Revert subsegment synchronization changes (#350)

* Revert "Don't lock segment from subsegment (#306)"

This reverts commit d5ccae2.

* Revert "Keep track of emitted in emitter. (#279)"

This reverts commit d66d69a.

* Revert "Remove subsegments lock (#278)"

This reverts commit adfb395.

* Revert "Lock all accesses to entities. (#250)"

This reverts commit f0a3b3a.

* add back errorprone annotations

* fixed shouldPropagate

* added back getSubsegmentsCopy

* added back compareAndSetEmitted

* whitespace fix

aws-xray-recorder-sdk-core/src/main/java/com/amazonaws/xray/emitters/UDPEmitter.java

@@ -83,24 +83,21 @@ public boolean sendSegment(Segment segment) {
         if (logger.isDebugEnabled()) {
             logger.debug(segment.prettySerialize());
         }
-        if (segment.compareAndSetEmitted(false, true)) {
-            byte[] bytes = (PROTOCOL_HEADER + PROTOCOL_DELIMITER + segment.serialize()).getBytes(StandardCharsets.UTF_8);
+
+        byte[] bytes = (PROTOCOL_HEADER + PROTOCOL_DELIMITER + segment.serialize()).getBytes(StandardCharsets.UTF_8);
 
-            if (bytes.length > UDP_PACKET_LIMIT) {
-                List<Subsegment> subsegments = segment.getSubsegmentsCopy();
-                logger.debug("Segment too large, sending subsegments to daemon first. bytes " + bytes.length + " subsegemnts "
-                            + subsegments.size());
-                for (Subsegment subsegment : subsegments) {
-                    sendSubsegment(subsegment);
-                    segment.removeSubsegment(subsegment);
-                }
-                bytes = (PROTOCOL_HEADER + PROTOCOL_DELIMITER + segment.serialize()).getBytes(StandardCharsets.UTF_8);
-                logger.debug("New segment size. bytes " + bytes.length);
+        if (bytes.length > UDP_PACKET_LIMIT) {
+            List<Subsegment> subsegments = segment.getSubsegmentsCopy();
+            logger.debug("Segment too large, sending subsegments to daemon first. bytes " + bytes.length + " subsegemnts "
+                        + subsegments.size());
+            for (Subsegment subsegment : subsegments) {
+                sendSubsegment(subsegment);
+                segment.removeSubsegment(subsegment);
             }
-            return sendData(bytes, segment);
-        } else {
-            return false;
+            bytes = (PROTOCOL_HEADER + PROTOCOL_DELIMITER + segment.serialize()).getBytes(StandardCharsets.UTF_8);
+            logger.debug("New segment size. bytes " + bytes.length);
         }
+        return sendData(bytes, segment);
     }
 
     /**
@@ -113,13 +110,8 @@ public boolean sendSubsegment(Subsegment subsegment) {
         if (logger.isDebugEnabled()) {
             logger.debug(subsegment.prettyStreamSerialize());
         }
-        if (subsegment.compareAndSetEmitted(false, true)) {
-            return sendData((PROTOCOL_HEADER + PROTOCOL_DELIMITER +
-                             subsegment.streamSerialize()).getBytes(StandardCharsets.UTF_8),
-                            subsegment);
-        } else {
-            return false;
-        }
+        return sendData((PROTOCOL_HEADER + PROTOCOL_DELIMITER + subsegment.streamSerialize()).getBytes(StandardCharsets.UTF_8),
+                        subsegment);
     }
 
     private boolean sendData(byte[] data, Entity entity) {

aws-xray-recorder-sdk-core/src/main/java/com/amazonaws/xray/entities/Entity.java

@@ -158,7 +158,7 @@ default void run(Runnable runnable, AWSXRayRecorder recorder) {
     void setNamespace(String namespace);
 
     /**
-     * @return an unused {@link ReentrantLock}
+     * @return the subsegmentsLock
      *
      * @deprecated This is for internal use of the SDK and will be made private.
      */
@@ -601,15 +601,17 @@ default void run(Runnable runnable, AWSXRayRecorder recorder) {
     boolean isEmitted();
 
     /**
-     * @deprecated Use {@link #compareAndSetEmitted(boolean, boolean)}
+     * Sets emitted on the entity.
      */
-    @Deprecated
     void setEmitted(boolean emitted);
 
     /**
      * Checks whether this {@link Entity} currently has emitted state of {@code current} and if so, set emitted state to
      * {@code next}. Returns {@code true} if the state was updated, or {@code false} otherwise.
+     *
+     * @deprecated Use {@link #setEmitted(boolean)}
      */
+    @Deprecated
     boolean compareAndSetEmitted(boolean current, boolean next);
 
     String serialize();