I am running performance tests on FiberServerSocketChannel, the test is very simple, it's dummy http server implementation that I try to load it, but the program behavior looks buggy.

I use some tool I wrote (you can use ab or any http benchmark tool you prefer): https://github.com/cmpxchg16/gobench

when I ran that command (no keepalive, 4 clients, 10 seconds test): $>go run gobench.go -k=false -u http://localhost:1234 -c 4 -t 10

I got ~reasonable results, but when I try 500 clients:

$>go run gobench.go -k=false -u http://localhost:1234 -c 500 -t 10

there are a lot of socket errors, and the throughput is very poor, also when I repeat the test over and over the whole clients was failed and the server not responding at all.

Env:

Ubuntu 13.10 JDK7 && JDK8 4 cores 16GB RAM fibers with javaagent 0.5.0

Note that for comparison I have some dummy implementation also in Go (below):

Server source code (based on test/fibers/io):

//###################################################################

package main;

import co.paralleluniverse.fibers.Fiber;
import co.paralleluniverse.fibers.FiberForkJoinScheduler;
import co.paralleluniverse.fibers.FiberScheduler;
import co.paralleluniverse.fibers.SuspendExecution;
import co.paralleluniverse.fibers.io.FiberServerSocketChannel;
import co.paralleluniverse.fibers.io.FiberSocketChannel;
import co.paralleluniverse.strands.SuspendableRunnable;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;

public class Main {
    private static final int PORT = 1234;
    private static final Charset charset = Charset.forName("UTF-8");
    private static final CharsetEncoder encoder = charset.newEncoder();
    private static FiberScheduler scheduler = new FiberForkJoinScheduler("test", 4);

    public static void main(String[] args) throws Exception {
        final Fiber server = new Fiber(scheduler, new SuspendableRunnable() {
            @Override
            public void run() throws SuspendExecution {
                try {
                    FiberServerSocketChannel socket = FiberServerSocketChannel.open().bind(new InetSocketAddress(PORT));

                    int counter = -1;
                    while(true)
                    {
                        FiberSocketChannel ch = socket.accept();
                        ++counter;
                        ByteBuffer buf = ByteBuffer.allocateDirect(1024);
                        int n = ch.read(buf);
                        String response = "HTTP/1.0 200 OK\r\n" +
                                           "Date: Fri, 31 Dec 1999 23:59:59 GMT\r\n" +
                                           "Content-Type: text/html\r\n" +
                                           "Content-Length: 0\r\n\r\n";
                        n = ch.write(encoder.encode(CharBuffer.wrap(response)));
                        ch.close();
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });

        server.start();
        server.join();
    }
}
//###################################################################

//###################################################################
GO:
//###################################################################

package main

import (
        "net"
        "os"
        "runtime"
)

const (
        RECV_BUF_LEN = 1024
)

func main() {
        runtime.GOMAXPROCS(runtime.NumCPU())
        println("Starting the server")

        listener, err := net.Listen("tcp", "0.0.0.0:1234")
        if err != nil {
                println("Error Listen:", err.Error())
                os.Exit(1)
        }

        for {
                conn, err := listener.Accept()
                if err != nil {
                        println("Error Accept:", err.Error())
                        return
                }
                go Handler(conn)
        }
}

func Handler(conn net.Conn) {
        defer conn.Close()
        buf := make([]byte, RECV_BUF_LEN)
        _, err := conn.Read(buf)
        if err != nil {
                println("Error Read:", err.Error())
                return
        }

        _, err = conn.Write([]byte("HTTP/1.0 200 OK\r\nDate: Fri, 31 Dec 1999 23:59:59 GMT\r\nContent-Type: text/html\r\nContent-Length: 0\r\n\r\n"))
        if err != nil {
                println("Error Write:", err.Error())
        }
}

I write a sample.but when i run it.

QUASAR WARNING: Quasar Java Agent isn't running. If you're using another instrumentation method you can ignore this message; otherwise, please refer to the Getting Started section in the Quasar documentation. Exception in thread "main" java.lang.IllegalArgumentException: Fiber class com.ailk.TestQuasar$1 has not been instrumented.

