--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/event-unixoid.c	Mon Aug 13 08:45:50 2007 +0200
@@ -0,0 +1,265 @@
+/* Code shared between all event loops that use select() and have a
+   different input descriptor for each device.
+   Copyright (C) 1991, 1992, 1993, 1994, 1995 Free Software Foundation, Inc.
+   Copyright (C) 1995 Board of Trustees, University of Illinois.
+   Copyright (C) 1995 Sun Microsystems, Inc.
+   Copyright (C) 1995, 1996 Ben Wing.
+
+This file is part of XEmacs.
+
+XEmacs 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, or (at your option) any
+later version.
+
+XEmacs 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 XEmacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* Synched up with: Not in FSF. */
+
+/* This file has been Mule-ized. */
+
+#include <config.h>
+#include "lisp.h"
+
+#include "console-stream.h"
+#include "console-tty.h"
+#include "device.h"
+#include "events.h"
+#include "process.h"
+
+#include "sysdep.h"
+#include "sysproc.h"		/* select stuff */
+#include "systime.h"
+
+/* Mask of bits indicating the descriptors that we wait for input on.
+   These work as follows:
+
+   input_wait_mask == mask of all file descriptors we select() on,
+                      including TTY/stream console descriptors,
+		      process descriptors, and the signal event pipe.
+		      Only used in event-tty.c; event-Xt.c uses
+		      XtAppAddInput(), and the call to select() is down in
+		      the guts of Xt.
+
+   non_fake_input_wait_mask == same as input_wait_mask but minus the
+                               signal event pipe.  Also only used in
+			       event-tty.c.
+
+   process_only_mask == only the process descriptors.
+
+   tty_only_mask == only the TTY/stream console descriptors.
+   */
+SELECT_TYPE input_wait_mask, non_fake_input_wait_mask;
+SELECT_TYPE process_only_mask, tty_only_mask;
+
+/* This is used to terminate the select(), when an event came in
+   through a signal (e.g. window-change or C-g on controlling TTY). */
+int signal_event_pipe[2];
+
+static int signal_event_pipe_initialized;
+
+int fake_event_occurred;
+
+int
+read_event_from_tty_or_stream_desc (struct Lisp_Event *event,
+				    struct console *con, int fd)
+{
+  unsigned char ch;
+  int nread;
+  Lisp_Object console = Qnil;
+
+  XSETCONSOLE (console, con);
+
+  nread = read (fd, &ch, 1);
+  if (nread <= 0)
+    {
+      /* deleting the console might not be safe right now ... */
+      enqueue_magic_eval_event (io_error_delete_console, console);
+      /* but we definitely need to unselect it to avoid infinite
+	 loops reading EOF's */
+      Fconsole_disable_input (console);
+    }
+  else
+    {
+      character_to_event (ch, event, con, 1);
+      event->channel = console;
+      return 1;
+    }
+  return 0;
+}
+
+void
+signal_fake_event (void)
+{
+  char byte = 0;
+  /* We do the write always.  Formerly I tried to "optimize" this
+     by setting a flag indicating whether we're blocking and only
+     doing the write in that case, but there is a race condition
+     if the signal occurs after we've checked for the signal
+     occurrence (which could occur in many places throughout
+     an iteration of the command loop, e.g. in status_notify()),
+     but before we set the blocking flag.
