//! /system/services/device-manager — the ring-3 process that turns the device
//! tree into a running system: **the matcher and the supervisor**
//! (docs/device-manager.md). The kernel enumerates the hardware and enforces the
//! claim capability (mechanism); this decides which driver serves which device,
//! spawns it, and keeps it alive (policy). Keeping that split in user space is
//! the whole point of the microkernel: the manager is an ordinary, restartable
//! process with no special privilege.
//!
//! M18.1 (this increment): the manager is a harness service on the well-known
//! `.device_manager` endpoint. Every driver is spawned **supervised** — exit
//! notifications land in the same loop as protocol messages. Drivers with an
//! assignment must `hello` within a deadline or be stopped; a driver that dies
//! is restarted with backoff, and a crash loop (three fast deaths) marks it
//! failed instead of respawning forever. Exit reasons (M17.2) drive the
//! decision: a clean exit meant to stop; only faults and missed deadlines
//! restart. Tree reports (`child_added`) land in M18.2.

const std = @import("std");
const device = @import("driver");
const ipc = @import("ipc");
const process = @import("process");
const service = @import("service");
const time = @import("time");
const memory = @import("memory");
const logging = @import("logging");
const device_manager_protocol = @import("device-manager-protocol");
const envelope = @import("envelope");
const registry = @import("device-registry");

/// The generated device-manager dispatch. One manager per system, so the handler
/// context is empty and the tables stay in this file's globals.
const Serve = device_manager_protocol.Protocol.Provider(void);

const Invocation = envelope.Invocation;
const Answer = envelope.Answer;
const fs = @import("file-system");

// --- the device registry ------------------------------------------------------
// Driver matching is data-driven and authoritative: /system/configuration/devices.csv (parsed by
// the device-registry module) names, per bus, which driver binds a reported
// device, the most-specific match winning. There is no compiled-in fallback — a
// device no row matches goes unbound and is logged. This retired the hand-kept
// pciDriverForIdentity / hidDriverFor / usbDriverForIdentity switch tables
// (docs/device-manager.md: "matching stays code until the third bus").

/// The CSV bytes, held for the life of the process because the parsed rules'
/// string fields (hid, driver) slice into this buffer.
var registry_source: [8192]u8 = undefined;
var registry_rules: [64]registry.Rule = undefined;
var registry_count: usize = 0;

/// Read and parse /system/configuration/devices.csv once at boot. The file lives in the initial
/// ramdisk, which the kernel serves directly — no filesystem service need be up
/// (fat is spawned after the manager), so this is a plain fs.open + read.
fn loadRegistry() void {
    var file = fs.open("/system/configuration/devices.csv", .{}) orelse {
        _ = logging.write("/system/services/device-manager: /system/configuration/devices.csv missing — nothing will match\n");
        return;
    };
    defer file.close();
    var used: usize = 0;
    while (used < registry_source.len) {
        const n = file.read(registry_source[used..]) orelse break;
        if (n == 0) break;
        used += n;
    }
    const result = registry.parse(registry_source[0..used], &registry_rules);
    registry_count = result.count;
    if (result.malformed != 0) std.log.info("/system/configuration/devices.csv: {d} malformed line(s) skipped", .{result.malformed});
    if (result.truncated) _ = logging.write("/system/services/device-manager: /system/configuration/devices.csv has more rules than the table holds\n");
    std.log.info("/system/configuration/devices.csv: {d} rule(s) loaded", .{registry_count});
}

/// Build a registry Identity from a bus driver's report: the bus it named, the
/// class triple unpacked from `identity` (0xCCSSPP — the same packing for a PCI
/// class code and a USB class triple), the widened numeric ids, and the ACPI hid.
fn identityFromReport(report: device_manager_protocol.ChildAdded) registry.Identity {
    const bus: registry.Bus = switch (report.bus) {
        @intFromEnum(device_manager_protocol.BusKind.pci) => .pci,
        @intFromEnum(device_manager_protocol.BusKind.usb) => .usb,
        @intFromEnum(device_manager_protocol.BusKind.acpi) => .acpi,
        else => .unknown,
    };
    const hid_len = std.mem.indexOfScalar(u8, &report.hid, 0) orelse report.hid.len;
    return .{
        .bus = bus,
        .base = @truncate(report.identity >> 16),
        .subclass = @truncate(report.identity >> 8),
        .prog_if = @truncate(report.identity),
        .vendor = report.vendor,
        .device = report.device,
        .subsystem = report.subsystem,
        .hid = report.hid[0..hid_len],
    };
}

