1293 lines
37 KiB
C
1293 lines
37 KiB
C
/* Event loop machinery for GDB, the GNU debugger.
|
||
Copyright (C) 1999-2016 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 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
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, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include "event-loop.h"
|
||
#include "event-top.h"
|
||
#include "queue.h"
|
||
#include "ser-event.h"
|
||
|
||
#ifdef HAVE_POLL
|
||
#if defined (HAVE_POLL_H)
|
||
#include <poll.h>
|
||
#elif defined (HAVE_SYS_POLL_H)
|
||
#include <sys/poll.h>
|
||
#endif
|
||
#endif
|
||
|
||
#include <sys/types.h>
|
||
#include "gdb_sys_time.h"
|
||
#include "gdb_select.h"
|
||
#include "observer.h"
|
||
|
||
/* Tell create_file_handler what events we are interested in.
|
||
This is used by the select version of the event loop. */
|
||
|
||
#define GDB_READABLE (1<<1)
|
||
#define GDB_WRITABLE (1<<2)
|
||
#define GDB_EXCEPTION (1<<3)
|
||
|
||
/* 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) (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
|
||
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 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. */
|
||
|
||
typedef struct gdb_event
|
||
{
|
||
/* Procedure to call to service this event. */
|
||
event_handler_func *proc;
|
||
|
||
/* Data to pass to the event handler. */
|
||
event_data data;
|
||
} *gdb_event_p;
|
||
|
||
/* Information about each file descriptor we register with the event
|
||
loop. */
|
||
|
||
typedef struct file_handler
|
||
{
|
||
int fd; /* File descriptor. */
|
||
int mask; /* Events we want to monitor: POLLIN, etc. */
|
||
int ready_mask; /* Events that have been seen since
|
||
the last time. */
|
||
handler_func *proc; /* Procedure to call when fd is ready. */
|
||
gdb_client_data client_data; /* Argument to pass to proc. */
|
||
int error; /* Was an error detected on this fd? */
|
||
struct file_handler *next_file; /* Next registered file descriptor. */
|
||
}
|
||
file_handler;
|
||
|
||
/* PROC is a function to be invoked when the READY flag is set. This
|
||
happens when there has been a signal and the corresponding signal
|
||
handler has 'triggered' this async_signal_handler for execution.
|
||
The actual work to be done in response to a signal will 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
|
||
async_signal_handler for each interesting signal. */
|
||
|
||
typedef struct async_signal_handler
|
||
{
|
||
int ready; /* If ready, call this handler
|
||
from the main event loop, using
|
||
invoke_async_handler. */
|
||
struct async_signal_handler *next_handler; /* Ptr to next handler. */
|
||
sig_handler_func *proc; /* Function to call to do the work. */
|
||
gdb_client_data client_data; /* Argument to async_handler_func. */
|
||
}
|
||
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;
|
||
|
||
/* Gdb_notifier is just a list of file descriptors gdb is interested in.
|
||
These are the input file descriptor, and the target file
|
||
descriptor. We have two flavors of the notifier, one for platforms
|
||
that have the POLL function, the other for those that don't, and
|
||
only support SELECT. Each of the elements in the gdb_notifier list is
|
||
basically a description of what kind of events gdb is interested
|
||
in, for each fd. */
|
||
|
||
/* As of 1999-04-30 only the input file descriptor is registered with the
|
||
event loop. */
|
||
|
||
/* Do we use poll or select ? */
|
||
#ifdef HAVE_POLL
|
||
#define USE_POLL 1
|
||
#else
|
||
#define USE_POLL 0
|
||
#endif /* HAVE_POLL */
|
||
|
||
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. */
|
||
file_handler *first_file_handler;
|
||
|
||
/* Next file handler to handle, for the select variant. To level
|
||
the fairness across event sources, we serve file handlers in a
|
||
round-robin-like fashion. The number and order of the polled
|
||
file handlers may change between invocations, but this is good
|
||
enough. */
|
||
file_handler *next_file_handler;
|
||
|
||
#ifdef HAVE_POLL
|
||
/* Ptr to array of pollfd structures. */
|
||
struct pollfd *poll_fds;
|
||
|
||
/* Next file descriptor to handle, for the poll variant. To level
|
||
the fairness across event sources, we poll the file descriptors
|
||
in a round-robin-like fashion. The number and order of the
|
||
polled file descriptors may change between invocations, but
|
||
this is good enough. */
|
||
int next_poll_fds_index;
|
||
|
||
/* Timeout in milliseconds for calls to poll(). */
|
||
int poll_timeout;
|
||
#endif
|
||
|
||
/* Masks to be used in the next call to select.
