util: add test for old version cgroup (#41976)

close #41808

resourcemanager/util/mock_gpool.go

@@ -38,7 +38,7 @@ func (*MockGPool) Tune(_ int) {
 
 // LastTunerTs is only for test
 func (*MockGPool) LastTunerTs() time.Time {
-	panic("implement me")
+	return time.Now().Add(-1 * 10 * time.Second)
 }
 
 // MaxInFlight is only for test

util/cgroup/BUILD.bazel

@@ -16,7 +16,51 @@ go_library(
         "@com_github_pingcap_errors//:errors",
         "@com_github_pingcap_log//:log",
         "@org_uber_go_zap//:zap",
-    ],
+    ] + select({
+        "@io_bazel_rules_go//go/platform:aix": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:android": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:darwin": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:dragonfly": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:freebsd": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:illumos": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:ios": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:js": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:linux": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:netbsd": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:openbsd": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:plan9": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:solaris": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "@io_bazel_rules_go//go/platform:windows": [
+            "@com_github_pingcap_failpoint//:failpoint",
+        ],
+        "//conditions:default": [],
+    }),
 )
 
 go_test(

util/cgroup/cgroup_cpu_linux.go

@@ -21,11 +21,22 @@ import (
 	"os"
 	"runtime"
 	"strings"
+
+	"github.com/pingcap/errors"
+	"github.com/pingcap/failpoint"
 )
 
 // GetCgroupCPU returns the CPU usage and quota for the current cgroup.
 func GetCgroupCPU() (CPUUsage, error) {
+	failpoint.Inject("GetCgroupCPUErr", func(val failpoint.Value) {
+		//nolint:forcetypeassert
+		if val.(bool) {
+			var cpuUsage CPUUsage
+			failpoint.Return(cpuUsage, errors.Errorf("mockAddBatchDDLJobsErr"))
+		}
+	})
 	cpuusage, err := getCgroupCPU("/")
+
 	cpuusage.NumCPU = runtime.NumCPU()
 	return cpuusage, err
 }

util/cgroup/cgroup_cpu_unsupport.go

@@ -18,11 +18,20 @@ package cgroup
 
 import (
 	"runtime"
+
+	"github.com/pingcap/errors"
+	"github.com/pingcap/failpoint"
 )
 
 // GetCgroupCPU returns the CPU usage and quota for the current cgroup.
 func GetCgroupCPU() (CPUUsage, error) {
 	var cpuUsage CPUUsage
+	failpoint.Inject("GetCgroupCPUErr", func(val failpoint.Value) {
+		//nolint:forcetypeassert
+		if val.(bool) {
+			failpoint.Return(cpuUsage, errors.Errorf("mockAddBatchDDLJobsErr"))
+		}
+	})
 	cpuUsage.NumCPU = runtime.NumCPU()
 	return cpuUsage, nil
 }

util/cpu/BUILD.bazel

@@ -19,9 +19,20 @@ go_library(
 go_test(
     name = "cpu_test",
     timeout = "short",
-    srcs = ["cpu_test.go"],
-    embed = [":cpu"],
+    srcs = [
+        "cpu_test.go",
+        "main_test.go",
+    ],
     flaky = True,
     race = "on",
-    deps = ["@com_github_stretchr_testify//require"],
+    shard_count = 2,
+    deps = [
+        ":cpu",
+        "//resourcemanager/scheduler",
+        "//resourcemanager/util",
+        "//testkit/testsetup",
+        "@com_github_pingcap_failpoint//:failpoint",
+        "@com_github_stretchr_testify//require",
+        "@org_uber_go_goleak//:goleak",
+    ],
 )

util/cpu/cpu_test.go

@@ -12,19 +12,23 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package cpu
+package cpu_test
 
 import (
 	"runtime"
 	"sync"
 	"testing"
 	"time"
 
+	"github.com/pingcap/failpoint"
+	"github.com/pingcap/tidb/resourcemanager/scheduler"
+	"github.com/pingcap/tidb/resourcemanager/util"
+	"github.com/pingcap/tidb/util/cpu"
 	"github.com/stretchr/testify/require"
 )
 
 func TestCPUValue(t *testing.T) {
-	observer := NewCPUObserver()
+	observer := cpu.NewCPUObserver()
 	exit := make(chan struct{})
 	var wg sync.WaitGroup
 	for i := 0; i < 10; i++ {
@@ -44,13 +48,49 @@ func TestCPUValue(t *testing.T) {
 	observer.Start()
 	for n := 0; n < 10; n++ {
 		time.Sleep(1 * time.Second)
-		value, unsupported := GetCPUUsage()
+		value, unsupported := cpu.GetCPUUsage()
 		require.False(t, unsupported)
-		require.GreaterOrEqual(t, value, 0.0)
+		require.Greater(t, value, 0.0)
 		require.Less(t, value, 1.0)
 	}
-
 	observer.Stop()
 	close(exit)
 	wg.Wait()
 }
+
+func TestFailpointCPUValue(t *testing.T) {
+	failpoint.Enable("github.com/pingcap/tidb/util/cgroup/GetCgroupCPUErr", "return(true)")
+	defer func() {
+		failpoint.Disable("github.com/pingcap/tidb/util/cgroup/GetCgroupCPUErr")
+	}()
+	observer := cpu.NewCPUObserver()
+	exit := make(chan struct{})
+	var wg sync.WaitGroup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for {
+				select {
+				case <-exit:
+					return
+				default:
+					runtime.Gosched()
+				}
+			}
+		}()
+	}
+	observer.Start()
+	for n := 0; n < 10; n++ {
+		time.Sleep(1 * time.Second)
+		value, unsupported := cpu.GetCPUUsage()
+		require.True(t, unsupported)
+		require.Equal(t, value, 0.0)
+	}
+	sch := scheduler.CPUScheduler{}
+	require.Equal(t, scheduler.Hold, sch.Tune(util.UNKNOWN, util.NewMockGPool("test")))
+	// we do not stop the observer, because we inject the fail-point and the observer will not start.
+	// if this test case happen goleak, it must have a bug.
+	close(exit)
+	wg.Wait()
+}

util/cpu/main_test.go

@@ -0,0 +1,33 @@
+// Copyright 2022 PingCAP, Inc.
+//
+// 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.
+
+package cpu_test
+
+import (
+	"testing"
+
+	"github.com/pingcap/tidb/testkit/testsetup"
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	opts := []goleak.Option{
+		goleak.IgnoreTopFunction("github.com/golang/glog.(*loggingT).flushDaemon"),
+		goleak.IgnoreTopFunction("github.com/lestrrat-go/httprc.runFetchWorker"),
+		goleak.IgnoreTopFunction("go.etcd.io/etcd/client/pkg/v3/logutil.(*MergeLogger).outputLoop"),
+		goleak.IgnoreTopFunction("go.opencensus.io/stats/view.(*worker).start"),
+	}
+	testsetup.SetupForCommonTest()
+	goleak.VerifyTestMain(m, opts...)
+}