541 lines
13 KiB
C
541 lines
13 KiB
C
/* Generic serial interface functions.
|
|
|
|
Copyright (C) 1992-1996, 1998-2001, 2003-2012 Free Software
|
|
Foundation, Inc.
|
|
|
|
This file is part of GDB.
|
|
|
|
This program is free software; you can redistribute it and/or modify
|
|
it under the terms of the GNU General Public License as published by
|
|
the Free Software Foundation; either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include "defs.h"
|
|
#include "serial.h"
|
|
#include "ser-base.h"
|
|
#include "event-loop.h"
|
|
|
|
#include "gdb_select.h"
|
|
#include "gdb_string.h"
|
|
#include <sys/time.h>
|
|
#ifdef USE_WIN32API
|
|
#include <winsock2.h>
|
|
#endif
|
|
|
|
|
|
static timer_handler_func push_event;
|
|
static handler_func fd_event;
|
|
|
|
/* Event handling for ASYNC serial code.
|
|
|
|
At any time the SERIAL device either: has an empty FIFO and is
|
|
waiting on a FD event; or has a non-empty FIFO/error condition and
|
|
is constantly scheduling timer events.
|
|
|
|
ASYNC only stops pestering its client when it is de-async'ed or it
|
|
is told to go away. */
|
|
|
|
/* Value of scb->async_state: */
|
|
enum {
|
|
/* >= 0 (TIMER_SCHEDULED) */
|
|
/* The ID of the currently scheduled timer event. This state is
|
|
rarely encountered. Timer events are one-off so as soon as the
|
|
event is delivered the state is shanged to NOTHING_SCHEDULED. */
|
|
FD_SCHEDULED = -1,
|
|
/* The fd_event() handler is scheduled. It is called when ever the
|
|
file descriptor becomes ready. */
|
|
NOTHING_SCHEDULED = -2
|
|
/* Either no task is scheduled (just going into ASYNC mode) or a
|
|
timer event has just gone off and the current state has been
|
|
forced into nothing scheduled. */
|
|
};
|
|
|
|
/* Identify and schedule the next ASYNC task based on scb->async_state
|
|
and scb->buf* (the input FIFO). A state machine is used to avoid
|
|
the need to make redundant calls into the event-loop - the next
|
|
scheduled task is only changed when needed. */
|
|
|
|
static void
|
|
reschedule (struct serial *scb)
|
|
{
|
|
if (serial_is_async_p (scb))
|
|
{
|
|
int next_state;
|
|
|
|
switch (scb->async_state)
|
|
{
|
|
case FD_SCHEDULED:
|
|
if (scb->bufcnt == 0)
|
|
next_state = FD_SCHEDULED;
|
|
else
|
|
{
|
|
delete_file_handler (scb->fd);
|
|
next_state = create_timer (0, push_event, scb);
|
|
}
|
|
break;
|
|
case NOTHING_SCHEDULED:
|
|
if (scb->bufcnt == 0)
|
|
{
|
|
add_file_handler (scb->fd, fd_event, scb);
|
|
next_state = FD_SCHEDULED;
|
|
}
|
|
else
|
|
{
|
|
next_state = create_timer (0, push_event, scb);
|
|
}
|
|
break;
|
|
default: /* TIMER SCHEDULED */
|
|
if (scb->bufcnt == 0)
|
|
{
|
|
delete_timer (scb->async_state);
|
|
add_file_handler (scb->fd, fd_event, scb);
|
|
next_state = FD_SCHEDULED;
|
|
}
|
|
else
|
|
next_state = scb->async_state;
|
|
break;
|
|
}
|
|
if (serial_debug_p (scb))
|
|
{
|
|
switch (next_state)
|
|
{
|
|
case FD_SCHEDULED:
|
|
if (scb->async_state != FD_SCHEDULED)
|
|
fprintf_unfiltered (gdb_stdlog, "[fd%d->fd-scheduled]\n",
|
|
scb->fd);
|
|
break;
|
|
default: /* TIMER SCHEDULED */
|
|
if (scb->async_state == FD_SCHEDULED)
|
|
fprintf_unfiltered (gdb_stdlog, "[fd%d->timer-scheduled]\n",
|
|
scb->fd);
|
|
break;
|
|
}
|
