sdk/fidl/fuchsia.device.manager/device-watcher.fidl

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.device.manager;

using zx;

/// This protocol represents watching a specific class of devices. Each client
/// that connects will be able to poll `NextDevice` to be able to get all devices.
protocol DeviceWatcher {
    /// A Hanging-Get API that returns the next device. This will not return until
    /// there is a new device available. Call this repeatedly to get all devices.
    /// If there is already an outstanding request then calling this again will return
    /// ZX_ERR_ALREADY_BOUND.
    NextDevice() -> (resource struct {
        device zx.handle:CHANNEL;
    }) error zx.status;
};