Swift Async/Await for C Callbacks - c

Question

I am trying to convert some code from objective-c to swift and along with that use async/await as much as possible.
This code leverages a C library that uses callbacks with a void* context. There are parts of our code where we need to "wait" until the callback is completed. This can often be 2 different callbacks for success or failure.
Below is an example of the code
class Test
{
var sessionStarted: Bool = false
let sessionSemaphore = DispatchSemaphore(value: 0)
// We need the session to be available once this function returns
func startSession() throws
{
guard !sessionStarted else {
print("Session already started")
return
}
let callback: KMSessionEventCallback = { inSession, inEvent, inContext in
guard let session = inSession, let context = inContext else { return }
let testContext: Test = Unmanaged<Test>.fromOpaque(context).takeUnretainedValue()
testContext.handleSessionUpdate(session: session, event: inEvent)
}
let result = KMSessionAttach("SessionTest", &callback, Unmanaged.passUnretained(self).toOpaque())
if result != KM_SUCCESS {
print("Failed to attach session")
}
// Currently uses a semaphore to wait. =(
let dispatchResult = self.sessionSemaphore.wait(timeout: .now() + DispatchTimeInterval.seconds(30))
if dispatchResult == .timedOut {
print("Waited 30 seconds and never attached session")
}
}
private func handleSessionUpdate(session: KMSession, event: KMSessionEvent)
{
switch event
{
case KM_SESSION_ATTACHED:
self.sessionStarted = true
case KM_SESSION_TERMINATED:
fallthrough
case KM_SESSION_FAILED:
fallthrough
case KM_SESSION_DETACHED:
self.sessionStarted = false
default:
print("Unknown State")
}
self.sessionSemaphore.signal()
}
}
I am struggling to figure out how to use continuations here because I cannot capture any context within these C callbacks.