|
||
Bits are set in response to calls to create_file_handler. */
|
||
fd_set check_masks[3];
|
||
|
||
/* What file descriptors were found ready by select. */
|
||
fd_set ready_masks[3];
|
||
|
||
/* Number of file descriptors to monitor (for poll). */
|
||
/* Number of valid bits (highest fd value + 1) (for select). */
|
||
int num_fds;
|
||
|
||
/* Time structure for calls to select(). */
|
||
struct timeval select_timeout;
|
||
|
||
/* Flag to tell whether the timeout should be used. */
|
||
int timeout_valid;
|
||
}
|
||
gdb_notifier;
|
||
|
||
/* Structure associated with a timer. PROC will be executed at the
|
||
first occasion after WHEN. */
|
||
struct gdb_timer
|
||
{
|
||
struct timeval when;
|
||
int timer_id;
|
||
struct gdb_timer *next;
|
||
timer_handler_func *proc; /* Function to call to do the work. */
|
||
gdb_client_data client_data; /* Argument to async_handler_func. */
|
||
};
|
||
|
||
/* List of currently active timers. It is sorted in order of
|
||
increasing timers. */
|
||
static struct
|
||
{
|
||
/* Pointer to first in timer list. */
|
||
struct gdb_timer *first_timer;
|
||
|
||
/* Id of the last timer created. */
|
||
int num_timers;
|
||
}
|
||
timer_list;
|
||
|
||
/* All the async_signal_handlers gdb is interested in are kept onto
|
||
this list. */
|
||
static struct
|
||
{
|
||
/* Pointer to first in handler list. */
|
||
async_signal_handler *first_handler;
|
||
|
||
/* Pointer to last in handler list. */
|
||
async_signal_handler *last_handler;
|
||
}
|
||
sighandler_list;
|
||
|
||
/* 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 int check_async_event_handlers (void);
|
||
static int gdb_wait_for_event (int);
|
||
static int update_wait_timeout (void);
|
||
static int poll_timers (void);
|
||
|
||
|
||
/* This event is signalled whenever an asynchronous handler needs to
|
||
defer an action to the event loop. */
|
||
static struct serial_event *async_signal_handlers_serial_event;
|
||
|
||
/* Callback registered with ASYNC_SIGNAL_HANDLERS_SERIAL_EVENT. */
|
||
|
||
static void
|
||
async_signals_handler (int error, gdb_client_data client_data)
|
||
{
|
||
/* Do nothing. Handlers are run by invoke_async_signal_handlers
|
||
from instead. */
|
||
}
|
||
|
||
void
|
||
initialize_async_signal_handlers (void)
|
||
{
|
||
async_signal_handlers_serial_event = make_serial_event ();
|
||
|
||
add_file_handler (serial_event_fd (async_signal_handlers_serial_event),
|
||
async_signals_handler, NULL);
|
||
}
|
||
|
||
/* Process one high level event. If nothing is ready at this time,
|
||
wait for something to happen (via gdb_wait_for_event), then process
|
||
it. Returns >0 if something was done otherwise returns <0 (this
|
||
can happen if there are no event sources to wait for). */
|
||
|
||
int
|
||
gdb_do_one_event (void)
|
||
{
|
||
static int event_source_head = 0;
|
||
const int number_of_sources = 3;
|
||
int current = 0;
|
||
|
||
/* First let's see if there are any asynchronous signal handlers
|
||
that are ready. These would be the result of invoking any of the
|
||
signal handlers. */
|
||
if (invoke_async_signal_handlers ())
|
||
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++)
|
||
{
|
||
int res;
|
||
|
||
switch (event_source_head)
|
||
{
|
||
case 0:
|
||
/* Are any timers that are ready? */
|
||
res = poll_timers ();
|
||
break;
|
||
case 1:
|
||
/* Are there events already waiting to be collected on the
|
||
monitored file descriptors? */
|
||
res = gdb_wait_for_event (0);
|
||
break;
|
||
case 2:
|
||
