fix(async): Changing all await calls to .ConfigureAwait(false)

rozele · rozele · commit b72bf77e25ff · 2016-10-05T09:47:20.000-04:00
The async calls in CodePush for ReactWindows can all be executed on any background thread, so adding .ConfigureAwait(false) can improve performance and reduce the likelihood of deadlock. The blocking calls in `InitializeUpdateAfterRestart()` were hanging, but now that .ConfigureAwait(false) is used pervasively, it is no longer a problem. Fixes #550
diff --git a/windows/CodePushNativeModule.cs b/windows/CodePushNativeModule.cs
@@ -57,7 +57,7 @@ public async void downloadUpdate(JObject updatePackage, bool notifyProgress, IPr
         {
             try
             {
-                updatePackage[CodePushConstants.BinaryModifiedTimeKey] = "" + await _codePush.GetBinaryResourcesModifiedTimeAsync();
+                updatePackage[CodePushConstants.BinaryModifiedTimeKey] = "" + await _codePush.GetBinaryResourcesModifiedTimeAsync().ConfigureAwait(false);
                 await _codePush.UpdateManager.DownloadPackageAsync(
                     updatePackage,
                     _codePush.AssetsBundleFileName,
@@ -80,9 +80,9 @@ await _codePush.UpdateManager.DownloadPackageAsync(
                                 .emit(CodePushConstants.DownloadProgressEventName, downloadProgress);
                         }
                     )
-                );
+                ).ConfigureAwait(false);
 
-                JObject newPackage = await _codePush.UpdateManager.GetPackageAsync((string)updatePackage[CodePushConstants.PackageHashKey]);
+                JObject newPackage = await _codePush.UpdateManager.GetPackageAsync((string)updatePackage[CodePushConstants.PackageHashKey]).ConfigureAwait(false);
                 promise.Resolve(newPackage);
             }
             catch (InvalidDataException e)
@@ -121,7 +121,7 @@ public void getConfiguration(IPromise promise)
         [ReactMethod]
         public async void getUpdateMetadata(UpdateState updateState, IPromise promise)
         {
-            JObject currentPackage = await _codePush.UpdateManager.GetCurrentPackageAsync();
+            JObject currentPackage = await _codePush.UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);
             if (currentPackage == null)
             {
                 promise.Resolve("");
@@ -146,7 +146,7 @@ public async void getUpdateMetadata(UpdateState updateState, IPromise promise)
             {
                 // The caller wants the running update, but the current
                 // one is pending, so we need to grab the previous.
-                promise.Resolve(await _codePush.UpdateManager.GetPreviousPackageAsync());
+                promise.Resolve(await _codePush.UpdateManager.GetPreviousPackageAsync().ConfigureAwait(false));
             }
             else
             {
@@ -179,7 +179,7 @@ public void getNewStatusReport(IPromise promise)
         [ReactMethod]
         public async void installUpdate(JObject updatePackage, InstallMode installMode, int minimumBackgroundDuration, IPromise promise)
         {
-            await _codePush.UpdateManager.InstallPackageAsync(updatePackage, SettingsManager.IsPendingUpdate(null));
+            await _codePush.UpdateManager.InstallPackageAsync(updatePackage, SettingsManager.IsPendingUpdate(null)).ConfigureAwait(false);
             var pendingHash = (string)updatePackage[CodePushConstants.PackageHashKey];
             SettingsManager.SavePendingUpdate(pendingHash, /* isLoading */false);
             if (installMode == InstallMode.OnNextResume)
@@ -191,7 +191,7 @@ public async void installUpdate(JObject updatePackage, InstallMode installMode,
                     {
                         Context.RunOnNativeModulesQueueThread(async () =>
                         {
-                            await LoadBundleAsync();
+                            await LoadBundleAsync().ConfigureAwait(false);
                         });
                     };
                         
@@ -219,7 +219,7 @@ public async void isFirstRun(string packageHash, IPromise promise)
             bool isFirstRun = _codePush.DidUpdate
                 && packageHash != null
                 && packageHash.Length > 0
-                && packageHash.Equals(await _codePush.UpdateManager.GetCurrentPackageHashAsync());
+                && packageHash.Equals(await _codePush.UpdateManager.GetCurrentPackageHashAsync().ConfigureAwait(false));
             promise.Resolve(isFirstRun);
         }
 
