ClassCastException when using limitedParallelism on Kotlin/Native

[Thomas-Vos]

My code uses Dispatchers.Default.limitedParallelism(1) on Kotlin/Native with the new memory model enabled. When launching a coroutine on this dispatcher, the following error is thrown:

Uncaught Kotlin exception: kotlin.ClassCastException: kotlinx.coroutines.internal.LimitedDispatcher cannot be cast to kotlinx.atomicfu.locks.SynchronizedObject
    at 0   common                              0x10a815d5f        kfun:kotlin.Throwable#<init>(kotlin.String?){} + 99 
    at 1   common                              0x10a80e89b        kfun:kotlin.Exception#<init>(kotlin.String?){} + 95 
    at 2   common                              0x10a80eaef        kfun:kotlin.RuntimeException#<init>(kotlin.String?){} + 95 
    at 3   common                              0x10a80f927        kfun:kotlin.ClassCastException#<init>(kotlin.String?){} + 95 
    at 4   common                              0x10a84644f        ThrowClassCastException + 655 
    at 5   common                              0x10a9f55e3        kfun:kotlinx.coroutines.internal.LimitedDispatcher.tryAllocateWorker#internal + 183 
    at 6   common                              0x10a9f535f        kfun:kotlinx.coroutines.internal.LimitedDispatcher#dispatch(kotlin.coroutines.CoroutineContext;kotlinx.coroutines.Runnable){} + 195 
    at 7   common                              0x10a9edfaf        kfun:kotlinx.coroutines.internal#resumeCancellableWith__at__kotlin.coroutines.Continuation<0:0>(kotlin.Result<0:0>;kotlin.Function1<kotlin.Throwable,kotlin.Unit>?){0§<kotlin.Any?>} + 895 
    at 8   common                              0x10a9ff0e7        kfun:kotlinx.coroutines.intrinsics#startCoroutineCancellable__at__kotlin.coroutines.SuspendFunction1<0:0,0:1>(0:0;kotlin.coroutines.Continuation<0:1>;kotlin.Function1<kotlin.Throwable,kotlin.Unit>?){0§<kotlin.Any?>;1§<kotlin.Any?>} + 411 
    at 9   common                              0x10a9ff2af        kfun:kotlinx.coroutines.intrinsics#startCoroutineCancellable$default__at__kotlin.coroutines.SuspendFunction1<0:0,0:1>(0:0;kotlin.coroutines.Continuation<0:1>;kotlin.Function1<kotlin.Throwable,kotlin.Unit>?;kotlin.Int){0§<kotlin.Any?>;1§<kotlin.Any?>} + 251 
    at 10  common                              0x10a956b8b        kfun:kotlinx.coroutines.CoroutineStart#invoke(kotlin.coroutines.SuspendFunction1<0:0,0:1>;0:0;kotlin.coroutines.Continuation<0:1>){0§<kotlin.Any?>;1§<kotlin.Any?>} + 259 
    at 11  common                              0x10a942637        kfun:kotlinx.coroutines.AbstractCoroutine#start(kotlinx.coroutines.CoroutineStart;0:0;kotlin.coroutines.SuspendFunction1<0:0,1:0>){0§<kotlin.Any?>} + 151 
    at 12  common                              0x10a946ce3        kfun:kotlinx.coroutines#launch__at__kotlinx.coroutines.CoroutineScope(kotlin.coroutines.CoroutineContext;kotlinx.coroutines.CoroutineStart;kotlin.coroutines.SuspendFunction1<kotlinx.coroutines.CoroutineScope,kotlin.Unit>){}kotlinx.coroutines.Job + 411 
    at 13  common                              0x10a946f17        kfun:kotlinx.coroutines#launch$default__at__kotlinx.coroutines.CoroutineScope(kotlin.coroutines.CoroutineContext?;kotlinx.coroutines.CoroutineStart?;kotlin.coroutines.SuspendFunction1<kotlinx.coroutines.CoroutineScope,kotlin.Unit>;kotlin.Int){}kotlinx.coroutines.Job + 427 
    at 14 ... 

I guess this function was not implemented for Kotlin/Native yet? Or is this a bug?

My project uses Coroutines version 1.6.0 and Kotlin 1.6.20-RC2.