I am trying to make a post request using Ktor HttpClient in

Question

I am trying to make a post request using Ktor HttpClient in commonMain on a singleThread using Dispatcher Default and I am getting this exception on iOS ```Uncaught Kotlin exception kotlin native IncorrectDereferenceException illegal attempt to access non shared lt object gt c1c6c8 from other thread at 0 shared 0x000000010ac441bd kfun kotlin Throwable lt init gt kotlin String + 93 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Throwable kt 23 37 at 1 shared 0x000000010ac3d0ab kfun kotlin Exception lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Exceptions kt 23 44 at 2 shared 0x000000010ac3d26b kfun kotlin RuntimeException lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Exceptions kt 34 44 at 3 shared 0x000000010ac7006b kfun kotlin native IncorrectDereferenceException lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin native Runtime kt 30 36 at 4 shared 0x000000010ac7438d ThrowIllegalObjectSharingException + 621 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin native concurrent Internal kt 98 11 at 5 shared 0x000000010ad5a002 ZN12 GLOBAL N 128throwIllegalSharingExceptionEP9ObjHeader + 34 at 6 shared 0x000000010ad5e52e ZNK27BackRefFromAssociatedObject3refEv + 78 at 7 shared 0x000000010ad44bd4 ZN12 GLOBAL N 111toKotlinImpEP11objc objectP13objc selectorPP9ObjHeader + 52 at 8 shared 0x000000010ad87c81 Kotlin Interop refFromObjC + 65 at 9 shared 0x000000010aff65ea 696f2e6b746f723a6b746f722d636c69656e742d696f73 knbridge28 + 330 opt buildAgent work a85294440dc5c6e ktor client ktor client ios darwin src io ktor client engine ios IosResponseReader kt 100 14 at 10 shared 0x000000010afff37a 696f2e6b746f723a6b746f722d636c69656e742d696f73 kncfun30 + 74 at 11 CFNetwork 0x00007fff22f31ade CFNetworkHTTPConnectionCacheSetLimit + 207606 at 12 Foundation 0x00007fff25752d51 NSBLOCKOPERATION IS CALLING OUT TO A BLOCK + 7 at 13 Foundation 0x00007fff25752c49 NSBlockOperation main + 98 at 14 Foundation 0x00007fff25755bd6 NSOPERATION IS INVOKING MAIN + 17 at 15 Foundation 0x00007fff25751e49 NSOperation start + 731 at 16 Foundation 0x00007fff25756530 NSOPERATIONQUEUE IS STARTING AN OPERATION + 17 at 17 Foundation 0x00007fff2575603a NSOQSchedule f + 182 at 18 libdispatch dylib 0x000000010b75a3c9 dispatch block async invoke2 + 83 at 19 libdispatch dylib 0x000000010b74bd48 dispatch client callout + 8 at 20 libdispatch dylib 0x000000010b759de6 dispatch main queue callback 4CF + 1500 at 21 CoreFoundation 0x00007fff23bd4049 CFRUNLOOP IS SERVICING THE MAIN DISPATCH QUEUE + 9 at 22 CoreFoundation 0x00007fff23bceca9 CFRunLoopRun + 2329 at 23 CoreFoundation 0x00007fff23bce066 CFRunLoopRunSpecific + 438 at 24 GraphicsServices 0x00007fff384c0bb0 GSEventRunModal + 65 at 25 UIKitCore 0x00007fff48092d4d UIApplicationMain + 1621 at 26 iosApp sample 0x000000010a8b905b main + 75 User iosApp sample iosApp sample AppDelegate swift 4 7 at 27 libdyld dylib 0x00007fff5227ec25 start + 1``` 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 1 coroutinesVersion = 1 3 9 native mt 2 Based on this documentation<https github com Kotlin kotlinx coroutines blob native mt kotlin native sharing md switching threads> for ` 1 3 9 native mt 2 ` my understanding is it should work Any help is appreciated

Thomas · Answer

Update Ktor to 1 4 2 and it should work

Thomas · Answer

Amritansh · Answer

thanks for replying Now I am getting a new error after the update stuck out tongue