|
}
|
|
scb->async_state = next_state;
|
|
}
|
|
}
|
|
|
|
/* FD_EVENT: This is scheduled when the input FIFO is empty (and there
|
|
is no pending error). As soon as data arrives, it is read into the
|
|
input FIFO and the client notified. The client should then drain
|
|
the FIFO using readchar(). If the FIFO isn't immediatly emptied,
|
|
push_event() is used to nag the client until it is. */
|
|
|
|
static void
|
|
fd_event (int error, void *context)
|
|
{
|
|
struct serial *scb = context;
|
|
if (error != 0)
|
|
{
|
|
scb->bufcnt = SERIAL_ERROR;
|
|
}
|
|
else if (scb->bufcnt == 0)
|
|
{
|
|
/* Prime the input FIFO. The readchar() function is used to
|
|
pull characters out of the buffer. See also
|
|
generic_readchar(). */
|
|
int nr;
|
|
nr = scb->ops->read_prim (scb, BUFSIZ);
|
|
if (nr == 0)
|
|
{
|
|
scb->bufcnt = SERIAL_EOF;
|
|
}
|
|
else if (nr > 0)
|
|
{
|
|
scb->bufcnt = nr;
|
|
scb->bufp = scb->buf;
|
|
}
|
|
else
|
|
{
|
|
scb->bufcnt = SERIAL_ERROR;
|
|
}
|
|
}
|
|
scb->async_handler (scb, scb->async_context);
|
|
reschedule (scb);
|
|
}
|
|
|
|
/* PUSH_EVENT: The input FIFO is non-empty (or there is a pending
|
|
error). Nag the client until all the data has been read. In the
|
|
case of errors, the client will need to close or de-async the
|
|
device before naging stops. */
|
|
|
|
static void
|
|
push_event (void *context)
|
|
{
|
|
struct serial *scb = context;
|
|
|
|
scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */
|
|
scb->async_handler (scb, scb->async_context);
|
|
/* re-schedule */
|
|
reschedule (scb);
|
|
}
|
|
|
|
/* Wait for input on scb, with timeout seconds. Returns 0 on success,
|
|
otherwise SERIAL_TIMEOUT or SERIAL_ERROR. */
|
|
|
|
static int
|
|
ser_base_wait_for (struct serial *scb, int timeout)
|
|
{
|
|
while (1)
|
|
{
|
|
int numfds;
|
|
struct timeval tv;
|
|
fd_set readfds, exceptfds;
|
|
|
|
/* NOTE: Some OS's can scramble the READFDS when the select()
|
|
call fails (ex the kernel with Red Hat 5.2). Initialize all
|
|
arguments before each call. */
|
|
|
|
tv.tv_sec = timeout;
|
|
tv.tv_usec = 0;
|
|
|
|
FD_ZERO (&readfds);
|
|
FD_ZERO (&exceptfds);
|
|
FD_SET (scb->fd, &readfds);
|
|
FD_SET (scb->fd, &exceptfds);
|
|
|
|
if (timeout >= 0)
|
|
numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, &tv);
|
|
else
|
|
numfds = gdb_select (scb->fd + 1, &readfds, 0, &exceptfds, 0);
|
|
|
|
if (numfds <= 0)
|
|
{
|
|
if (numfds == 0)
|
|
return SERIAL_TIMEOUT;
|
|
else if (errno == EINTR)
|
|
continue;
|
|
else
|
|
return SERIAL_ERROR; /* Got an error from select or
|
|
poll. */
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/* Read a character with user-specified timeout. TIMEOUT is number of seconds
|
|
to wait, or -1 to wait forever. Use timeout of 0 to effect a poll. Returns
|
|
char if successful. Returns -2 if timeout expired, EOF if line dropped
|
|
dead, or -3 for any other error (see errno in that case). */
|
|
|
|
static int
|
|
do_ser_base_readchar (struct serial *scb, int timeout)
|
|
{
|
|
int status;
|
|
int delta;
|
|
|
|
/* We have to be able to keep the GUI alive here, so we break the
|
|
original timeout into steps of 1 second, running the "keep the
|
|
GUI alive" hook each time through the loop.
