/* Event loop machinery for GDB, the GNU debugger.
- Copyright (C) 1999, 2000, 2001, 2002, 2005, 2006, 2007, 2008, 2009, 2010
- Free Software Foundation, Inc.
+ Copyright (C) 1999-2018 Free Software Foundation, Inc.
Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
This file is part of GDB.
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/>. */
+ 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)
#endif
#include <sys/types.h>
-#include "gdb_string.h"
-#include <errno.h>
-#include <sys/time.h>
-#include "exceptions.h"
-#include "gdb_assert.h"
+#include "gdb_sys_time.h"
#include "gdb_select.h"
+#include "observable.h"
+#include "top.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
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
+ 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
+ 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
case of async signal handlers, it is
invoke_async_signal_handler. */
-struct gdb_event
+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;
-
- /* Next in list of events or NULL. */
- struct gdb_event *next_event;
- };
+ } *gdb_event_p;
/* Information about each file descriptor we register with the event
- loop. */
+ loop. */
typedef struct file_handler
{
- int fd; /* File descriptor. */
- int mask; /* Events we want to monitor: POLLIN, etc. */
+ 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. */
+ 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
+/* 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.
+ 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. */
+ 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 */
+ 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;
}
async_event_handler;
-
-/* Event queue:
- - the first event in the queue is the head of the queue.
- It will be the next to be serviced.
- - the last event in the queue
-
- Events can be inserted at the front of the queue or at the end of
- the queue. Events will be extracted from the queue for processing
- starting from the head. Therefore, events inserted at the head of
- the queue will be processed in a last in first out fashion, while
- those inserted at the tail of the queue will be processed in a first
- in first out manner. All the fields are NULL if the queue is
- empty. */
-
-static struct
- {
- gdb_event *first_event; /* First pending event */
- gdb_event *last_event; /* Last pending event */
- }
-event_queue;
-
/* 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
+ 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
+ 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. */
+ in, for each fd. */
/* As of 1999-04-30 only the input file descriptor is registered with the
- event loop. */
+ event loop. */
/* Do we use poll or select ? */
#ifdef HAVE_POLL
static struct
{
- /* Ptr to head of file handler list. */
+ /* 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. */
+ /* Ptr to array of pollfd structures. */
struct pollfd *poll_fds;
- /* Timeout in milliseconds for calls to poll(). */
+ /* 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. */
+ Bits are set in response to calls to create_file_handler. */
fd_set check_masks[3];
- /* What file descriptors were found ready by select. */
+ /* 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) */
+ /* 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(). */
+ /* Time structure for calls to select(). */
struct timeval select_timeout;
- /* Flag to tell whether the timeout should be used. */
+ /* 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. */
+/* Structure associated with a timer. PROC will be executed at the
+ first occasion after WHEN. */
struct gdb_timer
{
- struct timeval when;
+ std::chrono::steady_clock::time_point 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 */
+ 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. */
+/* List of currently active timers. It is sorted in order of
+ increasing timers. */
static struct
{
- /* Pointer to first in timer list. */
+ /* Pointer to first in timer list. */
struct gdb_timer *first_timer;
- /* Id of the last timer created. */
+ /* 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. */
+ this list. */
static struct
{
- /* Pointer to first in handler list. */
+ /* Pointer to first in handler list. */
async_signal_handler *first_handler;
- /* Pointer to last in handler list. */
+ /* 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. */
+ this list. */
static struct
{
- /* Pointer to first in handler list. */
+ /* Pointer to first in handler list. */
async_event_handler *first_handler;
- /* Pointer to last in handler list. */
+ /* 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 int check_async_event_handlers (void);
static int gdb_wait_for_event (int);
-static void poll_timers (void);
+static int update_wait_timeout (void);
+static int poll_timers (void);
\f
-/* Insert an event object into the gdb event queue at
- the specified position.
- POSITION can be head or tail, with values TAIL, HEAD.
- EVENT_PTR points to the event to be inserted into the queue.
- The caller must allocate memory for the event. It is freed
- after the event has ben handled.
