/* Event loop machinery for GDB, the GNU debugger.
- Copyright 1999, 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009, 2010
+ Free Software Foundation, Inc.
Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "event-loop.h"
#include "gdb_string.h"
#include <errno.h>
#include <sys/time.h>
+#include "exceptions.h"
+#include "gdb_assert.h"
+#include "gdb_select.h"
+
+/* Data point to pass to the event handler. */
+typedef union event_data
+{
+ void *ptr;
+ int integer;
+} event_data;
typedef struct gdb_event gdb_event;
-typedef void (event_handler_func) (int);
+typedef void (event_handler_func) (event_data);
/* Event for the GDB event system. Events are queued by calling
async_queue_event and serviced later on by gdb_do_one_event. An
event can be, for instance, a file descriptor becoming ready to be
- read. Servicing an event simply means that the procedure PROC will
+ read. Servicing an event simply means that the procedure PROC will
be called. We have 2 queues, one for file handlers that we listen
to in the event loop, and one for the file handlers+events that are
- ready. The procedure PROC associated with each event is always the
- same (handle_file_event). Its duty is to invoke the handler
- associated with the file descriptor whose state change generated
- the event, plus doing other cleanups and such. */
+ ready. The procedure PROC associated with each event is dependant
+ of the event source. In the case of monitored file descriptors, it
+ is always the same (handle_file_event). Its duty is to invoke the
+ handler associated with the file descriptor whose state change
+ generated the event, plus doing other cleanups and such. In the
+ case of async signal handlers, it is
+ invoke_async_signal_handler. */
struct gdb_event
{
- event_handler_func *proc; /* Procedure to call to service this event. */
- int fd; /* File descriptor that is ready. */
- struct gdb_event *next_event; /* Next in list of events or NULL. */
+ /* Procedure to call to service this event. */
+ event_handler_func *proc;
+
+ /* Data to pass to the event handler. */
+ event_data data;
+
+ /* Next in list of events or NULL. */
+ struct gdb_event *next_event;
};
/* Information about each file descriptor we register with the event
be carried out by PROC at a later time, within process_event. This
provides a deferred execution of signal handlers.
Async_init_signals takes care of setting up such an
- asyn_signal_handler for each interesting signal. */
+ async_signal_handler for each interesting signal. */
typedef struct async_signal_handler
{
int ready; /* If ready, call this handler from the main event loop,
}
async_signal_handler;
+/* PROC is a function to be invoked when the READY flag is set. This
+ happens when the event has been marked with
+ MARK_ASYNC_EVENT_HANDLER. The actual work to be done in response
+ to an event will be carried out by PROC at a later time, within
+ process_event. This provides a deferred execution of event
+ handlers. */
+typedef struct async_event_handler
+ {
+ /* If ready, call this handler from the main event loop, using
+ invoke_event_handler. */
+ int ready;
+
+ /* Point to next handler. */
+ struct async_event_handler *next_handler;
+
+ /* Function to call to do the work. */
+ async_event_handler_func *proc;
+
+ /* Argument to PROC. */
+ gdb_client_data client_data;
+ }
+async_event_handler;
+
/* Event queue:
- the first event in the queue is the head of the queue.
