TEST-17-UDEV: add test case for queued events serialization/deserialization

test/units/TEST-17-UDEV.queued-events-serialization.sh

@@ -0,0 +1,75 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: LGPL-2.1-or-later
+set -ex
+set -o pipefail
+
+# shellcheck source=test/units/util.sh
+. "$(dirname "$0")"/util.sh
+
+# Test for queued events serialization on stop and deserialization on start.
+
+rules="/run/udev/rules.d/99-test-17.serialization.rules"
+
+mkdir -p "${rules%/*}"
+cat > "$rules" <<'EOF'
+SUBSYSTEM!="mem", GOTO="end"
+KERNEL!="null", GOTO="end"
+ACTION=="remove", GOTO="end"
+
+IMPORT{db}="INVOCATIONS"
+IMPORT{program}="/bin/bash -c 'systemctl show --property=InvocationID systemd-udevd.service'"
+ENV{INVOCATIONS}+="%E{ACTION}_%E{SEQNUM}_%E{InvocationID}"
+ACTION=="add", RUN+="/bin/bash -c ':> /tmp/marker'", RUN+="/usr/bin/sleep 10"
+
+LABEL="end"
+EOF
+
+udevadm control --reload --log-level=debug
+
+udevadm settle --timeout 30
+rm -f /tmp/marker
+
+# Save the current invocation ID of udevd.
+INVOCATION_BEFORE="$(systemctl show --property=InvocationID --value systemd-udevd.service)"
+
+# Trigger several actions.
+# The first 'add' event should be processed by the current invocation.
+for action in remove add change change change change; do
+    udevadm trigger --action="$action" /dev/null
+done
+
+# While processing the first 'add' event, request restarting udevd.
+# Hence, the queued subsequent 'change' events should be serialized,
+# then deserialized, requeued, and processed in the next invocation.
+timeout 10 bash -c 'until test -e /tmp/marker; do sleep .1; done'
+systemctl restart systemd-udevd.service
+udevadm settle --timeout 30
+
+# Get the invocation ID of the restarted udevd.
+INVOCATION_AFTER="$(systemctl show --property=InvocationID --value systemd-udevd.service)"
+
+udevadm info --no-pager /dev/null
+
+# Check the properties that records action, seqnum, and invocation ID.
+previous_seqnum=0
+expected_action=add
+expected_invocation="$INVOCATION_BEFORE"
+count=0
+while read -r action seqnum invocation; do
+    test "$seqnum" -gt "$previous_seqnum"
+    assert_eq "$action" "$expected_action"
+    assert_eq "$invocation" "$expected_invocation"
+
+    previous_seqnum="$seqnum"
+    expected_action=change
+    expected_invocation="$INVOCATION_AFTER"
+    : $((++count))
+done < <(udevadm info -q property --property=INVOCATIONS --value /dev/null | sed -e 's/ /\n/g; s/_/ /g')
+
+# Check the total number of events processed by the udevd.
+assert_eq "$count" "5"
+
+rm -f "$rules" /tmp/marker
+udevadm control --reload
+
+exit 0