iOS多线程通信：

gcd 相关

// async
DispatchQueue.global().async {
    // dosomething
    DispatchQueue.main.async {

    }
}

// DispatchSemaphore
// 并发数
let sema = DispatchSemaphore.init(value: 2)

DispatchQueue.global().async {


    // dosomething
    _ = sema.wait(timeout: DispatchTime.distantFuture)
    print(1)
    sema.signal()
}

DispatchQueue.global().async {


    // dosomething
    _ = sema.wait(timeout: DispatchTime.distantFuture)
    print(2)
    sema.signal()
}

// done
DispatchQueue.global().async {

    print("done")
}

直接 使用performSelector 动态方法调用

DispatchQueue.global().async(execute: { [unowned self] in

    sleep(3)
    self.perform(#selector(self.doItem1), with: params, afterDelay: 1)
    RunLoop.current.run()
})

通过MachPort端口通信

// ...
port = NSMachPort()
port?.setDelegate(self)
RunLoop.current.add(port ?? NSMachPort(), forMode: RunLoop.Mode.default)
// dosomething
DispatchQueue.global().async {
    self.port?.send(before: Date(), components: nil, from: nil, reserved: 0)
}

//
extension SelfClass:NSMachPortDelegate {
    func handleMachMessage(_ msg: UnsafeMutableRawPointer) {
        // doSomething
        print("msg")
    }
}