From: Tom Tromey Date: Mon, 13 Apr 2020 18:42:59 +0000 (-0600) Subject: Move event-loop.[ch] to gdbsupport/ X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=400b5eca00033a782467d28b23392b9cf428c2b1;p=binutils-gdb.git Move event-loop.[ch] to gdbsupport/ This moves event-loop.[ch] to gdbsupport/ and updates the uses in gdb. gdb/ChangeLog 2020-04-13 Tom Tromey * run-on-main-thread.c: Update include. * unittests/main-thread-selftests.c: Update include. * tui/tui-win.c: Update include. * tui/tui-io.c: Update include. * tui/tui-interp.c: Update include. * tui/tui-hooks.c: Update include. * top.h: Update include. * top.c: Update include. * ser-base.c: Update include. * remote.c: Update include. * remote-notif.c: Update include. * remote-fileio.c: Update include. * record-full.c: Update include. * record-btrace.c: Update include. * python/python.c: Update include. * posix-hdep.c: Update include. * mingw-hdep.c: Update include. * mi/mi-main.c: Update include. * mi/mi-interp.c: Update include. * main.c: Update include. * linux-nat.c: Update include. * interps.c: Update include. * infrun.c: Update include. * inf-loop.c: Update include. * event-top.c: Update include. * event-loop.c: Move to ../gdbsupport/. * event-loop.h: Move to ../gdbsupport/. * async-event.h: Update include. * Makefile.in (COMMON_SFILES, HFILES_NO_SRCDIR): Update. gdbsupport/ChangeLog 2020-04-13 Tom Tromey * event-loop.h: Move from ../gdb/. * event-loop.cc: Move from ../gdb/. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a108cd1dced..f624c15a4fe 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,35 @@ +2020-04-13 Tom Tromey + + * run-on-main-thread.c: Update include. + * unittests/main-thread-selftests.c: Update include. + * tui/tui-win.c: Update include. + * tui/tui-io.c: Update include. + * tui/tui-interp.c: Update include. + * tui/tui-hooks.c: Update include. + * top.h: Update include. + * top.c: Update include. + * ser-base.c: Update include. + * remote.c: Update include. + * remote-notif.c: Update include. + * remote-fileio.c: Update include. + * record-full.c: Update include. + * record-btrace.c: Update include. + * python/python.c: Update include. + * posix-hdep.c: Update include. + * mingw-hdep.c: Update include. + * mi/mi-main.c: Update include. + * mi/mi-interp.c: Update include. + * main.c: Update include. + * linux-nat.c: Update include. + * interps.c: Update include. + * infrun.c: Update include. + * inf-loop.c: Update include. + * event-top.c: Update include. + * event-loop.c: Move to ../gdbsupport/. + * event-loop.h: Move to ../gdbsupport/. + * async-event.h: Update include. + * Makefile.in (COMMON_SFILES, HFILES_NO_SRCDIR): Update. + 2020-04-13 Tom Tromey * tui/tui-win.c: Include async-event.h. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index bb96998630c..e3ce6a285f7 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -1019,7 +1019,6 @@ COMMON_SFILES = \ dwarf2/section.c \ dwarf2/stringify.c \ eval.c \ - event-loop.c \ event-top.c \ exceptions.c \ exec.c \ @@ -1254,7 +1253,6 @@ HFILES_NO_SRCDIR = \ dwarf2/index-common.h \ dwarf2/loc.h \ dwarf2/read.h \ - event-loop.h \ event-top.h \ exceptions.h \ exec.h \ diff --git a/gdb/async-event.h b/gdb/async-event.h index 408f7764f7c..3b3747a2604 100644 --- a/gdb/async-event.h +++ b/gdb/async-event.h @@ -19,7 +19,7 @@ #ifndef ASYNC_EVENT_H #define ASYNC_EVENT_H -#include "event-loop.h" +#include "gdbsupport/event-loop.h" struct async_signal_handler; struct async_event_handler; diff --git a/gdb/event-loop.c b/gdb/event-loop.c deleted file mode 100644 index e5347d2e3f0..00000000000 --- a/gdb/event-loop.c +++ /dev/null @@ -1,889 +0,0 @@ -/* Event loop machinery for GDB, the GNU debugger. - Copyright (C) 1999-2020 Free Software Foundation, Inc. - Written by Elena Zannoni 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 . */ - -#include "defs.h" -#include "event-loop.h" - -#include - -#ifdef HAVE_POLL -#if defined (HAVE_POLL_H) -#include -#elif defined (HAVE_SYS_POLL_H) -#include -#endif -#endif - -#include -#include "gdbsupport/gdb_sys_time.h" -#include "gdbsupport/gdb_select.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) - -/* 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; - -/* 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 -#include -#endif - -static struct - { - /* Ptr to head of file handler list. */ - file_handler *first_file_handler; - - /* Next file handler to handle, for the select variant. To level - the fairness across event sources, we serve file handlers in a - round-robin-like fashion. The number and order of the polled - file handlers may change between invocations, but this is good - enough. */ - file_handler *next_file_handler; - -#ifdef HAVE_POLL - /* Ptr to array of pollfd structures. */ - struct pollfd *poll_fds; - - /* Next file descriptor to handle, for the poll variant. To level - the fairness across event sources, we poll the file descriptors - in a round-robin-like fashion. The number and order of the - polled file descriptors may change between invocations, but - this is good enough. */ - int next_poll_fds_index; - - /* Timeout in milliseconds for calls to poll(). */ - int poll_timeout; -#endif - - /* Masks to be used in the next call to select. - Bits are set in response to calls to create_file_handler. */ - fd_set check_masks[3]; - - /* What file descriptors were found ready by select. */ - fd_set ready_masks[3]; - - /* Number of file descriptors to monitor (for poll). */ - /* Number