fix: tcp, udp sample the IPv4 and IPv6 counters in one PDH query (#2684)

Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/pdh/query_test.go

@@ -0,0 +1,155 @@
+// SPDX-License-Identifier: Apache-2.0
+//
+// Copyright The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build windows
+
+package pdh_test
+
+import (
+	"log/slog"
+	"sync"
+	"testing"
+
+	"github.com/prometheus-community/windows_exporter/internal/pdh"
+	"github.com/stretchr/testify/require"
+)
+
+type systemValues struct {
+	Processes float64 `perfdata:"Processes"`
+	Threads   float64 `perfdata:"Threads"`
+}
+
+type memoryValues struct {
+	AvailableBytes float64 `perfdata:"Available Bytes"`
+}
+
+func TestQuery(t *testing.T) {
+	t.Parallel()
+
+	query, err := pdh.NewQuery()
+	require.NoError(t, err)
+
+	system, err := pdh.NewQueryCollector[systemValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "System", nil)
+	require.NoError(t, err)
+
+	memory, err := pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "Memory", nil)
+	require.NoError(t, err)
+
+	var (
+		systemData []systemValues
+		memoryData []memoryValues
+	)
+
+	// One sample serves both collectors.
+	require.NoError(t, query.Collect())
+	require.NoError(t, system.Collect(&systemData))
+	require.NoError(t, memory.Collect(&memoryData))
+	require.Len(t, systemData, 1)
+	require.Len(t, memoryData, 1)
+	require.NotZero(t, systemData[0].Processes)
+	require.NotZero(t, memoryData[0].AvailableBytes)
+
+	// Closing one collector removes only its counters.
+	system.Close()
+	require.ErrorIs(t, system.Collect(&systemData), pdh.ErrPerformanceCounterNotInitialized)
+	require.NoError(t, query.Collect())
+	require.NoError(t, memory.Collect(&memoryData))
+	require.NotZero(t, memoryData[0].AvailableBytes)
+
+	memory.Close()
+	query.Close()
+	query.Close()
+
+	require.ErrorIs(t, query.Collect(), pdh.ErrPerformanceCounterNotInitialized)
+
+	_, err = pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "Memory", nil)
+	require.ErrorIs(t, err, pdh.ErrPerformanceCounterNotInitialized)
+
+	_, err = pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), nil, pdh.CounterTypeRaw, "Memory", nil)
+	require.ErrorIs(t, err, pdh.ErrPerformanceCounterNotInitialized)
+}
+
+// A collector whose object is missing reports the error, and the other
+// collector of the query keeps working.
+func TestQueryMissingObject(t *testing.T) {
+	t.Parallel()
+
+	query, err := pdh.NewQuery()
+	require.NoError(t, err)
+
+	defer query.Close()
+
+	missing, err := pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "Does Not Exist", nil)
+	require.Error(t, err)
+
+	defer missing.Close()
+
+	memory, err := pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "Memory", nil)
+	require.NoError(t, err)
+
+	defer memory.Close()
+
+	var data []memoryValues
+
+	require.NoError(t, query.Collect())
+	require.NoError(t, memory.Collect(&data))
+	require.NotEmpty(t, data)
+}
+
+func TestQueryConcurrentCollect(t *testing.T) {
+	t.Parallel()
+
+	query, err := pdh.NewQuery()
+	require.NoError(t, err)
+
+	system, err := pdh.NewQueryCollector[systemValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "System", nil)
+	require.NoError(t, err)
+
+	memory, err := pdh.NewQueryCollector[memoryValues](slog.New(slog.DiscardHandler), query, pdh.CounterTypeRaw, "Memory", nil)
+	require.NoError(t, err)
+
+	var wg sync.WaitGroup
+
+	for range 8 {
+		wg.Go(func() {
+			var (
+				systemData []systemValues
+				memoryData []memoryValues
+			)
+
+			for range 20 {
+				if err := query.Collect(); err != nil {
+					t.Error(err)
+
+					return
+				}
+
+				if err := system.Collect(&systemData); err != nil {
+					t.Error(err)
+				}
+
+				if err := memory.Collect(&memoryData); err != nil {
+					t.Error(err)
+				}
+			}
+		})
+	}
+
+	wg.Wait()
+
+	system.Close()
+	memory.Close()
+	query.Close()
+}