kotlinlang #ktor

Hi. Developing multiplatform library for Android and iOS. At the moment don't need anything specific for Android so targeting jvm and iOS. Getting an error on Android application when making a Ktor request call. By the way, I don't get a such error on unit test at commonMain module which runs against jvm. Any ideas what can cause this error?

io.ktor.client.call.NoTransformationFoundException: No transformation found: class io.ktor.utils.io.ByteChannelKt$ByteChannel$1 (Kotlin reflection is not available) -> class xxx.YYY (Kotlin reflection is not available)
    with response from <https://XXX>:
    status: 200 OK
    response headers: 
    cache-control: max-age=600
    , connection: keep-alive
    , content-type: application/json;charset=utf-8
    
        at io.ktor.client.call.HttpClientCall.receive(HttpClientCall.kt:84)

9 replies · 2 participants

ursus

10/24/2020, 11:48 PM

Hi, with ktor client, is there a equivalent of okhttp interceptors or authenticator?

👀 1

9 replies · 5 participants

Hyun

10/25/2020, 4:31 PM

Hi everyone, I need some advice from Ktor developers. I created a KMP library targeting backend, android, ios - To share api interface between server and client. - Without Http definition like GET, POST, Body, Query etc.. (so, it’s totally looks same with just ‘function’) will this be fine approach? or some advice for this approach? common

@Api
interface SampleApi {
    suspend fun getGreeting(name: String, job: String): String
}

client

inline fun <reified API> api(baseUrl: String = serverUrl): API = client.create(baseUrl)

scope.launch {
    api<SampleApi>().getGreeting("Hyun", "Programmer")
}

backend

class SampleController : SampleApi {
    override suspend fun getGreeting(name: String, job: String): String = "Hello $name($job)"
}

install(SimpleFeature) {
    routing {
        +SampleController()
    }
}

1 reply · 1 participant

Sourabh Rawat

10/26/2020, 10:57 AM

This does not seem to work and is throwing

Serializer for class 'ApiResponse' is not found

@Serializable
data class ApiResponse<T>(
    val result: T? = null,
    val error: ApiError? = null
)
call.respond(ApiResponse(result = gameEngine.newGame()))

Please help. Json.encodeToString(..) works fine. ktor config:

fun Application.mainModule() {

  install(ContentNegotiation) {
    json()
  }
  ...
}

Using ktor 1.4.1 and serialization 1.0.0

14 replies · 4 participants

rnett

10/27/2020, 1:04 AM

I've seen it mentioned in a few places that a kotlin native server is in the works (eventually). I assume you're going to have to write a HOCON parser for it, are there any plans to open source a multiplatform HOCON parser (and hopefully a kotlinx.serialization backend)?

❤️ 1

6 replies · 3 participants

napperley

10/27/2020, 3:34 AM

Keep on getting a segmentation fault when creating an instance of

HttpClient

using this project: https://gitlab.com/napperley/openfaas-weather-sample

6 replies · 3 participants

aleksey.tomin

10/27/2020, 5:10 AM

How can I use gzip for ktor-client POST requests (not response)? ktolin 1.4.10, ktor 1.4.1, native/curl I’ve added

ContentEncoding {
            gzip()
        }

But the server team says that request body not in gzip.

4 replies · 2 participants

Dario Pellegrini

10/27/2020, 1:19 PM

Hello everyone! Is there a way in Ktor to detect whenever a reques is canceled by the client? I have a long running process which could be canceled and I’d like to release some file resources it uses on client request’s cancellation. Can someone help me in doing this?

2 replies · 2 participants

Nikky

10/27/2020, 3:49 PM

i am getting

Fail to fetch

in browser tests to localhost seems to be somehow Access-Control-Allow-Origin
related can i ignore this or force the browser to ignore this with ktor-client ?

1 reply · 2 participants

Andrew Gazelka

10/28/2020, 12:54 AM

does ktor modify the URL sent into

client.get(url: String)

? because I am getting an Http error with ktor and no error with curl and I am really confused

1 reply · 1 participant

Joaquim Ley

10/28/2020, 2:55 PM

kotlinx.serialization.json.internal.JsonDecodingException: Unexpected JSON token at offset 82: Expected string literal with quotes.