/* Are there any asynchronous event handlers ready? */
|
||
res = check_async_event_handlers ();
|
||
break;
|
||
default:
|
||
internal_error (__FILE__, __LINE__,
|
||
"unexpected event_source_head %d",
|
||
event_source_head);
|
||
}
|
||
|
||
event_source_head++;
|
||
if (event_source_head == number_of_sources)
|
||
event_source_head = 0;
|
||
|
||
if (res > 0)
|
||
return 1;
|
||
}
|
||
|
||
/* 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 (1) < 0)
|
||
return -1;
|
||
|
||
/* If gdb_wait_for_event has returned 1, it means that one event has
|
||
been handled. We break out of the loop. */
|
||
return 1;
|
||
}
|
||
|
||
/* Start up the event loop. This is the entry point to the event loop
|
||
from the command loop. */
|
||
|
||
void
|
||
start_event_loop (void)
|
||
{
|
||
/* Loop until there is nothing to do. This is the entry point to
|
||
the event loop engine. gdb_do_one_event will process one event
|
||
for each invocation. It blocks waiting for an event and then
|
||
processes it. */
|
||
while (1)
|
||
{
|
||
int result = 0;
|
||
|
||
TRY
|
||
{
|
||
result = gdb_do_one_event ();
|
||
}
|
||
CATCH (ex, RETURN_MASK_ALL)
|
||
{
|
||
exception_print (gdb_stderr, ex);
|
||
|
||
/* 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 ();
|
||
/* 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. */
|
||
observer_notify_command_error ();
|
||
/* This call looks bizarre, but it is required. If the user
|
||
entered a command that caused an error,
|
||
after_char_processing_hook won't be called from
|
||
rl_callback_read_char_wrapper. Using a cleanup there
|
||
won't work, since we want this function to be called
|
||
after a new prompt is printed. */
|
||
if (after_char_processing_hook)
|
||
(*after_char_processing_hook) ();
|
||
/* Maybe better to set a flag to be checked somewhere as to
|
||
whether display the prompt or not. */
|
||
}
|
||
END_CATCH
|
||
|
||
if (result < 0)
|
||
break;
|
||
}
|
||
|
||
/* We are done with the event loop. There are no more event sources
|
||
to listen to. So we exit GDB. */
|
||
return;
|
||
}
|
||
|
||
|
||
/* Wrapper function for create_file_handler, so that the caller
|
||
doesn't have to know implementation details about the use of poll
|
||
vs. select. */
|
||
void
|
||
add_file_handler (int fd, handler_func * proc, gdb_client_data client_data)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
struct pollfd fds;
|
||
#endif
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
/* Check to see if poll () is usable. If not, we'll switch to
|
||
use select. This can happen on systems like
|
||
m68k-motorola-sys, `poll' cannot be used to wait for `stdin'.
|
||
On m68k-motorola-sysv, tty's are not stream-based and not
|
||
`poll'able. */
|
||
fds.fd = fd;
|
||
fds.events = POLLIN;
|
||
if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL))
|
||
use_poll = 0;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
create_file_handler (fd, POLLIN, proc, client_data);
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif
|
||
}
|
||
else
|
||
create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION,
|
||
proc, client_data);
|
||
}
|
||
|
||
/* Add a file handler/descriptor to the list of descriptors we are
|
||
interested in.
|
||
|
||
FD is the file descriptor for the file/stream to be listened to.
|
||
|
||
For the poll case, MASK is a combination (OR) of POLLIN,
|
||
POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND:
|
||
these are the events we are interested in. If any of them occurs,
|
||
proc should be called.
