Add unit test for AtomicCounter.

logs/logs.go

@@ -98,7 +98,7 @@ func (l *LogAgent) Run(ctx context.Context) {
 	for {
 		select {
 		case <-t.C:
-			log.Printf("D! [logagent] open file count, %v", tail.OpenFileCount.Get())
+			log.Printf("D! [logagent] open file count, %v", tail.OpenFileCount.Load())
 			for _, c := range l.collections {
 				srcs := c.FindLogSrc()
 				for _, src := range srcs {

plugins/inputs/logfile/tail/tail.go

@@ -10,9 +10,9 @@ import (
 	"io"
 	"os"
 	"sync"
+	"sync/atomic"
 	"time"
 
-	"github.com/aws/amazon-cloudwatch-agent/internal/atomiccounter"
 	"github.com/aws/amazon-cloudwatch-agent/plugins/inputs/logfile/tail/watch"
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/models"
@@ -24,7 +24,7 @@ var (
 	ErrDeletedNotReOpen         = errors.New("File was deleted, tail should now stop")
 	exitOnDeletionCheckDuration = time.Minute
 	exitOnDeletionWaitDuration  = 5 * time.Minute
-	OpenFileCount               = atomiccounter.NewAtomicCounter()
+	OpenFileCount               atomic.Int64
 )
 
 type Line struct {
@@ -122,7 +122,7 @@ func TailFile(filename string, config Config) (*Tail, error) {
 		if err != nil {
 			return nil, err
 		}
-		OpenFileCount.Increment()
+		OpenFileCount.Add(1)
 	}
 
 	if !config.ReOpen {
@@ -184,7 +184,7 @@ func (tail *Tail) closeFile() {
 	if tail.file != nil {
 		tail.file.Close()
 		tail.file = nil
-		OpenFileCount.Decrement()
+		OpenFileCount.Add(-1)
 	}
 }
 
@@ -209,7 +209,7 @@ func (tail *Tail) reopen() error {
 		}
 		break
 	}
-	OpenFileCount.Increment()
+	OpenFileCount.Add(1)
 	return nil
 }
 

plugins/inputs/logfile/tail/tail_test.go

@@ -99,15 +99,15 @@ func TestStopAtEOF(t *testing.T) {
 	assert.Equal(t, errStopAtEOF, tail.Err())
 
 	// Read to EOF
-	for i := 0; i < linesWrittenToFile - 3; i++ {
+	for i := 0; i < linesWrittenToFile-3; i++ {
 		<-tail.Lines
 	}
 
 	// Verify StopAtEOF() has completed.
 	select {
 	case <-done:
 		t.Log("StopAtEOF() completed (as expected)")
-	case <- time.After(time.Second * 1):
+	case <-time.After(time.Second * 1):
 		t.Fatalf("StopAtEOF() has not completed")
 	}
 
@@ -148,7 +148,7 @@ func setup(t *testing.T) (*os.File, *Tail, *testLogger) {
 	if err != nil {
 		t.Fatalf("failed to tail file %v: %v", tmpfile.Name(), err)
 	}
-	// Cannot expect OpenFileCount.Get() to be 1 because the TailFile struct
+	// Cannot expect OpenFileCount to be 1 because the TailFile struct
 	// was not created with MustExist=true, so file may not yet be opened.
 	return tmpfile, tail, &tl
 }
@@ -165,7 +165,7 @@ func readThreelines(t *testing.T, tail *Tail) {
 		}
 	}
 	// If file was readable, then expect it to exist.
-	assert.Equal(t, int64(1), OpenFileCount.Get())
+	assert.Equal(t, int64(1), OpenFileCount.Load())
 }
 
 func verifyTailerLogging(t *testing.T, tlog *testLogger, expectedErrorMsg string) {
@@ -182,7 +182,7 @@ func verifyTailerLogging(t *testing.T, tlog *testLogger, expectedErrorMsg string
 func verifyTailerExited(t *testing.T, tail *Tail) {
 	select {
 	case <-tail.Dead():
-		assert.Equal(t,  int64(0), OpenFileCount.Get())
+		assert.Equal(t, int64(0), OpenFileCount.Load())
 		return
 	default:
 		t.Errorf("Tailer is still alive after file removed and wait period")

plugins/inputs/logfile/tailersrc_test.go

@@ -46,7 +46,7 @@ func TestTailerSrc(t *testing.T) {
 	if err != nil {
 		t.Errorf("Failed to create temp file: %v", err)
 	}
-	beforeCount := tail.OpenFileCount.Get()
+	beforeCount := tail.OpenFileCount.Load()
 	tailer, err := tail.TailFile(file.Name(),
 		tail.Config{
 			ReOpen:      false,
@@ -63,7 +63,7 @@ func TestTailerSrc(t *testing.T) {
 		t.Errorf("Failed to create tailer src for file %v with error: %v", file, err)
 		return
 	}
-	assert.Equal(t, beforeCount + 1, tail.OpenFileCount.Get())
+	assert.Equal(t, beforeCount+1, tail.OpenFileCount.Load())
 	ts := NewTailerSrc(
 		"groupName", "streamName",
 		"destination",
@@ -152,7 +152,7 @@ func TestTailerSrc(t *testing.T) {
 	// Most test functions do not wait for the Tail to close the file.
 	// They rely on Tail to detect file deletion and close the file.
 	// So the count might be nonzero due to previous test cases.
-	assert.LessOrEqual(t, tail.OpenFileCount.Get(), beforeCount)
+	assert.LessOrEqual(t, tail.OpenFileCount.Load(), beforeCount)
 }
 
 func TestOffsetDoneCallBack(t *testing.T) {