So far this feature is a massive net negative, at least for me. Things put in ThreadLocal's are invariably not designed to be serialised, it involves poking around in JVM internals and the JVM treats ThreadLocal's specially - back when I was hitting serialisation issues the JVM would segfault due to the use of Unsafe.

Overall, I'd rather have a flag to disable this and have Quasar leave TLS slots alone.

(Copied from: https://groups.google.com/forum/#!topic/quasar-pulsar-user/wkENHH0xAIQ)

If you would consider the following pattern:

public class Start extends BasicActor<Object, Void> {
    @Override
    protected Void doRun() throws InterruptedException, SuspendExecution {
        Object call = RequestReplyHelper.call(new Mid().spawn(), new RequestMessage<Object>() {
        });
        System.out.println(call);
        return null;
    }
}

public class Mid extends BasicActor<RequestMessage<Object>, Void> {
    @Override
    protected Void doRun() throws InterruptedException, SuspendExecution {
        RequestMessage<Object> receive = receive();
        ActorRef<RequestMessage<Object>> spawn = new End().spawn();
        Object call = RequestReplyHelper.call(spawn, receive);
        RequestReplyHelper.reply(receive, call);
        return null;
    }
}

public class End extends BasicActor<RequestMessage<Object>, Void> {
    @Override
    protected Void doRun() throws InterruptedException, SuspendExecution {
        RequestMessage<Object> receive = receive();
        RequestReplyHelper.reply(receive, new Object());
        return null;
    }
}

new Start().spawn();

The behavior works fine. However, the following exception (see below) chain is thrown in relation to ExitMessage signaling (?). This seems like a RequestReplyHelper chain issue. Is there anything wrong with the code above? Thanks

java.lang.Object@7f681f5 Exception in Fiber "fiber-10000004" java.lang.RuntimeException at co.paralleluniverse.common.util.Exceptions.rethrow(Exceptions.java:26) at co.paralleluniverse.actors.behaviors.RequestReplyHelper$1.handleLifecycleMessage(RequestReplyHelper.java:167) at co.paralleluniverse.actors.SelectiveReceiveHelper.receive(SelectiveReceiveHelper.java:121) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:174) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:112) at com.xxx.services.rest.temp.Mid.doRun(Mid.java:17) at com.xxx.services.rest.temp.Mid.doRun(Mid.java:12) at co.paralleluniverse.actors.Actor.run0(Actor.java:691) at co.paralleluniverse.actors.ActorRunner.run(ActorRunner.java:51) at co.paralleluniverse.fibers.Fiber.run(Fiber.java:1026) WARNING: Uninstrumented methods (marked '') or call-sites (marked '!!') detected on the call stack: at co.paralleluniverse.common.util.Exceptions.rethrow(java.lang.Throwable) (Exceptions.java:26 bci: 29) ** at co.paralleluniverse.actors.behaviors.RequestReplyHelper$1.handleLifecycleMessage (RequestReplyHelper.java:167 bci: 41) ** at co.paralleluniverse.actors.SelectiveReceiveHelper.receive (SelectiveReceiveHelper.java:121 bci: 341) !! (instrumented suspendable calls at: []) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call (RequestReplyHelper.java:174 bci: 663) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call (RequestReplyHelper.java:112 bci: 335) at com.xxx.services.rest.temp.Mid.doRun (Mid.java:17 bci: 192) at com.xxx.services.rest.temp.Mid.doRun (Mid.java:12 bci: 1) (optimized) at co.paralleluniverse.actors.Actor.run0 (Actor.java:691 bci: 222) at co.paralleluniverse.actors.ActorRunner.run (ActorRunner.java:51 bci: 148) at co.paralleluniverse.fibers.Fiber.run (Fiber.java:1026 bci: 11) at co.paralleluniverse.fibers.Fiber.run1 (Fiber.java:1021 bci: 1) Exception in Fiber "fiber-10000004" java.lang.RuntimeException at co.paralleluniverse.common.util.Exceptions.rethrow(Exceptions.java:26) at co.paralleluniverse.actors.behaviors.RequestReplyHelper$1.handleLifecycleMessage(RequestReplyHelper.java:167) at co.paralleluniverse.actors.SelectiveReceiveHelper.receive(SelectiveReceiveHelper.java:121) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:174) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:112) at com.xxx.services.rest.temp.Mid.doRun(Mid.java:17) at com.xxx.services.rest.temp.Mid.doRun(Mid.java:12) at co.paralleluniverse.actors.Actor.run0(Actor.java:691) at co.paralleluniverse.actors.ActorRunner.run(ActorRunner.java:51) at co.paralleluniverse.fibers.Fiber.run(Fiber.java:1026) WARNING: Uninstrumented methods (marked '') or call-sites (marked '!!') detected on the call stack: at co.paralleluniverse.common.util.Exceptions.rethrow(java.lang.Throwable) (Exceptions.java:26 bci: 29) ** at co.paralleluniverse.actors.behaviors.RequestReplyHelper$1.handleLifecycleMessage (RequestReplyHelper.java:167 bci: 41) ** at co.paralleluniverse.actors.SelectiveReceiveHelper.receive (SelectiveReceiveHelper.java:121 bci: 341) !! (instrumented suspendable calls at: []) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call (RequestReplyHelper.java:174 bci: 663) at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call (RequestReplyHelper.java:112 bci: 335) at com.xxx.services.rest.temp.Mid.doRun (Mid.java:17 bci: 192) at com.xxx.services.rest.temp.Mid.doRun (Mid.java:12 bci: 1) (optimized) at co.paralleluniverse.actors.Actor.run0 (Actor.java:691 bci: 222) at co.paralleluniverse.actors.ActorRunner.run (ActorRunner.java:51 bci: 148) at co.paralleluniverse.fibers.Fiber.run (Fiber.java:1026 bci: 11) at co.paralleluniverse.fibers.Fiber.run1 (Fiber.java:1021 bci: 1)