|
||
|
||
For the select case, MASK is a combination of READABLE, WRITABLE,
|
||
EXCEPTION. PROC is the procedure that will be called when an event
|
||
occurs for FD. CLIENT_DATA is the argument to pass to PROC. */
|
||
|
||
static void
|
||
create_file_handler (int fd, int mask, handler_func * proc,
|
||
gdb_client_data client_data)
|
||
{
|
||
file_handler *file_ptr;
|
||
|
||
/* Do we already have a file handler for this file? (We may be
|
||
changing its associated procedure). */
|
||
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
if (file_ptr->fd == fd)
|
||
break;
|
||
}
|
||
|
||
/* It is a new file descriptor. Add it to the list. Otherwise, just
|
||
change the data associated with it. */
|
||
if (file_ptr == NULL)
|
||
{
|
||
file_ptr = XNEW (file_handler);
|
||
file_ptr->fd = fd;
|
||
file_ptr->ready_mask = 0;
|
||
file_ptr->next_file = gdb_notifier.first_file_handler;
|
||
gdb_notifier.first_file_handler = file_ptr;
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
gdb_notifier.num_fds++;
|
||
if (gdb_notifier.poll_fds)
|
||
gdb_notifier.poll_fds =
|
||
(struct pollfd *) xrealloc (gdb_notifier.poll_fds,
|
||
(gdb_notifier.num_fds
|
||
* sizeof (struct pollfd)));
|
||
else
|
||
gdb_notifier.poll_fds =
|
||
XNEW (struct pollfd);
|
||
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd;
|
||
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask;
|
||
(gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
if (mask & GDB_READABLE)
|
||
FD_SET (fd, &gdb_notifier.check_masks[0]);
|
||
else
|
||
FD_CLR (fd, &gdb_notifier.check_masks[0]);
|
||
|
||
if (mask & GDB_WRITABLE)
|
||
FD_SET (fd, &gdb_notifier.check_masks[1]);
|
||
else
|
||
FD_CLR (fd, &gdb_notifier.check_masks[1]);
|
||
|
||
if (mask & GDB_EXCEPTION)
|
||
FD_SET (fd, &gdb_notifier.check_masks[2]);
|
||
else
|
||
FD_CLR (fd, &gdb_notifier.check_masks[2]);
|
||
|
||
if (gdb_notifier.num_fds <= fd)
|
||
gdb_notifier.num_fds = fd + 1;
|
||
}
|
||
}
|
||
|
||
file_ptr->proc = proc;
|
||
file_ptr->client_data = client_data;
|
||
file_ptr->mask = mask;
|
||
}
|
||
|
||
/* Return the next file handler to handle, and advance to the next
|
||
file handler, wrapping around if the end of the list is
|
||
reached. */
|
||
|
||
static file_handler *
|
||
get_next_file_handler_to_handle_and_advance (void)
|
||
{
|
||
file_handler *curr_next;
|
||
|
||
/* The first time around, this is still NULL. */
|
||
if (gdb_notifier.next_file_handler == NULL)
|
||
gdb_notifier.next_file_handler = gdb_notifier.first_file_handler;
|
||
|
||
curr_next = gdb_notifier.next_file_handler;
|
||
gdb_assert (curr_next != NULL);
|
||
|
||
/* Advance. */
|
||
gdb_notifier.next_file_handler = curr_next->next_file;
|
||
/* Wrap around, if necessary. */
|
||
if (gdb_notifier.next_file_handler == NULL)
|
||
gdb_notifier.next_file_handler = gdb_notifier.first_file_handler;
|
||
|
||
return curr_next;
|
||
}
|
||
|
||
/* Remove the file descriptor FD from the list of monitored fd's:
|
||
i.e. we don't care anymore about events on the FD. */
|
||
void
|
||
delete_file_handler (int fd)
|
||
{
|
||
file_handler *file_ptr, *prev_ptr = NULL;
|
||
int i;
|
||
#ifdef HAVE_POLL
|
||
int j;
|
||
struct pollfd *new_poll_fds;
|
||
#endif
|
||
|
||
/* Find the entry for the given file. */
|
||
|
||
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
if (file_ptr->fd == fd)
|
||
break;
|
||
}
|
||
|
||
if (file_ptr == NULL)
|
||
return;
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
/* Create a new poll_fds array by copying every fd's information
|
||
but the one we want to get rid of. */
|
||
|
||
new_poll_fds = (struct pollfd *)
|
||
xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd));
|
||
|
||
for (i = 0, j = 0; i < gdb_notifier.num_fds; i++)
|
||
{
|
||
if ((gdb_notifier.poll_fds + i)->fd != fd)
|
||
{
|
||
(new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd;
