[PATCH] test: Wait for output to flush out in enable_pid

[PATCH] test: Wait for output to flush out in enable_pid

[eugene.loh]

From: Eugene Loh <eugene.loh@oracle.com>

Our luck with this test has been quite good, but it sometimes fails
to show its last lines of output.  That is, we send a USR1 to the
trigger processes to set off the final output and we immediately
cat the output files.  If there is any delay, the last output will
be missing.

Add a short delay so that the last output will be seen.

Signed-off-by: Eugene Loh <eugene.loh@oracle.com>
---
 test/unittest/usdt/tst.enable_pid.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/test/unittest/usdt/tst.enable_pid.sh b/test/unittest/usdt/tst.enable_pid.sh
index 7f4f68698..5a151c767 100755
--- a/test/unittest/usdt/tst.enable_pid.sh
+++ b/test/unittest/usdt/tst.enable_pid.sh
@@ -172,6 +172,9 @@ for pid in 1 $pid1 $pid2 '*'; do
 	kill -USR1 $pid2
 done
 
+# wait for last of the output to flush out
+sleep 2
+
 echo done
 echo "========== out 1"; cat out.1
 echo "========== out 2"; cat out.2
-- 
2.43.5

Re: [PATCH] test: Wait for output to flush out in enable_pid

[Nick Alcock]

On 8 Jun 2025, eugene loh told this:

> From: Eugene Loh <eugene.loh@oracle.com>
>
> Our luck with this test has been quite good, but it sometimes fails
> to show its last lines of output.  That is, we send a USR1 to the
> trigger processes to set off the final output and we immediately
> cat the output files.  If there is any delay, the last output will
> be missing.
>
> Add a short delay so that the last output will be seen.

Unavoidable if it's structured this way, but if you hit them with a USR2
and caught USR2 and had that do the same output as USR1 and then exit(),
and did a wait(1) for both of them, you could avoid this delay.

-- 
NULL && (void)