If kbd_buffer is becoming full, stop reading until it drains (Bug#6571).

* keyboard.c (input_available_signal): Declare.
(kbd_buffer_nr_stored): New function.
(kbd_buffer_store_event_hold): If kbd_buffer_nr_stored returns
more than KBD_BUFFER_SIZE/2, stop reding input (Bug#6571).
(kbd_buffer_get_event): If input is suspended and kbd_buffer_nr_stored
returns less than KBD_BUFFER_SIZE/4, resume reding input (Bug#6571).
(tty_read_avail_input): If input is on hold, return.
Don't read more that free slots in kbd_buffer (Bug#6571).

* process.h (hold_keyboard_input, unhold_keyboard_input)
(kbd_on_hold_p): Declare.

* process.c (kbd_is_on_hold): New variable.
(hold_keyboard_input, unhold_keyboard_input, kbd_on_hold_p): New
functions.
(wait_reading_process_output): If kbd_on_hold_p returns non-zero,
select on empty input mask.
(init_process): Initialize kbd_is_on_hold to 0.

1 files changed, 4 insertions, 0 deletions

diff --git a/src/process.h b/src/process.h
index a8cd0a02da6..12b91d697b9 100644
--- a/src/process.h
+++ b/src/process.h
@@ -170,5 +170,9 @@ extern Lisp_Object Qtime, Qctime;
 extern Lisp_Object list_system_processes (void);
 extern Lisp_Object system_process_attributes (Lisp_Object);
 
+extern void hold_keyboard_input (void);
+extern void unhold_keyboard_input (void);
+extern int kbd_on_hold_p (void);
+
 /* arch-tag: dffedfc4-d7bc-4b58-a26f-c16155449c72
    (do not change this comment) */