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Allow transient Windows GATT startup aborts to settle #674

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Merged
enaboapps merged 3 commits into from
Aug 30, 2026
Merged

Allow transient Windows GATT startup aborts to settle #674

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2d6fbc5
fix: settle transient Windows GATT aborts
OwenMcGirr Aug 30, 2026
9a76def
fix: publish settled advertising state
OwenMcGirr Aug 30, 2026
85b0e8a
fix: guard final GATT state publication
OwenMcGirr Aug 30, 2026
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278 changes: 223 additions & 55 deletions src-tauri/src/windows_runtime.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -48,6 +48,7 @@ const STATUS_UUID: GUID = GUID::from_u128(0x7a78f7eb_1d6d_4d92_9ef0_1f89d3db21f4
const NOTIFICATION_BYTES: usize = 160;
const MAX_QUEUED_NOTIFICATION_FRAMES: usize = 512;
const NOTIFICATION_DELIVERY_ERROR: &str = "Bluetooth notification could not be delivered.";
const ADVERTISEMENT_STARTUP_TIMEOUT: Duration = Duration::from_secs(2);

#[derive(Debug)]
struct QueuedNotificationMessage {
Expand Down Expand Up @@ -1001,7 +1002,6 @@ async fn start_gatt(
if let Some(args) = args.cloned() {
let status = args.Status()?;
let error = args.Error()?;
update_advertisement_status(&status_app, &status_shared, status, error);
let (recovering, active) = {
let lifecycle = status_lifecycle
.lock()
Expand All @@ -1012,16 +1012,21 @@ async fn start_gatt(
)
};
if recovering {
let startup_result =
if status == GattServiceProviderAdvertisementStatus::Started {
Some(Ok(()))
} else if advertisement_status_is_terminal_failure(status) {
Some(Err(format!(
"Bluetooth advertising failed to start ({status:?}, {error:?})."
)))
} else {
None
};
let decision = advertisement_startup_decision(status, error);
update_startup_advertisement_status(
&status_app,
&status_shared,
status,
error,
decision,
);
let startup_result = match decision {
AdvertisementStartupDecision::Ready => Some(Ok(())),
AdvertisementStartupDecision::Pending => None,
AdvertisementStartupDecision::Failed => Some(Err(format!(
"Bluetooth advertising failed to start ({status:?}, {error:?})."
))),
};
if let Some(startup_result) = startup_result {
if let Some(sender) = callback_advertising_sender
.lock()
Expand All @@ -1031,19 +1036,22 @@ async fn start_gatt(
let _ = sender.send(startup_result);
}
}
} else if advertisement_status_needs_recovery(status) && active {
let recovery_app = status_app.clone();
let recovery_shared = status_shared.clone();
let recovery_lifecycle = status_lifecycle.clone();
tauri::async_runtime::spawn(async move {
tokio::task::yield_now().await;
recover_after_advertising_stopped(
recovery_app,
recovery_shared,
recovery_lifecycle,
generation,
);
});
} else {
update_advertisement_status(&status_app, &status_shared, status, error);
if advertisement_status_needs_recovery(status) && active {
let recovery_app = status_app.clone();
let recovery_shared = status_shared.clone();
let recovery_lifecycle = status_lifecycle.clone();
tauri::async_runtime::spawn(async move {
tokio::task::yield_now().await;
recover_after_advertising_stopped(
recovery_app,
recovery_shared,
recovery_lifecycle,
generation,
);
});
}
}
}
Ok(())
Expand Down Expand Up @@ -1086,25 +1094,40 @@ async fn start_gatt(
let status = provider
.AdvertisementStatus()
.map_err(|error| error.to_string())?;
update_advertisement_status(&app, &shared, status, BluetoothError::Success);
if status == GattServiceProviderAdvertisementStatus::Started {
advertising_sender
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.take();
} else if advertisement_status_is_terminal_failure(status) {
advertising_sender
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.take();
return Err(format!(
"Bluetooth advertising did not start completely ({status:?})."
));
} else {
tokio::time::timeout(Duration::from_secs(2), advertising_receiver)
.await
.map_err(|_| "Bluetooth advertising did not report readiness in time.".to_string())?
.map_err(|_| "Bluetooth advertising readiness was cancelled.".to_string())??;
let decision = advertisement_startup_decision(status, BluetoothError::Success);
update_startup_advertisement_status(&app, &shared, status, BluetoothError::Success, decision);
match decision {
AdvertisementStartupDecision::Ready => {
advertising_sender
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.take();
}
AdvertisementStartupDecision::Failed => {
advertising_sender
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.take();
return Err(format!(
"Bluetooth advertising did not start completely ({status:?})."
));
}
AdvertisementStartupDecision::Pending => {
wait_for_advertising_readiness(
advertising_receiver,
ADVERTISEMENT_STARTUP_TIMEOUT,
|| {
provider
.AdvertisementStatus()
.map_err(|error| error.to_string())
},
)
.await?;
advertising_sender
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.take();
}
}
let mut lifecycle = lifecycle
.lock()
Expand All @@ -1120,21 +1143,86 @@ async fn start_gatt(
if !lifecycle.mark_active(generation) {
return Err("Bluetooth recovery was superseded before advertising became active.".into());
}
update_advertisement_status(&app, &shared, current_status, BluetoothError::Success);
Ok(())
}

