1244 lines
37 KiB
C
1244 lines
37 KiB
C
/* Event loop machinery for GDB, the GNU debugger.
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Copyright 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
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Written by Elena Zannoni <ezannoni@cygnus.com> of Cygnus Solutions.
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This file is part of GDB.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "event-loop.h"
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#include "event-top.h"
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#ifdef HAVE_POLL
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#if defined (HAVE_POLL_H)
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#include <poll.h>
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#elif defined (HAVE_SYS_POLL_H)
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#include <sys/poll.h>
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#endif
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#endif
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#include <sys/types.h>
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#include "gdb_string.h"
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#include <errno.h>
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#include <sys/time.h>
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#include "exceptions.h"
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#include "gdb_assert.h"
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typedef struct gdb_event gdb_event;
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typedef void (event_handler_func) (int);
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/* Event for the GDB event system. Events are queued by calling
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async_queue_event and serviced later on by gdb_do_one_event. An
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event can be, for instance, a file descriptor becoming ready to be
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read. Servicing an event simply means that the procedure PROC will
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be called. We have 2 queues, one for file handlers that we listen
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to in the event loop, and one for the file handlers+events that are
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ready. The procedure PROC associated with each event is always the
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same (handle_file_event). Its duty is to invoke the handler
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associated with the file descriptor whose state change generated
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the event, plus doing other cleanups and such. */
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struct gdb_event
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{
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event_handler_func *proc; /* Procedure to call to service this event. */
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int fd; /* File descriptor that is ready. */
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struct gdb_event *next_event; /* Next in list of events or NULL. */
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};
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/* Information about each file descriptor we register with the event
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loop. */
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typedef struct file_handler
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{
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int fd; /* File descriptor. */
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int mask; /* Events we want to monitor: POLLIN, etc. */
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int ready_mask; /* Events that have been seen since
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the last time. */
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handler_func *proc; /* Procedure to call when fd is ready. */
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gdb_client_data client_data; /* Argument to pass to proc. */
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int error; /* Was an error detected on this fd? */
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struct file_handler *next_file; /* Next registered file descriptor. */
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}
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file_handler;
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/* PROC is a function to be invoked when the READY flag is set. This
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happens when there has been a signal and the corresponding signal
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handler has 'triggered' this async_signal_handler for
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execution. The actual work to be done in response to a signal will
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be carried out by PROC at a later time, within process_event. This
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provides a deferred execution of signal handlers.
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Async_init_signals takes care of setting up such an
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asyn_signal_handler for each interesting signal. */
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typedef struct async_signal_handler
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{
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int ready; /* If ready, call this handler from the main event loop,
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using invoke_async_handler. */
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struct async_signal_handler *next_handler; /* Ptr to next handler */
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sig_handler_func *proc; /* Function to call to do the work */
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gdb_client_data client_data; /* Argument to async_handler_func */
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}
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async_signal_handler;
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/* Event queue:
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- the first event in the queue is the head of the queue.
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It will be the next to be serviced.
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- the last event in the queue
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Events can be inserted at the front of the queue or at the end of
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the queue. Events will be extracted from the queue for processing
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starting from the head. Therefore, events inserted at the head of
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the queue will be processed in a last in first out fashion, while
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those inserted at the tail of the queue will be processed in a first
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in first out manner. All the fields are NULL if the queue is
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empty. */
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static struct
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{
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gdb_event *first_event; /* First pending event */
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gdb_event *last_event; /* Last pending event */
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}
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event_queue;
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/* Gdb_notifier is just a list of file descriptors gdb is interested in.