of valid bits (highest fd value + 1) (for select). */ - int num_fds; - - /* Time structure for calls to select(). */ - struct timeval select_timeout; - - /* Flag to tell whether the timeout should be used. */ - int timeout_valid; - } -gdb_notifier; - -/* Structure associated with a timer. PROC will be executed at the - first occasion after WHEN. */ -struct gdb_timer - { - 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); -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; -} - - - -/* Wrapper function for create_file_handler, so that the caller - doesn't have to know implementation details about the use of poll - vs. select. */ -void -add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) -{ -#ifdef HAVE_POLL - struct pollfd fds; -#endif - - if (use_poll) - { -#ifdef HAVE_POLL - /* Check to see if poll () is usable. If not, we'll switch to - use select. This can happen on systems like - m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. - On m68k-motorola-sysv, tty's are not stream-based and not - `poll'able. */ - fds.fd = fd; - fds.events = POLLIN; - if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) - use_poll = 0; -#else - internal_error (__FILE__, __LINE__, - _("use_poll without HAVE_POLL")); -#endif /* HAVE_POLL */ - } - if (use_poll) - { -#ifdef HAVE_POLL - create_file_handler (fd, POLLIN, proc, client_data); -#else - internal_error (__FILE__, __LINE__, - _("use_poll without HAVE_POLL")); -#endif - } - else - create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, - proc, client_data); -} - -/* Add a file handler/descriptor to the list of descriptors we are - interested in. - - FD is the file descriptor for the file/stream to be listened to. - - For the poll case, MASK is a combination (OR) of POLLIN, - POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND: - these are the events we are interested in. If any of them occurs, - proc should be called. - - For the select case, MASK is a combination of READABLE, WRITABLE, - EXCEPTION. PROC is the procedure that will be called when an event - occurs for FD. CLIENT_DATA is the argument to pass to PROC. */ - -static void -create_file_handler (int fd, int mask, handler_func * proc, - gdb_client_data client_data) -{ - file_handler *file_ptr; - - /* Do we already have a file handler for this file? (We may be - changing its associated procedure). */ - for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; - file_ptr = file_ptr->next_file) - { - if (file_ptr->fd == fd) - break; - } - - /* It is a new file descriptor. Add it to the list. Otherwise, just - change the data associated with it. */ - if (file_ptr == NULL) - { - file_ptr = XNEW (file_handler); - file_ptr->fd = fd; - file_ptr->ready_mask = 0; - file_ptr->next_file = gdb_notifier.first_file_handler; - gdb_notifier.first_file_handler = file_ptr; - - if (use_poll) - { -#ifdef HAVE_POLL - gdb_notifier.num_fds++; - if (gdb_notifier.poll_fds) - gdb_notifier.poll_fds = - (struct pollfd *) xrealloc (gdb_notifier.poll_fds, - (gdb_notifier.num_fds - * sizeof (struct pollfd))); - else - gdb_notifier.poll_fds = - XNEW (struct pollfd); - (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; - (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; - (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; -#else - internal_error (__FILE__, __LINE__, - _("use_poll without HAVE_POLL")); -#endif /* HAVE_POLL */ - } - else - { - if (mask & GDB_READABLE) - FD_SET (fd, &gdb_notifier.check_masks[0]); - else - FD_CLR (fd, &gdb_notifier.check_masks[0]); - - if (mask & GDB_WRITABLE) - FD_SET (fd, &gdb_notifier.check_masks[1]); - else - FD_CLR (fd, &gdb_notifier.check_masks[1]); - - if (mask & GDB_EXCEPTION) - FD_SET (fd, &gdb_notifier.check_masks[2]); - else - FD_CLR (fd, &gdb_notifier.check_masks[2]); - - if (gdb_notifier.num_fds <= fd) - gdb_notifier.num_fds = fd + 1; - } - } - - file_ptr->proc = proc; - file_ptr->client_data = client_data; - file_ptr->mask = mask; -} - -/* Return the next file handler to handle, and advance to the next - file handler, wrapping around if the end of the list is - reached. */ - -static file_handler * -get_next_file_handler_to_handle_and_advance (void) -{ - file_handler *curr_next; - - /* The first time around, this is still NULL. */ - if (gdb_notifier.next_file_handler == NULL) - gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; - - curr_next = gdb_notifier.next_file_handler; - gdb_assert (curr_next != NULL); - - /* Advance. */ - gdb_notifier.next_file_handler = curr_next->next_file; - /* Wrap around, if necessary. */ - if (gdb_notifier.next_file_handler == NULL) - gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; - - return curr_next; -} - -/* Remove the file descriptor FD from the list of monitored fd's: - i.e. we don't care anymore about events on the FD. */ -void -delete_file_handler (int fd) -{ - file_handler *file_ptr, *prev_ptr = NULL; - int i; -#ifdef HAVE_POLL - int j; - struct pollfd *new_poll_fds; -#endif - - /* Find the entry for the given file. */ - - for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; - file_ptr = file_ptr->next_file) - { - if (file_ptr->fd == fd) - break; - } - - if (file_ptr == NULL) - return; - - if (use_poll) - { -#ifdef HAVE_POLL - /* Create a new poll_fds array by copying every fd's information - but the one we want to get rid of. */ - - new_poll_fds = (struct pollfd *) - xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); - - for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) - { - if ((gdb_notifier.poll_fds + i)->fd != fd) - { - (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; - (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; - (new_poll_fds + j)->revents - = (gdb_notifier.poll_fds + i)->revents; - j++; - } - } - xfree (gdb_notifier.poll_fds); - gdb_notifier.poll_fds = new_poll_fds; - gdb_notifier.num_fds--; -#else - internal_error (__FILE__, __LINE__, - _("use_poll without HAVE_POLL")); -#endif /* HAVE_POLL */ - } - else - { - if (file_ptr->mask & GDB_READABLE) - FD_CLR (fd, &gdb_notifier.check_masks[0]); - if (file_ptr->mask & GDB_WRITABLE) - FD_CLR (fd, &gdb_notifier.check_masks[1]); - if (file_ptr->mask & GDB_EXCEPTION) - FD_CLR (fd, &gdb_notifier.check_masks[2]); - - /* Find current max fd. */ - - if ((fd + 1) == gdb_notifier.num_fds) - { - gdb_notifier.num_fds--; - for (i = gdb_notifier.num_fds; i; i--) - { - if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) - || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) - || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) - break; - } - gdb_notifier.num_fds = i; - } - } - - /* Deactivate the file descriptor, by clearing its mask, - so that it will not fire again. */ - - file_ptr->mask = 0; - - /* If this file handler was going to be the next one to be handled, - advance to the next's next, if any. */ - if (gdb_notifier.next_file_handler == file_ptr) - { - if (file_ptr->next_file == NULL - && file_ptr == gdb_notifier.first_file_handler) - gdb_notifier.next_file_handler = NULL; - else - get_next_file_handler_to_handle_and_advance (); - } - - /* Get rid of the file handler in the file handler list. */ - if (file_ptr == gdb_notifier.first_file_handler) - gdb_notifier.first_file_handler = file_ptr->next_file; - else - { - for (prev_ptr = gdb_notifier.first_file_handler; - prev_ptr->next_file != file_ptr; - prev_ptr = prev_ptr->next_file) - ; - prev_ptr->next_file = file_ptr->next_file; - } - xfree (file_ptr); -} - -/* Handle the given event by calling the procedure associated to the - corresponding file handler. */ - -static void -handle_file_event (file_handler *file_ptr, int ready_mask) -{ - int mask; -#ifdef HAVE_POLL - int error_mask; -#endif - - { - { - /* With poll, the ready_mask could have any of three events - set to 1: POLLHUP, POLLERR, POLLNVAL. These events - cannot be used in the requested event mask (events), but - they can be returned in the return mask (revents). We - need to check for those event too, and add them to the - mask which will be passed to the handler. */ - - /* See if the desired events (mask) match the received - events (ready_mask). */ - - if (use_poll) - { -#ifdef HAVE_POLL - /* POLLHUP means EOF, but can be combined with POLLIN to - signal more data to read. */ - error_mask = POLLHUP | POLLERR | POLLNVAL; - mask = ready_mask & (file_ptr->mask | error_mask); - - if ((mask & (POLLERR | POLLNVAL)) != 0) - { - /* Work in progress. We may need to tell somebody - what kind of error we had. */ - if (mask & POLLERR) - 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) - (*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 -static struct timeval -duration_cast_timeval (const Duration &d) -{ - using namespace std::chrono; - seconds sec = duration_cast (d); - microseconds msec = duration_cast (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; -} diff --git a/gdb/event-loop.h b/gdb/event-loop.h deleted file mode 100644 index 2eaaa0c8b60..00000000000 --- a/gdb/event-loop.h +++ /dev/null @@ -1,102 +0,0 @@ -/* Definitions used by the GDB event loop. - Copyright (C) 1999-2020 Free Software Foundation, Inc. - Written by Elena Zannoni 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 . */ - -#ifndef EVENT_LOOP_H -#define EVENT_LOOP_H - -/* An event loop listens for events from multiple event sources. When - an event arrives, it is queued and processed by calling the - appropriate event handler. The event loop then continues to listen - for more events. An event loop completes when there are no event - sources to listen on. External event sources can be plugged into - the loop. - - There are 4 main components: - - a list of file descriptors to be monitored, GDB_NOTIFIER. - - a list of asynchronous event sources to be monitored, - ASYNC_EVENT_HANDLER_LIST. - - a list of events that have occurred, EVENT_QUEUE. - - a list of signal handling functions, SIGHANDLER_LIST. - - GDB_NOTIFIER keeps track of the file descriptor based event - sources. ASYNC_EVENT_HANDLER_LIST keeps track of asynchronous - event sources that are signalled by some component of gdb, usually - a target_ops instance. Event sources for gdb are currently the UI - and the target. Gdb communicates with the command line user - interface via the readline library and usually communicates with - remote targets via a serial port. Serial ports are represented in - GDB as file descriptors and select/poll calls. For native targets - instead, the communication varies across operating system debug - APIs, but usually consists of calls to ptrace and waits (via - signals) or calls to poll/select (via file descriptors). In the - current gdb, the code handling events related to the target resides - in wait_for_inferior for synchronous targets; or, for asynchronous - capable targets, by having the target register either a target - controlled file descriptor and/or an asynchronous event source in - the event loop, with the fetch_inferior_event function as the event - callback. In both the synchronous and asynchronous cases, usually - the target event is collected through the target_wait interface. - The target is free to install other event sources in the event loop - if it so requires. - - EVENT_QUEUE keeps track of the events that have happened during the - last iteration of the event loop, and need to be processed. An - event is represented by a procedure to be invoked in order to - process the event. The queue is scanned head to tail. If the - event of interest is a change of state in a file descriptor, then a - call to poll or select will be made to detect it. - - If the events generate signals, they are also queued by special - functions that are invoked through traditional signal handlers. - The actions to be taken is response to such events will be executed - when the SIGHANDLER_LIST is scanned, the next time through the - infinite loop. - - Corollary tasks are the creation and deletion of event sources. */ - -typedef void *gdb_client_data; -typedef void (handler_func) (int, gdb_client_data); -typedef void (timer_handler_func) (gdb_client_data); - -/* Exported functions from event-loop.c */ - -extern int gdb_do_one_event (void); -extern void delete_file_handler (int fd); -extern void add_file_handler (int fd, handler_func *proc, - gdb_client_data client_data); -extern int create_timer (int milliseconds, - timer_handler_func *proc, - gdb_client_data client_data); -extern void delete_timer (int id); - -/* Must be defined by client. */ - -extern void handle_event_loop_exception (const gdb_exception &); - -/* Must be defined by client. Returns true if any signal handler was - ready. */ - -extern int invoke_async_signal_handlers (); - -/* Must be defined by client. Returns true if any event handler was - ready. */ - -extern int check_async_event_handlers (); - -#endif /* EVENT_LOOP_H */ diff --git a/gdb/event-top.c b/gdb/event-top.c index 5d7a77b5b4b..ac0f3701016 100644 --- a/gdb/event-top.c +++ b/gdb/event-top.c @@ -25,7 +25,7 @@ #include "infrun.h" #include "target.h" #include "terminal.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "interps.h" #include diff --git a/gdb/inf-loop.c b/gdb/inf-loop.c index 987a8ef48fe..c40ae239426 100644 --- a/gdb/inf-loop.c +++ b/gdb/inf-loop.c @@ -20,7 +20,7 @@ #include "defs.h" #include "inferior.h" #include "infrun.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "inf-loop.h" #include "remote.h" diff --git a/gdb/infrun.c b/gdb/infrun.c index fc76649287c..0f00b93f269 100644 --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -56,7 +56,7 @@ #include "target-dcache.h" #include "terminal.h" #include "solist.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "thread-fsm.h" #include "gdbsupport/enum-flags.h" #include "progspace-and-thread.h" diff --git a/gdb/interps.c b/gdb/interps.c index 8c01091e50b..4b2e3fd37b0 100644 --- a/gdb/interps.c +++ b/gdb/interps.c @@ -32,7 +32,7 @@ #include "defs.h" #include "gdbcmd.h" #include "ui-out.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "interps.h" #include "completer.h" diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 28491859aa8..0a2bfdc57d4 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -47,7 +47,7 @@ #include /* for struct stat */ #include /* for O_RDONLY */ #include "inf-loop.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include #include diff --git a/gdb/main.c b/gdb/main.c index 67a3d0027e1..59cb14161be 100644 --- a/gdb/main.c +++ b/gdb/main.c @@ -28,7 +28,7 @@ #include #include #include -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "ui-out.h" #include "interps.h" diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c index e77093cfa28..7fe901bd68e 100644 --- a/gdb/mi/mi-interp.c +++ b/gdb/mi/mi-interp.c @@ -23,7 +23,7 @@ #include "interps.h" #include "event-top.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "inferior.h" #include "infrun.h" #include "ui-out.h" diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c index 68cbcdd4fcd..9c6323e52c6 100644 --- a/gdb/mi/mi-main.c +++ b/gdb/mi/mi-main.c @@ -33,7 +33,7 @@ #include "ui-out.h" #include "mi-out.h" #include "interps.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "gdbcore.h" /* For write_memory(). */ #include "value.h" diff --git a/gdb/mingw-hdep.c b/gdb/mingw-hdep.c index 016cf2d2310..43d99747659 100644 --- a/gdb/mingw-hdep.c +++ b/gdb/mingw-hdep.c @@ -20,7 +20,7 @@ #include "defs.h" #include "main.h" #include "serial.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "gdbsupport/gdb_select.h" diff --git a/gdb/posix-hdep.c b/gdb/posix-hdep.c index e5754cd701a..dfb230bc749 100644 --- a/gdb/posix-hdep.c +++ b/gdb/posix-hdep.c @@ -18,7 +18,7 @@ along with this program. If not, see . */ #include "defs.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "gdbsupport/gdb_select.h" diff --git a/gdb/python/python.c b/gdb/python/python.c index 6e243c1a07b..02543aea710 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -27,7 +27,7 @@ #include "objfiles.h" #include "value.h" #include "language.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "readline/tilde.h" #include "python.h" #include "extension-priv.h" diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c index acc5f3ba663..2ca9a61457a 100644 --- a/gdb/record-btrace.c +++ b/gdb/record-btrace.c @@ -36,7 +36,7 @@ #include "frame-unwind.h" #include "hashtab.h" #include "infrun.