4 replies · 2 participants

Carlos Fau

10/28/2020, 9:48 PM

Hi, we're trying to configure JSON in KTOR Server using kotlinx. We have Ktor 1.4.1, the documentations says to use the function

serialization()

but we can't find it in packages. Any help?

3 replies · 2 participants

turansky

10/30/2020, 1:45 PM

Is there common practice for

HttpClient

(JS client) ? Do I need single

HttpClient

if I have single API source?

GET /api/a
GET /api/b
GET /api/c
GET /api/d

1 reply · 2 participants

Elka

11/02/2020, 5:52 PM

Hello, Using the Ktor HttpClient on Android and iOS. I need to do some kind of json validation for authorization purposes… I am trying to create a

Feature

that parses the json, does the checking and then proceed with the response… The problem is that I cannot call

readBytes

twice. The second time it’s empty as the response has already been consumed when doing the validation. Is there any way to do it?

2 replies · 2 participants

John O'Reilly

11/03/2020, 8:12 AM

I have Ktor server with following CORS feature installed....works for "normal" requests but not for some reason for digest auth based login request

install(CORS) {
    anyHost()
    header("Authorization")
}

anyone aware of any other config needed to support that?

8 replies · 3 participants

Krystian Rybarczyk

11/04/2020, 2:42 PM

hey guys, I’ve found this sample for structured logging: https://github.com/ktorio/ktor-samples/blob/1.3.0/other/structured-logging/src/Application.kt but it’s not quite clear to me how I would use this logger inside other classes (say my service class) so that I can see all other log messages in the context of a particular requestId. Could anyone help?

👀 1

7 replies · 2 participants

Denis Ambatenne

11/06/2020, 10:35 AM

Vote on kTor plugin improvеments 🖖 Hi all! I am working on my version of the kTor plugin and thinking about the functions to cover. After researching several discussions and conduction interviews I came up with a list of features for the new plugin. Please vote by clicking on the relevant emoji. Thanks!!! Project creation 🥐 - Automatically pick features, upon which your chosen feature depends 🥖 - A More concise grouping of feature, like in Spring or Vertx (wed, data access, messaging e.t.c) 🥨 - Ability to choose between plain (currently via kTor plugin) or hierarchical (classical, that you get using Gradle) structure of the src/resources folders 🥞 - Ability to create an example project with recommended architecture for Restful service 🧀 - Ability to create an example project with recommended architecture for DB interaction 🍖 - Ability to create an example project with recommended architecture for event messaging 🍔 - Create a project with the support of different environments: dev, test, production, and custom 🍕 - Create a template project for the creation of a new kTor feature Development/Debugging 🌋 - UI with a list of all current routes (including nested ones) in the current project Testing 🐵 - Endpoint test results visualization Deployment ⚽- convenient way to configure deployment to Google ⚾ - convenient way to configure deployment to Azure 🏀 - convenient way to configure deployment to AWS 🏐- convenient way to configure deployment to Heroku 🏈 - convenient way to configure deployment to Jenkins CI/CD 🎾- convenient way to configure deployment to Travis CI/CD Documentation 🎷 - Swagger API generation and hosting Refactoring 🚒- UI to change the features used (and all the dependencies) in an existing project 🚕- List of unused features And of course, you can add any not listed feature in replies to this post :)

🚕 5

🥞 7

🚒 6

🏀 4

🍔 12

🥖 5

🍕 4

⚾ 3

🥐 3

🎾 3

🌋 19

🥨 4

🏐 4

🍖 6

⚽ 5

🐵 9

🧀 7

🎷 27

🏈 3

5 replies · 5 participants

Moses Mugisha

11/06/2020, 7:51 PM

How do I set

HttpClient.setMaxRequestsQueuedPerDestination()

for the jetty engine in ktor?

1 reply · 1 participant

nrobi

11/08/2020, 2:57 PM

Anyone experiencing this issue on K/N?

HttpClient: REQUEST https://... failed with exception: kotlinx.coroutines.CancellationException: Engine failed

Seems to be tied to

async

await

as it works as expected with

launch

3 replies · 2 participants

subashz

11/09/2020, 12:32 PM

How to enable cache-options in ktor's HttpClient ?