Since M13 was pushed out the co.paralleluniverse.fibers.Suspendable annotation can no longer be applied to a lambda as it could before because the annotation now needs to have the Kotlin target AnnotationTarget.EXPRESSION or else it will simply not compile. An example would be:

@Suspendable {
    println("Hi")
}

The above does not compile anymore because the annotation misses the target. I replaced the class by a custom variant using the Kotlin expression type:

package co.paralleluniverse.fibers

import kotlin.annotation.Retention
import kotlin.annotation.Target

@Retention // Defaults to RUNTIME
@Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER,
        AnnotationTarget.PROPERTY_SETTER, AnnotationTarget.CLASS,
        AnnotationTarget.FILE, AnnotationTarget.EXPRESSION)

annotation public class Suspendable

That does compile fine and results in compilation succeeding for the previously described example. However, replacing the packaged Suspendable annotation with the custom Kotlin variant seems to break the library (it does not detect instrumented methods anymore), so I'm looking for some kind of input on having this nifty feature working again.

Cheers.

Hey. First, I apologize for not being able to share all the code reproducing the problem which happens quite rarely (it seems like there is a race condition somewhere). But I can describe environment in some words - we have complex actor's interaction algorithm at our actor system, some of them are communicating via RequestReplyHelper#call. And sometimes this exception raises. The problems are

1. I don't have enough knowledge about actors mailbox queue internals, and don't understand what happens
2. There isn't lots of javadoc comments such internal classes like SingleConsumerQueueChannel, OwnedSynchronizer

So its hard for me to reason about the source of this exception. Could you help me to find out are we doing something wrong or is this a bug in quasar-actors? It would be great if you've already encountered this problem and know the mistakes we are doing. Thanks.