static unsigned char use_poll = USE_POLL;
+#ifdef USE_WIN32API
+#include <windows.h>
+#include <io.h>
+#endif
+
static struct
{
/* Ptr to head of file handler list. */
}
sighandler_list;
-/* Are any of the handlers ready? Check this variable using
- check_async_ready. This is used by process_event, to determine
- whether or not to invoke the invoke_async_signal_handler
- function. */
-static int async_handler_ready = 0;
-
-static void create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data);
-static void invoke_async_signal_handler (void);
-static void handle_file_event (int event_file_desc);
-static int gdb_wait_for_event (void);
-static int check_async_ready (void);
-static void async_queue_event (gdb_event * event_ptr, queue_position position);
-static gdb_event *create_file_event (int fd);
-static int process_event (void);
-static void handle_timer_event (int dummy);
+/* All the async_event_handlers gdb is interested in are kept onto
+ this list. */
+static struct
+ {
+ /* Pointer to first in handler list. */
+ async_event_handler *first_handler;
+
+ /* Pointer to last in handler list. */
+ async_event_handler *last_handler;
+ }
+async_event_handler_list;
+
+static int invoke_async_signal_handlers (void);
+static void create_file_handler (int fd, int mask, handler_func *proc,
+ gdb_client_data client_data);
+static void handle_file_event (event_data data);
+static void check_async_event_handlers (void);
+static void check_async_signal_handlers (void);
+static int gdb_wait_for_event (int);
static void poll_timers (void);
\f
}
}
+/* Create a generic event, to be enqueued in the event queue for
+ processing. PROC is the procedure associated to the event. DATA
+ is passed to PROC upon PROC invocation. */
+
+static gdb_event *
+create_event (event_handler_func proc, event_data data)
+{
+ gdb_event *event;
+
+ event = xmalloc (sizeof (*event));
+ event->proc = proc;
+ event->data = data;
+
+ return event;
+}
+
/* Create a file event, to be enqueued in the event queue for
processing. The procedure associated to this event is always
handle_file_event, which will in turn invoke the one that was
static gdb_event *
create_file_event (int fd)
{
- gdb_event *file_event_ptr;
+ event_data data;
- file_event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
- file_event_ptr->proc = handle_file_event;
- file_event_ptr->fd = fd;
- return (file_event_ptr);
+ data.integer = fd;
+ return create_event (handle_file_event, data);
}
/* Process one event.
or an asynchronous event handler can be invoked in response to
the reception of a signal.
If an event was processed (either way), 1 is returned otherwise
- 0 is returned.
+ 0 is returned.
Scan the queue from head to tail, processing therefore the high
priority events first, by invoking the associated event handler
procedure. */
{
gdb_event *event_ptr, *prev_ptr;
event_handler_func *proc;
- int fd;
+ event_data data;
/* First let's see if there are any asynchronous event handlers that
are ready. These would be the result of invoking any of the
signal handlers. */
- if (check_async_ready ())
- {
- invoke_async_signal_handler ();
- return 1;
- }
+ if (invoke_async_signal_handlers ())
+ return 1;
/* Look in the event queue to find an event that is ready
to be processed. */
/* Call the handler for the event. */
proc = event_ptr->proc;
- fd = event_ptr->fd;
+ data = event_ptr->data;
/* Let's get rid of the event from the event queue. We need to
do this now because while processing the event, the proc
xfree (event_ptr);
/* Now call the procedure associated with the event. */
- (*proc) (fd);
+ (*proc) (data);
return 1;
}
int
gdb_do_one_event (void *data)
{
- /* Any events already waiting in the queue? */
+ static int event_source_head = 0;
+ const int number_of_sources = 3;
+ int current = 0;
+
+ /* Any events already waiting in the queue? */
if (process_event ())
+ return 1;
+
+ /* To level the fairness across event sources, we poll them in a
+ round-robin fashion. */
+ for (current = 0; current < number_of_sources; current++)
{
- return 1;
+ switch (event_source_head)
+ {
+ case 0:
+ /* Are any timers that are ready? If so, put an event on the
+ queue. */
+ poll_timers ();
+ break;
+ case 1:
+ /* Are there events already waiting to be collected on the