@@ -237,7 +237,7 @@ public async void restartApp(bool onlyIfUpdateIsPending)
             // is current pending update, then reload the app.
             if (!onlyIfUpdateIsPending || SettingsManager.IsPendingUpdate(null))
             {
-                await LoadBundleAsync();
+                await LoadBundleAsync().ConfigureAwait(false);
             }
         }
         
@@ -254,7 +254,7 @@ internal async Task LoadBundleAsync()
 
             // #2) Update the locally stored JS bundle file path
             Type reactInstanceManagerType = typeof(ReactInstanceManager);
-            string latestJSBundleFile = await _codePush.GetJavaScriptBundleFileAsync(_codePush.AssetsBundleFileName);
+            string latestJSBundleFile = await _codePush.GetJavaScriptBundleFileAsync(_codePush.AssetsBundleFileName).ConfigureAwait(false);
             reactInstanceManagerType
                 .GetField("_jsBundleFile", BindingFlags.NonPublic | BindingFlags.Instance)
                 .SetValue(reactInstanceManager, latestJSBundleFile);
diff --git a/windows/CodePushReactPackage.cs b/windows/CodePushReactPackage.cs
@@ -85,8 +85,8 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa
         {
             AssetsBundleFileName = assetsBundleFileName;
             string binaryJsBundleUrl = CodePushConstants.AssetsBundlePrefix + assetsBundleFileName;
-            var binaryResourcesModifiedTime = await GetBinaryResourcesModifiedTimeAsync();
-            var packageFile = await UpdateManager.GetCurrentPackageBundleAsync(AssetsBundleFileName);
+            var binaryResourcesModifiedTime = await GetBinaryResourcesModifiedTimeAsync().ConfigureAwait(false);
+            var packageFile = await UpdateManager.GetCurrentPackageBundleAsync(AssetsBundleFileName).ConfigureAwait(false);
             if (packageFile == null)
             {
                 // There has not been any downloaded updates.
@@ -95,7 +95,7 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa
                 return binaryJsBundleUrl;
             }
 
-            var packageMetadata = await UpdateManager.GetCurrentPackageAsync();
+            var packageMetadata = await UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);
             long? binaryModifiedDateDuringPackageInstall = null;
             var binaryModifiedDateDuringPackageInstallString = (string)packageMetadata[CodePushConstants.BinaryModifiedTimeKey];
             if (binaryModifiedDateDuringPackageInstallString != null)
@@ -119,7 +119,7 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa
                 DidUpdate = false;
                 if (!MainPage.UseDeveloperSupport || !AppVersion.Equals(packageAppVersion))
                 {
-                    await ClearUpdatesAsync();
+                    await ClearUpdatesAsync().ConfigureAwait(false);
                 }
 
                 CodePushUtils.LogBundleUrl(binaryJsBundleUrl);
@@ -134,8 +134,8 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa
 
         internal async Task<long> GetBinaryResourcesModifiedTimeAsync()
         {
-            var assetJSBundleFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri(CodePushConstants.AssetsBundlePrefix + AssetsBundleFileName));
-            var fileProperties = await assetJSBundleFile.GetBasicPropertiesAsync();
+            var assetJSBundleFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri(CodePushConstants.AssetsBundlePrefix + AssetsBundleFileName)).AsTask().ConfigureAwait(false);
+            var fileProperties = await assetJSBundleFile.GetBasicPropertiesAsync().AsTask().ConfigureAwait(false);
             return fileProperties.DateModified.ToUnixTimeMilliseconds();
         }
         
@@ -170,7 +170,7 @@ internal void InitializeUpdateAfterRestart()
 
         internal async Task ClearUpdatesAsync()
         {
-            await UpdateManager.ClearUpdatesAsync();
+            await UpdateManager.ClearUpdatesAsync().ConfigureAwait(false);
             SettingsManager.RemovePendingUpdate();
             SettingsManager.RemoveFailedUpdates();
         }
@@ -181,18 +181,18 @@ internal async Task ClearUpdatesAsync()
 
         private async Task ClearReactDevBundleCacheAsync()
         {
-            var devBundleCacheFile = (StorageFile) await ApplicationData.Current.LocalFolder.TryGetItemAsync(CodePushConstants.ReactDevBundleCacheFileName);
+            var devBundleCacheFile = (StorageFile)await ApplicationData.Current.LocalFolder.TryGetItemAsync(CodePushConstants.ReactDevBundleCacheFileName).AsTask().ConfigureAwait(false);
             if (devBundleCacheFile != null)
             {
-                await devBundleCacheFile.DeleteAsync();
+                await devBundleCacheFile.DeleteAsync().AsTask().ConfigureAwait(false);
             }
         }
 