java.lang.IllegalMonitorStateException: attempt by Fiber@10000046:Communicator[task: ParkableForkJoinTask@56d103cb(Fiber@10000046), target: co.paralleluniverse.actors.ActorRunner@2c27afe, scheduler: co.paralleluniverse.fibers.FiberForkJoinScheduler@6a9637db] but owned by Fiber@10000046:Communicator[task: ParkableForkJoinTask@56d103cb(Fiber@10000046), target: co.paralleluniverse.actors.ActorRunner@2c27afe, scheduler: co.paralleluniverse.fibers.FiberForkJoinScheduler@6a9637db]
    at co.paralleluniverse.strands.OwnedSynchronizer.register(OwnedSynchronizer.java:36)
    at co.paralleluniverse.strands.channels.SingleConsumerQueueChannel.receive(SingleConsumerQueueChannel.java:87)
    at co.paralleluniverse.actors.Actor.receive(Actor.java:462)
    at co.paralleluniverse.actors.behaviors.BehaviorActor.behavior(BehaviorActor.java:236)
    at co.paralleluniverse.actors.behaviors.BehaviorActor.doRun(BehaviorActor.java:293)
    at co.paralleluniverse.actors.behaviors.BehaviorActor.doRun(BehaviorActor.java:36)
    at co.paralleluniverse.actors.Actor.run0(Actor.java:691)
    at co.paralleluniverse.actors.ActorRunner.run(ActorRunner.java:51)
    at co.paralleluniverse.fibers.Fiber.run(Fiber.java:1024)
    at co.paralleluniverse.fibers.Fiber.run1(Fiber.java:1019)
    at co.paralleluniverse.fibers.Fiber.exec(Fiber.java:730)
    at co.paralleluniverse.fibers.FiberForkJoinScheduler$FiberForkJoinTask.exec1(FiberForkJoinScheduler.java:265)
    at co.paralleluniverse.concurrent.forkjoin.ParkableForkJoinTask.doExec(ParkableForkJoinTask.java:116)
    at co.paralleluniverse.concurrent.forkjoin.ParkableForkJoinTask.exec(ParkableForkJoinTask.java:73)
    at co.paralleluniverse.fibers.FiberForkJoinScheduler$FiberForkJoinTask.doExec(FiberForkJoinScheduler.java:272)
    at co.paralleluniverse.fibers.Fiber.immediateExecHelper(Fiber.java:1205)
    at co.paralleluniverse.fibers.Fiber.exec(Fiber.java:1173)
    at co.paralleluniverse.fibers.Fiber.yieldAndUnpark1(Fiber.java:691)
    at co.paralleluniverse.fibers.Fiber.yieldAndUnpark(Fiber.java:619)
    at co.paralleluniverse.strands.Strand.yieldAndUnpark(Strand.java:531)
    at co.paralleluniverse.strands.OwnedSynchronizer.signalAndWait(OwnedSynchronizer.java:66)
    at co.paralleluniverse.strands.channels.QueueChannel.signalAndWait(QueueChannel.java:109)
    at co.paralleluniverse.strands.channels.QueueChannel.send0(QueueChannel.java:245)
    at co.paralleluniverse.strands.channels.QueueChannel.sendSync(QueueChannel.java:204)
    at co.paralleluniverse.actors.Mailbox.sendSync(Mailbox.java:73)
    at co.paralleluniverse.actors.Actor.sendSync(Actor.java:429)
    at co.paralleluniverse.actors.ActorRef.sendSync(ActorRef.java:97)
    at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:173)
    at co.paralleluniverse.actors.behaviors.RequestReplyHelper.call(RequestReplyHelper.java:112)

After calling ReentrantLock.lock() the following is thrown:

java.lang.NullPointerException
    at co.paralleluniverse.strands.Strand.park(Strand.java:495)
    at co.paralleluniverse.strands.concurrent.AbstractQueuedSynchronizer.parkAndCheckInterrupt(AbstractQueuedSynchronizer.java:838)
    at co.paralleluniverse.strands.concurrent.AbstractQueuedSynchronizer.acquireQueued(AbstractQueuedSynchronizer.java:872)
    at co.paralleluniverse.strands.concurrent.AbstractQueuedSynchronizer.acquire(AbstractQueuedSynchronizer.java:1203)
    at co.paralleluniverse.strands.concurrent.ReentrantLock$NonfairSync.lock(ReentrantLock.java:207)
    at co.paralleluniverse.strands.concurrent.ReentrantLock.lock(ReentrantLock.java:285)
    (...)
    at co.paralleluniverse.strands.SuspendableUtils$VoidSuspendableCallable.run(SuspendableUtils.java:42)
    at co.paralleluniverse.strands.SuspendableUtils$VoidSuspendableCallable.run(SuspendableUtils.java:30)
    at co.paralleluniverse.fibers.Fiber.run(Fiber.java:1012)
    at co.paralleluniverse.fibers.Fiber.run1(Fiber.java:1007)
    at co.paralleluniverse.fibers.Fiber.exec(Fiber.java:719)
    at co.paralleluniverse.fibers.FiberForkJoinScheduler$FiberForkJoinTask.exec1(FiberForkJoinScheduler.java:248)
    at co.paralleluniverse.concurrent.forkjoin.ParkableForkJoinTask.doExec(ParkableForkJoinTask.java:116)
    at co.paralleluniverse.concurrent.forkjoin.ParkableForkJoinTask.exec(ParkableForkJoinTask.java:73)
    at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
    at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:902)
    at java.util.concurrent.ForkJoinPool.scan(ForkJoinPool.java:1689)
    at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1644)
    at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)

