From d700646154d336a7bab2b0887b901c8e96a1eced Mon Sep 17 00:00:00 2001
From: Zhengyu Gu <zhengyu.gu@datadoghq.com>
Date: Thu, 16 Oct 2025 16:17:47 +0200
Subject: [PATCH 1/3] Race on late initializing crash tracking results JVM to
 crash

---
 .../src/main/java/datadog/trace/bootstrap/Agent.java        | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
index 48557510aa7..4ce40f6fa92 100644
--- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
+++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
@@ -63,6 +63,7 @@
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
+import java.nio.ByteBuffer;
 import java.security.CodeSource;
 import java.util.EnumSet;
 import java.util.concurrent.TimeUnit;
@@ -795,6 +796,11 @@ private static void startCrashTracking() {
       if (forceEarlyStart) {
         initializeCrashTrackingDefault();
       } else {
+        // To workaround JDK-8345810, we want to initialize nio early,
+        // which has dependence on libpthread. Creating a small nio ByteBuffer
+        // to force nio initialization.
+        ByteBuffer buffer = ByteBuffer.allocate(1);
+
         AgentTaskScheduler.get().execute(Agent::initializeCrashTrackingDefault);
       }
     } else {

From 51dcb98747fc3e5626ec5ad38bd45e32d4c5c67e Mon Sep 17 00:00:00 2001
From: Zhengyu Gu <zhengyu.gu@datadoghq.com>
Date: Fri, 17 Oct 2025 14:09:41 +0200
Subject: [PATCH 2/3] Use FileSystems.getDefault() to force loading nio library

---
 .../src/main/java/datadog/trace/bootstrap/Agent.java         | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
index 4ce40f6fa92..d1283f7ed2a 100644
--- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
+++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
@@ -63,7 +63,7 @@
 import java.net.MalformedURLException;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.nio.ByteBuffer;
+import java.nio.file.FileSystems;
 import java.security.CodeSource;
 import java.util.EnumSet;
 import java.util.concurrent.TimeUnit;
@@ -799,8 +799,7 @@ private static void startCrashTracking() {
         // To workaround JDK-8345810, we want to initialize nio early,
         // which has dependence on libpthread. Creating a small nio ByteBuffer
         // to force nio initialization.
-        ByteBuffer buffer = ByteBuffer.allocate(1);
-
+        FileSystems.getDefault();
         AgentTaskScheduler.get().execute(Agent::initializeCrashTrackingDefault);
       }
     } else {

From c96d5798e25fd0ddc129bda6224d0b36e2f351c3 Mon Sep 17 00:00:00 2001
From: Zhengyu Gu <zhengyu.gu@datadoghq.com>
Date: Mon, 20 Oct 2025 09:53:42 -0400
Subject: [PATCH 3/3] Force loading/initializing pthread early on main thread

---
 .../src/main/java/datadog/trace/bootstrap/Agent.java   | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
index d1283f7ed2a..5967bf705b5 100644
--- a/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
+++ b/dd-java-agent/agent-bootstrap/src/main/java/datadog/trace/bootstrap/Agent.java
@@ -291,6 +291,12 @@ public static void start(
       startCwsAgent();
     }
 
+    // To workaround JDK-8345810, we want to trigger loading/initializing of pthread library on
+    // main thread (Linux only)
+    if (OperatingSystem.isLinux()) {
+      FileSystems.getDefault();
+    }
+
     /*
      * Force the task scheduler init early. The exception profiling instrumentation may get in way of the initialization
      * when it will happen after the class transformers were added.
@@ -796,10 +802,6 @@ private static void startCrashTracking() {
       if (forceEarlyStart) {
         initializeCrashTrackingDefault();
       } else {
-        // To workaround JDK-8345810, we want to initialize nio early,
-        // which has dependence on libpthread. Creating a small nio ByteBuffer
-        // to force nio initialization.
-        FileSystems.getDefault();
         AgentTaskScheduler.get().execute(Agent::initializeCrashTrackingDefault);
       }
     } else {