mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-12-15 04:31:49 +08:00
400b5eca00
This moves event-loop.[ch] to gdbsupport/ and updates the uses in gdb. gdb/ChangeLog 2020-04-13 Tom Tromey <tom@tromey.com> * 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 <tom@tromey.com> * event-loop.h: Move from ../gdb/. * event-loop.cc: Move from ../gdb/.
103 lines
4.4 KiB
C
103 lines
4.4 KiB
C
/* Definitions used by the GDB event loop.
|
|
Copyright (C) 1999-2020 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/>. */
|
|
|
|
#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 */
|