(wait_reading_process_input) [!subprocesses]: Handle

[bpt/emacs.git] / src / process.c

diff --git a/src/process.c b/src/process.c
index 09d262f..6db62dc 100644 (file)
--- a/src/process.c
+++ b/src/process.c
@@ -2174,19 +2174,14 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
            set_waiting_for_input (&timeout);
        }
 
-      {
-       int old_timers_run = timers_run;
-       if (XINT (read_kbd) && detect_input_pending_run_timers (do_display))
-         {
-           nfds = 0;
-           FD_ZERO (&Available);
-         }
-       else if (timers_run != old_timers_run)
-         ;
-       else
-         nfds = select (MAXDESC, &Available, (SELECT_TYPE *)0, (SELECT_TYPE *)0,
-                        &timeout);
-      }
+      if (XINT (read_kbd) && detect_input_pending ())
+       {
+         nfds = 0;
+         FD_ZERO (&Available);
+       }
+      else
+       nfds = select (MAXDESC, &Available, (SELECT_TYPE *)0, (SELECT_TYPE *)0,
+                      &timeout);
 
       xerrno = errno;
 
@@ -3830,6 +3825,8 @@ extern int timers_run;
      1 to return when input is available, or
      -1 means caller will actually read the input, so don't throw to
        the quit handler.
+     a cons cell, meaning wait until its car is non-nil
+       (and gobble terminal input into the buffer if any arrives), or
      We know that read_kbd will never be a Lisp_Process, since
      `subprocesses' isn't defined.
 
@@ -3847,6 +3844,14 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
   EMACS_TIME end_time, timeout;
   SELECT_TYPE waitchannels;
   int xerrno;
+  Lisp_Object *wait_for_cell = 0;
+
+  /* If waiting for non-nil in a cell, record where.  */
+  if (CONSP (read_kbd))
+    {
+      wait_for_cell = &XCONS (read_kbd)->car;
+      XSETFASTINT (read_kbd, 0);
+    }
 
   /* What does time_limit really mean?  */
   if (time_limit || microsecs)
@@ -3874,17 +3879,16 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
       int nfds;
       int timeout_reduced_for_timers = 0;
 
-      if (XINT (read_kbd))
-       FD_SET (0, &waitchannels);
-      else
-       FD_ZERO (&waitchannels);
-
       /* If calling from keyboard input, do not quit
         since we want to return C-g as an input character.
         Otherwise, do pending quit if requested.  */
       if (XINT (read_kbd) >= 0)
        QUIT;
 
+      /* Exit now if the cell we're waiting for became non-nil.  */
+      if (wait_for_cell && ! NILP (*wait_for_cell))
+       break;
+
       /* Compute time from now till when time limit is up */
       /* Exit if already run out */
       if (time_limit > 0 || microsecs)
@@ -3899,13 +3903,22 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
         run timer events directly.
         (Callers that will immediately read keyboard events
         call timer_delay on their own.)  */
-      if (XINT (read_kbd) >= 0)
+      if (1)
        {
          EMACS_TIME timer_delay;
-         int old_timers_run = timers_run;
+         int old_timers_run;
+
+       retry:
+         old_timers_run = timers_run;
          timer_delay = timer_check (1);
          if (timers_run != old_timers_run && do_display)
-           redisplay_preserve_echo_area ();
+           {
+             redisplay_preserve_echo_area ();
+             /* We must retry, since a timer may have requeued itself
+                and that could alter the time delay.  */
+             goto retry;
+           }
+
          if (! EMACS_TIME_NEG_P (timer_delay) && time_limit != -1)
            {
              EMACS_TIME difference;
@@ -3923,15 +3936,30 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
       if (XINT (read_kbd) < 0)
        set_waiting_for_input (&timeout);
 
+      /* Wait till there is something to do.  */
+
+      if (! XINT (read_kbd) && wait_for_cell == 0)
+       FD_ZERO (&waitchannels);
+      else
+       FD_SET (0, &waitchannels);
+
       /* If a frame has been newly mapped and needs updating,
         reprocess its display stuff.  */
       if (frame_garbaged && do_display)
-       redisplay_preserve_echo_area ();
+       {
+         clear_waiting_for_input ();
+         redisplay_preserve_echo_area ();
+         if (XINT (read_kbd) < 0)
+           set_waiting_for_input (&timeout);
+       }
 
       {
        int old_timers_run = timers_run;
-       if (XINT (read_kbd) && detect_input_pending_run_timers (do_display))
-         nfds = 0;
+       if (XINT (read_kbd) && detect_input_pending ())
+         {
+           nfds = 0;
+           FD_ZERO (&waitchannels);
+         }
        else if (timers_run != old_timers_run)
          ;
        else
@@ -3972,13 +4000,17 @@ wait_reading_process_input (time_limit, microsecs, read_kbd, do_display)
 
       /* Check for keyboard input */
 
-      if (XINT (read_kbd) != 0
+      if ((XINT (read_kbd) != 0 || wait_for_cell)
          && detect_input_pending_run_timers (do_display))
        {
          swallow_events (do_display);
          if (detect_input_pending_run_timers (do_display))
            break;
        }
+
+      /* Exit now if the cell we're waiting for became non-nil.  */
+      if (wait_for_cell && ! NILP (*wait_for_cell))
+       break;
     }
 
   start_polling ();