+ monitored file descriptors? */
+ gdb_wait_for_event (0);
+ break;
+ case 2:
+ /* Are there any asynchronous event handlers ready? */
+ check_async_event_handlers ();
+ break;
+ }
+
+ event_source_head++;
+ if (event_source_head == number_of_sources)
+ event_source_head = 0;
}
- /* Are any timers that are ready? If so, put an event on the queue. */
- poll_timers ();
+ /* Handle any new events collected. */
+ if (process_event ())
+ return 1;
- /* Wait for a new event. If gdb_wait_for_event returns -1,
- we should get out because this means that there are no
- event sources left. This will make the event loop stop,
- and the application exit. */
+ /* Block waiting for a new event. If gdb_wait_for_event returns -1,
+ we should get out because this means that there are no event
+ sources left. This will make the event loop stop, and the
+ application exit. */
- if (gdb_wait_for_event () < 0)
- {
- return -1;
- }
+ if (gdb_wait_for_event (1) < 0)
+ return -1;
- /* Handle any new events occurred while waiting. */
+ /* Handle any new events occurred while waiting. */
if (process_event ())
- {
- return 1;
- }
+ return 1;
- /* If gdb_wait_for_event has returned 1, it means that one
- event has been handled. We break out of the loop. */
+ /* If gdb_wait_for_event has returned 1, it means that one event has
+ been handled. We break out of the loop. */
return 1;
}
longer any event sources registered. */
while (1)
{
- int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
- if (result < 0)
+ int gdb_result;
+
+ gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
+ if (gdb_result < 0)
break;
- if (result == 0)
+
+ /* If we long-jumped out of do_one_event, we probably
+ didn't get around to resetting the prompt, which leaves
+ readline in a messed-up state. Reset it here. */
+
+ if (gdb_result == 0)
{
+ /* If any exception escaped to here, we better enable
+ stdin. Otherwise, any command that calls async_disable_stdin,
+ and then throws, will leave stdin inoperable. */
+ async_enable_stdin ();
/* FIXME: this should really be a call to a hook that is
interface specific, because interfaces can display the
prompt in their own way. */
use_poll = 0;
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
if (use_poll)
create_file_handler (fd, POLLIN, proc, client_data);
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif
}
else
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
gdb_notifier.num_fds--;
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
event in the front of the event queue. */
static void
-handle_file_event (int event_file_desc)
+handle_file_event (event_data data)
{
file_handler *file_ptr;
int mask;
int error_mask;
int error_mask_returned;
#endif
+ int event_file_desc = data.integer;
/* Search the file handler list to find one that matches the fd in
the event. */
/* Work in progress. We may need to tell somebody what
kind of error we had. */
if (error_mask_returned & POLLHUP)
- printf_unfiltered ("Hangup detected on fd %d\n", file_ptr->fd);
+ printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr->fd);
if (error_mask_returned & POLLERR)
- printf_unfiltered ("Error detected on fd %d\n", file_ptr->fd);
+ printf_unfiltered (_("Error detected on fd %d\n"), file_ptr->fd);
if (error_mask_returned & POLLNVAL)
- printf_unfiltered ("Invalid or non-`poll'able fd %d\n", file_ptr->fd);
+ printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr->fd);
file_ptr->error = 1;
}
else
file_ptr->error = 0;
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
{
if (file_ptr->ready_mask & GDB_EXCEPTION)
{
- printf_unfiltered ("Exception condition detected on fd %d\n", file_ptr->fd);
+ printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr->fd);
file_ptr->error = 1;
}
else
}
}
-/* Called by gdb_do_one_event to wait for new events on the
- monitored file descriptors. Queue file events as they are
- detected by the poll.
- If there are no events, this function will block in the
- call to poll.
- Return -1 if there are no files descriptors to monitor,
- otherwise return 0. */
+/* Called by gdb_do_one_event to wait for new events on the monitored
+ file descriptors. Queue file events as they are detected by the
+ poll. If BLOCK and if there are no events, this function will
