Revert "[exporter/signalfx] Fix memory leak on shutdown (open-telemet…

…ry#30887)" (open-telemetry#31541)

This reverts commit 494bdb8.

The change introduced a flaky test, making the build unstable. Reverting
for now.

Examples:

-
https://github.com/open-telemetry/opentelemetry-collector-contrib/actions/runs/8135561006/job/22233883822
-
https://github.com/open-telemetry/opentelemetry-collector-contrib/actions/runs/8131615657/job/22221154096
-
https://github.com/open-telemetry/opentelemetry-collector-contrib/actions/runs/8118428574/job/22192725196

exporter/signalfxexporter/internal/apm/correlations/client.go

@@ -44,7 +44,6 @@ type CorrelationClient interface {
 	Delete(*Correlation, SuccessfulDeleteCB)
 	Get(dimName string, dimValue string, cb SuccessfulGetCB)
 	Start()
-	Shutdown()
 }
 
 type request struct {
@@ -388,9 +387,3 @@ func (cc *Client) Start() {
 	go cc.processChan()
 	go cc.processRetryChan()
 }
-
-// Shutdown the client. This will block until the context's cancel
-// function is complete.
-func (cc *Client) Shutdown() {
-	cc.wg.Wait()
-}

exporter/signalfxexporter/internal/apm/correlations/client_test.go

@@ -124,14 +124,18 @@ func makeHandler(t *testing.T, corCh chan<- *request, forcedRespCode *atomic.Val
 	})
 }
 
-func setup(t *testing.T) (CorrelationClient, *httptest.Server, chan *request, *atomic.Value, *atomic.Value, context.CancelFunc, context.Context) {
+func setup(t *testing.T) (CorrelationClient, chan *request, *atomic.Value, *atomic.Value, context.CancelFunc) {
 	serverCh := make(chan *request, 100)
 
 	var forcedRespCode atomic.Value
 	var forcedRespPayload atomic.Value
 	server := httptest.NewServer(makeHandler(t, serverCh, &forcedRespCode, &forcedRespPayload))
 
 	ctx, cancel := context.WithCancel(context.Background())
+	go func() {
+		<-ctx.Done()
+		server.Close()
+	}()
 
 	serverURL, err := url.Parse(server.URL)
 	if err != nil {
@@ -172,20 +176,13 @@ func setup(t *testing.T) (CorrelationClient, *httptest.Server, chan *request, *a
 	}
 	client.Start()
 
-	return client, server, serverCh, &forcedRespCode, &forcedRespPayload, cancel, ctx
-}
-
-func teardown(ctx context.Context, client CorrelationClient, server *httptest.Server, serverCh chan *request, cancel context.CancelFunc) {
-	close(serverCh)
-	cancel()
-	<-ctx.Done()
-	client.Shutdown()
-	server.Close()
+	return client, serverCh, &forcedRespCode, &forcedRespPayload, cancel
 }
 
 func TestCorrelationClient(t *testing.T) {
-	client, server, serverCh, forcedRespCode, forcedRespPayload, cancel, ctx := setup(t)
-	defer teardown(ctx, client, server, serverCh, cancel)
+	client, serverCh, forcedRespCode, forcedRespPayload, cancel := setup(t)
+	defer close(serverCh)
+	defer cancel()
 
 	for _, correlationType := range []Type{Service, Environment} {
 		for _, op := range []string{http.MethodPut, http.MethodDelete} {
@@ -245,7 +242,7 @@ func TestCorrelationClient(t *testing.T) {
 		client.Correlate(testData, CorrelateCB(func(_ *Correlation, _ error) {}))
 		// sending the testData twice tests deduplication, since the 500 status
 		// will trigger retries, and the requests should be deduped and the
-		// TotalRetriedUpdates should still only be 5
+		// TotalRertriedUpdates should still only be 5
 		client.Correlate(testData, CorrelateCB(func(_ *Correlation, _ error) {}))
 
 		cors := waitForCors(serverCh, 1, 4)

exporter/signalfxexporter/internal/apm/tracetracker/tracker_test.go

@@ -85,8 +85,7 @@ type correlationTestClient struct {
 	correlateCounter int64
 }
 
-func (c *correlationTestClient) Start()    { /*no-op*/ }
-func (c *correlationTestClient) Shutdown() { /*no-op*/ }
+func (c *correlationTestClient) Start() { /*no-op*/ }
 func (c *correlationTestClient) Get(_ string, dimValue string, cb correlations.SuccessfulGetCB) {
 	atomic.AddInt64(&c.getCounter, 1)
 	go func() {

exporter/signalfxexporter/internal/correlation/correlation.go

@@ -137,7 +137,6 @@ func (cor *Tracker) Shutdown(_ context.Context) error {
 	if cor != nil {
 		if cor.correlation != nil {
 			cor.correlation.cancel()
-			cor.correlation.CorrelationClient.Shutdown()
 		}
 
 		if cor.pTicker != nil {

exporter/signalfxexporter/internal/correlation/correlation_test.go

@@ -86,8 +86,6 @@ func TestTrackerStart(t *testing.T) {
 			} else {
 				require.NoError(t, err)
 			}
-
-			assert.NoError(t, tracker.Shutdown(context.Background()))
 		})
 	}
 }