|
|
|
|
Also, timeout = 0 means to poll, so we just set the delta to 0,
|
|
so we will only go through the loop once. */
|
|
|
|
delta = (timeout == 0 ? 0 : 1);
|
|
while (1)
|
|
{
|
|
/* N.B. The UI may destroy our world (for instance by calling
|
|
remote_stop,) in which case we want to get out of here as
|
|
quickly as possible. It is not safe to touch scb, since
|
|
someone else might have freed it. The
|
|
deprecated_ui_loop_hook signals that we should exit by
|
|
returning 1. */
|
|
|
|
if (deprecated_ui_loop_hook)
|
|
{
|
|
if (deprecated_ui_loop_hook (0))
|
|
return SERIAL_TIMEOUT;
|
|
}
|
|
|
|
status = ser_base_wait_for (scb, delta);
|
|
if (timeout > 0)
|
|
timeout -= delta;
|
|
|
|
/* If we got a character or an error back from wait_for, then we can
|
|
break from the loop before the timeout is completed. */
|
|
if (status != SERIAL_TIMEOUT)
|
|
break;
|
|
|
|
/* If we have exhausted the original timeout, then generate
|
|
a SERIAL_TIMEOUT, and pass it out of the loop. */
|
|
else if (timeout == 0)
|
|
{
|
|
status = SERIAL_TIMEOUT;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (status < 0)
|
|
return status;
|
|
|
|
status = scb->ops->read_prim (scb, BUFSIZ);
|
|
|
|
if (status <= 0)
|
|
{
|
|
if (status == 0)
|
|
return SERIAL_EOF;
|
|
else
|
|
/* Got an error from read. */
|
|
return SERIAL_ERROR;
|
|
}
|
|
|
|
scb->bufcnt = status;
|
|
scb->bufcnt--;
|
|
scb->bufp = scb->buf;
|
|
return *scb->bufp++;
|
|
}
|
|
|
|
/* Perform operations common to both old and new readchar. */
|
|
|
|
/* Return the next character from the input FIFO. If the FIFO is
|
|
empty, call the SERIAL specific routine to try and read in more
|
|
characters.
|
|
|
|
Initially data from the input FIFO is returned (fd_event()
|
|
pre-reads the input into that FIFO. Once that has been emptied,
|
|
further data is obtained by polling the input FD using the device
|
|
specific readchar() function. Note: reschedule() is called after
|
|
every read. This is because there is no guarentee that the lower
|
|
level fd_event() poll_event() code (which also calls reschedule())
|
|
will be called. */
|
|
|
|
int
|
|
generic_readchar (struct serial *scb, int timeout,
|
|
int (do_readchar) (struct serial *scb, int timeout))
|
|
{
|
|
int ch;
|
|
if (scb->bufcnt > 0)
|
|
{
|
|
ch = *scb->bufp;
|
|
scb->bufcnt--;
|
|
scb->bufp++;
|
|
}
|
|
else if (scb->bufcnt < 0)
|
|
{
|
|
/* Some errors/eof are are sticky. */
|
|
ch = scb->bufcnt;
|
|
}
|
|
else
|
|
{
|
|
ch = do_readchar (scb, timeout);
|
|
if (ch < 0)
|
|
{
|
|
switch ((enum serial_rc) ch)
|
|
{
|
|
case SERIAL_EOF:
|
|
case SERIAL_ERROR:
|
|
/* Make the error/eof stick. */
|
|
scb->bufcnt = ch;
|
|
break;
|
|
case SERIAL_TIMEOUT:
|
|
scb->bufcnt = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
/* Read any error output we might have. */
|
|
if (scb->error_fd != -1)
|
|
{
|
|
ssize_t s;
|
|
char buf[81];
|
|
|
|
for (;;)
|
|
{
|
|
char *current;
|
|
char *newline;
|
|
int to_read = 80;
|
|
|
|
int num_bytes = -1;
|
|
if (scb->ops->avail)
|
|
num_bytes = (scb->ops->avail)(scb, scb->error_fd);
|
|
if (num_bytes != -1)
|
|
to_read = (num_bytes < to_read) ? num_bytes : to_read;
|
|
|
|
if (to_read == 0)
|
|
break;
|
|
|
|
s = read (scb->error_fd, &buf, to_read);
|
|
if (s == -1)
|
|
break;
|
|
if (s == 0)
|
|
{
|
|
/* EOF */
|
|
close (scb->error_fd);
|
|
scb->error_fd = -1;
|
|
break;
|
|
}
|
|
|
|
/* In theory, embedded newlines are not a problem.