+ block in the call to poll. Return -1 if there are no files
+ descriptors to monitor, otherwise return 0. */
static int
-gdb_wait_for_event (void)
+gdb_wait_for_event (int block)
{
file_handler *file_ptr;
gdb_event *file_event_ptr;
if (use_poll)
{
#ifdef HAVE_POLL
- num_found =
- poll (gdb_notifier.poll_fds,
- (unsigned long) gdb_notifier.num_fds,
- gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1);
+ int timeout;
+
+ if (block)
+ timeout = gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1;
+ else
+ timeout = 0;
+
+ num_found = poll (gdb_notifier.poll_fds,
+ (unsigned long) gdb_notifier.num_fds, timeout);
/* Don't print anything if we get out of poll because of a
- signal. */
+ signal. */
if (num_found == -1 && errno != EINTR)
- perror_with_name ("Poll");
+ perror_with_name (("poll"));
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
{
+ struct timeval select_timeout;
+
+ struct timeval *timeout_p;
+ if (block)
+ timeout_p = gdb_notifier.timeout_valid
+ ? &gdb_notifier.select_timeout : NULL;
+ else
+ {
+ memset (&select_timeout, 0, sizeof (select_timeout));
+ timeout_p = &select_timeout;
+ }
+
gdb_notifier.ready_masks[0] = gdb_notifier.check_masks[0];
gdb_notifier.ready_masks[1] = gdb_notifier.check_masks[1];
gdb_notifier.ready_masks[2] = gdb_notifier.check_masks[2];
- num_found = select (gdb_notifier.num_fds,
- &gdb_notifier.ready_masks[0],
- &gdb_notifier.ready_masks[1],
- &gdb_notifier.ready_masks[2],
- gdb_notifier.timeout_valid
- ? &gdb_notifier.select_timeout : NULL);
+ num_found = gdb_select (gdb_notifier.num_fds,
+ &gdb_notifier.ready_masks[0],
+ &gdb_notifier.ready_masks[1],
+ &gdb_notifier.ready_masks[2],
+ timeout_p);
/* Clear the masks after an error from select. */
if (num_found == -1)
FD_ZERO (&gdb_notifier.ready_masks[0]);
FD_ZERO (&gdb_notifier.ready_masks[1]);
FD_ZERO (&gdb_notifier.ready_masks[2]);
- /* Dont print anything is we got a signal, let gdb handle it. */
+
+ /* Dont print anything if we got a signal, let gdb handle
+ it. */
if (errno != EINTR)
- perror_with_name ("Select");
+ perror_with_name (("select"));
}
}
file_event_ptr = create_file_event (file_ptr->fd);
async_queue_event (file_event_ptr, TAIL);
}
+ file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
}
-
- file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
}
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
return async_handler_ptr;
}
+/* Call the handler from HANDLER immediately. This function runs
+ signal handlers when returning to the event loop would be too
+ slow. */
+void
+call_async_signal_handler (struct async_signal_handler *handler)
+{
+ (*handler->proc) (handler->client_data);
+}
+
/* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
be used when the handlers are invoked, after we have waited for
some event. The caller of this function is the interrupt handler
void
mark_async_signal_handler (async_signal_handler * async_handler_ptr)
{
- ((async_signal_handler *) async_handler_ptr)->ready = 1;
- async_handler_ready = 1;
+ async_handler_ptr->ready = 1;
}
-/* Call all the handlers that are ready. */
-static void
-invoke_async_signal_handler (void)
+/* Call all the handlers that are ready. Returns true if any was
+ indeed ready. */
+static int
+invoke_async_signal_handlers (void)
{
async_signal_handler *async_handler_ptr;
+ int any_ready = 0;
- if (async_handler_ready == 0)
- return;
- async_handler_ready = 0;
-
- /* Invoke ready handlers. */
+ /* Invoke ready handlers. */
while (1)
{
}
if (async_handler_ptr == NULL)
break;
+ any_ready = 1;
async_handler_ptr->ready = 0;
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
}
- return;
+ return any_ready;
}
/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
else
{
prev_ptr = sighandler_list.first_handler;
- while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr)
+ while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr))
prev_ptr = prev_ptr->next_handler;
prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
if (sighandler_list.last_handler == (*async_handler_ptr))
(*async_handler_ptr) = NULL;
}
-/* Is it necessary to call invoke_async_signal_handler? */
-static int
-check_async_ready (void)
+/* Create an asynchronous event handler, allocating memory for it.