|
||
(new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events;
|
||
(new_poll_fds + j)->revents
|
||
= (gdb_notifier.poll_fds + i)->revents;
|
||
j++;
|
||
}
|
||
}
|
||
xfree (gdb_notifier.poll_fds);
|
||
gdb_notifier.poll_fds = new_poll_fds;
|
||
gdb_notifier.num_fds--;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
if (file_ptr->mask & GDB_READABLE)
|
||
FD_CLR (fd, &gdb_notifier.check_masks[0]);
|
||
if (file_ptr->mask & GDB_WRITABLE)
|
||
FD_CLR (fd, &gdb_notifier.check_masks[1]);
|
||
if (file_ptr->mask & GDB_EXCEPTION)
|
||
FD_CLR (fd, &gdb_notifier.check_masks[2]);
|
||
|
||
/* Find current max fd. */
|
||
|
||
if ((fd + 1) == gdb_notifier.num_fds)
|
||
{
|
||
gdb_notifier.num_fds--;
|
||
for (i = gdb_notifier.num_fds; i; i--)
|
||
{
|
||
if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0])
|
||
|| FD_ISSET (i - 1, &gdb_notifier.check_masks[1])
|
||
|| FD_ISSET (i - 1, &gdb_notifier.check_masks[2]))
|
||
break;
|
||
}
|
||
gdb_notifier.num_fds = i;
|
||
}
|
||
}
|
||
|
||
/* Deactivate the file descriptor, by clearing its mask,
|
||
so that it will not fire again. */
|
||
|
||
file_ptr->mask = 0;
|
||
|
||
/* If this file handler was going to be the next one to be handled,
|
||
advance to the next's next, if any. */
|
||
if (gdb_notifier.next_file_handler == file_ptr)
|
||
{
|
||
if (file_ptr->next_file == NULL
|
||
&& file_ptr == gdb_notifier.first_file_handler)
|
||
gdb_notifier.next_file_handler = NULL;
|
||
else
|
||
get_next_file_handler_to_handle_and_advance ();
|
||
}
|
||
|
||
/* Get rid of the file handler in the file handler list. */
|
||
if (file_ptr == gdb_notifier.first_file_handler)
|
||
gdb_notifier.first_file_handler = file_ptr->next_file;
|
||
else
|
||
{
|
||
for (prev_ptr = gdb_notifier.first_file_handler;
|
||
prev_ptr->next_file != file_ptr;
|
||
prev_ptr = prev_ptr->next_file)
|
||
;
|
||
prev_ptr->next_file = file_ptr->next_file;
|
||
}
|
||
xfree (file_ptr);
|
||
}
|
||
|
||
/* Handle the given event by calling the procedure associated to the
|
||
corresponding file handler. */
|
||
|
||
static void
|
||
handle_file_event (file_handler *file_ptr, int ready_mask)
|
||
{
|
||
int mask;
|
||
#ifdef HAVE_POLL
|
||
int error_mask;
|
||
#endif
|
||
|
||
{
|
||
{
|
||
/* With poll, the ready_mask could have any of three events
|
||
set to 1: POLLHUP, POLLERR, POLLNVAL. These events
|
||
cannot be used in the requested event mask (events), but
|
||
they can be returned in the return mask (revents). We
|
||
need to check for those event too, and add them to the
|
||
mask which will be passed to the handler. */
|
||
|
||
/* See if the desired events (mask) match the received
|
||
events (ready_mask). */
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
/* POLLHUP means EOF, but can be combined with POLLIN to
|
||
signal more data to read. */
|
||
error_mask = POLLHUP | POLLERR | POLLNVAL;
|
||
mask = ready_mask & (file_ptr->mask | error_mask);
|
||
|
||
if ((mask & (POLLERR | POLLNVAL)) != 0)
|
||
{
|
||
/* Work in progress. We may need to tell somebody
|
||
what kind of error we had. */
|
||
if (mask & POLLERR)
|
||
printf_unfiltered (_("Error detected on fd %d\n"),
|
||
file_ptr->fd);
|
||
if (mask & POLLNVAL)
|
||
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"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
if (ready_mask & GDB_EXCEPTION)
|
||
{
|
||
printf_unfiltered (_("Exception condition detected "
|
||
"on fd %d\n"), file_ptr->fd);
|
||
file_ptr->error = 1;
|
||
}
|
||
else
|
||
file_ptr->error = 0;
|
||
mask = ready_mask & file_ptr->mask;
|
||
}
|
||
|
||
/* If there was a match, then call the handler. */
|
||
if (mask != 0)
|
||
(*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Wait for new events on the monitored file descriptors. Run the
|
||
event handler if the first descriptor that is detected by the poll.