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "inf-loop.h" #include "inferior.h" #include diff --git a/gdb/record-full.c b/gdb/record-full.c index 4e1961af1bf..9c8bd18149b 100644 --- a/gdb/record-full.c +++ b/gdb/record-full.c @@ -31,7 +31,7 @@ #include "record-full.h" #include "elf-bfd.h" #include "gcore.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "inf-loop.h" #include "gdb_bfd.h" #include "observable.h" diff --git a/gdb/remote-fileio.c b/gdb/remote-fileio.c index f2dc9a66ead..df470fd86df 100644 --- a/gdb/remote-fileio.c +++ b/gdb/remote-fileio.c @@ -25,7 +25,7 @@ #include "gdbsupport/gdb_wait.h" #include #include "remote-fileio.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "target.h" #include "filenames.h" #include "gdbsupport/filestuff.h" diff --git a/gdb/remote-notif.c b/gdb/remote-notif.c index f41ebc3d735..2e5f124284b 100644 --- a/gdb/remote-notif.c +++ b/gdb/remote-notif.c @@ -35,7 +35,7 @@ #include "remote.h" #include "remote-notif.h" #include "observable.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "target.h" #include "inferior.h" #include "infrun.h" diff --git a/gdb/remote.c b/gdb/remote.c index d4919d99a90..495f9680c1e 100644 --- a/gdb/remote.c +++ b/gdb/remote.c @@ -49,7 +49,7 @@ #include "gdbsupport/gdb_sys_time.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "inf-loop.h" diff --git a/gdb/run-on-main-thread.c b/gdb/run-on-main-thread.c index 74ab1e19a57..2cc93e430d8 100644 --- a/gdb/run-on-main-thread.c +++ b/gdb/run-on-main-thread.c @@ -22,7 +22,7 @@ #if CXX_STD_THREAD #include #endif -#include "event-loop.h" +#include "gdbsupport/event-loop.h" /* The serial event used when posting runnables. */ diff --git a/gdb/ser-base.c b/gdb/ser-base.c index 8231ec51543..fb6f4e056ad 100644 --- a/gdb/ser-base.c +++ b/gdb/ser-base.c @@ -20,7 +20,7 @@ #include "defs.h" #include "serial.h" #include "ser-base.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "gdbsupport/gdb_select.h" #include "gdbsupport/gdb_sys_time.h" diff --git a/gdb/top.c b/gdb/top.c index 010aa6fb771..8b82bd3c038 100644 --- a/gdb/top.c +++ b/gdb/top.c @@ -42,7 +42,7 @@ #include "gdbsupport/version.h" #include "serial.h" #include "main.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "gdbthread.h" #include "extension.h" #include "interps.h" diff --git a/gdb/top.h b/gdb/top.h index 638e02cad4c..2147e2d4b48 100644 --- a/gdb/top.h +++ b/gdb/top.h @@ -21,7 +21,7 @@ #define TOP_H #include "gdbsupport/buffer.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "value.h" struct tl_interp_info; diff --git a/gdb/tui/tui-hooks.c b/gdb/tui/tui-hooks.c index 0e45e0e7507..793ca0e4469 100644 --- a/gdb/tui/tui-hooks.c +++ b/gdb/tui/tui-hooks.c @@ -26,7 +26,7 @@ #include "objfiles.h" #include "target.h" #include "gdbcore.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "frame.h" #include "breakpoint.h" diff --git a/gdb/tui/tui-interp.c b/gdb/tui/tui-interp.c index 090cf0e0d0c..10118af2741 100644 --- a/gdb/tui/tui-interp.c +++ b/gdb/tui/tui-interp.c @@ -22,7 +22,7 @@ #include "interps.h" #include "top.h" #include "event-top.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "ui-out.h" #include "cli-out.h" #include "tui/tui-data.h" diff --git a/gdb/tui/tui-io.c b/gdb/tui/tui-io.c index b5ee2a2b6b6..e7a8ac77bce 100644 --- a/gdb/tui/tui-io.c +++ b/gdb/tui/tui-io.c @@ -21,7 +21,7 @@ #include "defs.h" #include "target.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "event-top.h" #include "command.h" #include "top.h" diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c index df7480fc57c..7cb4aa9bbd4 100644 --- a/gdb/tui/tui-win.c +++ b/gdb/tui/tui-win.c @@ -33,7 +33,7 @@ #include "cli/cli-style.h" #include "top.h" #include "source.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #include "gdbcmd.h" #include "async-event.h" diff --git a/gdb/unittests/main-thread-selftests.c b/gdb/unittests/main-thread-selftests.c index c51f34ef41d..564a107b354 100644 --- a/gdb/unittests/main-thread-selftests.c +++ b/gdb/unittests/main-thread-selftests.c @@ -21,7 +21,7 @@ #include "gdbsupport/selftest.h" #include "gdbsupport/block-signals.h" #include "run-on-main-thread.h" -#include "event-loop.h" +#include "gdbsupport/event-loop.h" #if CXX_STD_THREAD #include #endif diff --git a/gdbsupport/ChangeLog b/gdbsupport/ChangeLog index a065a9abaff..1e64022c7c9 100644 --- a/gdbsupport/ChangeLog +++ b/gdbsupport/ChangeLog @@ -1,3 +1,8 @@ +2020-04-13 Tom Tromey + + * event-loop.h: Move from ../gdb/. + * event-loop.cc: Move from ../gdb/. + 2020-04-13 Tom Tromey * errors.h (flush_streams): Declare. diff --git a/gdbsupport/Makefile.am b/gdbsupport/Makefile.am index ee78a891b3b..e95ee5dbc50 100644 --- a/gdbsupport/Makefile.am +++ b/gdbsupport/Makefile.am @@ -46,6 +46,7 @@ libgdbsupport_a_SOURCES = \ common-utils.cc \ environ.cc \ errors.cc \ + event-loop.cc \ fileio.cc \ filestuff.cc \ format.cc \ diff --git a/gdbsupport/Makefile.in b/gdbsupport/Makefile.in index 7ed2e6fac23..5051ab31a49 100644 --- a/gdbsupport/Makefile.in +++ b/gdbsupport/Makefile.in @@ -149,16 +149,16 @@ am_libgdbsupport_a_OBJECTS = agent.$(OBJEXT) btrace-common.$(OBJEXT) \ buffer.$(OBJEXT) cleanups.$(OBJEXT) common-debug.$(OBJEXT) \ common-exceptions.$(OBJEXT) common-inferior.$(OBJEXT) \ common-regcache.$(OBJEXT) common-utils.$(OBJEXT) \ - environ.$(OBJEXT) errors.$(OBJEXT) fileio.$(OBJEXT) \ - filestuff.$(OBJEXT) format.$(OBJEXT) gdb-dlfcn.$(OBJEXT) \ - gdb_tilde_expand.$(OBJEXT) gdb_wait.$(OBJEXT) \ - gdb_vecs.$(OBJEXT) job-control.$(OBJEXT) netstuff.$(OBJEXT) \ - new-op.$(OBJEXT) pathstuff.$(OBJEXT) print-utils.$(OBJEXT) \ - ptid.$(OBJEXT) rsp-low.