+ Return a pointer to the newly created handler. PROC is the
+ function to call with CLIENT_DATA argument whenever the handler is
+ invoked. */
+async_event_handler *
+create_async_event_handler (async_event_handler_func *proc,
+ gdb_client_data client_data)
{
- return async_handler_ready;
+ async_event_handler *h;
+
+ h = xmalloc (sizeof (*h));
+ h->ready = 0;
+ h->next_handler = NULL;
+ h->proc = proc;
+ h->client_data = client_data;
+ if (async_event_handler_list.first_handler == NULL)
+ async_event_handler_list.first_handler = h;
+ else
+ async_event_handler_list.last_handler->next_handler = h;
+ async_event_handler_list.last_handler = h;
+ return h;
+}
+
+/* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information
+ will be used by gdb_do_one_event. The caller will be whoever
+ created the event source, and wants to signal that the event is
+ ready to be handled. */
+void
+mark_async_event_handler (async_event_handler *async_handler_ptr)
+{
+ async_handler_ptr->ready = 1;
+}
+
+struct async_event_handler_data
+{
+ async_event_handler_func* proc;
+ gdb_client_data client_data;
+};
+
+static void
+invoke_async_event_handler (event_data data)
+{
+ struct async_event_handler_data *hdata = data.ptr;
+ async_event_handler_func* proc = hdata->proc;
+ gdb_client_data client_data = hdata->client_data;
+
+ xfree (hdata);
+ (*proc) (client_data);
+}
+
+/* Check if any asynchronous event handlers are ready, and queue
+ events in the ready queue for any that are. */
+static void
+check_async_event_handlers (void)
+{
+ async_event_handler *async_handler_ptr;
+ struct async_event_handler_data *hdata;
+ struct gdb_event *event_ptr;
+ event_data data;
+
+ for (async_handler_ptr = async_event_handler_list.first_handler;
+ async_handler_ptr != NULL;
+ async_handler_ptr = async_handler_ptr->next_handler)
+ {
+ if (async_handler_ptr->ready)
+ {
+ async_handler_ptr->ready = 0;
+
+ hdata = xmalloc (sizeof (*hdata));
+
+ hdata->proc = async_handler_ptr->proc;
+ hdata->client_data = async_handler_ptr->client_data;
+
+ data.ptr = hdata;
+
+ event_ptr = create_event (invoke_async_event_handler, data);
+ async_queue_event (event_ptr, TAIL);
+ }
+ }
+}
+
+/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
+ Free the space allocated for it. */
+void
+delete_async_event_handler (async_event_handler **async_handler_ptr)
+{
+ async_event_handler *prev_ptr;
+
+ if (async_event_handler_list.first_handler == *async_handler_ptr)
+ {
+ async_event_handler_list.first_handler = (*async_handler_ptr)->next_handler;
+ if (async_event_handler_list.first_handler == NULL)
+ async_event_handler_list.last_handler = NULL;
+ }
+ else
+ {
+ prev_ptr = async_event_handler_list.first_handler;
+ while (prev_ptr && prev_ptr->next_handler != *async_handler_ptr)
+ prev_ptr = prev_ptr->next_handler;
+ prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
+ if (async_event_handler_list.last_handler == (*async_handler_ptr))
+ async_event_handler_list.last_handler = prev_ptr;
+ }
+ xfree (*async_handler_ptr);
+ *async_handler_ptr = NULL;
}
/* Create a timer that will expire in MILLISECONDS from now. When the
{
/* If the seconds field is greater or if it is the same, but the
microsecond field is greater. */
- if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) ||
- ((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
- && (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
+ if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec)
+ || ((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
+ && (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
break;
}
}
/* When a timer event is put on the event queue, it will be handled by
- this function. Just call the assiciated procedure and delete the
- timer event from the event queue. Repeat this for each timer that
- has expired. */
+ this function. Just call the associated procedure and delete the
+ timer event from the event queue. Repeat this for each timer that
+ has expired. */
static void
-handle_timer_event (int dummy)
+handle_timer_event (event_data dummy)
{
struct timeval time_now;
struct gdb_timer *timer_ptr, *saved_timer;
while (timer_ptr != NULL)
{
- if ((timer_ptr->when.tv_sec > time_now.tv_sec) ||
- ((timer_ptr->when.tv_sec == time_now.tv_sec) &&
- (timer_ptr->when.tv_usec > time_now.tv_usec)))
+ if ((timer_ptr->when.tv_sec > time_now.tv_sec)
+ || ((timer_ptr->when.tv_sec == time_now.tv_sec)
+ && (timer_ptr->when.tv_usec > time_now.tv_usec)))
break;
/* Get rid of the timer from the beginning of the list. */
{
event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
event_ptr->proc = handle_timer_event;
- event_ptr->fd = timer_list.first_timer->timer_id;
+ event_ptr->data.integer = timer_list.first_timer->timer_id;
async_queue_event (event_ptr, TAIL);
}
gdb_notifier.poll_timeout = delta.tv_sec * 1000;
#else
internal_error (__FILE__, __LINE__,
- "use_poll without HAVE_POLL");
+ _("use_poll without HAVE_POLL"));
#endif /* HAVE_POLL */
}
else
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