4 replies · 4 participants

hhariri

11/10/2020, 3:34 PM

Ktor 1.4.2 Released Please see [Change Log] for more details!

🎉 14

🙏 4

:party-parrot: 5

:ktor: 27

👍 12

1 reply · 2 participants

octylFractal

11/10/2020, 10:37 PM

it seems like the 1.4.2 release broke

call.receive()

with the jackson content negotiator, I get https://gist.github.com/octylFractal/f973cee5acd96ca757c7b6a83936800f

1 reply · 1 participant

Amritansh

11/11/2020, 1:32 AM

Uncaught Kotlin exception: kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[MainDispatcher, Continuation @ $postRequest$lambda-1COROUTINE$1]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers
    at 0   shared                              0x0000000103e8730c kfun:kotlin.Error#<init>(kotlin.String?;kotlin.Throwable?){} + 124 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Exceptions.kt:14:63)
    at 1   shared                              0x0000000103ffa913 kfun:kotlinx.coroutines.CoroutinesInternalError#<init>(kotlin.String;kotlin.Throwable){} + 115 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/common/src/Exceptions.common.kt:28:77)
    at 2   shared                              0x0000000104042bfa kfun:kotlinx.coroutines.DispatchedTask#handleFatalException(kotlin.Throwable?;kotlin.Throwable?){} + 938 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/common/src/internal/DispatchedTask.kt:93:22)
    at 3   shared                              0x00000001040427e8 kfun:kotlinx.coroutines.DispatchedTask#run(){} + 3512 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/common/src/internal/DispatchedTask.kt:64:13)
    at 4   shared                              0x000000010406b0f5 kfun:kotlinx.coroutines.DarwinMainDispatcher.dispatch$lambda-0#internal + 85 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/nativeDarwin/src/Dispatchers.kt:35:19)
    at 5   shared                              0x000000010406b4ab kfun:kotlinx.coroutines.DarwinMainDispatcher.$dispatch$lambda-0$FUNCTION_REFERENCE$43.invoke#internal + 59 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/nativeDarwin/src/Dispatchers.kt:34:51)
    at 6   shared                              0x000000010406b50b kfun:kotlinx.coroutines.DarwinMainDispatcher.$dispatch$lambda-0$FUNCTION_REFERENCE$43.$<bridge-UNN>invoke(){}#internal + 59 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/nativeDarwin/src/Dispatchers.kt:34:51)
    at 7   shared                              0x000000010406c5c4 _6f72672e6a6574627261696e732e6b6f746c696e783a6b6f746c696e782d636f726f7574696e65732d636f7265_knbridge8 + 180 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/nativeDarwin/src/Dispatchers.kt:34:51)
    at 8   libdispatch.dylib                   0x0000000104983dd4 _dispatch_call_block_and_release + 12
    at 9   libdispatch.dylib                   0x0000000104984d48 _dispatch_client_callout + 8
    at 10  libdispatch.dylib                   0x0000000104992de6 _dispatch_main_queue_callback_4CF + 1500
    at 11  CoreFoundation                      0x00007fff23bd4049 __CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE__ + 9
    at 12  CoreFoundation                      0x00007fff23bceca9 __CFRunLoopRun + 2329
    at 13  CoreFoundation                      0x00007fff23bce066 CFRunLoopRunSpecific + 438
    at 14  GraphicsServices                    0x00007fff384c0bb0 GSEventRunModal + 65
    at 15  UIKitCore                           0x00007fff48092d4d UIApplicationMain + 1621
    at 16  iosApp-sample                       0x0000000103b0405b main + 75 (/Users/atripathi/shared/iosApp-sample/iosApp-sample/AppDelegate.swift:4:7)
    at 17  libdyld.dylib                       0x00007fff5227ec25 start + 1
Caused by: kotlin.native.IncorrectDereferenceException: Trying to access top level value not marked as @ThreadLocal or @SharedImmutable from non-main thread
    at 0   shared                              0x0000000103e8e52d kfun:kotlin.Throwable#<init>(kotlin.String?){} + 93 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Throwable.kt:23:37)
    at 1   shared                              0x0000000103e8741b kfun:kotlin.Exception#<init>(kotlin.String?){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Exceptions.kt:23:44)
    at 2   shared                              0x0000000103e875db kfun:kotlin.RuntimeException#<init>(kotlin.String?){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/Exceptions.kt:34:44)
    at 3   shared                              0x0000000103eba3db kfun:kotlin.native.IncorrectDereferenceException#<init>(kotlin.String){} + 91 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/native/Runtime.kt:30:36)
    at 4   shared                              0x0000000103edbb61 ThrowIncorrectDereferenceException + 129 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/native/internal/RuntimeUtils.kt:103:11)