/// Whether some driver entry already serves registered device `device_id` —
/// a re-report after a bus restart must not spawn a second instance.
fn driverForDevice(device_id: u64) bool {
    for (&drivers) |*driver| {
        if (driver.used and driver.device_id == device_id) return true;
    }
    return false;
}

// --- supervision -------------------------------------------------------------

/// How long a protocol driver has to hello after its spawn.
const hello_deadline_ms: u64 = 3000;
/// Deaths faster than this count toward the crash loop; slower ones reset it.
const fast_death_ns: u64 = 2_000_000_000;
/// Consecutive fast deaths before the manager gives up on a driver.
const crash_loop_cap: u32 = 3;
/// Restart backoff: base << (restarts - 1), so 300 ms, 600 ms, 1200 ms.
const backoff_base_ms: u64 = 300;

const DriverState = enum {
    awaiting_hello, // spawned; the deadline is armed (protocol drivers only)
    running,
    restarting, // dead; respawn due at restart_due_ns
    stopped, // exited cleanly — it meant to; not restarted
    failed, // crash loop, or unspawnable; the manager gave up
};

const Driver = struct {
    used: bool = false,
    name_buffer: [64]u8 = undefined, // fits a full binary path (abi.maximum_process_name)
    name_len: usize = 0,
    // The assigned device id (becomes argv[1]), or device_manager_protocol.no_device.
    device_id: u64 = device_manager_protocol.no_device,
    // Whether this driver speaks the protocol (hello expected, deadline
    // enforced). Legacy drivers (e.g. ps2-bus) are supervised and restarted
    // but not yet required to hello.
    speaks_protocol: bool = false,
    process_id: u32 = 0,
    state: DriverState = .running,
    restarts: u32 = 0,
    spawn_ns: u64 = 0,
    hello_deadline_ns: u64 = 0,
    restart_due_ns: u64 = 0,

    fn name(driver: *const Driver) []const u8 {
        return driver.name_buffer[0..driver.name_len];
    }
};

const maximum_drivers = 16;
var drivers: [maximum_drivers]Driver = .{Driver{}} ** maximum_drivers;
var manager_endpoint: ipc.Handle = 0;
var test_restart_mode = false;
var test_usb_restart_mode = false;
var test_usb_killed = false;
var test_pci_restart_mode = false;
var test_scanout_restart_mode = false;
var test_scanout_killed = false;
var test_kill_pid: u32 = 0;
var test_kill_due_ns: u64 = 0;

/// The application subscribers (M18.3, the input-service pattern): endpoints
/// handed over as capabilities, each receiving every child add/remove as a
/// buffered message. A subscriber whose endpoint stops accepting (it died) is
/// dropped on the failed send.
const maximum_subscribers = 8;
var subscribers: [maximum_subscribers]?ipc.Handle = .{null} ** maximum_subscribers;

/// Push one event to every subscriber: the same struct a bus driver *called*
/// with, framed as an event instead — one encoding, both directions, told apart
/// by the packet's verb rather than by anything inside it. A subscriber whose
/// endpoint stops accepting (it died) is dropped on the failed send.
fn publish(
    comptime event: device_manager_protocol.Event,
    target: u64,
    payload: device_manager_protocol.Protocol.PayloadOf(event),
) void {
    var packet: [envelope.post_maximum]u8 = undefined;
    const framed = device_manager_protocol.Protocol.encodeEvent(event, target, payload, &packet) orelse return;
    for (&subscribers) |*slot| {
        if (slot.*) |handle| {
            if (!ipc.send(handle, framed)) slot.* = null; // dead subscriber
        }
    }
}

/// The manager's mirror of what bus drivers report (docs/device-manager.md "the
/// tree"): the children, keyed by (parent, bus address), each remembering which
/// driver instance reported it — that is what death-pruning sweeps by.
const Child = struct {
    used: bool = false,
    parent: u64 = 0,
    bus_address: u64 = 0,
    identity: u64 = 0,
    // The kernel device id (registered by the reporter), or device_manager_protocol.no_device.
    device_id: u64 = 0,
    reporter: u32 = 0, // the reporting driver instance's process id
};

const maximum_children = 64; // ACPI adds ~34 device nodes (M20.2), plus PCI + USB
var children: [maximum_children]Child = .{Child{}} ** maximum_children;