|
||
If BLOCK and if there are no events, this function will block in
|
||
the call to poll. Return 1 if an event was handled. Return -1 if
|
||
there are no file descriptors to monitor. Return 1 if an event was
|
||
handled, otherwise returns 0. */
|
||
|
||
static int
|
||
gdb_wait_for_event (int block)
|
||
{
|
||
file_handler *file_ptr;
|
||
int num_found = 0;
|
||
|
||
/* Make sure all output is done before getting another event. */
|
||
gdb_flush (gdb_stdout);
|
||
gdb_flush (gdb_stderr);
|
||
|
||
if (gdb_notifier.num_fds == 0)
|
||
return -1;
|
||
|
||
if (block)
|
||
update_wait_timeout ();
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
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. */
|
||
if (num_found == -1 && errno != EINTR)
|
||
perror_with_name (("poll"));
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("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 = 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 if we got a signal, let gdb handle
|
||
it. */
|
||
if (errno != EINTR)
|
||
perror_with_name (("select"));
|
||
}
|
||
}
|
||
|
||
/* Avoid looking at poll_fds[i]->revents if no event fired. */
|
||
if (num_found <= 0)
|
||
return 0;
|
||
|
||
/* Run event handlers. We always run just one handler and go back
|
||
to polling, in case a handler changes the notifier list. Since
|
||
events for sources we haven't consumed yet wake poll/select
|
||
immediately, no event is lost. */
|
||
|
||
/* To level the fairness across event descriptors, we handle them in
|
||
a round-robin-like fashion. The number and order of descriptors
|
||
may change between invocations, but this is good enough. */
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
int i;
|
||
int mask;
|
||
|
||
while (1)
|
||
{
|
||
if (gdb_notifier.next_poll_fds_index >= gdb_notifier.num_fds)
|
||
gdb_notifier.next_poll_fds_index = 0;
|
||
i = gdb_notifier.next_poll_fds_index++;
|
||
|
||
gdb_assert (i < gdb_notifier.num_fds);
|
||
if ((gdb_notifier.poll_fds + i)->revents)
|
||
break;
|
||
}
|
||
|
||
for (file_ptr = gdb_notifier.first_file_handler;
|
||
file_ptr != NULL;
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
if (file_ptr->fd == (gdb_notifier.poll_fds + i)->fd)
|
||
break;
|
||
}
|
||
gdb_assert (file_ptr != NULL);
|
||
|
||
mask = (gdb_notifier.poll_fds + i)->revents;
|
||
handle_file_event (file_ptr, mask);
|
||
return 1;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
/* See comment about even source fairness above. */
|
||
int mask = 0;
|
||
|
||
do
|
||
{
|
||
file_ptr = get_next_file_handler_to_handle_and_advance ();
|
||
|
||
if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0]))
|
||
mask |= GDB_READABLE;
|
||
if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[1]))
|
||
mask |= GDB_WRITABLE;
|
||
if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2]))
|
||
mask |= GDB_EXCEPTION;
|
||
}
|
||
while (mask == 0);
|
||
|
||
handle_file_event (file_ptr, mask);
|
||
return 1;
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Create an asynchronous handler, allocating memory for it.
|
||
Return a pointer to the newly created handler.
|
||
This pointer will be used to invoke the handler by
|
||
invoke_async_signal_handler.
|
||
PROC is the function to call with CLIENT_DATA argument
|
||
whenever the handler is invoked. */
|
||
async_signal_handler *
|
||
create_async_signal_handler (sig_handler_func * proc,
|
||
gdb_client_data client_data)
|
||
{
|
||
async_signal_handler *async_handler_ptr;
|
||
|
||
async_handler_ptr = XNEW (async_signal_handler);
|
||
async_handler_ptr->ready = 0;
|
||
async_handler_ptr->next_handler = NULL;
|
||
async_handler_ptr->proc = proc;
|
||
async_handler_ptr->client_data = client_data;
|
||
if (sighandler_list.first_handler == NULL)
|
||
sighandler_list.first_handler = async_handler_ptr;
|
||
else
|
||
sighandler_list.last_handler->next_handler = async_handler_ptr;
|
||
sighandler_list.last_handler = async_handler_ptr;
|
||
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 associated with a signal. */
|
||
void
|
||
mark_async_signal_handler (async_signal_handler * async_handler_ptr)
|
||
{
|
||
