mirror of
https://github.com/darlinghq/darling-gdb.git
synced 2024-11-29 15:00:34 +00:00
97 lines
4.3 KiB
C
97 lines
4.3 KiB
C
/* Definitions used by the GDB event loop.
|
|
Copyright 1999 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 2 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, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
/* 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 3 main components:
|
|
- a list of file descriptors to be monitored, GDB_NOTIFIER.
|
|
- a list of events that have occurred, EVENT_QUEUE.
|
|
- a list of signal handling functions, SIGHANDLER_LIST.
|
|
|
|
GDB_NOTIFIER keeps track of the event sources. 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 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 the wait_for_inferior function and in
|
|
various target specific files (*-tdep.c).
|
|
|
|
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 PTR gdb_client_data;
|
|
struct async_signal_handler;
|
|
typedef void (handler_func) (int, int, gdb_client_data);
|
|
typedef void (sig_handler_func) (gdb_client_data);
|
|
typedef void (timer_handler_func) (gdb_client_data);
|
|
|
|
/* Where to add an event onto the event queue, by queue_event. */
|
|
typedef enum
|
|
{
|
|
/* Add at tail of queue. It will be processed in first in first
|
|
out order. */
|
|
TAIL,
|
|
/* Add at head of queue. It will be processed in last in first out
|
|
order. */
|
|
HEAD
|
|
}
|
|
queue_position;
|
|
|
|
/* 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)
|
|
|
|
/* Exported functions from event-loop.c */
|
|
|
|
extern void start_event_loop (void);
|
|
extern void delete_file_handler (int fd);
|
|
extern void add_file_handler (int fd, handler_func * proc, gdb_client_data client_data);
|
|
extern void mark_async_signal_handler (struct async_signal_handler *async_handler_ptr);
|
|
extern struct async_signal_handler *
|
|
create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data);
|
|
extern void delete_async_signal_handler (struct async_signal_handler **async_handler_ptr);
|
|
extern void inferior_event_handler (int error, gdb_client_data client_data, int fd);
|
|
extern int create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data);
|
|
extern void delete_timer (int id);
|