0004485: Keyboard events incorrectly delivered to Graphics module's polling routines when compiled natively

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Date Submitted

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0004485

OCaml

OCaml general

public

2008-01-21 20:32

2012-09-15 11:48

Reporter

sharvil

Assigned To

Priority

normal

Severity

minor

Reproducibility

always

Status

confirmed

Resolution

open

Platform

OS Version

Product Version

3.10.1

Target Version

4.00.2+dev

Fixed in Version

Summary

0004485: Keyboard events incorrectly delivered to Graphics module's polling routines when compiled natively

Description

Keyboard events and other X events are delivered only after a mouse click in the sample application below. This behaviour is only observed when compiled natively.

The issue is related to the delivery of signals. When polling, SIGIO is not delivered in a timely fashion to its handler. Adding the following lines to the start of the function otherlibs/graph/events.c#caml_gr_wait_event_poll fixes the issue by forcing signal delivery.

enter_blocking_section();
leave_blocking_section();

Additional Information

Configuration:
--------------
OCaml: 3.10.1 (also tested on 3.9.2)
OS: Linux 2.6.16 (Debian Etch)
CPU: Dual-Core AMD Opteron @ 2.6GHz
Command Line: ocamlopt graphics.cmxa test.ml -o test; ./test

Steps to reproduce:
-------------------
1) Compile code below using ocamlopt
2) Run application
3) Type string "abc" with "OCaml graphics" window focused
4) Click mouse on "OCaml graphics" window

Sample code (test.ml):
----------------------
let main () =
    Graphics.open_graph " 320x320";

    let rec event_loop () =
        if Graphics.key_pressed () then
            Printf.printf "Key = %c\n%!" (Graphics.read_key ())
        ;

        if Graphics.button_down () then
        (
            let x, y = Graphics.mouse_pos () in
            Printf.printf "Mouse at %d,%d\n%!" x y
        );

        event_loop ()
    in

    event_loop ();
    Graphics.close_graph ()
;;

main ();;

Expected output:
----------------
Key = a
Key = b
Key = c
Mouse at xxx,yyy

Actual output:
--------------
Mouse at xxx,yyy
Key = a
Key = b
Key = c

Issue History
Date Modified	Username	Field	Change
2008-01-21 20:32	sharvil	New Issue
2008-01-22 13:14	doligez	Status	new => confirmed
2012-07-11 15:59	doligez	Target Version	=> 4.01.0+dev
2012-07-31 13:37	doligez	Target Version	4.01.0+dev => 4.00.1+dev
2012-09-15 11:48	doligez	Target Version	4.00.1+dev => 4.00.2+dev

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