492d29ea1c
This patch splits the TRY_CATCH macro into three, so that we go from
this:
~~~
volatile gdb_exception ex;
TRY_CATCH (ex, RETURN_MASK_ERROR)
{
}
if (ex.reason < 0)
{
}
~~~
to this:
~~~
TRY
{
}
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
~~~
Thus, we'll be getting rid of the local volatile exception object, and
declaring the caught exception in the catch block.
This allows reimplementing TRY/CATCH in terms of C++ exceptions when
building in C++ mode, while still allowing to build GDB in C mode
(using setjmp/longjmp), as a transition step.
TBC, after this patch, is it _not_ valid to have code between the TRY
and the CATCH blocks, like:
TRY
{
}
// some code here.
CATCH (ex, RETURN_MASK_ERROR)
{
}
END_CATCH
Just like it isn't valid to do that with C++'s native try/catch.
By switching to creating the exception object inside the CATCH block
scope, we can get rid of all the explicitly allocated volatile
exception objects all over the tree, and map the CATCH block more
directly to C++'s catch blocks.
The majority of the TRY_CATCH -> TRY+CATCH+END_CATCH conversion was
done with a script, rerun from scratch at every rebase, no manual
editing involved. After the mechanical conversion, a few places
needed manual intervention, to fix preexisting cases where we were
using the exception object outside of the TRY_CATCH block, and cases
where we were using "else" after a 'if (ex.reason) < 0)' [a CATCH
after this patch]. The result was folded into this patch so that GDB
still builds at each incremental step.
END_CATCH is necessary for two reasons:
First, because we name the exception object in the CATCH block, which
requires creating a scope, which in turn must be closed somewhere.
Declaring the exception variable in the initializer field of a for
block, like:
#define CATCH(EXCEPTION, mask) \
for (struct gdb_exception EXCEPTION; \
exceptions_state_mc_catch (&EXCEPTION, MASK); \
EXCEPTION = exception_none)
would avoid needing END_CATCH, but alas, in C mode, we build with C90,
which doesn't allow mixed declarations and code.
Second, because when TRY/CATCH are wired to real C++ try/catch, as
long as we need to handle cleanup chains, even if there's no CATCH
block that wants to catch the exception, we need for stop at every
frame in the unwind chain and run cleanups, then rethrow. That will
be done in END_CATCH.
After we require C++, we'll still need TRY/CATCH/END_CATCH until
cleanups are completely phased out -- TRY/CATCH in C++ mode will
save/restore the current cleanup chain, like in C mode, and END_CATCH
catches otherwise uncaugh exceptions, runs cleanups and rethrows, so
that C++ cleanups and exceptions can coexist.
IMO, this still makes the TRY/CATCH code look a bit more like a
newcomer would expect, so IMO worth it even if we weren't considering
C++.
gdb/ChangeLog.
2015-03-07 Pedro Alves <palves@redhat.com>
* common/common-exceptions.c (struct catcher) <exception>: No
longer a pointer to volatile exception. Now an exception value.
<mask>: Delete field.
(exceptions_state_mc_init): Remove all parameters. Adjust.
(exceptions_state_mc): No longer pop the catcher here.
(exceptions_state_mc_catch): New function.
(throw_exception): Adjust.
* common/common-exceptions.h (exceptions_state_mc_init): Remove
all parameters.
(exceptions_state_mc_catch): Declare.
(TRY_CATCH): Rename to ...
(TRY): ... this. Remove EXCEPTION and MASK parameters.
(CATCH, END_CATCH): New.
All callers adjusted.
gdb/gdbserver/ChangeLog:
2015-03-07 Pedro Alves <palves@redhat.com>
Adjust all callers of TRY_CATCH to use TRY/CATCH/END_CATCH
instead.
1191 lines
34 KiB
C
1191 lines
34 KiB
C
/* Event loop machinery for GDB, the GNU debugger.
|
||
Copyright (C) 1999-2015 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"
|
||
|
||
#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 <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;
|
||
|
||
#ifdef HAVE_POLL
|
||
/* Ptr to array of pollfd structures. */
|
||
struct pollfd *poll_fds;
|
||
|
||
/* 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);
|
||
|
||
|
||
/* 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 = (file_handler *) xmalloc (sizeof (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 =
|
||
(struct pollfd *) xmalloc (sizeof (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;
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* 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;
|
||
int i;
|
||
|
||
/* 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"));
|
||
}
|
||
}
|
||
|
||
/* 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. */
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
|
||
{
|
||
if ((gdb_notifier.poll_fds + i)->revents)
|
||
num_found--;
|
||
else
|
||
continue;
|
||
|
||
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;
|
||
}
|
||
|
||
if (file_ptr)
|
||
{
|
||
int 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
|
||
{
|
||
for (file_ptr = gdb_notifier.first_file_handler;
|
||
(file_ptr != NULL) && (num_found > 0);
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
int mask = 0;
|
||
|
||
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;
|
||
|
||
if (!mask)
|
||
continue;
|
||
else
|
||
num_found--;
|
||
|
||
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 =
|
||
(async_signal_handler *) xmalloc (sizeof (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;
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* Invoke 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 = 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;
|
||
}
|
||
|
||
/* 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 = (struct gdb_timer *) xmalloc (sizeof (*timer_ptr));
|
||
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;
|
||
}
|