Fix field-injection of ForkJoinTask on Java 25 (#10084)

* Turning off crash-tracking was hiding a bug on Java 25
* Preload a future no-op task to ensure workQueue.take() will use await with timeout during premain - otherwise on Java 25 it will load ForkJoinPool which in turn loads ForkJoinTask, which then means we lose the chance to field-inject context into ForkJoinTask instances
* Only apply workaround to the global task scheduler used during premain

Author: mcculls

dd-smoke-tests/field-injection/src/test/groovy/datadog/smoketest/FieldInjectionSmokeTest.groovy

@@ -61,7 +61,6 @@ class FieldInjectionSmokeTest extends Specification {
     command.add("-XX:ErrorFile=/tmp/hs_err_pid%p.log")
     // turn off these features as their debug output can break up our expected logging lines on IBM JVMs
     // causing random test failures (we are not testing these features here so they don't need to be on)
-    command.add("-Ddd.crashtracking.enabled=false")
     command.add("-Ddd.instrumentation.telemetry.enabled=false")
     command.add("-Ddd.remote_config.enabled=false")
     command.add("-Ddd.writer.type=TraceStructureWriter")

internal-api/src/main/java/datadog/trace/util/AgentTaskScheduler.java

@@ -4,6 +4,7 @@
 import static datadog.trace.util.AgentThreadFactory.AgentThread.TASK_SCHEDULER;
 import static datadog.trace.util.AgentThreadFactory.newAgentThread;
 import static java.util.concurrent.TimeUnit.MILLISECONDS;
+import static java.util.concurrent.TimeUnit.MINUTES;
 import static java.util.concurrent.TimeUnit.NANOSECONDS;
 import static java.util.concurrent.TimeUnit.SECONDS;
 
@@ -225,6 +226,12 @@ private void prepareWorkQueue() {
     } catch (final InterruptedException e) {
       // ignore, we only want to preload queue internals
     }
+    if (this == INSTANCE) {
+      // preload a future no-op task to ensure workQueue.take() will use await with timeout during
+      // premain - otherwise on Java 25 it will load ForkJoinPool which in turn loads ForkJoinTask,
+      // which then means we lose the chance to field-inject context into ForkJoinTask instances
+      workQueue.offer(FUTURE_NOOP_PLACEHOLDER);
+    }
   }
 
   // for testing
@@ -302,6 +309,9 @@ public void run() {
 
   private static final AtomicInteger TASK_SEQUENCE_GENERATOR = new AtomicInteger();
 
+  private static final PeriodicTask<Object> FUTURE_NOOP_PLACEHOLDER =
+      new PeriodicTask<>(null, new Scheduled<>(null), 10, 0, MINUTES);
+
   private static final class PeriodicTask<T> implements Delayed {
 
     private final Task<T> task;