- Events in the queue will be processed head to tail, therefore,
- events inserted at the head of the queue will be processed
- as last in first out. Event appended at the tail of the queue
- will be processed first in first out. */
-static void
-async_queue_event (gdb_event * event_ptr, queue_position position)
-{
- if (position == TAIL)
- {
- /* The event will become the new last_event. */
-
- event_ptr->next_event = NULL;
- if (event_queue.first_event == NULL)
- event_queue.first_event = event_ptr;
- else
- event_queue.last_event->next_event = event_ptr;
- event_queue.last_event = event_ptr;
- }
- else if (position == HEAD)
- {
- /* The event becomes the new first_event. */
-
- event_ptr->next_event = event_queue.first_event;
- if (event_queue.first_event == NULL)
- event_queue.last_event = event_ptr;
- event_queue.first_event = event_ptr;
- }
-}
+/* 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;
-/* 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. */
+/* Callback registered with ASYNC_SIGNAL_HANDLERS_SERIAL_EVENT. */
-static gdb_event *
-create_event (event_handler_func proc, event_data data)
+static void
+async_signals_handler (int error, gdb_client_data client_data)
{
- gdb_event *event;
-
- event = xmalloc (sizeof (*event));
- event->proc = proc;
- event->data = data;
-
- return event;
+ /* Do nothing. Handlers are run by invoke_async_signal_handlers
+ from instead. */
}
-/* 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
- associated to FD when it was registered with the event loop. */
-static gdb_event *
-create_file_event (int fd)
+void
+initialize_async_signal_handlers (void)
{
- event_data data;
+ async_signal_handlers_serial_event = make_serial_event ();
- data.integer = fd;
- return create_event (handle_file_event, data);
-}
-
-/* Process one event.
- The event can be the next one to be serviced in the event queue,
- 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.
- Scan the queue from head to tail, processing therefore the high
- priority events first, by invoking the associated event handler
- procedure. */
-static int
-process_event (void)
-{
- gdb_event *event_ptr, *prev_ptr;
- event_handler_func *proc;
- 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 (invoke_async_signal_handlers ())
- return 1;
-
- /* Look in the event queue to find an event that is ready
- to be processed. */
-
- for (event_ptr = event_queue.first_event; event_ptr != NULL;
- event_ptr = event_ptr->next_event)
- {
- /* Call the handler for the event. */
-
- proc = event_ptr->proc;
- 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
- function could end up calling 'error' and therefore jump out
- to the caller of this function, gdb_do_one_event. In that
- case, we would have on the event queue an event wich has been
- processed, but not deleted. */
-
- if (event_queue.first_event == event_ptr)
- {
- event_queue.first_event = event_ptr->next_event;
- if (event_ptr->next_event == NULL)
- event_queue.last_event = NULL;
- }
- else
- {
- prev_ptr = event_queue.first_event;
- while (prev_ptr->next_event != event_ptr)
- prev_ptr = prev_ptr->next_event;
-
- prev_ptr->next_event = event_ptr->next_event;
- if (event_ptr->next_event == NULL)
- event_queue.last_event = prev_ptr;
- }
- xfree (event_ptr);
-
- /* Now call the procedure associated with the event. */
- (*proc) (data);
- return 1;
- }
-
- /* this is the case if there are no event on the event queue. */
- return 0;
+ 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). If an error
- occurs catch_errors() which calls this function returns zero. */
+ can happen if there are no event sources to wait for). */
int
-gdb_do_one_event (void *data)
+gdb_do_one_event (void)
{
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 ())
+ /* 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? If so, put an event on the
- queue. */
- poll_timers ();
+ /* 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? */
- gdb_wait_for_event (0);
+ res = gdb_wait_for_event (0);
break;
case 2:
/* Are there any asynchronous event handlers ready? */
- check_async_event_handlers ();
+ 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;
- }
- /* Handle any new events collected. */
- if (process_event ())
- return 1;
+ 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
if (gdb_wait_for_event (1) < 0)
return -1;
- /* Handle any new events occurred while waiting. */
- if (process_event ())
- 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. */
+/* 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, called via catch_errors()
- will process one event for each invocation. It blocks waits for
- an event and then processes it. >0 when an event is processed, 0
- when catch_errors() caught an error and <0 when there are no
- longer any event sources registered. */
+ /* 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 gdb_result;
+ int result = 0;
- gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
- if (gdb_result < 0)
- break;
-