    at 5   shared                              0x0000000103fc5c89 CheckIsMainThread + 25
    at 6   shared                              0x00000001041a57e3 kfun:io.ktor.http.<get-HeaderFieldValueSeparators>#internal + 19 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-http/common/src/io/ktor/http/HeaderValueWithParameters.kt:10:9)
    at 7   shared                              0x00000001041a6e24 kfun:io.ktor.http.checkNeedEscape#internal + 356 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-http/common/src/io/ktor/http/HeaderValueWithParameters.kt:86:13)
    at 8   shared                              0x00000001041a65d5 kfun:io.ktor.http.HeaderValueWithParameters#toString(){}kotlin.String + 2101 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-http/common/src/io/ktor/http/HeaderValueWithParameters.kt:41:21)
    at 9   shared                              0x00000001041fb0f7 kfun:io.ktor.client.engine#mergeHeaders(io.ktor.http.Headers;io.ktor.http.content.OutgoingContent;kotlin.Function2<kotlin.String,kotlin.String,kotlin.Unit>){} + 3095 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-client/ktor-client-core/common/src/io/ktor/client/engine/Utils.kt:45:37)
    at 10  shared                              0x000000010423adfe kfun:io.ktor.client.engine.ios.IosClientEngine.$executeCOROUTINE$0#invokeSuspend(kotlin.Result<kotlin.Any?>){}kotlin.Any? + 5630 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-client/ktor-client-ios/darwin/src/io/ktor/client/engine/ios/IosClientEngine.kt:40:13)
    at 11  shared                              0x000000010423c2a4 kfun:io.ktor.client.engine.ios.IosClientEngine#execute(io.ktor.client.request.HttpRequestData){}io.ktor.client.request.HttpResponseData + 308 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-client/ktor-client-ios/darwin/src/io/ktor/client/engine/ios/IosClientEngine.kt:21:22)
    at 12  shared                              0x00000001041f813b kfun:io.ktor.client.engine.HttpClientEngine.$executeWithinCallContext$lambda-1COROUTINE$11.invokeSuspend#internal + 731 (/Users/administrator/Documents/agent/work/8d547b974a7be21f/ktor-client/ktor-client-core/common/src/io/ktor/client/engine/HttpClientEngine.kt:86:13)
    at 13  shared                              0x0000000103eafc16 kfun:kotlin.coroutines.native.internal.BaseContinuationImpl#resumeWith(kotlin.Result<kotlin.Any?>){} + 758 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/coroutines/ContinuationImpl.kt:30:39)
    at 14  shared                              0x00000001040424ff kfun:kotlinx.coroutines.DispatchedTask#run(){} + 2767 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/common/src/internal/DispatchedTask.kt:39:50)
    at 15  shared                              0x0000000103ff5ecf kfun:kotlinx.coroutines.EventLoopImplBase#processNextEvent(){}kotlin.Long + 799 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/common/src/EventLoop.common.kt:274:18)
    at 16  shared                              0x000000010405a228 kfun:kotlinx.coroutines#runEventLoop(kotlinx.coroutines.EventLoop?;kotlin.Function0<kotlin.Boolean>){} + 872 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/native/src/Builders.kt:80:40)
    at 17  shared                              0x0000000104062b85 kfun:kotlinx.coroutines.WorkerCoroutineDispatcherImpl.start$lambda-0#internal + 389 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/native/src/Workers.kt:49:17)
    at 18  shared                              0x0000000104062d5b kfun:kotlinx.coroutines.WorkerCoroutineDispatcherImpl.$start$lambda-0$FUNCTION_REFERENCE$35.invoke#internal + 59 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/native/src/Workers.kt:47:24)
    at 19  shared                              0x0000000104062dbb kfun:kotlinx.coroutines.WorkerCoroutineDispatcherImpl.$start$lambda-0$FUNCTION_REFERENCE$35.$<bridge-UNN>invoke(){}#internal + 59 (/opt/buildAgent/work/44ec6e850d5c63f0/kotlinx-coroutines-core/native/src/Workers.kt:47:24)
    at 20  shared                              0x0000000103ebdfe7 WorkerLaunchpad + 183 (/Users/teamcity/buildAgent/work/cae0e6559deed4c4/runtime/src/main/kotlin/kotlin/native/concurrent/Internal.kt:69:54)
    at 21  shared                              0x0000000103fbb09f _ZN6Worker19processQueueElementEb + 3135
    at 22  shared                              0x0000000103fba446 _ZN12_GLOBAL__N_113workerRoutineEPv + 54
    at 23  libsystem_pthread.dylib             0x00007fff524602eb _pthread_body + 126
    at 24  libsystem_pthread.dylib             0x00007fff52463249 _pthread_start + 66
    at 25  libsystem_pthread.dylib             0x00007fff5245f40d thread_start + 13
(lldb)