+
+     This should be OK as long as write() is reentrant, which
+     I'm fairly sure it is since it's a system call. */
+
+  if (signal_event_pipe_initialized)
+    /* In case a signal comes through while we're dumping */
+    {
+      int old_errno = errno;
+      write (signal_event_pipe[1], &byte, 1);
+      errno = old_errno;
+    }
+}
+
+void
+drain_signal_event_pipe (void)
+{
+  char chars[128];
+  /* The input end of the pipe has been set to non-blocking. */
+  while (read (signal_event_pipe[0], chars, sizeof (chars)) > 0)
+    ;
+}
+
+int
+event_stream_unixoid_select_console (struct console *con)
+{
+  int infd;
+
+  if (CONSOLE_STREAM_P (con))
+    infd = fileno (CONSOLE_STREAM_DATA (con)->infd);
+  else
+    {
+      assert (CONSOLE_TTY_P (con));
+      infd = CONSOLE_TTY_DATA (con)->infd;
+    }
+
+  assert (infd >= 0);
+
+  FD_SET (infd, &input_wait_mask);
+  FD_SET (infd, &non_fake_input_wait_mask);
+  FD_SET (infd, &tty_only_mask);
+  return infd;
+}
+
+int
+event_stream_unixoid_unselect_console (struct console *con)
+{
+  int infd;
+
+  if (CONSOLE_STREAM_P (con))
+    infd = fileno (CONSOLE_STREAM_DATA (con)->infd);
+  else
+    {
+      assert (CONSOLE_TTY_P (con));
+      infd = CONSOLE_TTY_DATA (con)->infd;
+    }
+
+  assert (infd >= 0);
+
+  FD_CLR (infd, &input_wait_mask);
+  FD_CLR (infd, &non_fake_input_wait_mask);
+  FD_CLR (infd, &tty_only_mask);
+  return infd;
+}
+
+int
+event_stream_unixoid_select_process (struct Lisp_Process *proc)
+{
+  int infd, outfd;
+
+  get_process_file_descriptors (proc, &infd, &outfd);
+  assert (infd >= 0);
+
+  FD_SET (infd, &input_wait_mask);
+  FD_SET (infd, &non_fake_input_wait_mask);
+  FD_SET (infd, &process_only_mask);
+  return infd;
+}
+
+int
+event_stream_unixoid_unselect_process (struct Lisp_Process *proc)
+{
+  int infd, outfd;
+
+  get_process_file_descriptors (proc, &infd, &outfd);
+  assert (infd >= 0);
+
+  FD_CLR (infd, &input_wait_mask);
+  FD_CLR (infd, &non_fake_input_wait_mask);
+  FD_CLR (infd, &process_only_mask);
+  return infd;
+}
+
+int
+poll_fds_for_input (SELECT_TYPE mask)
+{
+  EMACS_TIME sometime;
+  EMACS_SELECT_TIME select_time;
+  SELECT_TYPE temp_mask;
+  int retval;
+
+  while (1)
+    {
+      EMACS_SET_SECS_USECS (sometime, 0, 0);
+      EMACS_TIME_TO_SELECT_TIME (sometime, select_time);
+      temp_mask = mask;
+      /* To effect a poll, tell select() to block for zero seconds. */
+      retval = select (MAXDESC, &temp_mask, 0, 0, &select_time);
+      if (retval >= 0)
+	return retval;
+      if (errno != EINTR)
+	{
+	  /* Something went seriously wrong; don't abort since maybe
+	     the TTY just died at the wrong time. */
+	  fprintf (stderr, "xemacs: select failed: errno = %d\n", errno);
+	  return 0;
+	}
+      /* else, we got interrupted by a signal, so try again. */
+    }
+
+  RETURN_NOT_REACHED(0) /* not reached */
+}
+
+
+void
+init_event_unixoid (void)
+{
+  /* Do this first; the init_event_*_late() functions
+     pay attention to it. */
+  if (pipe (signal_event_pipe) < 0)
+    {
+      perror ("XEmacs: can't open pipe");
+      exit (-1);
+    }
+  signal_event_pipe_initialized = 1;
+  
+  /* Set it non-blocking so we can drain its output. */
+  set_descriptor_non_blocking (signal_event_pipe[0]);
+  
+  /* Also set the write descriptor non-blocking so we don't
+     hang in case a long time passes between times when
+     we drain the pipe. */
+  set_descriptor_non_blocking (signal_event_pipe[1]);
+  
+  /* WARNING: In order for the signal-event pipe to work correctly
+     and not cause lockups, the following need to be followed:
+     
+     1) event_pending_p() must ignore input on the signal-event pipe.
+     2) As soon as next_event() notices input on the signal-event
+     pipe, it must drain it. */
+  FD_ZERO (&input_wait_mask);
+  FD_ZERO (&non_fake_input_wait_mask);
+  FD_ZERO (&process_only_mask);
+  FD_ZERO (&tty_only_mask);
+  
+  FD_SET (signal_event_pipe[0], &input_wait_mask);
+}