$(OBJEXT) run-time-clock.$(OBJEXT) \ - safe-strerror.$(OBJEXT) scoped_mmap.$(OBJEXT) \ - signals.$(OBJEXT) signals-state-save-restore.$(OBJEXT) \ - tdesc.$(OBJEXT) thread-pool.$(OBJEXT) xml-utils.$(OBJEXT) \ - $(am__objects_1) + environ.$(OBJEXT) errors.$(OBJEXT) event-loop.$(OBJEXT) \ + fileio.$(OBJEXT) filestuff.$(OBJEXT) format.$(OBJEXT) \ + gdb-dlfcn.$(OBJEXT) gdb_tilde_expand.$(OBJEXT) \ + gdb_wait.$(OBJEXT) gdb_vecs.$(OBJEXT) job-control.$(OBJEXT) \ + netstuff.$(OBJEXT) new-op.$(OBJEXT) pathstuff.$(OBJEXT) \ + print-utils.$(OBJEXT) ptid.$(OBJEXT) rsp-low.$(OBJEXT) \ + run-time-clock.$(OBJEXT) safe-strerror.$(OBJEXT) \ + scoped_mmap.$(OBJEXT) signals.$(OBJEXT) \ + signals-state-save-restore.$(OBJEXT) tdesc.$(OBJEXT) \ + thread-pool.$(OBJEXT) xml-utils.$(OBJEXT) $(am__objects_1) libgdbsupport_a_OBJECTS = $(am_libgdbsupport_a_OBJECTS) AM_V_P = $(am__v_P_@AM_V@) am__v_P_ = $(am__v_P_@AM_DEFAULT_V@) @@ -368,6 +368,7 @@ libgdbsupport_a_SOURCES = \ common-utils.cc \ environ.cc \ errors.cc \ + event-loop.cc \ fileio.cc \ filestuff.cc \ format.cc \ @@ -471,6 +472,7 @@ distclean-compile: @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/common-utils.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/environ.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/errors.Po@am__quote@ +@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/event-loop.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/fileio.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/filestuff.Po@am__quote@ @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/format.Po@am__quote@ diff --git a/gdbsupport/event-loop.cc b/gdbsupport/event-loop.cc new file mode 100644 index 00000000000..f7ccc4eec47 --- /dev/null +++ b/gdbsupport/event-loop.cc @@ -0,0 +1,889 @@ +/* Event loop machinery for GDB, the GNU debugger. + Copyright (C) 1999-2020 Free Software Foundation, Inc. + Written by Elena Zannoni 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 . */ + +#include "gdbsupport/common-defs.h" +#include "gdbsupport/event-loop.h" + +#include + +#ifdef HAVE_POLL +#if defined (HAVE_POLL_H) +#include +#elif defined (HAVE_SYS_POLL_H) +#include +#endif +#endif + +#include +#include "gdbsupport/gdb_sys_time.h" +#include "gdbsupport/gdb_select.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) + +/* 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; + +/* 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 +#include +#endif + +static struct + { + /* Ptr to head of file handler list. */ + file_handler *first_file_handler; + + /* Next file handler to handle, for the select variant. To level + the fairness across event sources, we serve file handlers in a + round-robin-like fashion. The number and order of the polled + file handlers may change between invocations, but this is good + enough. */ + file_handler *next_file_handler; + +#ifdef HAVE_POLL + /* Ptr to array of pollfd structures. */ + struct pollfd *poll_fds; + + /* Next file descriptor to handle, for the poll variant. To level + the fairness across event sources, we poll the file descriptors + in a round-robin-like fashion. The number and order of the + polled file descriptors may change between invocations, but + this is good enough. */ + int next_poll_fds_index; + + /* Timeout in milliseconds for calls to poll(). */ + int poll_timeout; +#endif + + /* Masks to be used in the next call to select. + Bits are set in response to calls to create_file_handler. */ + fd_set check_masks[3]; + + /* What file descriptors were found ready by select. */ + fd_set ready_masks[3]; + + /* Number of file descriptors to monitor (for poll). */ + /* Number of valid bits (highest fd value + 1) (for select). */ + int num_fds; + + /* Time structure for calls to select(). */ + struct timeval select_timeout; + + /* Flag to tell whether the timeout should be used. */ + int timeout_valid; + } +gdb_notifier; + +/* Structure associated with a timer. PROC will be executed at the + first occasion after WHEN. */ +struct gdb_timer + { + 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); +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; +} + + + +/* Wrapper function for create_file_handler, so that the caller + doesn't have to know implementation details about the use of poll + vs. select. */ +void +add_file_handler (int fd, handler_func * proc, gdb_client_data client_data) +{ +#ifdef HAVE_POLL + struct pollfd fds; +#endif + + if (use_poll) + { +#ifdef HAVE_POLL + /* Check to see if poll () is usable. If not, we'll switch to + use select. This can happen on systems like + m68k-motorola-sys, `poll' cannot be used to wait for `stdin'. + On m68k-motorola-sysv, tty's are not stream-based and not + `poll'able. */ + fds.fd = fd; + fds.events = POLLIN; + if (poll (&fds, 1, 0) == 1 && (fds.revents & POLLNVAL)) + use_poll = 0; +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif /* HAVE_POLL */ + } + if (use_poll) + { +#ifdef HAVE_POLL + create_file_handler (fd, POLLIN, proc, client_data); +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif + } + else + create_file_handler (fd, GDB_READABLE | GDB_EXCEPTION, + proc, client_data); +} + +/* Add a file handler/descriptor to the list of descriptors we are + interested in. + + FD is the file descriptor for the file/stream to be listened to. + + For the poll case, MASK is a combination (OR) of POLLIN, + POLLRDNORM, POLLRDBAND, POLLPRI, POLLOUT, POLLWRNORM, POLLWRBAND: + these are the events we are interested in. If