fn advertisement_status_needs_recovery(status: GattServiceProviderAdvertisementStatus) -> bool {
status != GattServiceProviderAdvertisementStatus::Started
}

fn advertisement_status_is_terminal_failure(
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum AdvertisementStartupDecision {
Ready,
Pending,
Failed,
}

fn advertisement_startup_decision(
status: GattServiceProviderAdvertisementStatus,
) -> bool {
matches!(
status,
GattServiceProviderAdvertisementStatus::Aborted
| GattServiceProviderAdvertisementStatus::StartedWithoutAllAdvertisementData
)
error: BluetoothError,
) -> AdvertisementStartupDecision {
if status == GattServiceProviderAdvertisementStatus::Started {
AdvertisementStartupDecision::Ready
} else if status == GattServiceProviderAdvertisementStatus::StartedWithoutAllAdvertisementData
|| (status == GattServiceProviderAdvertisementStatus::Aborted
&& error != BluetoothError::Success)
{
AdvertisementStartupDecision::Failed
} else {
AdvertisementStartupDecision::Pending
}
}

async fn wait_for_advertising_readiness<F>(
receiver: tokio::sync::oneshot::Receiver<Result<(), String>>,
timeout: Duration,
final_status: F,
) -> Result<(), String>
where
F: FnOnce() -> Result<GattServiceProviderAdvertisementStatus, String>,
{
match tokio::time::timeout(timeout, receiver).await {
Ok(Ok(result)) => result,
Ok(Err(_cancelled)) => Err("Bluetooth advertising readiness was cancelled.".into()),
Err(_elapsed) => {
let status = final_status()?;
if status == GattServiceProviderAdvertisementStatus::Started {
Ok(())
} else {
Err(format!(
"Bluetooth advertising did not report readiness in time ({status:?})."
))
}
}
}
}

fn update_startup_advertisement_status(
app: &AppHandle,
shared: &SharedModel,
status: GattServiceProviderAdvertisementStatus,
error: BluetoothError,
decision: AdvertisementStartupDecision,
) {
match decision {
AdvertisementStartupDecision::Ready | AdvertisementStartupDecision::Failed => {
update_advertisement_status(app, shared, status, error);
}
AdvertisementStartupDecision::Pending => {
shared
.lock()
.unwrap_or_else(|poisoned| poisoned.into_inner())
.state
.bluetooth = BluetoothState::Initializing;
set_activity(
shared,
ActivityKind::Info,
"Waiting for Bluetooth advertising to become ready.",
);
emit_state(app, shared);
}
}
}

