bluetooth: Require context is connected for getCharacteristic(s)

third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp

Index: third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp
diff --git a/third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp b/third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp
index 4aa0caeaa30dc83494d81ed4d0fbeb2d019a8c23..ba41051685c1056b7f47514ab2b224338b71affc 100644
--- a/third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp
+++ b/third_party/WebKit/Source/modules/bluetooth/BluetoothRemoteGATTService.cpp
@@ -20,6 +20,15 @@
 
 namespace blink {
 
+namespace {
+
+const char kGATTServerDisconnected[] =
+    "GATT Server disconnected while retrieving characteristics.";
+const char kGATTServerNotConnected[] =
+    "GATT Server is disconnected. Cannot retrieve characteristics.";
+
+}  // namespace
+
 BluetoothRemoteGATTService::BluetoothRemoteGATTService(
     std::unique_ptr<WebBluetoothRemoteGATTService> webService,
     BluetoothDevice* device)
@@ -48,7 +57,12 @@ class GetCharacteristicsCallback
       BluetoothRemoteGATTService* service,
       mojom::blink::WebBluetoothGATTQueryQuantity quantity,
       ScriptPromiseResolver* resolver)
-      : m_service(service), m_quantity(quantity), m_resolver(resolver) {}
+      : m_service(service), m_quantity(quantity), m_resolver(resolver) {
+    // We always check that the device is connected before constructing this
+    // object.
+    CHECK(m_service->device()->gatt()->connected());
+    m_service->device()->gatt()->AddToActiveAlgorithms(m_resolver.get());
+  }
 
   void onSuccess(const WebVector<WebBluetoothRemoteGATTCharacteristicInit*>&
                      webCharacteristics) override {
@@ -56,6 +70,15 @@ class GetCharacteristicsCallback
         m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
       return;
 
+    // If the resolver is not in the set of ActiveAlgorithms then the frame
+    // disconnected so we reject.
+    if (!m_service->device()->gatt()->RemoveFromActiveAlgorithms(
+            m_resolver.get())) {
+      m_resolver->reject(
+          DOMException::create(NetworkError, kGATTServerDisconnected));
+      return;
+    }
+
     if (m_quantity == mojom::blink::WebBluetoothGATTQueryQuantity::SINGLE) {
       DCHECK_EQ(1u, webCharacteristics.size());
       m_resolver->resolve(BluetoothRemoteGATTCharacteristic::take(
@@ -80,6 +103,7 @@ class GetCharacteristicsCallback
     if (!m_resolver->getExecutionContext() ||
         m_resolver->getExecutionContext()->activeDOMObjectsAreStopped())
       return;
+    m_service->device()->gatt()->RemoveFromActiveAlgorithms(m_resolver.get());

[Jeffrey Yasskin, 2016/10/06 17:50:32]

https://webbluetoothcg.github.io/web-bluetooth/#connection-checking-wrapper says
to replace the real error with a NetworkError if we've disconnected during the
operation. We get there through the
https://webbluetoothcg.github.io/web-bluetooth/#query-the-bluetooth-cache step
of https://webbluetoothcg.github.io/web-bluetooth/#getgattchildren.

I think that's even the right behavior. ;-)

[ortuno, 2016/10/07 04:45:59]

Done.

     m_resolver->reject(BluetoothError::take(m_resolver, error));
   }
 
@@ -128,6 +152,12 @@ ScriptPromise BluetoothRemoteGATTService::getCharacteristicsImpl(
     ScriptState* scriptState,
     mojom::blink::WebBluetoothGATTQueryQuantity quantity,
     String characteristicsUUID) {
+  if (!device()->gatt()->connected()) {
+    return ScriptPromise::rejectWithDOMException(
+        scriptState,
+        DOMException::create(NetworkError, kGATTServerNotConnected));
+  }
+
   ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
   ScriptPromise promise = resolver->promise();