Amritansh · Answer

```Uncaught Kotlin exception kotlinx coroutines CoroutinesInternalError Fatal exception in coroutines machinery for DispatchedContinuation MainDispatcher Continuation $postRequest$lambda 1COROUTINE$1 Please read KDoc to handleFatalException method and report this incident to maintainers at 0 dogtag 0x0000000103e8730c kfun kotlin Error lt init gt kotlin String kotlin Throwable + 124 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Exceptions kt 14 63 at 1 dogtag 0x0000000103ffa913 kfun kotlinx coroutines CoroutinesInternalError lt init gt kotlin String kotlin Throwable + 115 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core common src Exceptions common kt 28 77 at 2 dogtag 0x0000000104042bfa kfun kotlinx coroutines DispatchedTask handleFatalException kotlin Throwable kotlin Throwable + 938 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core common src internal DispatchedTask kt 93 22 at 3 dogtag 0x00000001040427e8 kfun kotlinx coroutines DispatchedTask run + 3512 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core common src internal DispatchedTask kt 64 13 at 4 dogtag 0x000000010406b0f5 kfun kotlinx coroutines DarwinMainDispatcher dispatch$lambda 0 internal + 85 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core nativeDarwin src Dispatchers kt 35 19 at 5 dogtag 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 dogtag 0x000000010406b50b kfun kotlinx coroutines DarwinMainDispatcher $dispatch$lambda 0$FUNCTION REFERENCE$43 $ lt bridge UNN gt invoke internal + 59 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core nativeDarwin src Dispatchers kt 34 51 at 7 dogtag 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 DogTag 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 dogtag 0x0000000103e8e52d kfun kotlin Throwable lt init gt kotlin String + 93 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Throwable kt 23 37 at 1 dogtag 0x0000000103e8741b kfun kotlin Exception lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Exceptions kt 23 44 at 2 dogtag 0x0000000103e875db kfun kotlin RuntimeException lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin Exceptions kt 34 44 at 3 dogtag 0x0000000103eba3db kfun kotlin native IncorrectDereferenceException lt init gt kotlin String + 91 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin native Runtime kt 30 36 at 4 dogtag 0x0000000103edbb61 ThrowIncorrectDereferenceException + 129 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin native internal RuntimeUtils kt 103 11 at 5 dogtag 0x0000000103fc5c89 CheckIsMainThread + 25 at 6 dogtag 0x00000001041a57e3 kfun io ktor http lt get HeaderFieldValueSeparators gt internal + 19 Users administrator Documents agent work 8d547b974a7be21f ktor http common src io ktor http HeaderValueWithParameters kt 10 9 at 7 dogtag 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 dogtag 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 dogtag 0x00000001041fb0f7 kfun io ktor client engine mergeHeaders io ktor http Headers io ktor http content OutgoingContent kotlin Function2 lt kotlin String kotlin String kotlin Unit gt + 3095 Users administrator Documents agent work 8d547b974a7be21f ktor client ktor client core common src io ktor client engine Utils kt 45 37 at 10 dogtag 0x000000010423adfe kfun io ktor client engine ios IosClientEngine $executeCOROUTINE$0 invokeSuspend kotlin Result lt kotlin Any gt 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 dogtag 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 dogtag 0x00000001041f813b kfun io ktor client engine HttpClientEngine $executeWithinCallContext$lambda 1COROUTINE$11 invokeSuspend internal + 731 Users administrator Documents agent work 8d547b974a7be21f ktor client ktor client core common src io ktor client engine HttpClientEngine kt 86 13 at 13 dogtag 0x0000000103eafc16 kfun kotlin coroutines native internal BaseContinuationImpl resumeWith kotlin Result lt kotlin Any gt + 758 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin coroutines ContinuationImpl kt 30 39 at 14 dogtag 0x00000001040424ff kfun kotlinx coroutines DispatchedTask run + 2767 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core common src internal DispatchedTask kt 39 50 at 15 dogtag 0x0000000103ff5ecf kfun kotlinx coroutines EventLoopImplBase processNextEvent kotlin Long + 799 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core common src EventLoop common kt 274 18 at 16 dogtag 0x000000010405a228 kfun kotlinx coroutines runEventLoop kotlinx coroutines EventLoop kotlin Function0 lt kotlin Boolean gt + 872 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core native src Builders kt 80 40 at 17 dogtag 0x0000000104062b85 kfun kotlinx coroutines WorkerCoroutineDispatcherImpl start$lambda 0 internal + 389 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core native src Workers kt 49 17 at 18 dogtag 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 dogtag 0x0000000104062dbb kfun kotlinx coroutines WorkerCoroutineDispatcherImpl $start$lambda 0$FUNCTION REFERENCE$35 $ lt bridge UNN gt invoke internal + 59 opt buildAgent work 44ec6e850d5c63f0 kotlinx coroutines core native src Workers kt 47 24 at 20 dogtag 0x0000000103ebdfe7 WorkerLaunchpad + 183 Users teamcity buildAgent work cae0e6559deed4c4 runtime src main kotlin kotlin native concurrent Internal kt 69 54 at 21 dogtag 0x0000000103fbb09f ZN6Worker19processQueueElementEb + 3135 at 22 dogtag 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 ```

arnis71 · Answer

ktor calls for native target should only be done from the ui thread to do this in common module just make dedicated ktor dispatcher and make it IO for jvm and Main for native

Thomas · Answer

Ktor on iOS should work on Dispatchers Default as well

Thomas · Answer

I m using that and it works fine

Amritansh · Answer

< Thomas> can you share your dependency version for coroutine

Thomas · Answer

< Amritansh> I used a manually built version of Ktor that worked The fix was supposed to be in Ktor 1 4 2 but unfortunately this is a new issue See