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authorJason Molenda <jsm@bugshack.cygnus.com>1999-10-05 23:13:56 +0000
committerJason Molenda <jsm@bugshack.cygnus.com>1999-10-05 23:13:56 +0000
commitce8537f129e0aa7823f1e9ff610baea9edd4f9ce (patch)
tree44c31e9e3ca76fb002295a2ddafc1f6aa9a91a9e /gdb/ser-unix.c
parente61b94e5346142170a372e22f687753fcae79595 (diff)
downloadgdb-ce8537f129e0aa7823f1e9ff610baea9edd4f9ce.tar.gz
import gdb-1999-10-04 snapshot
Diffstat (limited to 'gdb/ser-unix.c')
-rw-r--r--gdb/ser-unix.c340
1 files changed, 273 insertions, 67 deletions
diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index 7c268a9f57e..c54d9170b05 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -34,7 +34,6 @@
#include "gdb_string.h"
#include "event-loop.h"
-
#ifdef HAVE_TERMIOS
struct hardwire_ttystate
@@ -71,9 +70,10 @@ static int hardwire_open (serial_t scb, const char *name);
static void hardwire_raw (serial_t scb);
static int wait_for (serial_t scb, int timeout);
static int hardwire_readchar (serial_t scb, int timeout);
+static int do_hardwire_readchar (serial_t scb, int timeout);
+static int generic_readchar (serial_t scb, int timeout, int (*do_readchar) (serial_t scb, int timeout));
static int rate_to_code (int rate);
static int hardwire_setbaudrate (serial_t scb, int rate);
-static int hardwire_write (serial_t scb, const char *str, int len);
static void hardwire_close (serial_t scb);
static int get_tty_state (serial_t scb, struct hardwire_ttystate * state);
static int set_tty_state (serial_t scb, struct hardwire_ttystate * state);
@@ -88,6 +88,11 @@ static int hardwire_flush_input (serial_t);
static int hardwire_send_break (serial_t);
static int hardwire_setstopbits (serial_t, int);
+static int do_unix_readchar (serial_t scb, int timeout);
+static timer_handler_func push_event;
+static handler_func fd_event;
+static void reschedule (serial_t scb);
+
void _initialize_ser_hardwire (void);
extern int (*ui_loop_hook) (int);
@@ -230,9 +235,11 @@ hardwire_print_tty_state (serial_t scb,
#ifdef HAVE_TERMIOS
fprintf_filtered (stream, "c_iflag = 0x%x, c_oflag = 0x%x,\n",
- state->termios.c_iflag, state->termios.c_oflag);
+ (int) state->termios.c_iflag,
+ (int) state->termios.c_oflag);
fprintf_filtered (stream, "c_cflag = 0x%x, c_lflag = 0x%x\n",
- state->termios.c_cflag, state->termios.c_lflag);
+ (int) state->termios.c_cflag,
+ (int) state->termios.c_lflag);
#if 0
/* This not in POSIX, and is not really documented by those systems
which have it (at least not Sun). */
@@ -325,8 +332,7 @@ hardwire_flush_output (serial_t scb)
static int
hardwire_flush_input (serial_t scb)
{
- scb->bufcnt = 0;
- scb->bufp = scb->buf;
+ ser_unix_flush_input (scb);
#ifdef HAVE_TERMIOS
return tcflush (scb->fd, TCIFLUSH);
@@ -418,9 +424,14 @@ hardwire_raw (serial_t scb)
timeout occur in the read() in hardwire_read().
*/
-/* FIXME: Don't replace this with the equivalent ser_unix*() until the
- old TERMIOS/SGTTY/... timer code has been flushed. cagney
- 1999-09-16. */
+/* FIXME: cagney/1999-09-16: Don't replace this with the equivalent
+ ser_unix*() until the old TERMIOS/SGTTY/... timer code has been
+ flushed. . */
+
+/* NOTE: cagney/1999-09-30: Much of the code below is dead. The only
+ possible values of the TIMEOUT parameter are ONE and ZERO.
+ Consequently all the code that tries to handle the possability of
+ an overflowed timer is unnecessary. */
static int
wait_for (serial_t scb, int timeout)
@@ -544,14 +555,11 @@ wait_for (serial_t scb, int timeout)
that. */
static int
-hardwire_readchar (serial_t scb, int timeout)
+do_hardwire_readchar (serial_t scb, int timeout)
{
int status, delta;
int detach = 0;
- if (scb->bufcnt-- > 0)
- return *scb->bufp++;
-
if (timeout > 0)
timeout++;
@@ -583,15 +591,11 @@ hardwire_readchar (serial_t scb, int timeout)
if (status < 0)
return status;
- /* NOTE: cagney/1999-09-17: See ser_unix_readchar() for reason
- why ASYNC reads are character by character. */
-
- scb->bufcnt = read (scb->fd, scb->buf,
- (SERIAL_IS_ASYNC_P (scb) ? 1 : BUFSIZ));
+ status = read (scb->fd, scb->buf, BUFSIZ);
- if (scb->bufcnt <= 0)
+ if (status <= 0)
{
- if (scb->bufcnt == 0)
+ if (status == 0)
{
/* Zero characters means timeout (it could also be EOF, but
we don't (yet at least) distinguish). */
@@ -611,12 +615,20 @@ hardwire_readchar (serial_t scb, int timeout)
return SERIAL_ERROR; /* Got an error from read */
}
+ scb->bufcnt = status;
scb->bufcnt--;
scb->bufp = scb->buf;
return *scb->bufp++;
}
}
+static int
+hardwire_readchar (serial_t scb, int timeout)
+{
+ return generic_readchar (scb, timeout, do_hardwire_readchar);
+}
+
+
#ifndef B19200
#define B19200 EXTA
#endif
@@ -812,28 +824,6 @@ hardwire_setstopbits (scb, num)
return set_tty_state (scb, &state);
}
-/* FIXME: Don't replace this with the equivalent ser_unix*() until the
- old TERMIOS/SGTTY/... timer code has been flushed. cagney
- 1999-09-16. */
-
-static int
-hardwire_write (serial_t scb, const char *str, int len)
-{
- int cc;
-
- while (len > 0)
- {
- cc = write (scb->fd, str, len);
-
- if (cc < 0)
- return 1;
- len -= cc;
- str += cc;
- }
- return 0;
-}
-
-
static void
hardwire_close (serial_t scb)
{
@@ -911,15 +901,12 @@ ser_unix_wait_for (serial_t scb, int timeout)
char if successful. Returns -2 if timeout expired, EOF if line dropped
dead, or -3 for any other error (see errno in that case). */
-int
-ser_unix_readchar (serial_t scb, int timeout)
+static int
+do_unix_readchar (serial_t scb, int timeout)
{
int status;
int delta;
- if (scb->bufcnt-- > 0)
- return *scb->bufp++;
-
/* 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.
