8365630: jdk/jfr/tool/TestPrintContextual.java fails with wrong spanId

Reviewed-by: shade

Author: egahlin

test/jdk/jdk/jfr/tool/TestPrintContextual.java

@@ -25,6 +25,7 @@
 
 import java.nio.file.Files;
 import java.nio.file.Path;
+import java.time.Instant;
 import java.util.AbstractMap;
 import java.util.ArrayList;
 import java.util.List;
@@ -264,7 +265,8 @@ private static void testDeepContext() throws Exception {
         }
     }
 
-    private static void span(int depth) {
+    private static void span(int depth) throws InterruptedException {
+        awaitUniqueTimestamp();
         SpanEvent span = new SpanEvent();
         span.name = "span";
         span.spanId = depth;
@@ -277,6 +279,13 @@ private static void span(int depth) {
         span.commit();
     }
 
+    private static void awaitUniqueTimestamp() throws InterruptedException {
+        Instant timestamp = Instant.now();
+        while (timestamp.equals(Instant.now())) {
+            Thread.sleep(1);
+        }
+    }
+
     // Tests that context values are only inhjected into events in the same thread.
     private static void testThreadedContext() throws Exception {
         try (Recording r = new Recording()) {