This is what my implementation looks like

fun postRequest() {
        MainScope().launch {
            withContext(Dispatchers.Default) {
                 HttpClient().post("URL"){
                   body = "some json"
                 }
            }
        }
    }

This request is working fine for the Android application and only throws the exception in iOS. Also if I try to run HttpClient().post on the main thread, it works fine on iOS and I am successfully able to send the request. ktorVersion = "1.4.2" coroutinesVersion = "1.3.9-native-mt-2"

15 replies · 4 participants

dm6801

11/11/2020, 6:51 PM

Getting an exception when trying to use Session feature (cookies) combined with SSL Caused by: java.lang.UnsupportedOperationException: null at io.ktor.server.netty.http2.NettyHttp2ApplicationRequest.getCookies(NettyHttp2ApplicationRequest.kt:64) at io.ktor.sessions.SessionTransportCookie.receive(SessionTransportCookie.kt:28) at io.ktor.sessions.SessionsKt.receiveSessionData(Sessions.kt:204) at io.ktor.sessions.Sessions$Feature$install$1.invokeSuspend(Sessions.kt:59) NettyHttp2ApplicationRequest:64:

override val cookies: RequestCookies
    get() = throw UnsupportedOperationException()

working as intended or should I open a youtrack bug?

1 reply · 1 participant

goto1134

11/11/2020, 7:19 PM

Are there any plans or milestones to support OAuth token refreshing?

2 replies · 2 participants

Robert Jaros

11/11/2020, 9:46 PM

I'm getting this runtime error after migrating to from 1.4.1 to 1.4.2:

java.lang.IllegalStateException: Using blocking primitives on this dispatcher is not allowed. Consider using async channel instead or use blocking primitives in withContext(<http://Dispatchers.IO|Dispatchers.IO>) instead.

It looks like it has something to do with Jackson. Is this a known issue?

3 replies · 2 participants

Archie

11/12/2020, 8:42 AM

Hi have anyone work with making Ktor Client and Coil-Kt work together? I need to configure Ktor and Coil to use the same configuration, (Default Request, Interceptor, Auth, etc. etc.) But

Ktor

require

HttpClientEngine

but

Coil

needs the

OkHttpClient

itself. Is there a way to make both work together?

2 replies · 2 participants

tieskedh

11/12/2020, 5:45 PM

I want to create a data-receiver object which has no dependencies on Ktor. That's why I translated the ByteReadChannel to a Flow using common-Kotlin. I don't have much experience in this area, so my question is: Is this method safe and is it the best way?

suspend inline fun ByteReadChannel.toFlow(): Flow<ByteArray> {
    return flow {
        do {
            read { source, start, endExclusive ->
                val array = when {
                    endExclusive > start -> {
                        val mem = source.slice(start, endExclusive - start)
                        val byteArray = ByteArray(mem.size.toInt())
                        mem.copyTo(byteArray, 0, mem.size.toInt())
                        byteArray
                    }
                    else -> byteArrayOf()
                }

                emit(array)
                255
            }
            if (isClosedForRead) break
        } while (currentCoroutineContext().isActive)
    }
}

2 replies · 2 participants

Alberto Quario

11/13/2020, 4:52 PM

Hi, I have added metrics to an application like this:

install(MicrometerMetrics) {
        registry = DatadogMeterRegistry(config, Clock.SYSTEM)
        ...
    }

Would it be possible to access and reuse the same registry for adding custom metrics in handlers? Thanks!

