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- /* Event loop machinery for GDB, the GNU debugger.
- Copyright (C) 1999-2022 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 "gdbsupport/common-defs.h"
- #include "gdbsupport/event-loop.h"
- #include <chrono>
- #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 "gdbsupport/gdb_sys_time.h"
- #include "gdbsupport/gdb_select.h"
- /* See event-loop.h. */
- debug_event_loop_kind debug_event_loop;
- /* 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)
- /* Information about each file descriptor we register with the event
- loop. */
- struct file_handler
- {
- /* File descriptor. */
- int fd;
- /* Events we want to monitor: POLLIN, etc. */
- int mask;
- /* Events that have been seen since the last time. */
- int ready_mask;
- /* Procedure to call when fd is ready. */
- handler_func *proc;
- /* Argument to pass to proc. */
- gdb_client_data client_data;
- /* User-friendly name of this handler. */
- std::string name;
- /* If set, this file descriptor is used for a user interface. */
- bool is_ui;
- /* Was an error detected on this fd? */
- int error;
- /* Next registered file descriptor. */
- struct file_handler *next_file;
- };
- /* 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
- /* 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. */
- 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
- {
- 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. */
- };
- /* 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;
- static void create_file_handler (int fd, int mask, handler_func *proc,
- gdb_client_data client_data,
- std::string &&name, bool is_ui);
- 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;
- }
- /* See event-loop.h */
- void
- add_file_handler (int fd, handler_func *proc, gdb_client_data client_data,
- std::string &&name, bool is_ui)
- {
- #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, std::move (name),
- is_ui);
- #else
- internal_error (__FILE__, __LINE__,
- _("use_poll without HAVE_POLL"));
- #endif
- }
- else
- create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION,
- proc, client_data, std::move (name), is_ui);
- }
- /* Helper for add_file_handler.
- 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, std::string &&name,
- bool is_ui)
- {
- 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 = new 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;
- file_ptr->name = std::move (name);
- file_ptr->is_ui = is_ui;
- }
- /* 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;
- }
- delete 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)
- warning (_("Error detected on fd %d"), file_ptr->fd);
- if (mask & POLLNVAL)
- warning (_("Invalid or non-`poll'able fd %d"),
- 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)
- {
- warning (_("Exception condition detected on fd %d"),
- 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)
- {
- event_loop_ui_debug_printf (file_ptr->is_ui,
- "invoking fd file handler `%s`",
- file_ptr->name.c_str ());
- 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. */
- flush_streams ();
- 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 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 ms, timer_handler_func *proc,
- gdb_client_data client_data)
- {
- using namespace std::chrono;
- struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
- steady_clock::time_point time_now = steady_clock::now ();
- 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. */
- for (timer_index = timer_list.first_timer;
- timer_index != NULL;
- timer_index = timer_index->next)
- {
- if (timer_index->when > timer_ptr->when)
- 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;
- }
- delete timer_ptr;
- gdb_notifier.timeout_valid = 0;
- }
- /* Convert a std::chrono duration to a struct timeval. */
- 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;
- }
- /* 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)
- {
- using namespace std::chrono;
- steady_clock::time_point time_now = steady_clock::now ();
- struct timeval timeout;
- if (timer_list.first_timer->when < time_now)
- {
- /* It expired already. */
- timeout.tv_sec = 0;
- timeout.tv_usec = 0;
- }
- else
- {
- steady_clock::duration d = timer_list.first_timer->when - time_now;
- timeout = duration_cast_timeval (d);
- }
- /* Update the timeout for select/ poll. */
- if (use_poll)
- {
- #ifdef HAVE_POLL
- gdb_notifier.poll_timeout = timeout.tv_sec * 1000;
- #else
- internal_error (__FILE__, __LINE__,
- _("use_poll without HAVE_POLL"));
- #endif /* HAVE_POLL */
- }
- else
- {
- 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;
- }
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