/// Record (or refresh) a reported child. Refreshing matters: a restarted bus
/// driver re-reports what it rediscovers, and the same (parent, port) must not
/// duplicate.
fn addChild(parent: u64, bus_address: u64, identity: u64, device_id: u64, reporter: u32) bool {
    var free: ?*Child = null;
    for (&children) |*child| {
        if (child.used and child.parent == parent and child.bus_address == bus_address) {
            child.identity = identity;
            child.device_id = device_id;
            child.reporter = reporter;
            return true;
        }
        if (!child.used and free == null) free = child;
    }
    const slot = free orelse return false;
    slot.* = .{ .used = true, .parent = parent, .bus_address = bus_address, .identity = identity, .device_id = device_id, .reporter = reporter };
    return true;
}

/// Prune every child a dead driver instance reported: the children describe
/// protocol state (slots, rings) that died with the process — keeping the nodes
/// would be keeping a lie. The restarted instance rediscovers and re-reports.
/// Watchers hear the honest story: removed now, added again on rediscovery.
fn pruneChildrenOf(reporter: u32) void {
    for (&children) |*child| {
        if (child.used and child.reporter == reporter) {
            std.log.info("child removed (device {d} port {d})", .{ child.parent, child.bus_address });
            child.used = false;
            publish(.child_removed, 0, .{ .parent = child.parent, .bus_address = child.bus_address });
        }
    }
}

/// How many children a driver instance has reported (the test-usb-restart
/// trigger counts these).
fn childCountOf(reporter: u32) u32 {
    var n: u32 = 0;
    for (&children) |*child| {
        if (child.used and child.reporter == reporter) n += 1;
    }
    return n;
}

fn driverByProcess(process_id: u32) ?*Driver {
    for (&drivers) |*driver| {
        if (driver.used and driver.process_id == process_id) return driver;
    }
    return null;
}

/// Whether a singleton driver is already in the table (two ACPI nodes can both
/// map to ps2-bus; one instance serves both).
fn alreadySupervised(name: []const u8) bool {
    for (&drivers) |*driver| {
        if (driver.used and std.mem.eql(u8, driver.name(), name)) return true;
    }
    return false;
}

/// Record a driver in the table and spawn its first instance.
fn addDriver(name: []const u8, device_id: u64, speaks_protocol: bool) void {
    for (&drivers) |*driver| {
        if (driver.used) continue;
        const n = @min(name.len, driver.name_buffer.len);
        @memcpy(driver.name_buffer[0..n], name[0..n]);
        driver.name_len = n;
        driver.device_id = device_id;
        driver.speaks_protocol = speaks_protocol;
        driver.used = true;
        spawnDriver(driver);
        return;
    }
    std.log.info("driver table full; cannot supervise {s}", .{name});
}

/// (Re)spawn a driver instance: supervised on the manager's own endpoint, the
/// device id as argv[1] when it has one, the hello deadline armed when it
/// speaks the protocol.
fn spawnDriver(driver: *Driver) void {
    var id_text: [20]u8 = undefined;
    var arguments: [1][]const u8 = undefined;
    var argument_count: usize = 0;
    if (driver.device_id != device_manager_protocol.no_device) {
        arguments[0] = std.fmt.bufPrint(&id_text, "{d}", .{driver.device_id}) catch return;
        argument_count = 1;
    }
    const child = process.spawnSupervised(driver.name(), arguments[0..argument_count], manager_endpoint) orelse {
        std.log.info("failed to spawn {s}", .{driver.name()});
        driver.state = .failed;
        return;
    };
    driver.process_id = child;
    driver.spawn_ns = time.clock();
    if (driver.speaks_protocol) {
        driver.state = .awaiting_hello;
        driver.hello_deadline_ns = driver.spawn_ns + hello_deadline_ms * 1_000_000;
        _ = time.timerOnce(manager_endpoint, hello_deadline_ms + 100);
    } else {
        driver.state = .running;
    }
    if (driver.device_id != device_manager_protocol.no_device) {
        std.log.info("spawned {s} for device {d}", .{ driver.name(), driver.device_id });
    } else {
        std.log.info("spawned {s}", .{driver.name()});
    }
}