- /* 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)
+ 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 ();
- /* FIXME: this should really be a call to a hook that is
- interface specific, because interfaces can display the
- prompt in their own way. */
- display_gdb_prompt (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. */
+ current_ui->prompt_state = PROMPT_NEEDED;
+ gdb::observers::command_error.notify ();
/* 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
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. */
+ 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. */
+ /* We are done with the event loop. There are no more event sources
+ to listen to. So we exit GDB. */
return;
}
\f
/* Wrapper function for create_file_handler, so that the caller
doesn't have to know implementation details about the use of poll
- vs. select. */
+ vs. select. */
void
add_file_handler (int fd, handler_func * proc, gdb_client_data client_data)
{
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
+ /* 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. */
+ `poll'able. */
fds.fd = fd;
fds.events = POLLIN;
if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL))
#endif
}
else
- create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, proc, client_data);
+ 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. */
+ 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)
+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). */
+ /* 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)
{
break;
}
- /* It is a new file descriptor. Add it to the list. Otherwise, just
- change the data associated with it. */
+ /* 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 = XNEW (file_handler);
file_ptr->fd = fd;
file_ptr->ready_mask = 0;
file_ptr->next_file = gdb_notifier.first_file_handler;
* sizeof (struct pollfd)));
else
gdb_notifier.poll_fds =
- (struct pollfd *) xmalloc (sizeof (struct pollfd));
+ 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;
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. */
+ i.e. we don't care anymore about events on the FD. */
void
delete_file_handler (int fd)
{
struct pollfd *new_poll_fds;
#endif
- /* Find the entry for the given file. */
+ /* 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 (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. */
+ /* 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));
+ 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++)
{
{
(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;
+ (new_poll_fds + j)->revents
+ = (gdb_notifier.poll_fds + i)->revents;
j++;
}
}
if (file_ptr->mask & GDB_EXCEPTION)
FD_CLR (fd, &gdb_notifier.check_masks[2]);
- /* Find current max fd. */
+ /* Find current max fd. */
if ((fd + 1) == gdb_notifier.num_fds)
{
}
/* Deactivate the file descriptor, by clearing its mask,
- so that it will not fire again. */
+ so that it will not fire again. */
file_ptr->mask = 0;
- /* Get rid of the file handler in the file handler list. */
+ /* 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
}
/* Handle the given event by calling the procedure associated to the
- corresponding file handler. Called by process_event indirectly,
- through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
- event in the front of the event queue. */
+ corresponding file handler. */
+
static void
-handle_file_event (event_data data)
+handle_file_event (file_handler *file_ptr, int ready_mask)
{
- file_handler *file_ptr;
int mask;
#ifdef HAVE_POLL
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. */
- for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
- file_ptr = file_ptr->next_file)
{
- if (file_ptr->fd == event_file_desc)
{
/* 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. */
+ 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). */
+ 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 = (file_ptr->ready_mask & file_ptr->mask) |
- (file_ptr->ready_mask & error_mask);
- error_mask_returned = mask & error_mask;
+ mask = ready_mask & (file_ptr->mask | error_mask);
- if (error_mask_returned != 0)
+ if ((mask & (POLLERR | POLLNVAL)) != 0)
{
- /* 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);
- if (error_mask_returned & POLLERR)
- 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);
+ /* 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
}
else
{
- if (file_ptr->ready_mask & GDB_EXCEPTION)
+ if (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
file_ptr->error = 0;
- mask = file_ptr->ready_mask & file_ptr->mask;
+ mask = ready_mask & file_ptr->mask;
}
- /* Clear the received events for next time around. */
- file_ptr->ready_mask = 0;
-
- /* If there was a match, then call the handler. */
+ /* If there was a match, then call the handler. */
if (mask != 0)
(*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
- break;
}
}
}
-/* 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. */
+/* 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;
- gdb_event *file_event_ptr;
int num_found = 0;
- int i;