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These are the input file descriptor, and the target file
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descriptor. We have two flavors of the notifier, one for platforms
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that have the POLL function, the other for those that don't, and
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only support SELECT. Each of the elements in the gdb_notifier list is
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basically a description of what kind of events gdb is interested
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in, for each fd. */
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/* As of 1999-04-30 only the input file descriptor is registered with the
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event loop. */
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/* Do we use poll or select ? */
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#ifdef HAVE_POLL
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#define USE_POLL 1
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#else
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#define USE_POLL 0
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#endif /* HAVE_POLL */
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static unsigned char use_poll = USE_POLL;
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#ifdef USE_WIN32API
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#include <windows.h>
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#include <io.h>
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#endif
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static struct
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{
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/* Ptr to head of file handler list. */
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file_handler *first_file_handler;
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#ifdef HAVE_POLL
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/* Ptr to array of pollfd structures. */
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struct pollfd *poll_fds;
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/* Timeout in milliseconds for calls to poll(). */
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int poll_timeout;
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#endif
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/* Masks to be used in the next call to select.
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Bits are set in response to calls to create_file_handler. */
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fd_set check_masks[3];
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/* What file descriptors were found ready by select. */
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fd_set ready_masks[3];
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/* Number of file descriptors to monitor. (for poll) */
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/* Number of valid bits (highest fd value + 1). (for select) */
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int num_fds;
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/* Time structure for calls to select(). */
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struct timeval select_timeout;
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/* Flag to tell whether the timeout should be used. */
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int timeout_valid;
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}
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gdb_notifier;
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/* Structure associated with a timer. PROC will be executed at the
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first occasion after WHEN. */
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struct gdb_timer
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{
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struct timeval when;
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int timer_id;
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struct gdb_timer *next;
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timer_handler_func *proc; /* Function to call to do the work */
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gdb_client_data client_data; /* Argument to async_handler_func */
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}
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gdb_timer;
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/* List of currently active timers. It is sorted in order of
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increasing timers. */
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static struct
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{
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/* Pointer to first in timer list. */
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struct gdb_timer *first_timer;
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/* Id of the last timer created. */
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int num_timers;
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}
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timer_list;
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/* All the async_signal_handlers gdb is interested in are kept onto
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this list. */
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static struct
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{
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/* Pointer to first in handler list. */
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async_signal_handler *first_handler;
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/* Pointer to last in handler list. */
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async_signal_handler *last_handler;
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}
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sighandler_list;
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/* Are any of the handlers ready? Check this variable using
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check_async_ready. This is used by process_event, to determine
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whether or not to invoke the invoke_async_signal_handler
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function. */
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static int async_handler_ready = 0;
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static void create_file_handler (int fd, int mask, handler_func * proc, gdb_client_data client_data);
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static void invoke_async_signal_handler (void);
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static void handle_file_event (int event_file_desc);
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static int gdb_wait_for_event (void);
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static int check_async_ready (void);
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static void async_queue_event (gdb_event * event_ptr, queue_position position);
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static gdb_event *create_file_event (int fd);
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static int process_event (void);
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static void handle_timer_event (int dummy);
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static void poll_timers (void);
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/* Insert an event object into the gdb event queue at
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the specified position.
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POSITION can be head or tail, with values TAIL, HEAD.
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EVENT_PTR points to the event to be inserted into the queue.
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The caller must allocate memory for the event. It is freed
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after the event has ben handled.
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Events in the queue will be processed head to tail, therefore,
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events inserted at the head of the queue will be processed
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as last in first out. Event appended at the tail of the queue
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will be processed first in first out. */
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static void
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async_queue_event (gdb_event * event_ptr, queue_position position)
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{
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if (position == TAIL)
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{
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/* The event will become the new last_event. */
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event_ptr->next_event = NULL;
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if (event_queue.first_event == NULL)
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event_queue.first_event = event_ptr;
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else
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event_queue.last_event->next_event = event_ptr;
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event_queue.last_event = event_ptr;
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}
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else if (position == HEAD)
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{
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/* The event becomes the new first_event. */
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event_ptr->next_event = event_queue.first_event;
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if (event_queue.first_event == NULL)
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event_queue.last_event = event_ptr;
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event_queue.first_event = event_ptr;
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}
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}
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/* Create a file event, to be enqueued in the event queue for
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processing. The procedure associated to this event is always
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handle_file_event, which will in turn invoke the one that was
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associated to FD when it was registered with the event loop. */
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static gdb_event *
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create_file_event (int fd)
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{
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gdb_event *file_event_ptr;
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file_event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
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file_event_ptr->proc = handle_file_event;
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file_event_ptr->fd = fd;
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return (file_event_ptr);
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}
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/* Process one event.