fn recover_after_advertising_stopped(
Expand Down Expand Up @@ -2073,11 +2161,12 @@ fn release_input_session() {
#[cfg(test)]
mod tests {
use super::{
advertisement_status_needs_recovery, pointer_profile_for_display, run_notification_worker,
select_notification_bytes, should_cancel_pending_pairings,
tasklist_has_other_switchify_process, validate_notification_statuses,
NotificationDispatcher, MAX_QUEUED_NOTIFICATION_FRAMES, NOTIFICATION_BYTES,
NOTIFICATION_DELIVERY_ERROR,
advertisement_startup_decision, advertisement_status_needs_recovery,
pointer_profile_for_display, run_notification_worker, select_notification_bytes,
should_cancel_pending_pairings, tasklist_has_other_switchify_process,
validate_notification_statuses, wait_for_advertising_readiness,
AdvertisementStartupDecision, NotificationDispatcher, MAX_QUEUED_NOTIFICATION_FRAMES,
NOTIFICATION_BYTES, NOTIFICATION_DELIVERY_ERROR,
};
use crate::display_navigation::Display;
use crate::input::AndroidTypingRoute;
Expand All @@ -2091,6 +2180,7 @@ mod tests {
use std::sync::{Arc, Mutex};
use std::time::Duration;
use tokio::sync::oneshot;
use windows::Devices::Bluetooth::BluetoothError;
use windows::Devices::Bluetooth::GenericAttributeProfile::{
GattCommunicationStatus, GattServiceProviderAdvertisementStatus,
};
Expand Down Expand Up @@ -2190,6 +2280,84 @@ mod tests {
));
}

#[test]
fn transient_startup_statuses_wait_for_windows_to_settle() {
for status in [
GattServiceProviderAdvertisementStatus::Created,
GattServiceProviderAdvertisementStatus::Stopped,
GattServiceProviderAdvertisementStatus::Aborted,
] {
assert_eq!(
advertisement_startup_decision(status, BluetoothError::Success),
AdvertisementStartupDecision::Pending
);
}
assert_eq!(
advertisement_startup_decision(
GattServiceProviderAdvertisementStatus::Started,
BluetoothError::Success,
),
AdvertisementStartupDecision::Ready
);
}

#[test]
fn real_abort_errors_and_incomplete_advertising_fail_startup() {
assert_eq!(
advertisement_startup_decision(
GattServiceProviderAdvertisementStatus::Aborted,
BluetoothError::OtherError,
),
AdvertisementStartupDecision::Failed
);
assert_eq!(
advertisement_startup_decision(
GattServiceProviderAdvertisementStatus::StartedWithoutAllAdvertisementData,
BluetoothError::Success,
),
AdvertisementStartupDecision::Failed
);
}

#[tokio::test]
async fn transient_abort_can_be_followed_by_started() {
let (sender, receiver) = oneshot::channel();
sender.send(Ok(())).unwrap();
wait_for_advertising_readiness(receiver, Duration::from_secs(1), || {
panic!("a ready callback must avoid the timeout status check")
})
.await
.unwrap();
}

#[tokio::test]
async fn persistent_abort_fails_after_the_settling_window() {
let (_sender, receiver) = oneshot::channel();
assert_eq!(
wait_for_advertising_readiness(receiver, Duration::ZERO, || {
Ok(GattServiceProviderAdvertisementStatus::Aborted)
})
.await,
Err(format!(
"Bluetooth advertising did not report readiness in time ({:?}).",
GattServiceProviderAdvertisementStatus::Aborted
))
);
}

#[tokio::test]
async fn cancelled_startup_stops_waiting_for_readiness() {
let (sender, receiver) = oneshot::channel();
drop(sender);
assert_eq!(
wait_for_advertising_readiness(receiver, Duration::from_secs(1), || {
panic!("a cancelled callback must avoid the timeout status check")
})
.await,
Err("Bluetooth advertising readiness was cancelled.".into())
);
}

#[test]
fn notification_size_uses_the_smallest_current_subscriber_limit() {
assert_eq!(select_notification_bytes([Some(514)]), Some(514));
Expand Down