From 2a4a6dc908284d94c55b5b62ba114d0e25434cea Mon Sep 17 00:00:00 2001
From: Tatu Saloranta <tatu.saloranta@iki.fi>
Date: Fri, 19 Apr 2024 17:50:58 -0700
Subject: [PATCH] Fix #1256: revert #1117, default recycler pool again
 `threadLocalPool()` (for 2.17.1+) (#1267)

---
 release-notes/VERSION-2.x                          |  2 ++
 .../jackson/core/util/JsonRecyclerPools.java       |  8 +++++---
 src/test/java/perf/RecyclerPoolTest.java           | 14 +++++++-------
 3 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/release-notes/VERSION-2.x b/release-notes/VERSION-2.x
index 5c29854ff0..5abff8a45b 100644
--- a/release-notes/VERSION-2.x
+++ b/release-notes/VERSION-2.x
@@ -18,6 +18,8 @@ a pure JSON library.
 
 #1241: Fix `NumberInput.looksLikeValidNumber()` implementation
  (contributed by @pjfanning)
+#1256: Revert #1117: change default recycler pool back to `threadLocalPool()`
+  for 2.17.1
 
 2.17.0 (12-Mar-2024)
 
diff --git a/src/main/java/com/fasterxml/jackson/core/util/JsonRecyclerPools.java b/src/main/java/com/fasterxml/jackson/core/util/JsonRecyclerPools.java
index 4547b2c36b..bf724294cc 100644
--- a/src/main/java/com/fasterxml/jackson/core/util/JsonRecyclerPools.java
+++ b/src/main/java/com/fasterxml/jackson/core/util/JsonRecyclerPools.java
@@ -19,14 +19,16 @@ public final class JsonRecyclerPools
 {
     /**
      * Method to call to get the default recycler pool instance:
-     * as of Jackson 2.17 this is same as calling
-     * {@link #newLockFreePool()}; earlier 
+     * as of Jackson 2.17.x and earlier (except for 2.17.0) this is same as calling
+     * {@link #threadLocalPool()} -- 2.17.0 temporarily had this call
+     * {@link #newLockFreePool()} (but reverted due to problems reported).
+     * Will likely be changed in 2.18.0 to something else.
      *
      * @return the default {@link RecyclerPool} implementation to use
      *   if no specific implementation desired.
      */
     public static RecyclerPool<BufferRecycler> defaultPool() {
-        return newLockFreePool();
+        return threadLocalPool();
     }
 
     /**
diff --git a/src/test/java/perf/RecyclerPoolTest.java b/src/test/java/perf/RecyclerPoolTest.java
index 5165bfbf14..d0dc967d5a 100644
--- a/src/test/java/perf/RecyclerPoolTest.java
+++ b/src/test/java/perf/RecyclerPoolTest.java
@@ -24,7 +24,7 @@
  */
 public class RecyclerPoolTest
 {
-    final static int THREAD_COUNT = 100;
+    final static int THREAD_COUNT = 200;
 
     final static int RUNTIME_SECS = 60;
 
@@ -100,7 +100,8 @@ void testUntil(JsonFactory jsonF,
              long endTimeMsecs, int threadId, AtomicLong calls)
     {
         final Random rnd = new Random(threadId);
-        final byte[] JSON_INPUT = "\"abc\"".getBytes(StandardCharsets.UTF_8);
+        final byte[] JSON_INPUT = "42 "
+                .getBytes(StandardCharsets.UTF_8);
 
         while (System.currentTimeMillis() < endTimeMsecs) {
             try {
@@ -144,7 +145,6 @@ private void _testWrite(JsonFactory jsonF) throws Exception
         StringWriter w = new StringWriter(16);
         JsonGenerator g = jsonF.createGenerator(w);
         g.writeStartArray();
-        g.writeString("foobar");
         g.writeEndArray();
         g.close();
     }
@@ -154,15 +154,15 @@ public static void main(String[] args) throws Exception
         RecyclerPoolTest test = new RecyclerPoolTest(THREAD_COUNT);
         List<String> results = Arrays.asList(
             test.testPool(JsonFactory.builder()
-                    .recyclerPool(JsonRecyclerPools.newConcurrentDequePool())
+                    .recyclerPool(JsonRecyclerPools.newLockFreePool())
                     .build(),
-                RUNTIME_SECS),
+                RUNTIME_SECS * 1000),
             test.testPool(JsonFactory.builder()
-                    .recyclerPool(JsonRecyclerPools.newBoundedPool(THREAD_COUNT - 5))
+                    .recyclerPool(JsonRecyclerPools.newConcurrentDequePool())
                     .build(),
                 RUNTIME_SECS),
             test.testPool(JsonFactory.builder()
-                    .recyclerPool(JsonRecyclerPools.newLockFreePool())
+                    .recyclerPool(JsonRecyclerPools.newBoundedPool(THREAD_COUNT - 5))
                     .build(),
                 RUNTIME_SECS)
         );