#!/bin/bash
#
# Copyright (C) 2020 Francis Deslauriers <francis.deslauriers@efficios.com>
#
# SPDX-License-Identifier: LGPL-2.1-only

CURDIR=$(dirname "$0")/
TESTDIR=$CURDIR/../../../

TMPDIR=$(mktemp -d)

TESTAPP_PATH="$TESTDIR/utils/testapp"
TESTAPP_NAME="gen-ust-events"
TESTAPP_BIN="$TESTAPP_PATH/$TESTAPP_NAME/$TESTAPP_NAME"

TESTPOINT_BASE_PATH=$(readlink -f "$TMPDIR/lttng.t_p_n")
TESTPOINT_PIPE_PATH=$(mktemp -u "${TESTPOINT_BASE_PATH}.XXXXXX")
TESTPOINT=$(readlink -f "${CURDIR}/.libs/libpause_sessiond.so")

SH_TAP=1

# shellcheck source=../../../utils/utils.sh
source "$TESTDIR/utils/utils.sh"
# shellcheck source=./util_event_generator.sh
source "$CURDIR/util_event_generator.sh"

FULL_LTTNG_BIN="${TESTDIR}/../src/bin/lttng/${LTTNG_BIN}"
FULL_LTTNG_SESSIOND_BIN="${TESTDIR}/../src/bin/lttng-sessiond/lttng-sessiond"

UST_NUM_TESTS=18
KERNEL_NUM_TESTS=17
NUM_TESTS=$(($UST_NUM_TESTS + $KERNEL_NUM_TESTS))

plan_tests $NUM_TESTS

function test_kernel_notifier_discarded_count
{
	local sessiond_pipe=()
	local trigger_name="my_trigger"
	local list_triggers_stdout=$(mktemp -t list_triggers_stdout.XXXXXX)

	# Used on sessiond launch.
	LTTNG_SESSIOND_ENV_VARS="LTTNG_TESTPOINT_ENABLE=1 \
		NOTIFIER_PAUSE_PIPE_PATH=${TESTPOINT_PIPE_PATH} \
		LD_PRELOAD=${TESTPOINT}"

	diag "Kernel event notifer error counter"

	start_lttng_sessiond_notap

	# This is needed since the testpoint creates a pipe with the sessiond
	# type suffixed.
	for f in "$TESTPOINT_BASE_PATH"*; do
		sessiond_pipe+=("$f")
	done

	lttng_add_trigger_ok "$trigger_name" \
		--condition on-event --kernel lttng_test_filter_event \
		--action notify

	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is not present.
	cat "$list_triggers_stdout" | grep -v --quiet "discarded tracer messages"
	ok $? "No discarded tracer notification message"

	tail -n 1 "$list_triggers_stdout" | grep --quiet "errors: none"
	ok $? "Trigger 'errors: none' notification message"

	# Stop consumption of notifier tracer notifications.
	diag "Pause consumption of tracer messages"
	echo -n 1 > $sessiond_pipe

	# The notifier ring buffer configuration is currently made of 16 4096
	# bytes subbuffers. Each kernel notification is at least 42 bytes long.
	# To fill it, we need to generate (16 * 4096)/42 = 1561 notifications.
	# That number is a bit larger than what we need since some of the space
	# is lost in subbuffer boundaries.
	echo -n "2000" > /proc/lttng-test-filter-event

	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is present. To avoid
	# false positives.
	cat "$list_triggers_stdout" | grep --quiet "discarded tracer messages"
	ok $? "Tracer notification discarded line printed"

	# Confirm that the number of dicarded tracer messages is not zero.
	cat "$list_triggers_stdout" | grep --quiet "discarded tracer messages: 0"
	isnt $? 0 "Discarded tracer notification number non-zero as expected"

	lttng_remove_trigger_ok "$trigger_name"

	# Confirm that no notifier is enabled.
	list_triggers_line_count=$("$FULL_LTTNG_BIN" list-triggers | wc -l)
	is "$list_triggers_line_count" "0" "No \`on-event\` kernel notifier enabled as expected"

	# Enable another notifier and list it to confirm the counter was cleared.
	lttng_add_trigger_ok "$trigger_name" \
		--condition on-event --kernel lttng_test_filter_event \
		--action notify

	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is not present.
	cat "$list_triggers_stdout" | grep -v --quiet "discarded tracer messages"
	ok $? "No discarded tracer notification message"

	tail -n 1 "$list_triggers_stdout" | grep --quiet "errors: none"
	ok $? "Trigger 'errors: none' notification message"

	lttng_remove_trigger_ok "$trigger_name"

	stop_lttng_sessiond_notap

	unset LTTNG_SESSIOND_ENV_VARS

	rm -f "$list_triggers_stdout"
}

function test_kernel_notifier_discarded_count_max_bucket
{
	start_lttng_sessiond "" "--event-notifier-error-number-of-bucket=3"

	diag "Kernel event notifer error counter bucket limit"
	for i in $(seq 3); do
		lttng_add_trigger_ok "$i" \
			--condition on-event --kernel my_event_that_doesnt_need_to_really_exist_$i \
			--action notify
	done

	for i in $(seq 4 5); do
		lttng_add_trigger_fail "$i" \
			--condition on-event --kernel my_event_that_doesnt_need_to_really_exist_$i \
			--action notify
	done

	stop_lttng_sessiond_notap
}

function test_ust_notifier_discarded_count
{
	local sessiond_pipe=()
	local trigger_name="my_trigger"
	local list_triggers_stdout=$(mktemp -t list_triggers_stdout.XXXXXX)
	local NR_USEC_WAIT=0
	local PIPE_SIZE
	local NR_ITER

	diag "UST event notifer error counter"

