ChannelTrace.java

import com.sun.btrace.AnyType;
import com.sun.btrace.annotations.*;

import static com.sun.btrace.BTraceUtils.*;

@BTrace
public class ChannelTrace {

  @TLS static boolean subscribed = false;

  // Play adds http-body-subscriber
  @OnMethod(clazz = "com.typesafe.netty.http.HttpStreamsHandler", method = "unbufferedWrite", location = @Location(Kind.ENTRY))
  public static void onUnbufferedWrite(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType ctx, AnyType out) {
    subscribed = true;
    print(name(currentThread()) + " " + pcn + "." + pmn + ": ctx = " + ctx + "\n");
  }

  // Play removes http-body-subscriber
  @OnMethod(clazz = "com.typesafe.netty.http.HttpStreamsHandler", method = "completeBody", location = @Location(Kind.ENTRY))
  public static void onCompleteBody(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType ctx) {
    subscribed = false;
    print(name(currentThread()) + " " + pcn + "." + pmn + ":    ctx = " + ctx + "\n");
  }

  @OnMethod(clazz = "play.core.server.netty.PlayRequestHandler", method = "exceptionCaught", location = @Location(Kind.ENTRY))
  public static void onExceptionCaught(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
    subscribed = false;
    print(name(currentThread()) + " " + pcn + "." + pmn + "\n");
  }

  // Something is added to the pipeline
  @OnMethod(clazz = "io.netty.channel.DefaultChannelPipeline", method = "addAfter0", location = @Location(Kind.ENTRY))
  public static void onPipelineAddAfter0(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType ctx, AnyType newCtx) {
    print(name(currentThread()) + " " + pcn + "." + pmn + ": newCtx = " + newCtx + "\n");
  }

  // Something is removed from the pipeline
  @OnMethod(clazz = "io.netty.channel.DefaultChannelPipeline", method = "remove0", location = @Location(Kind.ENTRY))
  public static void onPipelineRemove0(@ProbeClassName String pcn, @ProbeMethodName String pmn, AnyType ctx) {
    print(name(currentThread()) + " " + pcn + "." + pmn + ":      ctx = " + ctx + "\n" /*+ jstackStr(7) + "\n"*/);
  }

  @OnMethod(clazz = "io.netty.channel.DefaultChannelPipeline", method = "/fire.*/", location = @Location(Kind.ENTRY))
  public static void onPipelineEvent(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
    print(name(currentThread()) + " " + pcn + "." + pmn + "\n");
  }

  // DefaultChannelPipeline.destroy removes all handlers from the pipeline
  @OnMethod(clazz = "io.netty.channel.DefaultChannelPipeline", method = "destroy", location = @Location(Kind.ENTRY))
  public static void onPipelineDestroy(@ProbeClassName String pcn, @ProbeMethodName String pmn) {
    if (subscribed) {
      print("[This is not supposed to happen]\n");
    }
  }
}