- /* Make sure all output is done before getting another event. */
+ /* 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
else
{
struct timeval select_timeout;
-
struct timeval *timeout_p;
+
if (block)
timeout_p = gdb_notifier.timeout_valid
? &gdb_notifier.select_timeout : NULL;
&gdb_notifier.ready_masks[2],
timeout_p);
- /* Clear the masks after an error from select. */
+ /* Clear the masks after an error from select. */
if (num_found == -1)
{
FD_ZERO (&gdb_notifier.ready_masks[0]);
}
}
- /* Enqueue all detected file events. */
+ /* 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
- for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
+ int i;
+ int mask;
+
+ while (1)
{
- if ((gdb_notifier.poll_fds + i)->revents)
- num_found--;
- else
- continue;
+ 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++;
- 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 (i < gdb_notifier.num_fds);
+ if ((gdb_notifier.poll_fds + i)->revents)
+ break;
+ }
- if (file_ptr)
- {
- /* Enqueue an event only if this is still a new event for
- this fd. */
- if (file_ptr->ready_mask == 0)
- {
- 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;
- }
+ 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"));
}
else
{
- for (file_ptr = gdb_notifier.first_file_handler;
- (file_ptr != NULL) && (num_found > 0);
- file_ptr = file_ptr->next_file)
+ /* See comment about even source fairness above. */
+ int mask = 0;
+
+ do
{
- int mask = 0;
+ file_ptr = get_next_file_handler_to_handle_and_advance ();
if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[0]))
mask |= GDB_READABLE;
mask |= GDB_WRITABLE;
if (FD_ISSET (file_ptr->fd, &gdb_notifier.ready_masks[2]))
mask |= GDB_EXCEPTION;
-
- if (!mask)
- continue;
- else
- num_found--;
-
- /* Enqueue an event only if this is still a new event for
- this fd. */
-
- if (file_ptr->ready_mask == 0)
- {
- file_event_ptr = create_file_event (file_ptr->fd);
- async_queue_event (file_event_ptr, TAIL);
- }
- file_ptr->ready_mask = mask;
}
+ while (mask == 0);
+
+ handle_file_event (file_ptr, mask);
+ return 1;
}
return 0;
}
\f
-/* Create an asynchronous handler, allocating memory for it.
+/* 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. */
+ whenever the handler is invoked. */
async_signal_handler *
-create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data)
+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 = XNEW (async_signal_handler);
async_handler_ptr->ready = 0;
async_handler_ptr->next_handler = NULL;
async_handler_ptr->proc = proc;
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. */
+/* 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
-call_async_signal_handler (struct async_signal_handler *handler)
+mark_async_signal_handler (async_signal_handler * async_handler_ptr)
{
- (*handler->proc) (handler->client_data);
+ async_handler_ptr->ready = 1;
+ serial_event_set (async_signal_handlers_serial_event);
}
-/* 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. */
+/* See event-loop.h. */
+
void
-mark_async_signal_handler (async_signal_handler * async_handler_ptr)
+clear_async_signal_handler (async_signal_handler *async_handler_ptr)
{
- async_handler_ptr->ready = 1;
+ 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;
- /* Invoke ready handlers. */
+ /* 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)
{
break;
any_ready = 1;
async_handler_ptr->ready = 0;
+ /* Async signal handlers have no connection to whichever was the
+ current UI, and thus always run on the main one. */
+ current_ui = main_ui;
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
}
return any_ready;
}
-/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
+/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
Free the space allocated for it. */
void
delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
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;
{
async_event_handler *h;
- h = xmalloc (sizeof (*h));
+ h = XNEW (struct async_event_handler);
h->ready = 0;
h->next_handler = NULL;
h->proc = proc;
async_handler_ptr->ready = 1;
}
-struct async_event_handler_data
-{
- async_event_handler_func* proc;
- gdb_client_data client_data;
-};
+/* See event-loop.h. */
-static void
-invoke_async_event_handler (event_data data)
+void
+clear_async_event_handler (async_event_handler *async_handler_ptr)
{
- 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);
+ async_handler_ptr->ready = 0;
}
-/* Check if any asynchronous event handlers are ready, and queue
- events in the ready queue for any that are. */
-static void
+/* 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;
- 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;
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);
+ (*async_handler_ptr->proc) (async_handler_ptr->client_data);
+ return 1;
}
}
+
+ return 0;
}
/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
if (async_event_handler_list.first_handler == *async_handler_ptr)
{
- async_event_handler_list.first_handler = (*async_handler_ptr)->next_handler;
