Fix sdktrace.TraceProvider Shutdown/ForceFlush when no processor regi…

…ster

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

CHANGELOG.md

@@ -23,6 +23,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Fixed
 
 - Use default view if instrument does not match any registered view of a reader. (#3224, #3237)
+- `sdktrace.TraceProvider.Shutdown` and `sdktrace.TraceProvider.ForceFlush` to not return error when no processor register. (#3268)
 
 ## [0.32.1] Metric SDK (Alpha) - 2022-09-22
 

sdk/trace/provider.go

@@ -116,7 +116,7 @@ func NewTracerProvider(opts ...TracerProviderOption) *TracerProvider {
 		spanLimits:  o.spanLimits,
 		resource:    o.resource,
 	}
-
+	tp.spanProcessors.Store(spanProcessorStates{})
 	global.Info("TracerProvider created", "config", o)
 
 	for _, sp := range o.processors {
@@ -163,26 +163,20 @@ func (p *TracerProvider) RegisterSpanProcessor(s SpanProcessor) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
 	newSPS := spanProcessorStates{}
-	if old, ok := p.spanProcessors.Load().(spanProcessorStates); ok {
-		newSPS = append(newSPS, old...)
-	}
-	newSpanSync := &spanProcessorState{
-		sp:    s,
-		state: &sync.Once{},
-	}
-	newSPS = append(newSPS, newSpanSync)
+	newSPS = append(newSPS, p.spanProcessors.Load().(spanProcessorStates)...)
+	newSPS = append(newSPS, &spanProcessorState{sp: s, state: &sync.Once{}})
 	p.spanProcessors.Store(newSPS)
 }
 
 // UnregisterSpanProcessor removes the given SpanProcessor from the list of SpanProcessors.
 func (p *TracerProvider) UnregisterSpanProcessor(s SpanProcessor) {
 	p.mu.Lock()
 	defer p.mu.Unlock()
-	spss := spanProcessorStates{}
-	old, ok := p.spanProcessors.Load().(spanProcessorStates)
-	if !ok || len(old) == 0 {
+	old := p.spanProcessors.Load().(spanProcessorStates)
+	if len(old) == 0 {
 		return
 	}
+	spss := spanProcessorStates{}
 	spss = append(spss, old...)
 
 	// stop the span processor if it is started and remove it from the list
@@ -213,10 +207,7 @@ func (p *TracerProvider) UnregisterSpanProcessor(s SpanProcessor) {
 // ForceFlush immediately exports all spans that have not yet been exported for
 // all the registered span processors.
 func (p *TracerProvider) ForceFlush(ctx context.Context) error {
-	spss, ok := p.spanProcessors.Load().(spanProcessorStates)
-	if !ok {
-		return fmt.Errorf("failed to load span processors")
-	}
+	spss := p.spanProcessors.Load().(spanProcessorStates)
 	if len(spss) == 0 {
 		return nil
 	}
@@ -237,10 +228,11 @@ func (p *TracerProvider) ForceFlush(ctx context.Context) error {
 
 // Shutdown shuts down the span processors in the order they were registered.
 func (p *TracerProvider) Shutdown(ctx context.Context) error {
-	spss, ok := p.spanProcessors.Load().(spanProcessorStates)
-	if !ok {
-		return fmt.Errorf("failed to load span processors")
+	spss := p.spanProcessors.Load().(spanProcessorStates)
+	if len(spss) == 0 {
+		return nil
 	}
+
 	var retErr error
 	for _, sps := range spss {
 		select {

sdk/trace/provider_test.go

@@ -28,41 +28,45 @@ import (
 	"go.opentelemetry.io/otel/trace"
 )
 
-type basicSpanProcesor struct {
-	running             bool
+type basicSpanProcessor struct {
+	flushed             bool
+	closed              bool
 	injectShutdownError error
 }
 
-func (t *basicSpanProcesor) Shutdown(context.Context) error {
-	t.running = false
+func (t *basicSpanProcessor) Shutdown(context.Context) error {
+	t.closed = true
 	return t.injectShutdownError
 }
 
-func (t *basicSpanProcesor) OnStart(context.Context, ReadWriteSpan) {}
-func (t *basicSpanProcesor) OnEnd(ReadOnlySpan)                     {}
-func (t *basicSpanProcesor) ForceFlush(context.Context) error {
+func (t *basicSpanProcessor) OnStart(context.Context, ReadWriteSpan) {}
+func (t *basicSpanProcessor) OnEnd(ReadOnlySpan)                     {}
+func (t *basicSpanProcessor) ForceFlush(context.Context) error {
+	t.flushed = true
 	return nil
 }
 
+func TestForceFlushAndShutdownTraceProviderWithoutProcessor(t *testing.T) {
+	stp := NewTracerProvider()
+	assert.NoError(t, stp.ForceFlush(context.Background()))
+	assert.NoError(t, stp.Shutdown(context.Background()))
+}
+
 func TestShutdownTraceProvider(t *testing.T) {
 	stp := NewTracerProvider()
-	sp := &basicSpanProcesor{}
+	sp := &basicSpanProcessor{}
 	stp.RegisterSpanProcessor(sp)
 
-	sp.running = true
-
-	_ = stp.Shutdown(context.Background())
-
-	if sp.running {
-		t.Errorf("Error shutdown basicSpanProcesor\n")
-	}
+	assert.NoError(t, stp.ForceFlush(context.Background()))
+	assert.True(t, sp.flushed, "error shutdown basicSpanProcessor")
+	assert.NoError(t, stp.Shutdown(context.Background()))
+	assert.True(t, sp.closed, "error shutdown basicSpanProcessor")
 }
 
 func TestFailedProcessorShutdown(t *testing.T) {
 	stp := NewTracerProvider()
 	spErr := errors.New("basic span processor shutdown failure")
-	sp := &basicSpanProcesor{
-		running:             true,
+	sp := &basicSpanProcessor{
 		injectShutdownError: spErr,
 	}
 	stp.RegisterSpanProcessor(sp)
@@ -76,12 +80,10 @@ func TestFailedProcessorsShutdown(t *testing.T) {
 	stp := NewTracerProvider()
 	spErr1 := errors.New("basic span processor shutdown failure1")
 	spErr2 := errors.New("basic span processor shutdown failure2")
-	sp1 := &basicSpanProcesor{
-		running:             true,
+	sp1 := &basicSpanProcessor{
 		injectShutdownError: spErr1,
 	}
-	sp2 := &basicSpanProcesor{
-		running:             true,
+	sp2 := &basicSpanProcessor{
 		injectShutdownError: spErr2,
 	}
 	stp.RegisterSpanProcessor(sp1)
@@ -90,16 +92,15 @@ func TestFailedProcessorsShutdown(t *testing.T) {
 	err := stp.Shutdown(context.Background())
 	assert.Error(t, err)
 	assert.EqualError(t, err, "basic span processor shutdown failure1; basic span processor shutdown failure2")
-	assert.False(t, sp1.running)
-	assert.False(t, sp2.running)
+	assert.True(t, sp1.closed)
+	assert.True(t, sp2.closed)
 }
 
 func TestFailedProcessorShutdownInUnregister(t *testing.T) {
 	handler.Reset()
 	stp := NewTracerProvider()
 	spErr := errors.New("basic span processor shutdown failure")
-	sp := &basicSpanProcesor{
-		running:             true,
+	sp := &basicSpanProcessor{
 		injectShutdownError: spErr,
 	}
 	stp.RegisterSpanProcessor(sp)