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The event can be the next one to be serviced in the event queue,
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or an asynchronous event handler can be invoked in response to
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the reception of a signal.
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If an event was processed (either way), 1 is returned otherwise
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0 is returned.
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Scan the queue from head to tail, processing therefore the high
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priority events first, by invoking the associated event handler
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procedure. */
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static int
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process_event (void)
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{
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gdb_event *event_ptr, *prev_ptr;
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event_handler_func *proc;
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int fd;
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/* First let's see if there are any asynchronous event handlers that
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are ready. These would be the result of invoking any of the
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signal handlers. */
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if (check_async_ready ())
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{
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invoke_async_signal_handler ();
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return 1;
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}
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/* Look in the event queue to find an event that is ready
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to be processed. */
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for (event_ptr = event_queue.first_event; event_ptr != NULL;
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event_ptr = event_ptr->next_event)
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{
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/* Call the handler for the event. */
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proc = event_ptr->proc;
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fd = event_ptr->fd;
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/* Let's get rid of the event from the event queue. We need to
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do this now because while processing the event, the proc
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function could end up calling 'error' and therefore jump out
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to the caller of this function, gdb_do_one_event. In that
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case, we would have on the event queue an event wich has been
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processed, but not deleted. */
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if (event_queue.first_event == event_ptr)
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{
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event_queue.first_event = event_ptr->next_event;
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if (event_ptr->next_event == NULL)
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event_queue.last_event = NULL;
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}
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else
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{
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prev_ptr = event_queue.first_event;
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while (prev_ptr->next_event != event_ptr)
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prev_ptr = prev_ptr->next_event;
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prev_ptr->next_event = event_ptr->next_event;
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if (event_ptr->next_event == NULL)
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event_queue.last_event = prev_ptr;
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}
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xfree (event_ptr);
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/* Now call the procedure associated with the event. */
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(*proc) (fd);
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return 1;
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}
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/* this is the case if there are no event on the event queue. */
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return 0;
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}
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/* Process one high level event. If nothing is ready at this time,
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wait for something to happen (via gdb_wait_for_event), then process
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it. Returns >0 if something was done otherwise returns <0 (this
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can happen if there are no event sources to wait for). If an error
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occurs catch_errors() which calls this function returns zero. */