+ 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;
}
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;
*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. */
+/* Create a timer that will expire in MS milliseconds from now. When
+ the timer is ready, PROC will be executed. At creation, the timer
+ is added 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)
+create_timer (int ms, timer_handler_func *proc,
+ gdb_client_data client_data)
{
+ using namespace std::chrono;
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);
+ steady_clock::time_point time_now = steady_clock::now ();
- 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 = new gdb_timer ();
+ timer_ptr->when = time_now + milliseconds (ms);
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. */
+ 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)))
+ if (timer_index->when > timer_ptr->when)
break;
}
}
/* There is a chance that the creator of the timer wants to get rid of
- it before it expires. */
+ it before it expires. */
void
delete_timer (int id)
{
struct gdb_timer *timer_ptr, *prev_timer = NULL;
- /* Find the entry for the given timer. */
+ /* 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 == NULL)
return;
- /* Get rid of the timer in the timer list. */
+ /* Get rid of the timer in the timer list. */
if (timer_ptr == timer_list.first_timer)
timer_list.first_timer = timer_ptr->next;
else
;
prev_timer->next = timer_ptr->next;
}
- xfree (timer_ptr);
+ delete timer_ptr;
gdb_notifier.timeout_valid = 0;
}
-/* When a timer event is put on the event queue, it will be handled by
- 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 (event_data dummy)
-{
- struct timeval time_now;
- struct gdb_timer *timer_ptr, *saved_timer;
+/* Convert a std::chrono duration to a struct timeval. */
- gettimeofday (&time_now, NULL);
- timer_ptr = timer_list.first_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)))
- break;
-
- /* Get rid of the timer from the beginning of the list. */
- timer_list.first_timer = timer_ptr->next;
- saved_timer = timer_ptr;
- timer_ptr = timer_ptr->next;
- /* Call the procedure associated with that timer. */
- (*saved_timer->proc) (saved_timer->client_data);
- xfree (saved_timer);
- }
-
- gdb_notifier.timeout_valid = 0;
+template<typename Duration>
+static struct timeval
+duration_cast_timeval (const Duration &d)
+{
+ using namespace std::chrono;
+ seconds sec = duration_cast<seconds> (d);
+ microseconds msec = duration_cast<microseconds> (d - sec);
+
+ struct timeval tv;
+ tv.tv_sec = sec.count ();
+ tv.tv_usec = msec.count ();
+ return tv;
}
-/* Check whether any timers in the timers queue are ready. If at least
- one timer is ready, stick an event onto the event queue. Even in
- case more than one timer is ready, one event is enough, because the
- handle_timer_event() will go through the timers list and call the
- procedures associated with all that have expired. Update the
- timeout for the select() or poll() as well. */
-static void
-poll_timers (void)
-{
- struct timeval time_now, delta;
- gdb_event *event_ptr;
+/* Update the timeout for the select() or poll(). Returns true if the
+ timer has already expired, false otherwise. */
+static int
+update_wait_timeout (void)
+{
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;
- }
+ using namespace std::chrono;
+ steady_clock::time_point time_now = steady_clock::now ();
+ struct timeval timeout;
- /* Oops it expired already. Tell select / poll to return
- immediately. (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))
+ if (timer_list.first_timer->when < time_now)
{
- delta.tv_sec = 0;
- delta.tv_usec = 0;
+ /* It expired already. */
+ timeout.tv_sec = 0;
+ timeout.tv_usec = 0;
}
-
- if (delta.tv_sec == 0 && delta.tv_usec == 0)
+ else
{
- event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
- event_ptr->proc = handle_timer_event;
- event_ptr->data.integer = timer_list.first_timer->timer_id;
- async_queue_event (event_ptr, TAIL);
+ steady_clock::duration d = timer_list.first_timer->when - time_now;
+ timeout = duration_cast_timeval (d);
}
- /* Now we need to update the timeout for select/ poll, because we
- don't want to sit there while this timer is expiring. */
+ /* Update the timeout for select/ poll. */
if (use_poll)
{
#ifdef HAVE_POLL
- gdb_notifier.poll_timeout = delta.tv_sec * 1000;
+ gdb_notifier.poll_timeout = timeout.tv_sec * 1000;
#else
internal_error (__FILE__, __LINE__,
_("use_poll without HAVE_POLL"));
}
else
{
- gdb_notifier.select_timeout.tv_sec = delta.tv_sec;
- gdb_notifier.select_timeout.tv_usec = delta.tv_usec;
+ gdb_notifier.select_timeout.tv_sec = timeout.tv_sec;
+ gdb_notifier.select_timeout.tv_usec = timeout.tv_usec;
}
gdb_notifier.timeout_valid = 1;
+
+ if (timer_list.first_timer->when < time_now)
+ 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. */
+ delete timer_ptr;
+
+ /* Call the procedure associated with that timer. */
+ (proc) (client_data);
+
+ return 1;
+ }
+
+ return 0;
}
projects / thirdparty / binutils-gdb.git / blobdiff