         private async Task RollbackPackageAsync()
         {
-            JObject failedPackage = await UpdateManager.GetCurrentPackageAsync();
+            JObject failedPackage = await UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);
             SettingsManager.SaveFailedUpdate(failedPackage);
-            await UpdateManager.RollbackPackageAsync();
+            await UpdateManager.RollbackPackageAsync().ConfigureAwait(false);
             SettingsManager.RemovePendingUpdate();
         }
 
diff --git a/windows/CodePushUtils.cs b/windows/CodePushUtils.cs
@@ -12,7 +12,7 @@ internal class CodePushUtils
     {
         internal async static Task<JObject> GetJObjectFromFileAsync(StorageFile file)
         {
-            string jsonString = await FileIO.ReadTextAsync(file);
+            string jsonString = await FileIO.ReadTextAsync(file).AsTask().ConfigureAwait(false);
             if (jsonString.Length == 0)
             {
                 return new JObject();
diff --git a/windows/FileUtils.cs b/windows/FileUtils.cs
@@ -8,15 +8,15 @@ internal class FileUtils
     {
         internal async static Task MergeFoldersAsync(StorageFolder source, StorageFolder target)
         {
-            foreach (StorageFile sourceFile in await source.GetFilesAsync())
+            foreach (StorageFile sourceFile in await source.GetFilesAsync().AsTask().ConfigureAwait(false))
             {
-                await sourceFile.CopyAndReplaceAsync(await target.CreateFileAsync(sourceFile.Name, CreationCollisionOption.OpenIfExists));
+                await sourceFile.CopyAndReplaceAsync(await target.CreateFileAsync(sourceFile.Name, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false)).AsTask().ConfigureAwait(false);
             }
             
-            foreach (StorageFolder sourceDirectory in await source.GetFoldersAsync())
+            foreach (StorageFolder sourceDirectory in await source.GetFoldersAsync().AsTask().ConfigureAwait(false))
             {
-                StorageFolder nextTargetSubDir = await target.CreateFolderAsync(sourceDirectory.Name, CreationCollisionOption.OpenIfExists);
-                await MergeFoldersAsync(sourceDirectory, nextTargetSubDir);
+                StorageFolder nextTargetSubDir = await target.CreateFolderAsync(sourceDirectory.Name, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false);
+                await MergeFoldersAsync(sourceDirectory, nextTargetSubDir).ConfigureAwait(false);
             }
         }
     }
diff --git a/windows/UpdateManager.cs b/windows/UpdateManager.cs
diff --git a/windows/UpdateUtils.cs b/windows/UpdateUtils.cs