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int
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gdb_do_one_event (void *data)
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{
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/* Any events already waiting in the queue? */
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if (process_event ())
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{
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return 1;
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}
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/* Are any timers that are ready? If so, put an event on the queue. */
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poll_timers ();
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/* Wait for a new event. If gdb_wait_for_event returns -1,
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we should get out because this means that there are no
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event sources left. This will make the event loop stop,
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and the application exit. */
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if (gdb_wait_for_event () < 0)
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{
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return -1;
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}
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/* Handle any new events occurred while waiting. */
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if (process_event ())
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{
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return 1;
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}
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/* If gdb_wait_for_event has returned 1, it means that one
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event has been handled. We break out of the loop. */
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return 1;
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}
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/* Start up the event loop. This is the entry point to the event loop
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from the command loop. */
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void
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start_event_loop (void)
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{
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/* Loop until there is nothing to do. This is the entry point to the
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event loop engine. gdb_do_one_event, called via catch_errors()
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will process one event for each invocation. It blocks waits for
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an event and then processes it. >0 when an event is processed, 0
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when catch_errors() caught an error and <0 when there are no
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longer any event sources registered. */
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while (1)
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{
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int gdb_result;
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gdb_result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
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if (gdb_result < 0)
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break;
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/* If we long-jumped out of do_one_event, we probably
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didn't get around to resetting the prompt, which leaves
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readline in a messed-up state. Reset it here. */
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if (gdb_result == 0)
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{
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||
/* FIXME: this should really be a call to a hook that is
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interface specific, because interfaces can display the
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prompt in their own way. */
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display_gdb_prompt (0);
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/* This call looks bizarre, but it is required. If the user
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||
entered a command that caused an error,
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after_char_processing_hook won't be called from
|
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rl_callback_read_char_wrapper. Using a cleanup there
|
||
won't work, since we want this function to be called
|
||
after a new prompt is printed. */
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||
if (after_char_processing_hook)
|
||
(*after_char_processing_hook) ();
|
||
/* Maybe better to set a flag to be checked somewhere as to
|
||
whether display the prompt or not. */
|
||
}
|
||
}
|
||
|
||
/* We are done with the event loop. There are no more event sources
|
||
to listen to. So we exit GDB. */
|
||
return;
|
||
}
|
||
|
||
|
||
/* 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 = (file_handler *) xmalloc (sizeof (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 =
