From 9784ed760eebbc12407c919d787e9bb1fa7fbc62 Mon Sep 17 00:00:00 2001
From: Matteo Croce <teknoraver@meta.com>
Date: Sat, 5 Oct 2024 01:39:37 +0200
Subject: [PATCH] timer: add unit tests for DeferReactivation

Create a unit test for systemd timer DeferReactivation config option.
The test works by creating a timer which fires every 5 seconds and
starts an unit which runs for 5 seconds.
With DeferReactivation=true, the timer must fire every 5+5 seconds,
instead of the 5 it fires normally.

As we need at least two timer runs to check if the delta is correct,
the test duration on success will be at least 20 seconds.
To be safe, the test script waits 35 seconds: this is enough to get
at least three runs but low enough to avoid clogging the CI.
---
 .../realtime-test.service                     |  6 +++++
 .../realtime-test.timer                       | 10 ++++++++
 test/TEST-74-AUX-UTILS/meson.build            |  2 ++
 .../TEST-74-AUX-UTILS.defer_reactivation.sh   | 23 +++++++++++++++++++
 4 files changed, 41 insertions(+)
 create mode 100644 test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.service
 create mode 100644 test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.timer
 create mode 100755 test/units/TEST-74-AUX-UTILS.defer_reactivation.sh

diff --git a/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.service b/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.service
new file mode 100644
index 00000000000..a754626828b
--- /dev/null
+++ b/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.service
@@ -0,0 +1,6 @@
+[Unit]
+Description=Testing systemd timers
+
+[Service]
+Type=simple
+ExecStart=sh -c 'date +%%s >>/tmp/realtime-test.log ; sleep 5'
diff --git a/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.timer b/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.timer
new file mode 100644
index 00000000000..b870b41628b
--- /dev/null
+++ b/test/TEST-74-AUX-UTILS/TEST-74-AUX-UTILS.units/realtime-test.timer
@@ -0,0 +1,10 @@
+[Unit]
+Description=Testing systemd timers
+
+[Timer]
+OnCalendar=*:*:0/5
+AccuracySec=1us
+DeferReactivation=true
+
+[Install]
+WantedBy=timers.target
diff --git a/test/TEST-74-AUX-UTILS/meson.build b/test/TEST-74-AUX-UTILS/meson.build
index 668ad492ca6..543eee195ff 100644
--- a/test/TEST-74-AUX-UTILS/meson.build
+++ b/test/TEST-74-AUX-UTILS/meson.build
@@ -7,3 +7,5 @@ integration_tests += [
                 'vm' : true,
         },
 ]
+
+testdata_subdirs += [meson.current_source_dir() / 'TEST-74-AUX-UTILS.units']
diff --git a/test/units/TEST-74-AUX-UTILS.defer_reactivation.sh b/test/units/TEST-74-AUX-UTILS.defer_reactivation.sh
new file mode 100755
index 00000000000..d1b113d1ab0
--- /dev/null
+++ b/test/units/TEST-74-AUX-UTILS.defer_reactivation.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -eux
+set -o pipefail
+
+systemctl start realtime-test.timer
+
+sleep 35
+mindelta=10
+
+last=
+while read -r time; do
+    if [ -n "$last" ]; then
+        delta=$((time - last))
+        if [ "$delta" -lt $mindelta ]; then
+            echo "Timer fired too early: $delta < $mindelta" >/failed
+            break
+        fi
+    fi
+    last=$time
+done </tmp/realtime-test.log
+
+test ! -s /failed
-- 
2.47.3