	PIPE_SIZE=$("$CURDIR"/default_pipe_size_getter)
	if [ $? -ne 0 ]; then
		BAIL_OUT "Failed to get system default pipe size"
	else
		diag "Default system pipe size: $PIPE_SIZE bytes"
	fi

	# Find the number of events needed to overflow the event notification
	# pipe buffer. Each LTTng-UST notification is at least 42 bytes long.
	# Double that number to ensure enough events are created to overflow
	# the buffer.
	NR_ITER=$(( (PIPE_SIZE / 42) * 2 ))
	diag "Test application will emit $NR_ITER events"

	# Used on sessiond launch.
	LTTNG_SESSIOND_ENV_VARS="LTTNG_TESTPOINT_ENABLE=1 \
		NOTIFIER_PAUSE_PIPE_PATH=${TESTPOINT_PIPE_PATH} \
		LD_PRELOAD=${TESTPOINT}"

	start_lttng_sessiond_notap

	# This is needed since the testpoint create a pipe with the sessiond
	# type suffixed.
	for f in "$TESTPOINT_BASE_PATH"*; do
		sessiond_pipe+=("$f")
	done

	lttng_add_trigger_ok "$trigger_name" \
		--condition on-event --userspace tp:tptest \
		--action notify

	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is not present.
	cat "$list_triggers_stdout" | grep -v --quiet "discarded tracer messages"
	ok $? "No discarded tracer notification message"

	tail -n 1 "$list_triggers_stdout" | grep --quiet "errors: none"
	ok $? "Trigger 'errors: none' notification message"

	# Stop consumption of notifier tracer notifications.
	diag "Pause consumption of tracer messages"
	echo -n 1 > $sessiond_pipe

	$TESTAPP_BIN -i $NR_ITER -w $NR_USEC_WAIT
	ok $? "Generating $NR_ITER tracer notifications"

	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is present. To avoid
	# false positive.
	cat "$list_triggers_stdout" | grep --quiet "discarded tracer messages"
	ok $? "Tracer notification discarded line printed"

	# Confirm that the number of discarded tracer messages is not zero.
	cat "$list_triggers_stdout" | grep --quiet "discarded tracer messages: 0"
	isnt $? 0 "Discarded tracer notification number non-zero as expected"

	# Remove the notifier.
	lttng_remove_trigger_ok "$trigger_name"

	# Confirm that no notifier is enabled.
	list_triggers_line_count=$("$FULL_LTTNG_BIN" list-triggers | wc -l)
	is "$list_triggers_line_count" "0" "No \`on-event\` userspace notifier enabled as expected"

	# Enable another notifier and list it to confirm the counter was cleared.
	lttng_add_trigger_ok "$trigger_name" \
		--condition on-event --userspace tp:tptest \
		--action notify

	# Confirm that the discarded notification line is not present.
	"$FULL_LTTNG_BIN" list-triggers > "$list_triggers_stdout"

	# Confirm that the discarded notification line is not present.
	cat "$list_triggers_stdout" | grep -v --quiet "discarded tracer messages"
	ok $? "No discarded tracer notification message"

	tail -n 1 "$list_triggers_stdout" | grep --quiet "errors: none"
	ok $? "Trigger 'errors: none' notification message"

	lttng_remove_trigger_ok "$trigger_name"

	stop_lttng_sessiond_notap

	unset LTTNG_SESSIOND_ENV_VARS

	rm -f "$list_triggers_stdout"
}
function test_ust_notifier_discarded_count_max_bucket
{
	start_lttng_sessiond "" "--event-notifier-error-number-of-bucket=3"

	diag "UST event notifer error counter bucket limit"
	for i in $(seq 3); do
		lttng_add_trigger_ok "$i" \
			--condition on-event --userspace my_event_that_doesnt_need_to_really_exist_$i \
			--action notify
	done

	for i in $(seq 4 5); do
		lttng_add_trigger_fail "$i" \
			--condition on-event --userspace my_event_that_doesnt_need_to_really_exist_$i \
			--action notify
	done

	stop_lttng_sessiond_notap
}

test_ust_notifier_discarded_count
test_ust_notifier_discarded_count_max_bucket

if [ "$(id -u)" == "0" ]; then

	validate_lttng_modules_present

	modprobe lttng-test

	test_kernel_notifier_discarded_count

	test_kernel_notifier_discarded_count_max_bucket

	modprobe --remove lttng-test

	rm -rf "${sessiond_pipe[@]}" 2> /dev/null
else
	# Kernel tests are skipped.
	skip 0 "Root access is needed. Skipping all kernel notification tests." $KERNEL_NUM_TESTS
fi

rm -rf "$TMPDIR"