Bug 599970 - Add GetInterface for nsIEventTarget on Connection

r=asuth

storage/src/mozStorageAsyncStatement.cpp

@@ -271,7 +271,8 @@ AsyncStatement::~AsyncStatement()
     // nsCOMPtr.  Which it is not; it's an nsRefPtr.
     Connection *forgottenConn = nsnull;
     mDBConnection.swap(forgottenConn);
-    (void)::NS_ProxyRelease(forgottenConn->threadOpenedOn, forgottenConn);
+    (void)::NS_ProxyRelease(forgottenConn->threadOpenedOn,
+                            static_cast<mozIStorageConnection *>(forgottenConn));
   }
 }
 

storage/src/mozStorageConnection.cpp

@@ -322,7 +322,7 @@ public:
     return NS_OK;
   }
 private:
-  nsCOMPtr<Connection> mConnection;
+  nsRefPtr<Connection> mConnection;
   nsCOMPtr<nsIEventTarget> mCallingThread;
   nsCOMPtr<nsIRunnable> mCallbackEvent;
 };
@@ -352,9 +352,10 @@ Connection::~Connection()
   (void)Close();
 }
 
-NS_IMPL_THREADSAFE_ISUPPORTS1(
+NS_IMPL_THREADSAFE_ISUPPORTS2(
   Connection,
-  mozIStorageConnection
+  mozIStorageConnection,
+  nsIInterfaceRequestor
 )
 
 nsIEventTarget *
@@ -641,6 +642,22 @@ Connection::getFilename()
   return leafname;
 }
 
+////////////////////////////////////////////////////////////////////////////////
+//// nsIInterfaceRequestor
+
+NS_IMETHODIMP
+Connection::GetInterface(const nsIID &aIID,
+                         void **_result)
+{
+  if (aIID.Equals(NS_GET_IID(nsIEventTarget))) {
+    nsIEventTarget *background = getAsyncExecutionTarget();
+    NS_IF_ADDREF(background);
+    *_result = background;
+    return NS_OK;
+  }
+  return NS_ERROR_NO_INTERFACE;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 //// mozIStorageConnection
 

storage/src/mozStorageConnection.h

@@ -38,12 +38,13 @@
  *
  * ***** END LICENSE BLOCK ***** */
 
-#ifndef MOZSTORAGECONNECTION_H
-#define MOZSTORAGECONNECTION_H
+#ifndef mozilla_storage_Connection_h
+#define mozilla_storage_Connection_h
 
 #include "nsAutoPtr.h"
 #include "nsCOMPtr.h"
 #include "mozilla/Mutex.h"
+#include "nsIInterfaceRequestor.h"
 
 #include "nsString.h"
 #include "nsDataHashtable.h"
@@ -65,10 +66,12 @@ namespace mozilla {
 namespace storage {
 
 class Connection : public mozIStorageConnection
+                 , public nsIInterfaceRequestor
 {
 public:
   NS_DECL_ISUPPORTS
   NS_DECL_MOZISTORAGECONNECTION
+  NS_DECL_NSIINTERFACEREQUESTOR
 
   /**
    * Structure used to describe user functions on the database connection.
@@ -244,4 +247,4 @@ private:
 } // namespace storage
 } // namespace mozilla
 
-#endif /* MOZSTORAGECONNECTION_H */
+#endif // mozilla_storage_Connection_h

storage/test/test_true_async.cpp

@@ -39,6 +39,7 @@
 #include "storage_test_harness.h"
 #include "prthread.h"
 #include "nsIEventTarget.h"
+#include "nsIInterfaceRequestorUtils.h"
 
 #include "sqlite3.h"
 
@@ -221,6 +222,14 @@ get_conn_async_thread(mozIStorageConnection *db)
   nsCOMPtr<nsIThread> asyncThread;
   threadMan->GetThreadFromPRThread(last_non_watched_thread,
                                    getter_AddRefs(asyncThread));
+
+  // Additionally, check that the thread we get as the background thread is the
+  // same one as the one we report from getInterface.
+  nsCOMPtr<nsIEventTarget> target = do_GetInterface(db);
+  nsCOMPtr<nsIThread> allegedAsyncThread = do_QueryInterface(target);
+  PRThread *allegedPRThread;
+  (void)allegedAsyncThread->GetPRThread(&allegedPRThread);
+  do_check_eq(allegedPRThread, last_non_watched_thread);
   return asyncThread.forget();
 }
 

storage/test/unit/test_storage_connection.js

@@ -482,6 +482,18 @@ function test_clone_copies_overridden_functions()
   run_next_test();
 }
 
+function test_getInterface()
+{
+  let db = getOpenedDatabase();
+  let target = db.QueryInterface(Ci.nsIInterfaceRequestor)
+                 .getInterface(Ci.nsIEventTarget);
+  // Just check that target is non-null.  Other tests will ensure that it has
+  // the correct value.
+  do_check_true(target != null);
+
+  run_next_test();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 //// Test Runner
 
@@ -513,6 +525,7 @@ var tests = [
   test_close_clone_fails,
   test_clone_copies_functions,
   test_clone_copies_overridden_functions,
+  test_getInterface,
 ];
 let index = 0;