/// A driver died. Prune what it reported first — then the exit reason (M17.2)
/// is the whole restart decision: a clean exit meant to stop; anything else
/// restarts with backoff until the crash-loop cap.
fn onDriverExit(driver: *Driver) void {
    pruneChildrenOf(driver.process_id);
    const reason = process.exitReason(driver.process_id) orelse .fault;
    if (reason == .exited) {
        driver.state = .stopped;
        std.log.info("{s} exited cleanly; not restarting", .{driver.name()});
        return;
    }
    const now = time.clock();
    const alive_ns = now - driver.spawn_ns;
    driver.restarts = if (alive_ns < fast_death_ns) driver.restarts + 1 else 1;
    if (driver.restarts >= crash_loop_cap) {
        driver.state = .failed;
        std.log.info("{s} is failing repeatedly (crash loop); giving up", .{driver.name()});
        return;
    }
    const delay_ms = backoff_base_ms << @intCast(driver.restarts - 1);
    driver.state = .restarting;
    driver.restart_due_ns = now + delay_ms * 1_000_000;
    std.log.info("restarting {s} in {d} ms (died: {s})", .{ driver.name(), delay_ms, @tagName(reason) });
    _ = time.timerOnce(manager_endpoint, delay_ms + 50);
}

/// A timer landed: sweep every deadline. Overdue hellos are killed (the exit
/// notification then routes through the normal restart policy); due restarts
/// respawn. Timers carry no id on purpose — the table is the state, and one
/// sweep serves every armed deadline.
fn sweepDeadlines() void {
    const now = time.clock();
    if (test_kill_pid != 0 and now >= test_kill_due_ns) {
        std.log.info("test mode: killing the reporter", .{});
        _ = process.kill(test_kill_pid);
        test_kill_pid = 0;
    }
    for (&drivers) |*driver| {
        if (!driver.used) continue;
        switch (driver.state) {
            .awaiting_hello => if (now >= driver.hello_deadline_ns) {
                std.log.info("{s} missed its hello deadline", .{driver.name()});
                _ = process.kill(driver.process_id);
                // The exit notification finishes the job via onDriverExit.
            },
            .restarting => if (now >= driver.restart_due_ns) spawnDriver(driver),
            else => {},
        }
    }
}

// --- the harness callbacks -----------------------------------------------------

fn initialise(endpoint: ipc.Handle) bool {
    manager_endpoint = endpoint;

    // Load the authoritative driver-match registry before any bus driver can
    // report a device to match against it.
    loadRegistry();

    // Enumerate into a heap buffer (too big for the one-page user stack).
    const buffer = memory.allocator().alloc(device.DeviceDescriptor, 64) catch {
        _ = logging.write("/system/services/device-manager: out of memory\n");
        return false;
    };
    const total = device.enumerate(buffer);
    const count = @min(total, buffer.len);

    var matched: usize = 0;
    for (buffer[0..count]) |descriptor| {
        if (descriptor.class == @intFromEnum(device.DeviceClass.pci_host_bridge)) {
            // The PCI bus driver: enumeration in ring 3 (M19), one instance
            // per bridge, the bridge id as its assignment.
            matched += 1;
            addDriver("pci-bus", descriptor.id, true);
            continue;
        }
        // Nothing else is matched from the boot snapshot today. The kernel-seeded
        // HPET timer node is served by the kernel's own clock (docs/timers.md), not
        // a user-space driver; PCI functions and PS/2 _HID devices arrive later as
        // pci-bus / acpi-service reports and match in onChildAdded (docs/discovery.md).
        // A fuller system's static class->driver manifest (docs/device-manager.md)
        // would slot in here.
    }

    // The discovery service (docs/discovery.md): one per firmware, packed
    // under the neutral name "discovery", spawned once at startup. It finds and
    // claims the acpi-tables (or devicetree-blob) node itself. Not a per-device
    // match — it is the discoverer, not a driver bound to one device.
    addDriver("discovery", device_manager_protocol.no_device, false);

    if (test_restart_mode) {
        // The driver-restart scenario's fixture: claims device 0 (the tree
        // root, otherwise unclaimed), hellos, then faults — driving backoff,
        // re-claim-after-death, and the crash-loop cap deterministically.
        addDriver("crash-test", 0, true);
    }

    if (matched == 0) {
        _ = logging.write("/system/services/device-manager: no matchable devices\n");
    } else {
        _ = logging.write("/system/services/device-manager: ok\n");
    }
    return true;
}