async_handler_ptr->ready = 1;
|
||
serial_event_set (async_signal_handlers_serial_event);
|
||
}
|
||
|
||
/* See event-loop.h. */
|
||
|
||
void
|
||
clear_async_signal_handler (async_signal_handler *async_handler_ptr)
|
||
{
|
||
async_handler_ptr->ready = 0;
|
||
}
|
||
|
||
/* See event-loop.h. */
|
||
|
||
int
|
||
async_signal_handler_is_marked (async_signal_handler *async_handler_ptr)
|
||
{
|
||
return async_handler_ptr->ready;
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* We're going to handle all pending signals, so no need to wake up
|
||
the event loop again the next time around. Note this must be
|
||
cleared _before_ calling the callbacks, to avoid races. */
|
||
serial_event_clear (async_signal_handlers_serial_event);
|
||
|
||
/* Invoke all ready handlers. */
|
||
|
||
while (1)
|
||
{
|
||
for (async_handler_ptr = sighandler_list.first_handler;
|
||
async_handler_ptr != NULL;
|
||
async_handler_ptr = async_handler_ptr->next_handler)
|
||
{
|
||
if (async_handler_ptr->ready)
|
||
break;
|
||
}
|
||
if (async_handler_ptr == NULL)
|
||
break;
|
||
any_ready = 1;
|
||
async_handler_ptr->ready = 0;
|
||
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
|
||
}
|
||
|
||
return any_ready;
|
||
}
|
||
|
||
/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
|
||
Free the space allocated for it. */
|
||
void
|
||
delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
|
||
{
|
||
async_signal_handler *prev_ptr;
|
||
|
||
if (sighandler_list.first_handler == (*async_handler_ptr))
|
||
{
|
||
sighandler_list.first_handler = (*async_handler_ptr)->next_handler;
|
||
if (sighandler_list.first_handler == NULL)
|
||
sighandler_list.last_handler = NULL;
|
||
}
|
||
else
|
||
{
|
||
prev_ptr = sighandler_list.first_handler;
|
||
while (prev_ptr && prev_ptr->next_handler != (*async_handler_ptr))
|
||
prev_ptr = prev_ptr->next_handler;
|
||
gdb_assert (prev_ptr);
|
||
prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
|
||
if (sighandler_list.last_handler == (*async_handler_ptr))
|
||
sighandler_list.last_handler = prev_ptr;
|
||
}
|
||
xfree ((*async_handler_ptr));
|
||
(*async_handler_ptr) = NULL;
|
||
}
|
||
|
||
/* 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)
|
||
{
|
||
async_event_handler *h;
|
||
|
||
h = XNEW (struct async_event_handler);
|
||
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;
|
||
}
|
||
|
||
/* See event-loop.h. */
|
||
|
||
void
|
||
clear_async_event_handler (async_event_handler *async_handler_ptr)
|
||
{
|
||
async_handler_ptr->ready = 0;
|
||
}
|
||
|
||
/* Check if asynchronous event handlers are ready, and call the
|
||
handler function for one that is. */
|
||
|
||
static int
|
||
check_async_event_handlers (void)
|
||
{
|
||
async_event_handler *async_handler_ptr;
|
||
|
||
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;
|
||
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
|
||
return 1;
|
||
}
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* 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;
|
||
gdb_assert (prev_ptr);
|
||
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
|
||
timer is ready, PROC will be executed. At creation, the timer is
|
||
aded to the timers queue. This queue is kept sorted in order of
|
||
increasing timers. Return a handle to the timer struct. */
|
||
int
|
||
create_timer (int milliseconds, timer_handler_func * proc,
|
||
gdb_client_data client_data)
|
||
{
|
||
struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
|
||
struct timeval time_now, delta;
|
||
|
||
/* Compute seconds. */
|
||
delta.tv_sec = milliseconds / 1000;
|
||
/* Compute microseconds. */
|
||
delta.tv_usec = (milliseconds % 1000) * 1000;
|
||
|
||
gettimeofday (&time_now, NULL);
|
||
|
||
timer_ptr = XNEW (struct gdb_timer);
|
||
timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec;
|
||
timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec;
|
||
/* Carry? */
|
||
if (timer_ptr->when.tv_usec >= 1000000)
|
||
{
|
||
timer_ptr->when.tv_sec += 1;
|
||
timer_ptr->when.tv_usec -= 1000000;
|
||
}
|
||
timer_ptr->proc = proc;
|
||
timer_ptr->client_data = client_data;
|
||
timer_list.num_timers++;