I'd like to request a feature. Allowing fibers to set priorities would be, in my opinion, a wonderful enhancement.

This is a major feature that threads have over fibers. From the User Manual:

Fibers provide functionality similar to threads, and a similar API, but they’re not managed by the OS.

Setting a priority is a major feature of threads over fibers. If this is added to the fiber (and strand) API, this would make fibers even more powerful.

Edit: To clarify, since Fibers use a non-preemptive scheduler and are OS independent, I am suggesting to only use the same API as threads, but not the same (OS dependent) prioritization approach as threads. I think the most straight forward approach may be to implement priorities such that:

• Any fiber with a high priority will be started on a worker thread before (or at the same time as) a fiber with a low priority.
• Any already running fibers with a low priority will remain running until they block as normal.
• The priority should only dictate the order in which to run queued fibers, and will not affect already running fibers in any way.
• Priorities can be changed at any time and by anyone with a reference to the Fiber.
• Any change in priority will not have any affect until the next time a fiber blocks and a new fiber is selected to run.
• By default, a fiber will have the same priority as the strand that spawned it.

It isn't clear to me how to use the serialisation framework. Imagine I have a fiber that's blocked waiting to receive something on a channel. Before blocking, I'd like to serialise the state of the fiber to checkpoint it, so if the app dies whilst the fiber is waiting, I can reload it from disk and restart it. But I can't combine the two as the serialisation support requires use of the lower level parkAndSerialise method.

Sometimes under heavy load and using cascading messages, some messages seem to get lost. When monitoring the actors, the number of received messages for some actors are too low.

I have attached a small sample project. I have to run the sample 3-5 times for the problem to occur.

Please keep in mind, that I am new to Quasar and might be doing something completely wrong.

Test environment Macbook Pro:

• 2,5 GHz Intel Core i7
• 16 GB RAM
• OSX 10.11.5

Java:

• Oracle Java 1.8.0_60-b27 server vm
• Maven 3.0.5 to build and run

bugreport.zip

Hi @pron !

I remember it was possible to call fibers without @Suspendable, but now I see it's mandatory. Is it possible somehow to avoid it? I'm developing the DSL and it's a bit ugly to add @Suspendable everywhere in human-readable DSL :(

Thanks!

Now, when I try to start a Fiber, I have to use generated code similar to traditional Thread

Fiber<Void> echo = new Fiber<Void>("ECHO", () -> { // lambda }).start();

Can you consider a functional programming style that provides a pattern for chained operators.

like: go(() -> { /* lambda */ });

This will make it easier for me in the chain call.

help! run failed

env:jdk1.8 ，win10

dependency: org.springframework.boot spring-boot-starter 2.2.10.RELEASE co.paralleluniverse quasar-core 0.7.10 co.paralleluniverse quasar-actors 0.7.10

package:

  public static Unsafe getUnsafe() {
        try {
            return Unsafe.getUnsafe();
        } catch (SecurityException se) {
            try {
                return java.security.AccessController.doPrivileged(new java.security.PrivilegedExceptionAction<Unsafe>() {
                    @Override
                    public Unsafe run() throws Exception {
                        final Class<sun.misc.Unsafe> k = sun.misc.Unsafe.class;
                        if (true) {
                            final Field f = k.getDeclaredField("theUnsafe");
                            f.setAccessible(true);
                            final Object x = f.get(null);
                            return k.cast(x);
                        } else {
                            for (Field f : k.getDeclaredFields()) {
                                f.setAccessible(true);
                                final Object x = f.get(null);
                                if (k.isInstance(x))
                                    return k.cast(x);
                            }
                            throw new NoSuchFieldError("the Unsafe");
                        }
                    }
                });
            } catch (java.security.PrivilegedActionException e) {
                throw new RuntimeException("Could not initialize intrinsics", e.getCause());
            }
        }
    }

why would you use "if(true) .... else ..." in this method? do you forget to fill the expression of if?

