Track coroutine events in arbitrary code

[eupp]

Currently, the Lincheck supports only top-level suspend functions declared as operations.

That is, the following code is supported:

class RendezvousChannelTest {
    private val channel = Channel<Int>()

    @Operation
    suspend fun send(value: Int) = channel.send(value)
    
    ...
    
}

But the coroutines launched by the user code are not tracked and thus may work incorrectly.
For example, the following code may not work as expected:

class LaunchTest {

    @Operation
    fun do(value: Int) {
       launch { ... }
    }
    
    ...
    
}

In order to support the latter case, the Lincheck need to be able to intercept coroutine's events (suspension, resumption, etc) in an arbitrary code.

Pros:

• Being able to run arbitrary code with coroutines support leads to a simpler and more intuitive behavior from the user's point of view.

Cons:

• Currently, the primary use case of Lincheck is to test concurrent data structures and synchronization primitives. This type of code rarely requires to create custom coroutines inside operations.

[ndkoval]

@eupp, why would a data structure launch a coroutine?

[eupp]

why would a data structure launch a coroutine?

I mentioned that this is unlikely case:

Currently, the primary use case of Lincheck is to test concurrent data structures and synchronization primitives. This type of code rarely requires to create custom coroutines inside operations.

But I would rather prefer to keep this as a tracking issue, in case we discover such cases later (or users will report something related).