Simplify zio instrumentation (#14808)

Author: laurit

instrumentation/zio/zio-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/zio/v2_0/TracingSupervisor.java

@@ -18,17 +18,11 @@
 @SuppressWarnings("unchecked")
 public final class TracingSupervisor extends Supervisor<Object> {
 
-  @SuppressWarnings("rawtypes")
-  public static final VirtualField<Fiber.Runtime, FiberContext> RUNTIME_FIBER_CONTEXT =
+  public static final TracingSupervisor INSTANCE = new TracingSupervisor();
+  private static final VirtualField<Fiber.Runtime<?, ?>, FiberContext> RUNTIME_FIBER_CONTEXT =
       VirtualField.find(Fiber.Runtime.class, FiberContext.class);
 
-  @SuppressWarnings("rawtypes")
-  private final VirtualField<Fiber.Runtime, FiberContext> virtualField;
-
-  @SuppressWarnings("rawtypes")
-  public TracingSupervisor(VirtualField<Fiber.Runtime, FiberContext> virtualField) {
-    this.virtualField = virtualField;
-  }
+  private TracingSupervisor() {}
 
   @Override
   @SuppressWarnings("rawtypes")
@@ -44,23 +38,23 @@ public <R, E, A1> void onStart(
       Fiber.Runtime<E, A1> fiber,
       Unsafe unsafe) {
     FiberContext context = FiberContext.create();
-    virtualField.set(fiber, context);
+    RUNTIME_FIBER_CONTEXT.set(fiber, context);
   }
 
   @Override
   public <R, E, A1> void onEnd(Exit<E, A1> value, Fiber.Runtime<E, A1> fiber, Unsafe unsafe) {}
 
   @Override
   public <E, A1> void onSuspend(Fiber.Runtime<E, A1> fiber, Unsafe unsafe) {
-    FiberContext context = virtualField.get(fiber);
+    FiberContext context = RUNTIME_FIBER_CONTEXT.get(fiber);
     if (context != null) {
       context.onSuspend();
     }
   }
 
   @Override
   public <E, A1> void onResume(Fiber.Runtime<E, A1> fiber, Unsafe unsafe) {
-    FiberContext context = virtualField.get(fiber);
+    FiberContext context = RUNTIME_FIBER_CONTEXT.get(fiber);
     if (context != null) {
       context.onResume();
     }

instrumentation/zio/zio-2.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/zio/v2_0/ZioRuntimeInstrumentation.java

@@ -5,7 +5,6 @@
 
 package io.opentelemetry.javaagent.instrumentation.zio.v2_0;
 
-import static io.opentelemetry.javaagent.instrumentation.zio.v2_0.TracingSupervisor.RUNTIME_FIBER_CONTEXT;
 import static net.bytebuddy.matcher.ElementMatchers.isMethod;
 import static net.bytebuddy.matcher.ElementMatchers.named;
 
@@ -37,7 +36,7 @@ private DefaultSupervisor() {}
     @Advice.OnMethodExit(suppress = Throwable.class)
     @Advice.AssignReturned.ToReturned
     public static Object onExit(@Advice.Return Supervisor<?> supervisor) {
-      return supervisor.$plus$plus(new TracingSupervisor(RUNTIME_FIBER_CONTEXT));
+      return supervisor.$plus$plus(TracingSupervisor.INSTANCE);
     }
   }
 }