1 files changed, 115 insertions, 0 deletions
diff --git a/tools/testing/selftests/net/lib/sh/defer.sh b/tools/testing/selftests/net/lib/sh/defer.sh
new file mode 100644
index 000000000000..082f5d38321b
--- /dev/null
+++ b/tools/testing/selftests/net/lib/sh/defer.sh
@@ -0,0 +1,115 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# map[(scope_id,track,cleanup_id) -> cleanup_command]
+# track={d=default | p=priority}
+declare -A __DEFER__JOBS
+
+# map[(scope_id,track) -> # cleanup_commands]
+declare -A __DEFER__NJOBS
+
+# scope_id of the topmost scope.
+__DEFER__SCOPE_ID=0
+
+__defer__ndefer_key()
+{
+	local track=$1; shift
+
+	echo $__DEFER__SCOPE_ID,$track
+}
+
+__defer__defer_key()
+{
+	local track=$1; shift
+	local defer_ix=$1; shift
+
+	echo $__DEFER__SCOPE_ID,$track,$defer_ix
+}
+
+__defer__ndefers()
+{
+	local track=$1; shift
+
+	echo ${__DEFER__NJOBS[$(__defer__ndefer_key $track)]}
+}
+
+__defer__run()
+{
+	local track=$1; shift
+	local defer_ix=$1; shift
+	local defer_key=$(__defer__defer_key $track $defer_ix)
+
+	${__DEFER__JOBS[$defer_key]}
+	unset __DEFER__JOBS[$defer_key]
+}
+
+__defer__schedule()
+{
+	local track=$1; shift
+	local ndefers=$(__defer__ndefers $track)
+	local ndefers_key=$(__defer__ndefer_key $track)
+	local defer_key=$(__defer__defer_key $track $ndefers)
+	local defer="$@"
+
+	__DEFER__JOBS[$defer_key]="$defer"
+	__DEFER__NJOBS[$ndefers_key]=$((ndefers + 1))
+}
+
+__defer__scope_wipe()
+{
+	__DEFER__NJOBS[$(__defer__ndefer_key d)]=0
+	__DEFER__NJOBS[$(__defer__ndefer_key p)]=0
+}
+
+defer_scope_push()
+{
+	((__DEFER__SCOPE_ID++))
+	__defer__scope_wipe
+}
+
+defer_scope_pop()
+{
+	local defer_ix
+
+	for ((defer_ix=$(__defer__ndefers p); defer_ix-->0; )); do
+		__defer__run p $defer_ix
+	done
+
+	for ((defer_ix=$(__defer__ndefers d); defer_ix-->0; )); do
+		__defer__run d $defer_ix
+	done
+
+	__defer__scope_wipe
+	((__DEFER__SCOPE_ID--))
+}
+
+defer()
+{
+	__defer__schedule d "$@"
+}
+
+defer_prio()
+{
+	__defer__schedule p "$@"
+}
+
+defer_scopes_cleanup()
+{
+	while ((__DEFER__SCOPE_ID >= 0)); do
+		defer_scope_pop
+	done
+}
+
+in_defer_scope()
+{
+	local ret
+
+	defer_scope_push
+	"$@"
+	ret=$?
+	defer_scope_pop
+
+	return $ret
+}
+
+__defer__scope_wipe