CoreBluetooth: Handle orphaned objects

When a device has disconnected and then reconnected, existing references to bluetooth objects may become orphaned and accessing their parent object will return `nil`.
alexmoon · Oct 4, 2024 · 054dfe8 · 054dfe8
1 parent 70be759
commit 054dfe8
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Showing 4 changed files with 74 additions and 26 deletions.
diff --git a/src/corebluetooth/characteristic.rs b/src/corebluetooth/characteristic.rs
@@ -56,8 +56,13 @@ impl CharacteristicImpl {
 
     /// Read the value of this characteristic from the device
     pub async fn read(&self) -> Result<Vec<u8>> {
-        let service = self.inner.service();
-        let peripheral = service.peripheral();
+        let service = self
+            .inner
+            .service()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "service not found"))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
@@ -92,8 +97,13 @@ impl CharacteristicImpl {
     /// Write the value of this descriptor on the device to `value` and request the device return a response indicating
     /// a successful write.
     pub async fn write(&self, value: &[u8]) -> Result<()> {
-        let service = self.inner.service();
-        let peripheral = service.peripheral();
+        let service = self
+            .inner
+            .service()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "service not found"))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
@@ -126,8 +136,13 @@ impl CharacteristicImpl {
 
     /// Write the value of this descriptor on the device to `value` without requesting a response.
     pub async fn write_without_response(&self, value: &[u8]) -> Result<()> {
-        let service = self.inner.service();
-        let peripheral = service.peripheral();
+        let service = self
+            .inner
+            .service()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "service not found"))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
@@ -156,7 +171,11 @@ impl CharacteristicImpl {
 
     /// Get the maximum amount of data that can be written in a single packet for this characteristic.
     pub fn max_write_len(&self) -> Result<usize> {
-        let peripheral = self.inner.service().peripheral();
+        let peripheral = self.inner.service().and_then(|x| x.peripheral()).ok_or(Error::new(
+            ErrorKind::NotFound,
+            None,
+            "peripheral not found",
+        ))?;
         Ok(peripheral.maximum_write_value_length_for_type(CBCharacteristicWriteType::WithoutResponse))
     }
 
@@ -174,12 +193,17 @@ impl CharacteristicImpl {
             return Err(Error::new(
                 ErrorKind::NotSupported,
                 None,
-                "characteristic does not support indications or notifications".to_string(),
+                "characteristic does not support indications or notifications",
             ));
         };
 
-        let service = self.inner.service();
-        let peripheral = service.peripheral();
+        let service = self
+            .inner
+            .service()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "service not found"))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
@@ -188,8 +212,9 @@ impl CharacteristicImpl {
 
         peripheral.set_notify(&self.inner, true);
         let guard = defer(move || {
-            let peripheral = self.inner.service().peripheral();
-            peripheral.set_notify(&self.inner, false);
+            if let Some(peripheral) = self.inner.service().and_then(|x| x.peripheral()) {
+                peripheral.set_notify(&self.inner, false);
+            }
         });
 
         loop {
@@ -254,8 +279,13 @@ impl CharacteristicImpl {
 
     /// Discover the descriptors associated with this characteristic.
     pub async fn discover_descriptors(&self) -> Result<Vec<Descriptor>> {
-        let service = self.inner.service();
-        let peripheral = service.peripheral();
+        let service = self
+            .inner
+            .service()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "service not found"))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {

diff --git a/src/corebluetooth/descriptor.rs b/src/corebluetooth/descriptor.rs
@@ -76,8 +76,14 @@ impl DescriptorImpl {
 
     /// Read the value of this descriptor from the device
     pub async fn read(&self) -> Result<Vec<u8>> {
-        let service = self.inner.characteristic().service();
-        let peripheral = service.peripheral();
+        let service = self.inner.characteristic().and_then(|x| x.service()).ok_or(Error::new(
+            ErrorKind::NotFound,
+            None,
+            "service not found",
+        ))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
@@ -108,8 +114,14 @@ impl DescriptorImpl {
 
     /// Write the value of this descriptor on the device to `value`
     pub async fn write(&self, value: &[u8]) -> Result<()> {
-        let service = self.inner.characteristic().service();
-        let peripheral = service.peripheral();
+        let service = self.inner.characteristic().and_then(|x| x.service()).ok_or(Error::new(
+            ErrorKind::NotFound,
+            None,
+            "service not found",
+        ))?;
+        let peripheral = service
+            .peripheral()
+            .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
         let mut receiver = self.delegate.sender().new_receiver();
 
         if peripheral.state() != CBPeripheralState::CONNECTED {

diff --git a/src/corebluetooth/service.rs b/src/corebluetooth/service.rs
@@ -55,7 +55,10 @@ impl ServiceImpl {
     }
 
     async fn discover_characteristics_inner(&self, uuids: Option<&NSArray<CBUUID>>) -> Result<Vec<Characteristic>> {
-        let peripheral = self.inner.peripheral();
+        let peripheral =
+            self.inner
+                .peripheral()
+                .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
             return Err(ErrorKind::NotConnected.into());
@@ -123,7 +126,10 @@ impl ServiceImpl {
     }
 
     async fn discover_included_services_inner(&self, uuids: Option<&NSArray<CBUUID>>) -> Result<Vec<Service>> {
-        let peripheral = self.inner.peripheral();
+        let peripheral =
+            self.inner
+                .peripheral()
+                .ok_or(Error::new(ErrorKind::NotFound, None, "peripheral not found"))?;
 
         if peripheral.state() != CBPeripheralState::CONNECTED {
             return Err(ErrorKind::NotConnected.into());

diff --git a/src/corebluetooth/types.rs b/src/corebluetooth/types.rs
@@ -499,8 +499,8 @@ impl CBService {
         autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, UUID]) })
     }
 
-    pub fn peripheral(&self) -> ShareId<CBPeripheral> {
-        autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, peripheral]) })
+    pub fn peripheral(&self) -> Option<ShareId<CBPeripheral>> {
+        autoreleasepool(move || unsafe { option_from_ptr(msg_send![self, peripheral]) })
     }
 
     pub fn is_primary(&self) -> bool {
@@ -522,8 +522,8 @@ impl CBCharacteristic {
         autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, UUID]) })
     }
 
-    pub fn service(&self) -> ShareId<CBService> {
-        autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, service]) })
+    pub fn service(&self) -> Option<ShareId<CBService>> {
+        autoreleasepool(move || unsafe { option_from_ptr(msg_send![self, service]) })
     }
 
     pub fn value(&self) -> Option<ShareId<NSData>> {
@@ -554,8 +554,8 @@ impl CBDescriptor {
         autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, UUID]) })
     }
 
-    pub fn characteristic(&self) -> ShareId<CBCharacteristic> {
-        autoreleasepool(move || unsafe { ShareId::from_ptr(msg_send![self, characteristic]) })
+    pub fn characteristic(&self) -> Option<ShareId<CBCharacteristic>> {
+        autoreleasepool(move || unsafe { option_from_ptr(msg_send![self, characteristic]) })
     }
 
     pub fn value(&self) -> Option<ShareId<NSObject>> {