Bug_inheritActorContext.swift

import Foundation

@_silgen_name("swift_task_isOnExecutor")
public func _taskIsOnExecutor<Executor: SerialExecutor>(_ executor: Executor) -> Bool



final class MySerialExecutor: SerialExecutor {
    private let queue: DispatchQueue = .init(label: "Hello")
    
    func enqueue(_ job: consuming ExecutorJob) {
        let job: UnownedJob = .init(job)
        
        queue.async {
            job.runSynchronously(on: self.asUnownedSerialExecutor())
        }
    }
    
    func isSameExclusiveExecutionContext(other: MySerialExecutor) -> Bool {
        queue == other.queue
    }
}



actor MyActor {
    private let executor: MySerialExecutor = .init()
    nonisolated var unownedExecutor: UnownedSerialExecutor {
        executor.asUnownedSerialExecutor()
    }
    
    func foo_1() async {
        let executor: any SerialExecutor = self.executor
        //    await foo_2 {
        
        await Task {
            // ??? 
            _ = self
            
            // true or false, depending on whether `_ = self` is commented out or not
            print(_taskIsOnExecutor(executor))
            
            let libdispatch: UnsafeMutableRawPointer = dlopen("/usr/lib/system/introspection/libdispatch.dylib", RTLD_NOW)!
            let symbol: UnsafeMutableRawPointer = dlsym(libdispatch, "dispatch_get_current_queue")!
            
            typealias Function = @convention(c) () -> dispatch_queue_t
            
            let dispatch_get_current_queue: Function = unsafeBitCast(symbol, to: Function.self)
            let queue: DispatchQueue = dispatch_get_current_queue()
            
            // "Hello" or "com.apple.root.default-qos.cooperative", depending on whether `_ = self` is commented out or not
            print(queue.label)
        }.value
        
        //    }
    }
    
//    private func foo_2(@_inheritActorContext _ block: @Sendable () async -> Void) async {
//        await block()
//    }
}



@main
struct MyScript {
    static func main() async {
        let myActor: MyActor = .init()
        await myActor.foo_1()
    }
}