|
||
(struct pollfd *) xmalloc (sizeof (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;
|
||
}
|
||
|
||
/* 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;
|
||
|
||
/* 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. Called by process_event indirectly,
|
||
through event_ptr->proc. EVENT_FILE_DESC is file descriptor of the
|
||
event in the front of the event queue. */
|
||
static void
|
||
handle_file_event (int event_file_desc)
|
||
{
|
||
file_handler *file_ptr;
|
||
int mask;
|
||
#ifdef HAVE_POLL
|
||
int error_mask;
|
||
int error_mask_returned;
|
||
#endif
|
||
|
||
/* Search the file handler list to find one that matches the fd in
|
||
the event. */
|
||
for (file_ptr = gdb_notifier.first_file_handler; file_ptr != NULL;
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
if (file_ptr->fd == event_file_desc)
|
||
{
|
||
/* With poll, the ready_mask could have any of three events
|
||
set to 1: POLLHUP, POLLERR, POLLNVAL. These events cannot
|
||
be used in the requested event mask (events), but they
|
||
can be returned in the return mask (revents). We need to
|
||
check for those event too, and add them to the mask which
|
||
will be passed to the handler. */
|
||
|
||
/* See if the desired events (mask) match the received
|
||
events (ready_mask). */
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
error_mask = POLLHUP | POLLERR | POLLNVAL;
|
||
mask = (file_ptr->ready_mask & file_ptr->mask) |
|
||
(file_ptr->ready_mask & error_mask);
|
||
error_mask_returned = mask & error_mask;
|
||
|
||
if (error_mask_returned != 0)
|
||
{
|
||
/* Work in progress. We may need to tell somebody what
|
||
kind of error we had. */
|
||
if (error_mask_returned & POLLHUP)
|
||
printf_unfiltered (_("Hangup detected on fd %d\n"), file_ptr->fd);
|
||
if (error_mask_returned & POLLERR)
|
||
printf_unfiltered (_("Error detected on fd %d\n"), file_ptr->fd);
|
||
if (error_mask_returned & POLLNVAL)
|
||
printf_unfiltered (_("Invalid or non-`poll'able fd %d\n"), file_ptr->fd);
|
||
file_ptr->error = 1;
|
||
}
|
||
else
|
||
file_ptr->error = 0;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
if (file_ptr->ready_mask & GDB_EXCEPTION)
|
||
{
|
||
printf_unfiltered (_("Exception condition detected on fd %d\n"), file_ptr->fd);
|
||
file_ptr->error = 1;
|
||
}
|
||
else
|
||
file_ptr->error = 0;
|
||
mask = file_ptr->ready_mask & file_ptr->mask;
|
||
}
|
||
|
||
/* Clear the received events for next time around. */
|
||
file_ptr->ready_mask = 0;
|
||
|
||
/* If there was a match, then call the handler. */
|
||
if (mask != 0)
|
||
(*file_ptr->proc) (file_ptr->error, file_ptr->client_data);
|
||
break;
|
||
}
|
||
}
|
||
}
|
||
|
||
/* Wrapper for select. This function is not yet exported from this
|
||
file because it is not sufficiently general. For example,
|
||
ser-base.c uses select to check for socket activity, and this
|
||
function does not support sockets under Windows, so we do not want
|
||
to use gdb_select in ser-base.c. */
|
||
|
||
static int
|
||
gdb_select (int n, fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
|
||
struct timeval *timeout)
|
||
{
|
||
#ifdef USE_WIN32API
|
||
HANDLE handles[MAXIMUM_WAIT_OBJECTS];
|
||
HANDLE h;
|
||
DWORD event;
|
||
DWORD num_handles;
|
||
int fd;
|
||
int num_ready;
|
||
|
||
num_handles = 0;
|
||
for (fd = 0; fd < n; ++fd)
|
||
{
|
||
/* EXCEPTFDS is silently ignored. GDB always sets GDB_EXCEPTION
|
||
when calling add_file_handler, but there is no natural analog
|
||
under Windows. */
|
||
/* There is no support yet for WRITEFDS. At present, this isn't
|
||
used by GDB -- but we do not want to silently ignore WRITEFDS
|
||
if something starts using it. */
|
||
gdb_assert (!FD_ISSET (fd, writefds));
|
||
if (FD_ISSET (fd, readfds))
|
||
{
|
||
gdb_assert (num_handles < MAXIMUM_WAIT_OBJECTS);
|
||
handles[num_handles++] = (HANDLE) _get_osfhandle (fd);
|
||
}
|
||
}
|
||
event = WaitForMultipleObjects (num_handles,
|
||
handles,
|
||
FALSE,
|
||
timeout
|
||
? (timeout->tv_sec * 1000 + timeout->tv_usec)
|
||
: INFINITE);
|
||
/* EVENT can only be a value in the WAIT_ABANDONED_0 range if the
|
||
HANDLES included an abandoned mutex. Since GDB doesn't use
|
||
mutexes, that should never occur. */
|
||
gdb_assert (!(WAIT_ABANDONED_0 <= event
|
||
&& event < WAIT_ABANDONED_0 + num_handles));
|
||
if (event == WAIT_FAILED)
|
||
return -1;
|
||
if (event == WAIT_TIMEOUT)
|
||
return 0;
|
||
/* Run through the READFDS, clearing bits corresponding to descriptors
|
||
for which input is unavailable. */
|
||
num_ready = num_handles;
|
||
h = handles[event - WAIT_OBJECT_0];
|
||
for (fd = 0; fd < n; ++fd)
|
||
{
|
||
HANDLE fd_h;
|
||
if (!FD_ISSET (fd, readfds))
|
||
continue;
|
||
fd_h = (HANDLE) _get_osfhandle (fd);
|
||
/* This handle might be ready, even though it wasn't the handle
|
||
returned by WaitForMultipleObjects. */
|
||
if (fd_h != h && WaitForSingleObject (fd_h, 0) != WAIT_OBJECT_0)
|
||
{
|
||
FD_CLR (fd, readfds);
|
||
--num_ready;
|
||
}
|
||
}
|
||
/* We never report any descriptors available for writing or with
|
||
exceptional conditions. */
|
||
FD_ZERO (writefds);
|
||
FD_ZERO (exceptfds);
|
||
|
||
return num_ready;
|
||
#else
|
||
return select (n, readfds, writefds, exceptfds, timeout);
|
||
#endif
|
||
}
|
||
|
||
/* Called by gdb_do_one_event to wait for new events on the
|
||
monitored file descriptors. Queue file events as they are
|
||
detected by the poll.
|
||
If there are no events, this function will block in the
|
||
call to poll.