3 replies · 2 participants

Rob Hurkes

11/13/2020, 7:41 PM

Hey all! Anyone come across this issue with ktor 1.4+ yet? Using Jackson content negotiation, JSON response objects greater than 4kb in size throw an exception

Exception in thread "eventLoopGroupProxy-3-6" kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[UnsafeBlockingTrampoline@762b17ae, Continuation at <http://io.ktor.utils.io|io.ktor.utils.io>.jvm.javaio.OutputAdapter$loop$1.loop(Blocking.kt:311)@64588a54]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers

. The actual cause is further down the stack trace:

Caused by: java.lang.ClassCastException: class kotlin.coroutines.jvm.internal.CompletedContinuation cannot be cast to class kotlinx.coroutines.DispatchedContinuation (kotlin.coroutines.jvm.internal.CompletedContinuation and kotlinx.coroutines.DispatchedContinuation are in unnamed module of loader 'app')
	at kotlinx.coroutines.CoroutineDispatcher.releaseInterceptedContinuation(CoroutineDispatcher.kt:103)

I've got a minimal reproduction example up at https://github.com/rhurkes/ktor-playground/commit/989b512bd7209735fd4d223b839d20d307c533c3

4 replies · 1 participant

Title

Rob Hurkes

11/13/2020, 7:41 PM

Hey all! Anyone come across this issue with ktor 1.4+ yet? Using Jackson content negotiation, JSON response objects greater than 4kb in size throw an exception

Exception in thread "eventLoopGroupProxy-3-6" kotlinx.coroutines.CoroutinesInternalError: Fatal exception in coroutines machinery for DispatchedContinuation[UnsafeBlockingTrampoline@762b17ae, Continuation at <http://io.ktor.utils.io|io.ktor.utils.io>.jvm.javaio.OutputAdapter$loop$1.loop(Blocking.kt:311)@64588a54]. Please read KDoc to 'handleFatalException' method and report this incident to maintainers

. The actual cause is further down the stack trace:

Caused by: java.lang.ClassCastException: class kotlin.coroutines.jvm.internal.CompletedContinuation cannot be cast to class kotlinx.coroutines.DispatchedContinuation (kotlin.coroutines.jvm.internal.CompletedContinuation and kotlinx.coroutines.DispatchedContinuation are in unnamed module of loader 'app')
	at kotlinx.coroutines.CoroutineDispatcher.releaseInterceptedContinuation(CoroutineDispatcher.kt:103)

I've got a minimal reproduction example up at https://github.com/rhurkes/ktor-playground/commit/989b512bd7209735fd4d223b839d20d307c533c3

It's similar to some other issues I've seen, but I'm not using coroutines in my app code at all, and the reproduction is rather simple. I don't mind filing a youtrack ticket for this, but wanted to check here first.

Appears to be related to this commit from 1.4.2: https://github.com/ktorio/ktor/commit/0dfada8cd8e438d724ce77e9cd0d8b09a6b8c6dc#diff-9004ca70aa325dbcfa7d3ce09d193306f9f33bfd9c7c7732875f008e294feb6d For some reason larger responses that go through

ContentNegotiation

are ending up tying to

park()

with

ProhibitedParking

which leads to this exception

java.lang.UnsupportedOperationException: Parking is prohibited on this thread. Most likely you are using blocking operation on the wrong thread/dispatcher that doesn't allow blocking. Consider wrapping you blocking code withContext(<http://Dispatchers.IO|Dispatchers.IO>) {...}.

because this work (regardless of size) ends up running through a

withBlocking

here: https://github.com/ktorio/ktor/blob/master/ktor-http/jvm/src/io/ktor/http/content/OutputStreamContent.kt#L23

I'm assuming that exception is what's bringing this

CompletedContinuation

into the mix.

Maybe a missed call to

withBlockingAndRedispatch

? Hard to say, debugging threading issues isn't my bread and butter 😅

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