any of them occurs, + proc should be called. + + For the select case, MASK is a combination of READABLE, WRITABLE, + EXCEPTION. PROC is the procedure that will be called when an event + occurs for FD. CLIENT_DATA is the argument to pass to PROC. */ + +static void +create_file_handler (int fd, int mask, handler_func * proc, + gdb_client_data client_data) +{ + file_handler *file_ptr; + + /* Do we already have a file handler for this file? (We may be + changing its associated procedure). */ + for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; + file_ptr = file_ptr->next_file) + { + if (file_ptr->fd == fd) + break; + } + + /* It is a new file descriptor. Add it to the list. Otherwise, just + change the data associated with it. */ + if (file_ptr == NULL) + { + file_ptr = XNEW (file_handler); + file_ptr->fd = fd; + file_ptr->ready_mask = 0; + file_ptr->next_file = gdb_notifier.first_file_handler; + gdb_notifier.first_file_handler = file_ptr; + + if (use_poll) + { +#ifdef HAVE_POLL + gdb_notifier.num_fds++; + if (gdb_notifier.poll_fds) + gdb_notifier.poll_fds = + (struct pollfd *) xrealloc (gdb_notifier.poll_fds, + (gdb_notifier.num_fds + * sizeof (struct pollfd))); + else + gdb_notifier.poll_fds = + XNEW (struct pollfd); + (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->fd = fd; + (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->events = mask; + (gdb_notifier.poll_fds + gdb_notifier.num_fds - 1)->revents = 0; +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif /* HAVE_POLL */ + } + else + { + if (mask & GDB_READABLE) + FD_SET (fd, &gdb_notifier.check_masks[0]); + else + FD_CLR (fd, &gdb_notifier.check_masks[0]); + + if (mask & GDB_WRITABLE) + FD_SET (fd, &gdb_notifier.check_masks[1]); + else + FD_CLR (fd, &gdb_notifier.check_masks[1]); + + if (mask & GDB_EXCEPTION) + FD_SET (fd, &gdb_notifier.check_masks[2]); + else + FD_CLR (fd, &gdb_notifier.check_masks[2]); + + if (gdb_notifier.num_fds <= fd) + gdb_notifier.num_fds = fd + 1; + } + } + + file_ptr->proc = proc; + file_ptr->client_data = client_data; + file_ptr->mask = mask; +} + +/* Return the next file handler to handle, and advance to the next + file handler, wrapping around if the end of the list is + reached. */ + +static file_handler * +get_next_file_handler_to_handle_and_advance (void) +{ + file_handler *curr_next; + + /* The first time around, this is still NULL. */ + if (gdb_notifier.next_file_handler == NULL) + gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; + + curr_next = gdb_notifier.next_file_handler; + gdb_assert (curr_next != NULL); + + /* Advance. */ + gdb_notifier.next_file_handler = curr_next->next_file; + /* Wrap around, if necessary. */ + if (gdb_notifier.next_file_handler == NULL) + gdb_notifier.next_file_handler = gdb_notifier.first_file_handler; + + return curr_next; +} + +/* Remove the file descriptor FD from the list of monitored fd's: + i.e. we don't care anymore about events on the FD. */ +void +delete_file_handler (int fd) +{ + file_handler *file_ptr, *prev_ptr = NULL; + int i; +#ifdef HAVE_POLL + int j; + struct pollfd *new_poll_fds; +#endif + + /* Find the entry for the given file. */ + + for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL; + file_ptr = file_ptr->next_file) + { + if (file_ptr->fd == fd) + break; + } + + if (file_ptr == NULL) + return; + + if (use_poll) + { +#ifdef HAVE_POLL + /* Create a new poll_fds array by copying every fd's information + but the one we want to get rid of. */ + + new_poll_fds = (struct pollfd *) + xmalloc ((gdb_notifier.num_fds - 1) * sizeof (struct pollfd)); + + for (i = 0, j = 0; i < gdb_notifier.num_fds; i++) + { + if ((gdb_notifier.poll_fds + i)->fd != fd) + { + (new_poll_fds + j)->fd = (gdb_notifier.poll_fds + i)->fd; + (new_poll_fds + j)->events = (gdb_notifier.poll_fds + i)->events; + (new_poll_fds + j)->revents + = (gdb_notifier.poll_fds + i)->revents; + j++; + } + } + xfree (gdb_notifier.poll_fds); + gdb_notifier.poll_fds = new_poll_fds; + gdb_notifier.num_fds--; +#else + internal_error (__FILE__, __LINE__, + _("use_poll without HAVE_POLL")); +#endif /* HAVE_POLL */ + } + else + { + if (file_ptr->mask & GDB_READABLE) + FD_CLR (fd, &gdb_notifier.check_masks[0]); + if (file_ptr->mask & GDB_WRITABLE) + FD_CLR (fd, &gdb_notifier.check_masks[1]); + if (file_ptr->mask & GDB_EXCEPTION) + FD_CLR (fd, &gdb_notifier.check_masks[2]); + + /* Find current max fd. */ + + if ((fd + 1) == gdb_notifier.num_fds) + { + gdb_notifier.num_fds--; + for (i = gdb_notifier.num_fds; i; i--) + { + if (FD_ISSET (i - 1, &gdb_notifier.check_masks[0]) + || FD_ISSET (i - 1, &gdb_notifier.check_masks[1]) + || FD_ISSET (i - 1, &gdb_notifier.check_masks[2])) + break; + } + gdb_notifier.num_fds = i; + } + } + + /* Deactivate the file descriptor, by clearing its mask, + so that it will not fire again. */ + + file_ptr->mask = 0; + + /* If this file handler was going to be the next one to be handled, + advance to the next's next, if any. */ + if (gdb_notifier.next_file_handler == file_ptr) + { + if (file_ptr->next_file == NULL + && file_ptr == gdb_notifier.first_file_handler) + gdb_notifier.next_file_handler = NULL; + else + get_next_file_handler_to_handle_and_advance (); + } + + /* Get rid of the file handler in the file handler list. */ + if (file_ptr == gdb_notifier.first_file_handler) + gdb_notifier.first_file_handler = file_ptr->next_file; + else + { + for (prev_ptr = gdb_notifier.first_file_handler; + prev_ptr->next_file != file_ptr; + prev_ptr = prev_ptr->next_file) + ; + prev_ptr->next_file = file_ptr->next_file; + } + xfree (file_ptr); +} + +/* Handle the given event by calling the procedure associated to the + corresponding file handler. */ + +static void +handle_file_event (file_handler *file_ptr, int ready_mask) +{ + int mask; +#ifdef HAVE_POLL + int error_mask; +#endif + + { + { + /* With poll, the ready_mask could have any of three events + set to 1: POLLHUP, POLLERR, POLLNVAL. These events + cannot be used in the requested event mask (events), but + they can be returned in the return mask (revents). We + need to check for those event too, and add them to the + mask which will be passed to the handler. */ + + /* See if the desired events (mask) match the received + events (ready_mask). */ + + if (use_poll) + { +#ifdef HAVE_POLL + /* POLLHUP means EOF, but can be combined with POLLIN to + signal more data to read. */ + error_mask = POLLHUP | POLLERR | POLLNVAL; + mask = ready_mask & (file_ptr->mask | error_mask); + + if ((mask & (POLLERR | POLLNVAL)) != 0) + { + /* Work in progress. We may need to tell somebody + what kind of error we had. */ + if (mask & POLLERR) + 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) + (*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 +static struct timeval +duration_cast_timeval (const Duration &d) +{ + using namespace std::chrono; + seconds sec = duration_cast (d); + microseconds msec = duration_cast (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; +} diff --git a/gdbsupport/event-loop.h b/gdbsupport/event-loop.h new file mode 100644 index 00000000000..2eaaa0c8b60 --- /dev/null +++ b/gdbsupport/event-loop.h @@ -0,0 +1,102 @@ +/* Definitions used by the GDB event loop. + Copyright (C) 1999-2020 Free Software Foundation, Inc. + Written by Elena Zannoni 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 . */ + +#ifndef EVENT_LOOP_H +#define EVENT_LOOP_H + +/* An event loop listens for events from multiple event sources. When + an event arrives, it is queued and processed by calling the + appropriate event handler. The event loop then continues to listen + for more events. An event loop completes when there are no event + sources to listen on. External event sources can be plugged into + the loop. + + There are 4 main components: + - a list of file descriptors to be monitored, GDB_NOTIFIER. + - a list of asynchronous event sources to be monitored, + ASYNC_EVENT_HANDLER_LIST. + - a list of events that have occurred, EVENT_QUEUE. + - a list of signal handling functions, SIGHANDLER_LIST. + + GDB_NOTIFIER keeps track of the file descriptor based event + sources. ASYNC_EVENT_HANDLER_LIST keeps track of asynchronous + event sources that are signalled by some component of gdb, usually + a target_ops instance. Event sources for gdb are currently the UI + and the target. Gdb communicates with the command line user + interface via the readline library and usually communicates with + remote targets via a serial port. Serial ports are represented in + GDB as file descriptors and select/poll calls. For native targets + instead, the communication varies across operating system debug + APIs, but usually consists of calls to ptrace and waits (via + signals) or calls to poll/select (via file descriptors). In the + current gdb, the code handling events related to the target resides + in wait_for_inferior for synchronous targets; or, for asynchronous + capable targets, by having the target register either a target + controlled file descriptor and/or an asynchronous event source in + the event loop, with the fetch_inferior_event function as the event + callback. In both the synchronous and asynchronous cases, usually + the target event is collected through the target_wait interface. + The target is free to install other event sources in the event loop + if it so requires. + + EVENT_QUEUE keeps track of the events that have happened during the + last iteration of the event loop, and need to be processed. An + event is represented by a procedure to be invoked in order to + process the event. The queue is scanned head to tail. If the + event of interest is a change of state in a file descriptor, then a + call to poll or select will be made to detect it. + + If the events generate signals, they are also queued by special + functions that are invoked through traditional signal handlers. + The actions to be taken is response to such events will be executed + when the SIGHANDLER_LIST is scanned, the next time through the + infinite loop. + + Corollary tasks are the creation and deletion of event sources. */ + +typedef void *gdb_client_data; +typedef void (handler_func) (int, gdb_client_data); +typedef void (timer_handler_func) (gdb_client_data); + +/* Exported functions from event-loop.c */ + +extern int gdb_do_one_event (void); +extern void delete_file_handler (int fd); +extern void add_file_handler (int fd, handler_func *proc, + gdb_client_data client_data); +extern int create_timer (int milliseconds, + timer_handler_func *proc, + gdb_client_data client_data); +extern void delete_timer (int id); + +/* Must be defined by client. */ + +extern void handle_event_loop_exception (const gdb_exception &); + +/* Must be defined by client. Returns true if any signal handler was + ready. */ + +extern int invoke_async_signal_handlers (); + +/* Must be defined by client. Returns true if any event handler was + ready. */ + +extern int check_async_event_handlers (); + +#endif /* EVENT_LOOP_H */