@@ -969,20 +956,14 @@ ser_unix_readchar (serial_t scb, int timeout)
while (1)
{
- /* FIXME: cagney/1999-09-17: ASYNC: The ASYNC serial code needs
- to be modified so that it agressivly tries to drain its local
- input buffer. Until this is done, the read() below can only
- take in single characters. This is to ensure that
- unprocessed data doesn't end up sitting in the input fifo. */
- scb->bufcnt = read (scb->fd, scb->buf,
- (SERIAL_IS_ASYNC_P (scb) ? 1 : BUFSIZ));
- if (scb->bufcnt != -1 || errno != EINTR)
+ status = read (scb->fd, scb->buf, BUFSIZ);
+ if (status != -1 || errno != EINTR)
break;
}
- if (scb->bufcnt <= 0)
+ if (status <= 0)
{
- if (scb->bufcnt == 0)
+ if (status == 0)
return SERIAL_TIMEOUT; /* 0 chars means timeout [may need to
distinguish between EOF & timeouts
someday] */
@@ -990,11 +971,70 @@ ser_unix_readchar (serial_t scb, int timeout)
return SERIAL_ERROR; /* Got an error from read */
}
+ 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. */
+
+static int
+generic_readchar (serial_t scb, int timeout,
+ int (do_readchar) (serial_t 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;
+ }
+ }
+ }
+ reschedule (scb);
+ return ch;
+}
+
+int
+ser_unix_readchar (serial_t scb, int timeout)
+{
+ return generic_readchar (scb, timeout, do_unix_readchar);
+}
+
int
ser_unix_nop_noflush_set_tty_state (serial_t scb,
serial_ttystate new_ttystate,
@@ -1048,9 +1088,16 @@ ser_unix_nop_flush_output (serial_t scb)
}
int
-ser_unix_nop_flush_input (serial_t scb)
+ser_unix_flush_input (serial_t scb)
{
- return 0;
+ if (scb->bufcnt >= 0)
+ {
+ scb->bufcnt = 0;
+ scb->bufp = scb->buf;
+ return 0;
+ }
+ else
+ return SERIAL_ERROR;
}
int
@@ -1065,24 +1112,186 @@ ser_unix_nop_drain_output (serial_t scb)
return 0;
}
+
+
+/* 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
-ser_unix_event (int error, int fd, gdb_client_data context)
+reschedule (serial_t 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)
+{
+ serial_t 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;
+ do
+ {
+ nr = read (scb->fd, scb->buf, BUFSIZ);
+ }
+ while (nr == -1 && errno == EINTR);
+ 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)
{
serial_t scb = context;
- scb->async_handler (error, scb->async_context, fd);
+ scb->async_state = NOTHING_SCHEDULED; /* Timers are one-off */
+ scb->async_handler (scb, scb->async_context);
+ /* re-schedule */
+ reschedule (scb);
}
+/* Put the SERIAL device into/out-of ASYNC mode. */
+
void
ser_unix_async (serial_t scb,
int async_p)
{
if (async_p)
{
- add_file_handler (scb->fd, ser_unix_event, scb);
+ /* 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
{
- delete_file_handler (scb->fd);
+ if (SERIAL_DEBUG_P (scb))
+ fprintf_unfiltered (gdb_stdlog, "[fd%d->synchronous]\n",
+ scb->fd);
+ /* De-schedule what ever tasks are currently scheduled. */
+ switch (scb->async_state)
+ {
+ case FD_SCHEDULED:
+ delete_file_handler (scb->fd);
+ break;
+ NOTHING_SCHEDULED:
+ break;
+ default: /* TIMER SCHEDULED */
+ delete_timer (scb->async_state);
+ break;
+ }
}
}
@@ -1099,10 +1308,7 @@ _initialize_ser_hardwire (void)
the old TERMIOS/SGTTY/... timer code has been flushed. cagney
1999-09-16. */
ops->readchar = hardwire_readchar;
- /* FIXME: Don't replace this with the equivalent ser_unix*() until
- the old TERMIOS/SGTTY/... timer code has been flushed. cagney
- 1999-09-16. */
- ops->write = hardwire_write;
+ ops->write = ser_unix_write;
ops->flush_output = hardwire_flush_output;
ops->flush_input = hardwire_flush_input;
ops->send_break = hardwire_send_break;