async_handler_ptr));
940 (*async_handler_ptr) = NULL;
943 /* Is it necessary to call invoke_async_signal_handler? */
945 check_async_ready (void)
947 return async_handler_ready;
950 /* Create a timer that will expire in MILLISECONDS from now. When the
951 timer is ready, PROC will be executed. At creation, the timer is
952 aded to the timers queue. This queue is kept sorted in order of
953 increasing timers. Return a handle to the timer struct. */
955 create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data)
957 struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
958 struct timeval time_now, delta;
960 /* compute seconds */
961 delta.tv_sec = milliseconds / 1000;
962 /* compute microseconds */
963 delta.tv_usec = (milliseconds % 1000) * 1000;
965 gettimeofday (&time_now, NULL);
967 timer_ptr = (struct gdb_timer *) xmalloc (sizeof (gdb_timer));
968 timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec;
969 timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec;
971 if (timer_ptr->when.tv_usec >= 1000000)
973 timer_ptr->when.tv_sec += 1;
974 timer_ptr->when.tv_usec -= 1000000;
976 timer_ptr->proc = proc;
977 timer_ptr->client_data = client_data;
978 timer_list.num_timers++;
979 timer_ptr->timer_id = timer_list.num_timers;
981 /* Now add the timer to the timer queue, making sure it is sorted in
982 increasing order of expiration. */
984 for (timer_index = timer_list.first_timer;
986 timer_index = timer_index->next)
988 /* If the seconds field is greater or if it is the same, but the
989 microsecond field is greater. */
990 if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) ||
991 ((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
992 && (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
996 if (timer_index == timer_list.first_timer)
998 timer_ptr->next = timer_list.first_timer;
999 timer_list.first_timer = timer_ptr;
1004 for (prev_timer = timer_list.first_timer;
1005 prev_timer->next != timer_index;
1006 prev_timer = prev_timer->next)
1009 prev_timer->next = timer_ptr;
1010 timer_ptr->next = timer_index;
1013 gdb_notifier.timeout_valid = 0;
1014 return timer_ptr->timer_id;
1017 /* There is a chance that the creator of the timer wants to get rid of
1018 it before it expires. */
1020 delete_timer (int id)
1022 struct gdb_timer *timer_ptr, *prev_timer = NULL;
1024 /* Find the entry for the given timer. */
1026 for (timer_ptr = timer_list.first_timer; timer_ptr != NULL;
1027 timer_ptr = timer_ptr->next)
1029 if (timer_ptr->timer_id == id)
1033 if (timer_ptr == NULL)
1035 /* Get rid of the timer in the timer list. */
1036 if (timer_ptr == timer_list.first_timer)
1037 timer_list.first_timer = timer_ptr->next;
1040 for (prev_timer = timer_list.first_timer;
1041 prev_timer->next != timer_ptr;
1042 prev_timer = prev_timer->next)
1044 prev_timer->next = timer_ptr->next;
1046 free ((char *) timer_ptr);
1048 gdb_notifier.timeout_valid = 0;
1051 /* When a timer event is put on the event queue, it will be handled by
1052 this function. Just call the assiciated procedure and delete the
1053 timer event from the event queue. Repeat this for each timer that
1056 handle_timer_event (int dummy)
1058 struct timeval time_now;
1059 struct gdb_timer *timer_ptr, *saved_timer;
1061 gettimeofday (&time_now, NULL);
1062 timer_ptr = timer_list.first_timer;
1064 while (timer_ptr != NULL)
1066 if ((timer_ptr->when.tv_sec > time_now.tv_sec) ||
1067 ((timer_ptr->when.tv_sec == time_now.tv_sec) &&
1068 (timer_ptr->when.tv_usec > time_now.tv_usec)))
1071 /* Get rid of the timer from the beginning of the list. */
1072 timer_list.first_timer = timer_ptr->next;
1073 saved_timer = timer_ptr;
1074 timer_ptr = timer_ptr->next;
1075 /* Call the procedure associated with that timer. */
1076 (*saved_timer->proc) (saved_timer->client_data);
1080 gdb_notifier.timeout_valid = 0;
1083 /* Check whether any timers in the timers queue are ready. If at least
1084 one timer is ready, stick an event onto the event queue. Even in
1085 case more than one timer is ready, one event is enough, because the
1086 handle_timer_event() will go through the timers list and call the
1087 procedures associated with all that have expired. Update the
1088 timeout for the select() or poll() as well. */
1092 struct timeval time_now, delta;
1093 gdb_event *event_ptr;
1095 if (timer_list.first_timer != NULL)
1097 gettimeofday (&time_now, NULL);
1098 delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec;
1099 delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec;
1101 if (delta.tv_usec < 0)
1104 delta.tv_usec += 1000000;
1107 /* Oops it expired already. Tell select / poll to return
1108 immediately. (Cannot simply test if delta.tv_sec is negative
1109 because time_t might be unsigned.) */
1110 if (timer_list.first_timer->when.tv_sec < time_now.tv_sec
1111 || (timer_list.first_timer->when.tv_sec == time_now.tv_sec
1112 && timer_list.first_timer->when.tv_usec < time_now.tv_usec))
1118 if (delta.tv_sec == 0 && delta.tv_usec == 0)
1120 event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
1121 event_ptr->proc = handle_timer_event;
1122 event_ptr->fd = timer_list.first_timer->timer_id;
1123 async_queue_event (event_ptr, TAIL);
1126 /* Now we need to update the timeout for select/ poll, because we
1127 don't want to sit there while this timer is expiring. */
1129 gdb_notifier.timeout = delta.tv_sec * 1000;
1131 gdb_notifier.timeout.tv_sec = delta.tv_sec;
1132 gdb_notifier.timeout.tv_usec = delta.tv_usec;
1134 gdb_notifier.timeout_valid = 1;
1137 gdb_notifier.timeout_valid = 0;