From b80e9857d241bb25d3bf079517e1c5ede7ebd9db Mon Sep 17 00:00:00 2001
From: Tyler Benson <tyler.benson@datadoghq.com>
Date: Thu, 20 Feb 2020 11:14:36 -0800
Subject: [PATCH] Reorder java-concurrent matchers

Move the expensive matcher to last.

In theory this should help, but did not seem to make a significant difference in basic startup benchmarks.
---
 .../AbstractExecutorInstrumentation.java      | 51 ++++++++++---------
 .../concurrent/FutureInstrumentation.java     |  4 +-
 2 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/AbstractExecutorInstrumentation.java b/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/AbstractExecutorInstrumentation.java
index 4fe6518f94..a7f52c27ae 100644
--- a/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/AbstractExecutorInstrumentation.java
+++ b/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/AbstractExecutorInstrumentation.java
@@ -102,33 +102,34 @@ public abstract class AbstractExecutorInstrumentation extends Instrumenter.Defau
 
   @Override
   public ElementMatcher<TypeDescription> typeMatcher() {
-    final ElementMatcher.Junction<TypeDescription> matcher =
-        not(isInterface()).and(safeHasInterface(named(Executor.class.getName())));
-    if (TRACE_ALL_EXECUTORS) {
-      return matcher;
+    ElementMatcher.Junction<TypeDescription> matcher = not(isInterface());
+    if (!TRACE_ALL_EXECUTORS) {
+      matcher =
+          matcher.and(
+              new ElementMatcher<TypeDescription>() {
+                @Override
+                public boolean matches(final TypeDescription target) {
+                  boolean whitelisted = WHITELISTED_EXECUTORS.contains(target.getName());
+
+                  // Check for possible prefixes match only if not whitelisted already
+                  if (!whitelisted) {
+                    for (final String name : WHITELISTED_EXECUTORS_PREFIXES) {
+                      if (target.getName().startsWith(name)) {
+                        whitelisted = true;
+                        break;
+                      }
+                    }
+                  }
+
+                  if (!whitelisted) {
+                    log.debug("Skipping executor instrumentation for {}", target.getName());
+                  }
+                  return whitelisted;
+                }
+              });
     }
     return matcher.and(
-        new ElementMatcher<TypeDescription>() {
-          @Override
-          public boolean matches(final TypeDescription target) {
-            boolean whitelisted = WHITELISTED_EXECUTORS.contains(target.getName());
-
-            // Check for possible prefixes match only if not whitelisted already
-            if (!whitelisted) {
-              for (final String name : WHITELISTED_EXECUTORS_PREFIXES) {
-                if (target.getName().startsWith(name)) {
-                  whitelisted = true;
-                  break;
-                }
-              }
-            }
-
-            if (!whitelisted) {
-              log.debug("Skipping executor instrumentation for {}", target.getName());
-            }
-            return whitelisted;
-          }
-        });
+        safeHasInterface(named(Executor.class.getName()))); // Apply expensive matcher last.
   }
 
   @Override
diff --git a/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/FutureInstrumentation.java b/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/FutureInstrumentation.java
index bf1fd2f591..11e67055b4 100644
--- a/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/FutureInstrumentation.java
+++ b/dd-java-agent/instrumentation/java-concurrent/src/main/java/datadog/trace/instrumentation/java/concurrent/FutureInstrumentation.java
@@ -79,7 +79,6 @@ public final class FutureInstrumentation extends Instrumenter.Default {
   @Override
   public ElementMatcher<TypeDescription> typeMatcher() {
     return not(isInterface())
-        .and(safeHasInterface(named(Future.class.getName())))
         .and(
             new ElementMatcher<TypeDescription>() {
               @Override
@@ -90,7 +89,8 @@ public final class FutureInstrumentation extends Instrumenter.Default {
                 }
                 return whitelisted;
               }
-            });
+            })
+        .and(safeHasInterface(named(Future.class.getName()))); // Apply expensive matcher last.
   }
 
   @Override