[PATCH] [gdb/testsuite] Fix timeout in gdb.tui/resize-2.exp

[PATCH] [gdb/testsuite] Fix timeout in gdb.tui/resize-2.exp

[Tom de Vries]

When running test-case gdb.tui/resize-2.exp with taskset -c 0, I sometimes run
into:
...
tui disable^[[40;1H^M(gdb) PASS: $exp: tui disable
^M^[[K(gdb) FAIL: $exp: two prompt redisplays after resize (timeout)
...

The test-case does "Term::resize 24 80 0" while having the settings of an
earlier "Term::resize 40 90", so both dimensions change.

When TUI is enabled, we call Term::resize with wait_for_msg == 1, and the proc:
- calls stty to change one dimension,
- waits for the message (enabled by "maint set tui-resize-message on")
  confirming the resize has happened,
- calls stty to change the other dimension, and again
- waits for the message confirming the resize has happened.

Since TUI is disabled, we call Term::resize with wait_for_msg == 0 because the
message is not printed, so stty is called twice, and afterwards we check for
the results of the two resizes, which is the test that is failing.

The problem is that not waiting for a response after each stty call opens up
the possibility of the responses being merged.

Fix this by calling Term::resize twice, changing one dimension at a time, and
waiting for a single prompt redisplay after each one.

Tested on x86_64-linux.

PR testsuite/31822
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31822
---
 gdb/testsuite/gdb.tui/resize-2.exp | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/gdb/testsuite/gdb.tui/resize-2.exp b/gdb/testsuite/gdb.tui/resize-2.exp
index 0f1f0b9eb1e..729e1ee23f9 100644
--- a/gdb/testsuite/gdb.tui/resize-2.exp
+++ b/gdb/testsuite/gdb.tui/resize-2.exp
@@ -59,11 +59,23 @@ gdb_test_multiple "tui disable" "" {
     }
 }
 
-# Resize with TUI disabled, so don't wait for the resize message.
+# Resize with TUI disabled, so don't wait for the resize message.  Instead,
+# do it in two steps, and wait for a prompt redisplay for each.  If we do
+# this in one step, it's unpredictable how may prompt redisplays we'll get.
+Term::resize 24 90 0
+set screen_dim { 0 0 90 24 }
+
+gdb_test_multiple "" "prompt redisplays after first resize" {
+    -re "\r.*$gdb_prompt $" {
+	pass $gdb_test_name
+    }
+}
+
 Term::resize 24 80 0
 set screen_dim { 0 0 80 24 }
-gdb_test_multiple "" "two prompt redisplays after resize" {
-    -re "\r.*$gdb_prompt \r.*$gdb_prompt $" {
+
+gdb_test_multiple "" "prompt redisplays after second resize" {
+    -re "\r.*$gdb_prompt $" {
 	pass $gdb_test_name
     }
 }

base-commit: 9736d941f271a6c3c14dcbeb5ad03a5fc4106b45
-- 
2.35.3

Re: [PATCH] [gdb/testsuite] Fix timeout in gdb.tui/resize-2.exp

[Alexandra Petlanova Hajkova]

[-- Attachment #1: Type: text/plain, Size: 1754 bytes --]

On Fri, May 31, 2024 at 10:43 AM Tom de Vries <tdevries@suse.de> wrote:

> When running test-case gdb.tui/resize-2.exp with taskset -c 0, I sometimes
> run
> into:
> ...
> tui disable^[[40;1H^M(gdb) PASS: $exp: tui disable
> ^M^[[K(gdb) FAIL: $exp: two prompt redisplays after resize (timeout)
> ...
>
> The test-case does "Term::resize 24 80 0" while having the settings of an
> earlier "Term::resize 40 90", so both dimensions change.
>
> When TUI is enabled, we call Term::resize with wait_for_msg == 1, and the
> proc:
> - calls stty to change one dimension,
> - waits for the message (enabled by "maint set tui-resize-message on")
>   confirming the resize has happened,
> - calls stty to change the other dimension, and again
> - waits for the message confirming the resize has happened.
>
> Since TUI is disabled, we call Term::resize with wait_for_msg == 0 because
> the
> message is not printed, so stty is called twice, and afterwards we check
> for
> the results of the two resizes, which is the test that is failing.
>
> The problem is that not waiting for a response after each stty call opens
> up
> the possibility of the responses being merged.
>
> Fix this by calling Term::resize twice, changing one dimension at a time,
> and
> waiting for a single prompt redisplay after each one.
>
> Tested on x86_64-linux.
>
> PR testsuite/31822
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31822
>
> I think the changes are reasonable.
I've tried this on ppc64le, Fedora Rawhide, I haven't run into the
described failure even without the patch but I
can confirm everything passes including the additional gdb_test_multiple.

 Reviewed-By: Alexandra Petlanova Hajkova <ahajkova@redhat.com>

Re: [PATCH] [gdb/testsuite] Fix timeout in gdb.tui/resize-2.exp

[Tom de Vries]

On 6/2/24 17:28, Alexandra Petlanova Hajkova wrote:
> 
> 
> On Fri, May 31, 2024 at 10:43 AM Tom de Vries <tdevries@suse.de 
> <mailto:tdevries@suse.de>> wrote:
> 
>     When running test-case gdb.tui/resize-2.exp with taskset -c 0, I
>     sometimes run
>     into:
>     ...
>     tui disable^[[40;1H^M(gdb) PASS: $exp: tui disable
>     ^M^[[K(gdb) FAIL: $exp: two prompt redisplays after resize (timeout)
>     ...
> 
>     The test-case does "Term::resize 24 80 0" while having the settings
>     of an
>     earlier "Term::resize 40 90", so both dimensions change.
> 
>     When TUI is enabled, we call Term::resize with wait_for_msg == 1,
>     and the proc:
>     - calls stty to change one dimension,
>     - waits for the message (enabled by "maint set tui-resize-message on")
>        confirming the resize has happened,
>     - calls stty to change the other dimension, and again
>     - waits for the message confirming the resize has happened.
> 
>     Since TUI is disabled, we call Term::resize with wait_for_msg == 0
>     because the
>     message is not printed, so stty is called twice, and afterwards we
>     check for
>     the results of the two resizes, which is the test that is failing.
> 
>     The problem is that not waiting for a response after each stty call
>     opens up
>     the possibility of the responses being merged.
> 
>     Fix this by calling Term::resize twice, changing one dimension at a
>     time, and
>     waiting for a single prompt redisplay after each one.
> 
>     Tested on x86_64-linux.
> 
>     PR testsuite/31822
>     Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31822
>     <https://sourceware.org/bugzilla/show_bug.cgi?id=31822>
> 
> I think the changes are reasonable.
> I've tried this on ppc64le, Fedora Rawhide, I haven't run into the 
> described failure even without the patch but I
> can confirm everything passes including the additional gdb_test_multiple.
> 
>   Reviewed-By: Alexandra Petlanova Hajkova <ahajkova@redhat.com 

Thanks for the review, pushed.

Thanks,
- Tom


> <mailto:ahajkova@redhat.com>>