|
||
Return -1 if there are no files descriptors to monitor,
|
||
otherwise return 0. */
|
||
static int
|
||
gdb_wait_for_event (void)
|
||
{
|
||
file_handler *file_ptr;
|
||
gdb_event *file_event_ptr;
|
||
int num_found = 0;
|
||
int i;
|
||
|
||
/* Make sure all output is done before getting another event. */
|
||
gdb_flush (gdb_stdout);
|
||
gdb_flush (gdb_stderr);
|
||
|
||
if (gdb_notifier.num_fds == 0)
|
||
return -1;
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
num_found =
|
||
poll (gdb_notifier.poll_fds,
|
||
(unsigned long) gdb_notifier.num_fds,
|
||
gdb_notifier.timeout_valid ? gdb_notifier.poll_timeout : -1);
|
||
|
||
/* 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
|
||
{
|
||
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],
|
||
gdb_notifier.timeout_valid
|
||
? &gdb_notifier.select_timeout : NULL);
|
||
|
||
/* 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 is we got a signal, let gdb handle it. */
|
||
if (errno != EINTR)
|
||
perror_with_name (("select"));
|
||
}
|
||
}
|
||
|
||
/* Enqueue all detected file events. */
|
||
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
for (i = 0; (i < gdb_notifier.num_fds) && (num_found > 0); i++)
|
||
{
|
||
if ((gdb_notifier.poll_fds + i)->revents)
|
||
num_found--;
|
||
else
|
||
continue;
|
||
|
||
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;
|
||
}
|
||
|
||
if (file_ptr)
|
||
{
|
||
/* Enqueue an event only if this is still a new event for
|
||
this fd. */
|
||
if (file_ptr->ready_mask == 0)
|
||
{
|
||
file_event_ptr = create_file_event (file_ptr->fd);
|
||
async_queue_event (file_event_ptr, TAIL);
|
||
}
|
||
}
|
||
|
||
file_ptr->ready_mask = (gdb_notifier.poll_fds + i)->revents;
|
||
}
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
for (file_ptr = gdb_notifier.first_file_handler;
|
||
(file_ptr != NULL) && (num_found > 0);
|
||
file_ptr = file_ptr->next_file)
|
||
{
|
||
int mask = 0;
|
||
|
||
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;
|
||
|
||
if (!mask)
|
||
continue;
|
||
else
|
||
num_found--;
|
||
|
||
/* Enqueue an event only if this is still a new event for
|
||
this fd. */
|
||
|
||
if (file_ptr->ready_mask == 0)
|
||
{
|
||
file_event_ptr = create_file_event (file_ptr->fd);
|
||
async_queue_event (file_event_ptr, TAIL);
|
||
}
|
||
file_ptr->ready_mask = mask;
|
||
}
|
||
}
|
||
return 0;
|
||
}
|
||
|
||
|
||
/* Create an asynchronous handler, allocating memory for it.
|
||
Return a pointer to the newly created handler.
|
||
This pointer will be used to invoke the handler by
|
||
invoke_async_signal_handler.
|
||
PROC is the function to call with CLIENT_DATA argument
|
||
whenever the handler is invoked. */
|
||
async_signal_handler *
|
||
create_async_signal_handler (sig_handler_func * proc, gdb_client_data client_data)
|
||
{
|
||
async_signal_handler *async_handler_ptr;
|
||
|
||
async_handler_ptr =
|
||
(async_signal_handler *) xmalloc (sizeof (async_signal_handler));
|
||
async_handler_ptr->ready = 0;
|
||
async_handler_ptr->next_handler = NULL;
|
||
async_handler_ptr->proc = proc;
|
||
async_handler_ptr->client_data = client_data;
|
||
if (sighandler_list.first_handler == NULL)
|
||
sighandler_list.first_handler = async_handler_ptr;
|
||
else
|
||
sighandler_list.last_handler->next_handler = async_handler_ptr;
|
||
sighandler_list.last_handler = async_handler_ptr;
|
||
return async_handler_ptr;
|
||
}
|
||
|
||
/* Mark the handler (ASYNC_HANDLER_PTR) as ready. This information will
|
||
be used when the handlers are invoked, after we have waited for
|
||
some event. The caller of this function is the interrupt handler
|
||
associated with a signal. */
|
||
void
|
||
mark_async_signal_handler (async_signal_handler * async_handler_ptr)
|
||
{
|
||
((async_signal_handler *) async_handler_ptr)->ready = 1;
|
||
async_handler_ready = 1;
|
||
}
|
||
|
||
/* Call all the handlers that are ready. */
|
||
static void
|
||
invoke_async_signal_handler (void)
|
||
{
|
||
async_signal_handler *async_handler_ptr;
|
||
|
||
if (async_handler_ready == 0)
|
||
return;
|
||
async_handler_ready = 0;
|
||
|
||
/* Invoke ready handlers. */
|
||
|
||
while (1)
|
||
{
|
||
for (async_handler_ptr = sighandler_list.first_handler;
|
||
async_handler_ptr != NULL;
|
||
async_handler_ptr = async_handler_ptr->next_handler)
|
||
{
|
||
if (async_handler_ptr->ready)
|
||
break;
|
||
}
|
||
if (async_handler_ptr == NULL)
|
||
break;
|
||
async_handler_ptr->ready = 0;
|
||
(*async_handler_ptr->proc) (async_handler_ptr->client_data);
|
||
}
|
||
|
||
return;
|
||
}
|
||
|
||
/* Delete an asynchronous handler (ASYNC_HANDLER_PTR).
