"You have attempted to perform a blocking operation on a IO thread" using Kotlin with pananche orm and suspend fun

[kenyee]

I get this error with Quarkus 2.6.2 (and 2.7.0CR1):

BlockingOperationNotAllowedException: You have attempted to perform a blocking operation on a IO thread. This is not allowed, as blocking the IO thread will cause major performance issues with your application. If you want to perform blocking EntityManager operations make sure you are doing it from a worker thread.

I'm using the "io.quarkus:quarkus-hibernate-orm-panache-kotlin" artifact which doesn't seem to support reactive-hibernate with the "io.quarkus:quarkus-resteasy-reactive" artifact.

The resource/controller looks like this:
@get
@produces(MediaType.TEXT_PLAIN)
suspend fun list(): List {
return projectRepository.list(null)
}

Has anyone used Panache w/ Kotlin and plain Hibernate or gotten Panache to work with reactive hibernate and Kotlin?

[quarkus-bot[bot]]

/cc @evanchooly

[kenyee]

Hmm...might be related to this: #16785

[kenyee]

Tried adding @Blocking to indicate it can run on a blocking thread and I get this:
"Suspendable @Blocking methods are not supported yet"

[kenyee]

Doing this to do the blocking hibernate access also doesn't work:

    suspend fun list(): List<Project> {
        return withContext(Dispatchers.Unconfined) {
            projectRepository.list(null)
        }
    }

[kenyee]

Removing the suspend off the method works fine though 🤷

This probably belongs in the Kotlin documentation...