|
|
But for MI, we want each output line to have just
|
|
one newline for legibility. So output things
|
|
in newline chunks. */
|
|
buf[s] = '\0';
|
|
current = buf;
|
|
while ((newline = strstr (current, "\n")) != NULL)
|
|
{
|
|
*newline = '\0';
|
|
fputs_unfiltered (current, gdb_stderr);
|
|
fputs_unfiltered ("\n", gdb_stderr);
|
|
current = newline + 1;
|
|
}
|
|
fputs_unfiltered (current, gdb_stderr);
|
|
}
|
|
}
|
|
|
|
reschedule (scb);
|
|
return ch;
|
|
}
|
|
|
|
int
|
|
ser_base_readchar (struct serial *scb, int timeout)
|
|
{
|
|
return generic_readchar (scb, timeout, do_ser_base_readchar);
|
|
}
|
|
|
|
int
|
|
ser_base_write (struct serial *scb, const char *str, int len)
|
|
{
|
|
int cc;
|
|
|
|
while (len > 0)
|
|
{
|
|
cc = scb->ops->write_prim (scb, str, len);
|
|
|
|
if (cc < 0)
|
|
return 1;
|
|
len -= cc;
|
|
str += cc;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ser_base_flush_output (struct serial *scb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ser_base_flush_input (struct serial *scb)
|
|
{
|
|
if (scb->bufcnt >= 0)
|
|
{
|
|
scb->bufcnt = 0;
|
|
scb->bufp = scb->buf;
|
|
return 0;
|
|
}
|
|
else
|
|
return SERIAL_ERROR;
|
|
}
|
|
|
|
int
|
|
ser_base_send_break (struct serial *scb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ser_base_drain_output (struct serial *scb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
ser_base_raw (struct serial *scb)
|
|
{
|
|
return; /* Always in raw mode. */
|
|
}
|
|
|
|
serial_ttystate
|
|
ser_base_get_tty_state (struct serial *scb)
|
|
{
|
|
/* Allocate a dummy. */
|
|
return (serial_ttystate) XMALLOC (int);
|
|
}
|
|
|
|
serial_ttystate
|
|
ser_base_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
|
|
{
|
|
/* Allocate another dummy. */
|
|
return (serial_ttystate) XMALLOC (int);
|
|
}
|
|
|
|
int
|
|
ser_base_set_tty_state (struct serial *scb, serial_ttystate ttystate)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int
|
|
ser_base_noflush_set_tty_state (struct serial *scb,
|
|
serial_ttystate new_ttystate,
|
|
serial_ttystate old_ttystate)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
void
|
|
ser_base_print_tty_state (struct serial *scb,
|
|
serial_ttystate ttystate,
|
|
struct ui_file *stream)
|
|
{
|
|
/* Nothing to print. */
|
|
return;
|
|
}
|
|
|
|
int
|
|
ser_base_setbaudrate (struct serial *scb, int rate)
|
|
{
|
|
return 0; /* Never fails! */
|
|
}
|
|
|
|
int
|
|
ser_base_setstopbits (struct serial *scb, int num)
|
|
{
|
|
return 0; /* Never fails! */
|
|
}
|
|
|
|
/* Put the SERIAL device into/out-of ASYNC mode. */
|
|
|
|
void
|
|
ser_base_async (struct serial *scb,
|
|
int async_p)
|
|
{
|
|
if (async_p)
|
|
{
|
|
/* Force a re-schedule. */
|
|
scb->async_state = NOTHING_SCHEDULED;
|
|
if (serial_debug_p (scb))
|
|
fprintf_unfiltered (gdb_stdlog, "[fd%d->asynchronous]\n",
|
|
scb->fd);
|
|
reschedule (scb);
|
|
}
|
|
else
|
|
{
|
|
if (serial_debug_p (scb))
|
|
fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n",
|
|
scb->fd);
|
|
/* De-schedule whatever tasks are currently scheduled. */
|
|
switch (scb->async_state)
|
|
{
|
|
case FD_SCHEDULED:
|
|
delete_file_handler (scb->fd);
|
|
break;
|
|
case NOTHING_SCHEDULED:
|
|
break;
|
|
default: /* TIMER SCHEDULED */
|
|
delete_timer (scb->async_state);
|
|
break;
|
|
}
|
|
}
|
|
}
|