|
||
Free the space allocated for it. */
|
||
void
|
||
delete_async_signal_handler (async_signal_handler ** async_handler_ptr)
|
||
{
|
||
async_signal_handler *prev_ptr;
|
||
|
||
if (sighandler_list.first_handler == (*async_handler_ptr))
|
||
{
|
||
sighandler_list.first_handler = (*async_handler_ptr)->next_handler;
|
||
if (sighandler_list.first_handler == NULL)
|
||
sighandler_list.last_handler = NULL;
|
||
}
|
||
else
|
||
{
|
||
prev_ptr = sighandler_list.first_handler;
|
||
while (prev_ptr->next_handler != (*async_handler_ptr) && prev_ptr)
|
||
prev_ptr = prev_ptr->next_handler;
|
||
prev_ptr->next_handler = (*async_handler_ptr)->next_handler;
|
||
if (sighandler_list.last_handler == (*async_handler_ptr))
|
||
sighandler_list.last_handler = prev_ptr;
|
||
}
|
||
xfree ((*async_handler_ptr));
|
||
(*async_handler_ptr) = NULL;
|
||
}
|
||
|
||
/* Is it necessary to call invoke_async_signal_handler? */
|
||
static int
|
||
check_async_ready (void)
|
||
{
|
||
return async_handler_ready;
|
||
}
|
||
|
||
/* Create a timer that will expire in MILLISECONDS from now. When the
|
||
timer is ready, PROC will be executed. At creation, the timer is
|
||
aded to the timers queue. This queue is kept sorted in order of
|
||
increasing timers. Return a handle to the timer struct. */
|
||
int
|
||
create_timer (int milliseconds, timer_handler_func * proc, gdb_client_data client_data)
|
||
{
|
||
struct gdb_timer *timer_ptr, *timer_index, *prev_timer;
|
||
struct timeval time_now, delta;
|
||
|
||
/* compute seconds */
|
||
delta.tv_sec = milliseconds / 1000;
|
||
/* compute microseconds */
|
||
delta.tv_usec = (milliseconds % 1000) * 1000;
|
||
|
||
gettimeofday (&time_now, NULL);
|
||
|
||
timer_ptr = (struct gdb_timer *) xmalloc (sizeof (gdb_timer));
|
||
timer_ptr->when.tv_sec = time_now.tv_sec + delta.tv_sec;
|
||
timer_ptr->when.tv_usec = time_now.tv_usec + delta.tv_usec;
|
||
/* carry? */
|
||
if (timer_ptr->when.tv_usec >= 1000000)
|
||
{
|
||
timer_ptr->when.tv_sec += 1;
|
||
timer_ptr->when.tv_usec -= 1000000;
|
||
}
|
||
timer_ptr->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 the seconds field is greater or if it is the same, but the
|
||
microsecond field is greater. */
|
||
if ((timer_index->when.tv_sec > timer_ptr->when.tv_sec) ||
|
||
((timer_index->when.tv_sec == timer_ptr->when.tv_sec)
|
||
&& (timer_index->when.tv_usec > timer_ptr->when.tv_usec)))
|
||
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;
|
||
}
|
||
xfree (timer_ptr);
|
||
|
||
gdb_notifier.timeout_valid = 0;
|
||
}
|
||
|
||
/* When a timer event is put on the event queue, it will be handled by
|
||
this function. Just call the assiciated procedure and delete the
|
||
timer event from the event queue. Repeat this for each timer that
|
||
has expired. */
|
||
static void
|
||
handle_timer_event (int dummy)
|
||
{
|
||
struct timeval time_now;
|
||