/// Set by `onSubscribe` when the subscriber table has taken ownership of the
/// capability the call carried, and read by `onMessage`, where the turn's
/// `Arrival` lives. The generated dispatch hands a handler the raw handle rather
/// than the `Arrival` — deliberately, since a handler has no business closing the
/// turn's property — so the *claim* travels back out this way. One turn, one
/// handler, one thread: there is nothing here to race.
var capability_claimed = false;

fn onMessage(message: []const u8, reply: []u8, sender: u32, arrived: *ipc.Arrival) usize {
    capability_claimed = false;
    const written = Serve.dispatch({}, handlers, message, sender, arrived.peek(), reply);
    if (capability_claimed) _ = arrived.take();
    return written;
}

const handlers = Serve.Handlers{
    .hello = onHello,
    .child_added = onChildAdded,
    .child_removed = onChildRemoved,
    .enumerate = onEnumerate,
    .subscribe = onSubscribe,
};

/// The handshake. The device this driver was assigned is the packet's target.
fn onHello(_: void, invocation: Invocation(device_manager_protocol.Hello), _: Answer(void)) isize {
    if (invocation.request.version != device_manager_protocol.version) {
        std.log.info("refused hello (version {d}) from process {d}", .{ invocation.request.version, invocation.sender });
        return -envelope.EPROTO;
    }
    const driver = driverByProcess(invocation.sender) orelse {
        std.log.info("hello from unknown process {d}", .{invocation.sender});
        return -envelope.EPERM;
    };
    driver.state = .running;
    std.log.info("hello from {s} (device {d})", .{ driver.name(), invocation.target });
    // Resilience drill (V6): once, kill the virtio-gpu driver a moment after it hellos, so
    // the normal restart policy respawns it — the compositor must survive and re-attach.
    if (test_scanout_restart_mode and !test_scanout_killed and std.mem.eql(u8, driver.name(), "/system/drivers/virtio-gpu")) {
        test_scanout_killed = true;
        test_kill_pid = invocation.sender;
        test_kill_due_ns = time.clock() + 1_500_000_000;
        _ = time.timerOnce(manager_endpoint, 1600);
    }
    return 0;
}

/// A bus driver reported a discovered device: mirror it, publish it, match a
/// driver for it — and in the restart drills kill the reporter once, the
/// deterministic trigger for prune -> backoff -> respawn -> re-report.
fn onChildAdded(_: void, invocation: Invocation(device_manager_protocol.ChildAdded), _: Answer(void)) isize {
    const report = invocation.request;
    const sender = invocation.sender;
    // The registered kernel device id is the packet's target, not a field: what
    // the manager hands a matched driver as its argv assignment.
    const device_id = invocation.target;

    var status: isize = 0;
    if (driverByProcess(sender)) |driver| {
        if (!addChild(report.parent, report.bus_address, report.identity, device_id, sender)) status = -envelope.ENOSPC;
        std.log.info("child added (device {d} port {d}, identity {d}) by {s}", .{ report.parent, report.bus_address, report.identity, driver.name() });
        if (status == 0) publish(.child_added, device_id, report);
        // Matching from reports (M19.3), now data-driven via the /system/configuration/devices.csv
        // registry: a registered child gets the most-specific driver its identity
        // matches, once — re-reports after a bus restart dedupe on the registered
        // id, exactly like the registrations do.
        if (status == 0 and device_id != device_manager_protocol.no_device) {
            const id = identityFromReport(report);
            if (registry.matchDriver(registry_rules[0..registry_count], id)) |match| {
                if (match.ambiguous)
                    std.log.info("/system/configuration/devices.csv: multiple equally-specific rules match the device {s} reported; binding {s}", .{ driver.name(), match.driver });
                if (id.bus == .acpi) {
                    // An hid-matched driver (ps2-bus) is a singleton that finds its
                    // own devices once spawned — spawn it once, no device assignment.
                    if (!alreadySupervised(match.driver)) addDriver(match.driver, device_manager_protocol.no_device, false);
                } else {
                    // A per-device driver: one instance, the registered id as argv[1].
                    if (!driverForDevice(device_id)) addDriver(match.driver, device_id, true);
                }
            }
        }
    } else {
        status = -envelope.EPERM;
    }
    if (test_pci_restart_mode and !test_usb_killed) {
        if (driverByProcess(sender)) |driver| {
            if (std.mem.eql(u8, driver.name(), "pci-bus") and childCountOf(sender) >= 3) {
                // The pci restart drill: kill the enumerator after it has
                // reported; the respawn must re-register without duplicates
                // (M19.0 idempotence, proven end to end by pci-scan).
                test_usb_killed = true;
                test_kill_pid = sender;
                test_kill_due_ns = time.clock() + 1_000_000_000;
                _ = time.timerOnce(manager_endpoint, 1100);
            }
        }
    }
    if (test_usb_restart_mode and !test_usb_killed and childCountOf(sender) >= 2) {
        // Only the xHCI reporter is the drill's victim — pci-bus also reports
        // now, and whichever finishes second must not trigger the kill.
        if (driverByProcess(sender)) |driver| {
            if (std.mem.eql(u8, driver.name(), "/system/drivers/usb-xhci-bus")) {
                // Delayed, not immediate: the device-list scenario's subscriber
                // needs a window to enumerate and subscribe before the events.
                test_usb_killed = true;
                test_kill_pid = sender;
                test_kill_due_ns = time.clock() + 2_000_000_000;
                _ = time.timerOnce(manager_endpoint, 2100);
            }
        }
    }
    return status;
}