When I migrated to Java 11 and quasar 0.8.0 and Vertx core 4.0.0-milestone5. The following errors were encountered. The first is that quasar fails to instrument any class - failing out of the box with this Exception:

[quasar] ERROR: java/lang/Object java.lang.IllegalArgumentException at co.paralleluniverse.asm.ClassReader.(Unknown Source) at co.paralleluniverse.asm.ClassReader.(Unknown Source) at co.paralleluniverse.asm.ClassReader.(Unknown Source) at co.paralleluniverse.fibers.instrument.MethodDatabase.checkFileAndClose(MethodDatabase.java:344) at co.paralleluniverse.fibers.instrument.MethodDatabase.checkClass(MethodDatabase.java:324) at co.paralleluniverse.fibers.instrument.MethodDatabase.getOrLoadClassEntry(MethodDatabase.java:183) at co.paralleluniverse.fibers.instrument.SimpleSuspendableClassifier.isSuspendable(SimpleSuspendableClassifier.java:156) at co.paralleluniverse.fibers.instrument.SimpleSuspendableClassifier.isSuspendable(SimpleSuspendableClassifier.java:164) at co.paralleluniverse.fibers.instrument.DefaultSuspendableClassifier.isSuspendable(DefaultSuspendableClassifier.java:47) at co.paralleluniverse.fibers.instrument.InstrumentClass.visitMethod(InstrumentClass.java:147) at co.paralleluniverse.asm.ClassReader.b(Unknown Source) at co.paralleluniverse.asm.ClassReader.accept(Unknown Source) at co.paralleluniverse.asm.ClassReader.accept(Unknown Source) at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:134) at co.paralleluniverse.fibers.instrument.QuasarInstrumentor.instrumentClass(QuasarInstrumentor.java:94) at co.paralleluniverse.fibers.instrument.JavaAgent$Transformer.transform(JavaAgent.java:209) at java.instrument/java.lang.instrument.ClassFileTransformer.transform(ClassFileTransformer.java:246) at java.instrument/sun.instrument.TransformerManager.transform(TransformerManager.java:188) at java.instrument/sun.instrument.InstrumentationImpl.transform(InstrumentationImpl.java:563) at java.base/java.lang.ClassLoader.defineClass1(Native Method) at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1016) at java.base/java.security.SecureClassLoader.defineClass(SecureClassLoader.java:174) at java.base/jdk.internal.loader.BuiltinClassLoader.defineClass(BuiltinClassLoader.java:802) at java.base/jdk.internal.loader.BuiltinClassLoader.findClassOnClassPathOrNull(BuiltinClassLoader.java:700) at java.base/jdk.internal.loader.BuiltinClassLoader.loadClassOrNull(BuiltinClassLoader.java:623) at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:581) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:178) at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521) at org.slf4j.impl.StaticLoggerBinder.(StaticLoggerBinder.java:59) at org.slf4j.impl.StaticLoggerBinder.(StaticLoggerBinder.java:50) at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150) at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124) at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:417) at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:362) at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:388) at com.hotleads.web.app.MainApplication.(MainApplication.java:17)

However when I change SDK to Java 1.8 and quasar 0.7.5 and Vertx core 4.0.0-milestone2, things work as expected. Note - that this may not be a Vertx-Quasar issue. When the SDK is changed to Java 11 - quasar fails to instrument every single class at runtime. Please advise. Having to keep my platform at 1.8 is not advisable and migrating to Java 11 using quasar 0.8.0 fails out the box. What am I missing?

this should fix quasar issue with Kotlin 1.3, the idea is to instrument any static synthetic method whose name ends with $default if it comes after a suspendable method with the same name (except for the $default suffix) and a similar signature (more details about it will follow).

I did some manual testing and it seems to work, it relies on the fact that the Kotlin compiler writes the $default methods only after their base counterparts (which could be problematic since, although this is the current behavior, there is no guarantee around its stability).