Add synchronization to SimpleLogRecordProcessor and SimpleSpanProcessor to ensure thread-safe export of logs and spans respectively (#6885)

Author: slodha

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/export/SimpleLogRecordProcessor.java

@@ -41,6 +41,8 @@ public final class SimpleLogRecordProcessor implements LogRecordProcessor {
       Collections.newSetFromMap(new ConcurrentHashMap<>());
   private final AtomicBoolean isShutdown = new AtomicBoolean(false);
 
+  private final Object exporterLock = new Object();
+
   /**
    * Returns a new {@link SimpleLogRecordProcessor} which exports logs to the {@link
    * LogRecordExporter} synchronously.
@@ -64,7 +66,12 @@ private SimpleLogRecordProcessor(LogRecordExporter logRecordExporter) {
   public void onEmit(Context context, ReadWriteLogRecord logRecord) {
     try {
       List<LogRecordData> logs = Collections.singletonList(logRecord.toLogRecordData());
-      CompletableResultCode result = logRecordExporter.export(logs);
+      CompletableResultCode result;
+
+      synchronized (exporterLock) {
+        result = logRecordExporter.export(logs);
+      }
+
       pendingExports.add(result);
       result.whenComplete(
           () -> {

sdk/trace/src/main/java/io/opentelemetry/sdk/trace/export/SimpleSpanProcessor.java

@@ -41,6 +41,8 @@ public final class SimpleSpanProcessor implements SpanProcessor {
       Collections.newSetFromMap(new ConcurrentHashMap<>());
   private final AtomicBoolean isShutdown = new AtomicBoolean(false);
 
+  private final Object exporterLock = new Object();
+
   /**
    * Returns a new {@link SimpleSpanProcessor} which exports spans to the {@link SpanExporter}
    * synchronously.
@@ -86,7 +88,12 @@ public void onEnd(ReadableSpan span) {
     if (span != null && (exportUnsampledSpans || span.getSpanContext().isSampled())) {
       try {
         List<SpanData> spans = Collections.singletonList(span.toSpanData());
-        CompletableResultCode result = spanExporter.export(spans);
+        CompletableResultCode result;
+
+        synchronized (exporterLock) {
+          result = spanExporter.export(spans);
+        }
+
         pendingExports.add(result);
         result.whenComplete(
             () -> {