struct gdb_timer *timer_ptr, *saved_timer;
|
||
|
||
gettimeofday (&time_now, NULL);
|
||
timer_ptr = timer_list.first_timer;
|
||
|
||
while (timer_ptr != NULL)
|
||
{
|
||
if ((timer_ptr->when.tv_sec > time_now.tv_sec) ||
|
||
((timer_ptr->when.tv_sec == time_now.tv_sec) &&
|
||
(timer_ptr->when.tv_usec > time_now.tv_usec)))
|
||
break;
|
||
|
||
/* Get rid of the timer from the beginning of the list. */
|
||
timer_list.first_timer = timer_ptr->next;
|
||
saved_timer = timer_ptr;
|
||
timer_ptr = timer_ptr->next;
|
||
/* Call the procedure associated with that timer. */
|
||
(*saved_timer->proc) (saved_timer->client_data);
|
||
xfree (saved_timer);
|
||
}
|
||
|
||
gdb_notifier.timeout_valid = 0;
|
||
}
|
||
|
||
/* Check whether any timers in the timers queue are ready. If at least
|
||
one timer is ready, stick an event onto the event queue. Even in
|
||
case more than one timer is ready, one event is enough, because the
|
||
handle_timer_event() will go through the timers list and call the
|
||
procedures associated with all that have expired. Update the
|
||
timeout for the select() or poll() as well. */
|
||
static void
|
||
poll_timers (void)
|
||
{
|
||
struct timeval time_now, delta;
|
||
gdb_event *event_ptr;
|
||
|
||
if (timer_list.first_timer != NULL)
|
||
{
|
||
gettimeofday (&time_now, NULL);
|
||
delta.tv_sec = timer_list.first_timer->when.tv_sec - time_now.tv_sec;
|
||
delta.tv_usec = timer_list.first_timer->when.tv_usec - time_now.tv_usec;
|
||
/* borrow? */
|
||
if (delta.tv_usec < 0)
|
||
{
|
||
delta.tv_sec -= 1;
|
||
delta.tv_usec += 1000000;
|
||
}
|
||
|
||
/* Oops it expired already. Tell select / poll to return
|
||
immediately. (Cannot simply test if delta.tv_sec is negative
|
||
because time_t might be unsigned.) */
|
||
if (timer_list.first_timer->when.tv_sec < time_now.tv_sec
|
||
|| (timer_list.first_timer->when.tv_sec == time_now.tv_sec
|
||
&& timer_list.first_timer->when.tv_usec < time_now.tv_usec))
|
||
{
|
||
delta.tv_sec = 0;
|
||
delta.tv_usec = 0;
|
||
}
|
||
|
||
if (delta.tv_sec == 0 && delta.tv_usec == 0)
|
||
{
|
||
event_ptr = (gdb_event *) xmalloc (sizeof (gdb_event));
|
||
event_ptr->proc = handle_timer_event;
|
||
event_ptr->fd = timer_list.first_timer->timer_id;
|
||
async_queue_event (event_ptr, TAIL);
|
||
}
|
||
|
||
/* Now we need to update the timeout for select/ poll, because we
|
||
don't want to sit there while this timer is expiring. */
|
||
if (use_poll)
|
||
{
|
||
#ifdef HAVE_POLL
|
||
gdb_notifier.poll_timeout = delta.tv_sec * 1000;
|
||
#else
|
||
internal_error (__FILE__, __LINE__,
|
||
_("use_poll without HAVE_POLL"));
|
||
#endif /* HAVE_POLL */
|
||
}
|
||
else
|
||
{
|
||
gdb_notifier.select_timeout.tv_sec = delta.tv_sec;
|
||
gdb_notifier.select_timeout.tv_usec = delta.tv_usec;
|
||
}
|
||
gdb_notifier.timeout_valid = 1;
|
||
}
|
||
else
|
||
gdb_notifier.timeout_valid = 0;
|
||
}
|