# Copyright (c) 2017 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Johnny C. Lam.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
#
# NAME
#	cleanup.subr -- run functions upon improper exit
#
# SYNOPSIS
#	task_cleanup
#
#	task_cleanup_add_hook <funcname> ...
#
# DESCRIPTION
#	The task_cleanup function runs the hooks previously added by the
#	task_cleanup_add_hook function upon receiving a signal for improper
#	exit.
#
# SIGNALS
#	SIGHUP, SIGINT, SIGTERM
#		Run the hooks in the order listed.
#

__task_cleanup__="yes"
__task_cleanup_init__="_task_cleanup_init"

task_cleanup()
{
	set -- $__task_cleanup_hooks__
	local hook
	for hook; do $hook; done
}

task_cleanup_add_hook()
{
	__task_cleanup_hooks__="$__task_cleanup_hook__ $*"
}

_task_cleanup_init()
{
	# Trap signals to trigger task_cleanup().
	trap "task_cleanup; exit 1" 1 2 15
}

# Static variable that holds a list of names of hooks.
__task_cleanup_hooks__=