|
||
timer_ptr->timer_id = timer_list.num_timers;
|
||
|
||
/* Now add the timer to the timer queue, making sure it is sorted in
|
||
increasing order of expiration. */
|
||
|
||
for (timer_index = timer_list.first_timer;
|
||
timer_index != NULL;
|
||
timer_index = timer_index->next)
|
||
{
|
||
/* 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)))
|
||
break;
|
||
}
|
||
|
||
if (timer_index == timer_list.first_timer)
|
||
{
|
||
timer_ptr->next = timer_list.first_timer;
|
||
timer_list.first_timer = timer_ptr;
|
||
|
||
}
|
||
else
|
||
{
|
||
for (prev_timer = timer_list.first_timer;
|
||
prev_timer->next != timer_index;
|
||
prev_timer = prev_timer->next)
|
||
;
|
||
|
||
prev_timer->next = timer_ptr;
|
||
timer_ptr->next = timer_index;
|
||
}
|
||
|
||
gdb_notifier.timeout_valid = 0;
|
||
return timer_ptr->timer_id;
|
||
}
|
||
|
||
/* There is a chance that the creator of the timer wants to get rid of
|
||
it before it expires. */
|
||
void
|
||
delete_timer (int id)
|
||
{
|
||
struct gdb_timer *timer_ptr, *prev_timer = NULL;
|
||
|
||
/* Find the entry for the given timer. */
|
||
|
||
for (timer_ptr = timer_list.first_timer; timer_ptr != NULL;
|
||
timer_ptr = timer_ptr->next)
|
||
{
|
||
if (timer_ptr->timer_id == id)
|
||
break;
|
||
}
|
||
|
||
if (timer_ptr == NULL)
|
||
return;
|
||
/* Get rid of the timer in the timer list. */
|
||
if (timer_ptr == timer_list.first_timer)
|
||
timer_list.first_timer = timer_ptr->next;
|
||
else
|
||
{
|
||
for (prev_timer = timer_list.first_timer;
|
||
prev_timer->next != timer_ptr;
|
||
prev_timer = prev_timer->next)
|
||
;
|
||
prev_timer->next = timer_ptr->next;
|
||
}
|
||
xfree (timer_ptr);
|
||
|
||
gdb_notifier.timeout_valid = 0;
|
||
}
|
||
|
||
/* Update the timeout for the select() or poll(). Returns true if the
|
||
timer has already expired, false otherwise. */
|
||
|
||
static int
|
||
update_wait_timeout (void)
|
||
{
|
||
struct timeval time_now, delta;
|
||
|
||
if (timer_list.first_timer != NULL)
|
||
{
|
||
gettimeofday (&time_now, NULL);
|
||
delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec;
|
||
delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec;
|
||
/* Borrow? */
|
||
if (delta.tv_usec < 0)
|
||
{
|
||
delta.tv_sec -= 1;
|
||
delta.tv_usec += 1000000;
|
||
}
|
||
|
||
/* Cannot simply test if delta.tv_sec is negative because time_t
|
||
might be unsigned. */
|
||
if (timer_list.first_timer->when.tv_sec < time_now.tv_sec
|
||
|| (timer_list.first_timer->when.tv_sec == time_now.tv_sec
|
||
&& timer_list.first_timer->when.tv_usec < time_now.tv_usec))
|
||
{
|
||
/* It expired already. */
|
||
delta.tv_sec = 0;
|
||
delta.tv_usec = 0;
|
||
}
|
||
|
||
/* Update the timeout for select/ poll. */
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
gdb_notifier.poll_timeout = delta.tv_sec * 1000;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
gdb_notifier.select_timeout.tv_sec = delta.tv_sec;
|
||
gdb_notifier.select_timeout.tv_usec = delta.tv_usec;
|
||
}
|
||
gdb_notifier.timeout_valid = 1;
|
||
|
||
if (delta.tv_sec == 0 && delta.tv_usec == 0)
|
||
return 1;
|
||
}
|
||
else
|
||
gdb_notifier.timeout_valid = 0;
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Check whether a timer in the timers queue is ready. If a timer is
|
||
ready, call its handler and return. Update the timeout for the
|
||
select() or poll() as well. Return 1 if an event was handled,
|
||
otherwise returns 0.*/
|
||
|
||
static int
|
||
poll_timers (void)
|
||
{
|
||
if (update_wait_timeout ())
|
||
{
|
||
struct gdb_timer *timer_ptr = timer_list.first_timer;
|
||
timer_handler_func *proc = timer_ptr->proc;
|
||
gdb_client_data client_data = timer_ptr->client_data;
|
||
|
||
/* Get rid of the timer from the beginning of the list. */
|
||
timer_list.first_timer = timer_ptr->next;
|
||
|
||
/* Delete the timer before calling the callback, not after, in
|
||
case the callback itself decides to try deleting the timer
|
||
too. */
|
||
xfree (timer_ptr);
|
||
|
||
/* Call the procedure associated with that timer. */
|
||
(proc) (client_data);
|
||
|
||
return 1;
|
||
}
|
||
|
||
return 0;
|
||
}
|