Does anybody understand why this crash on X64/ARM6...

# kotlin-native

[Martin Gagnon]

Does anybody understand why this crash on X64/ARM64 ?

open class IOSSerialDispatchQueue(identifier: String) : DispatchQueue {
    private val serialQueue = dispatch_queue_create(
        "com.mirego.trikot.foundation.serial_dispatch_queue.$identifier",
        dispatch_queue_serial_t()
    )

    override fun isSerial() = true

    override fun dispatch(block: DispatchBlock) {
        freeze(block)

        dispatch_async(serialQueue, freeze {
            runQueueTask(block)
        })
    }

    private fun runQueueTask(block: DispatchBlock) {
        block()
    }
}

The crash happens in class initialization at line dispatch_queue_create("...", dispatch_queue_serial_t()) . I can reproduce with the following swift code let _ = IOSSerialDispatchQueue(identifier: "None") in my AppDelegate.swift file . The crash is EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0) (Kotlin 1.4)

[svyatoslav.scherbina]

dispatch_queue_serial_t()

I don’t think this should actually work.
dispatch_queue_serial_t is just a typealias for NSObject, so dispatch_queue_serial_t() is an NSObject.
Please refer to the documentation for details on valid values for the second parameter of dispatch_queue_create.