/// A bus driver reported a device gone (hot-unplug). Addressed by the composite
/// (parent, bus address) the reporter knows, which is why that pair is the
/// packet's body rather than its target.
fn onChildRemoved(_: void, invocation: Invocation(device_manager_protocol.ChildRemoved), _: Answer(void)) isize {
    const report = invocation.request;
    var status: isize = -envelope.ENOENT;
    for (&children) |*child| {
        if (child.used and child.parent == report.parent and child.bus_address == report.bus_address and child.reporter == invocation.sender) {
            std.log.info("child removed (device {d} port {d})", .{ child.parent, child.bus_address });
            child.used = false;
            status = 0;
        }
    }
    return status;
}

/// The reserved `enumerate` verb: the mirror, one `ChildEntry` per known child,
/// packed into the reply's tail. How many arrived is the reply's own length —
/// `Status.len` — so no count header is spent saying it twice.
fn onEnumerate(_: void, _: Invocation(void), answer: Answer(void)) isize {
    const entry_size = @sizeOf(device_manager_protocol.ChildEntry);
    const tail = answer.tail();
    var written: usize = 0;
    for (&children) |*child| {
        if (!child.used) continue;
        if (written + entry_size > tail.len) break;
        const entry = device_manager_protocol.ChildEntry{ .parent = child.parent, .bus_address = child.bus_address, .identity = child.identity };
        @memcpy(tail[written..][0..entry_size], std.mem.asBytes(&entry));
        written += entry_size;
    }
    return @intCast(written);
}

/// The reserved `subscribe` verb: an application's endpoint arrived as the call's
/// capability. The table taking a slot is what claims it; a full table refuses
/// and lets the turn close it, so a subscribe storm cannot spend the handle table.
fn onSubscribe(_: void, invocation: Invocation(void), _: Answer(void)) isize {
    const endpoint = invocation.capability orelse return -envelope.EPROTO;
    for (&subscribers) |*slot| {
        if (slot.* == null) {
            slot.* = endpoint;
            capability_claimed = true; // the table holds it from here
            return 0;
        }
    }
    return -envelope.ENOSPC;
}

fn onNotification(badge: u64) void {
    if (badge & ipc.notify_exit_bit != 0) {
        const dead: u32 = @intCast(badge & ~(ipc.notify_badge_bit | ipc.notify_exit_bit));
        if (driverByProcess(dead)) |driver| onDriverExit(driver);
        return;
    }
    if (badge & ipc.notify_timer_bit != 0) sweepDeadlines();
}

pub fn main(init: process.Init) void {
    if (init.arguments.get(1)) |mode| {
        test_restart_mode = std.mem.eql(u8, mode, "test-restart");
        test_usb_restart_mode = std.mem.eql(u8, mode, "test-usb-restart");
        test_pci_restart_mode = std.mem.eql(u8, mode, "test-pci-restart");
        test_scanout_restart_mode = std.mem.eql(u8, mode, "test-scanout-restart");
    }
    service.run(device_manager_protocol.message_maximum, .{
        .service = "device-manager",
        .init = initialise,
        .on_message = onMessage,
        .on_notification = onNotification,
    });
}