Original file line number	Diff line number	Diff line change
`@@ -57,7 +57,7 @@ public async void downloadUpdate(JObject updatePackage, bool notifyProgress, IPr`
`57`	`57`	`{`
`58`	`58`	`try`
`59`	`59`	`{`
`60`		`- updatePackage[CodePushConstants.BinaryModifiedTimeKey] = "" + await _codePush.GetBinaryResourcesModifiedTimeAsync();`
	`60`	`+ updatePackage[CodePushConstants.BinaryModifiedTimeKey] = "" + await _codePush.GetBinaryResourcesModifiedTimeAsync().ConfigureAwait(false);`
`61`	`61`	`await _codePush.UpdateManager.DownloadPackageAsync(`
`62`	`62`	`updatePackage,`
`63`	`63`	`_codePush.AssetsBundleFileName,`
`@@ -80,9 +80,9 @@ await _codePush.UpdateManager.DownloadPackageAsync(`
`80`	`80`	`.emit(CodePushConstants.DownloadProgressEventName, downloadProgress);`
`81`	`81`	`}`
`82`	`82`	`)`
`83`		`- );`
	`83`	`+ ).ConfigureAwait(false);`
`84`	`84`
`85`		`- JObject newPackage = await _codePush.UpdateManager.GetPackageAsync((string)updatePackage[CodePushConstants.PackageHashKey]);`
	`85`	`+ JObject newPackage = await _codePush.UpdateManager.GetPackageAsync((string)updatePackage[CodePushConstants.PackageHashKey]).ConfigureAwait(false);`
`86`	`86`	`promise.Resolve(newPackage);`
`87`	`87`	`}`
`88`	`88`	`catch (InvalidDataException e)`
`@@ -121,7 +121,7 @@ public void getConfiguration(IPromise promise)`
`121`	`121`	`[ReactMethod]`
`122`	`122`	`public async void getUpdateMetadata(UpdateState updateState, IPromise promise)`
`123`	`123`	`{`
`124`		`- JObject currentPackage = await _codePush.UpdateManager.GetCurrentPackageAsync();`
	`124`	`+ JObject currentPackage = await _codePush.UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);`
`125`	`125`	`if (currentPackage == null)`
`126`	`126`	`{`
`127`	`127`	`promise.Resolve("");`
`@@ -146,7 +146,7 @@ public async void getUpdateMetadata(UpdateState updateState, IPromise promise)`
`146`	`146`	`{`
`147`	`147`	`// The caller wants the running update, but the current`
`148`	`148`	`// one is pending, so we need to grab the previous.`
`149`		`- promise.Resolve(await _codePush.UpdateManager.GetPreviousPackageAsync());`
	`149`	`+ promise.Resolve(await _codePush.UpdateManager.GetPreviousPackageAsync().ConfigureAwait(false));`
`150`	`150`	`}`
`151`	`151`	`else`
`152`	`152`	`{`
`@@ -179,7 +179,7 @@ public void getNewStatusReport(IPromise promise)`
`179`	`179`	`[ReactMethod]`
`180`	`180`	`public async void installUpdate(JObject updatePackage, InstallMode installMode, int minimumBackgroundDuration, IPromise promise)`
`181`	`181`	`{`
`182`		`- await _codePush.UpdateManager.InstallPackageAsync(updatePackage, SettingsManager.IsPendingUpdate(null));`
	`182`	`+ await _codePush.UpdateManager.InstallPackageAsync(updatePackage, SettingsManager.IsPendingUpdate(null)).ConfigureAwait(false);`
`183`	`183`	`var pendingHash = (string)updatePackage[CodePushConstants.PackageHashKey];`
`184`	`184`	`SettingsManager.SavePendingUpdate(pendingHash, /* isLoading */false);`
`185`	`185`	`if (installMode == InstallMode.OnNextResume)`
`@@ -191,7 +191,7 @@ public async void installUpdate(JObject updatePackage, InstallMode installMode,`
`191`	`191`	`{`
`192`	`192`	`Context.RunOnNativeModulesQueueThread(async () =>`
`193`	`193`	`{`
`194`		`- await LoadBundleAsync();`
	`194`	`+ await LoadBundleAsync().ConfigureAwait(false);`
`195`	`195`	`});`
`196`	`196`	`};`
`197`	`197`
`@@ -219,7 +219,7 @@ public async void isFirstRun(string packageHash, IPromise promise)`
`219`	`219`	`bool isFirstRun = _codePush.DidUpdate`
`220`	`220`	`&& packageHash != null`
`221`	`221`	`&& packageHash.Length > 0`
`222`		`- && packageHash.Equals(await _codePush.UpdateManager.GetCurrentPackageHashAsync());`
	`222`	`+ && packageHash.Equals(await _codePush.UpdateManager.GetCurrentPackageHashAsync().ConfigureAwait(false));`
`223`	`223`	`promise.Resolve(isFirstRun);`
`224`	`224`	`}`
`225`	`225`
`@@ -237,7 +237,7 @@ public async void restartApp(bool onlyIfUpdateIsPending)`
`237`	`237`	`// is current pending update, then reload the app.`
`238`	`238`	`if (!onlyIfUpdateIsPending \|\| SettingsManager.IsPendingUpdate(null))`
`239`	`239`	`{`
`240`		`- await LoadBundleAsync();`
	`240`	`+ await LoadBundleAsync().ConfigureAwait(false);`
`241`	`241`	`}`
`242`	`242`	`}`
`243`	`243`
`@@ -254,7 +254,7 @@ internal async Task LoadBundleAsync()`
`254`	`254`
`255`	`255`	`// #2) Update the locally stored JS bundle file path`
`256`	`256`	`Type reactInstanceManagerType = typeof(ReactInstanceManager);`
`257`		`- string latestJSBundleFile = await _codePush.GetJavaScriptBundleFileAsync(_codePush.AssetsBundleFileName);`
	`257`	`+ string latestJSBundleFile = await _codePush.GetJavaScriptBundleFileAsync(_codePush.AssetsBundleFileName).ConfigureAwait(false);`
`258`	`258`	`reactInstanceManagerType`
`259`	`259`	`.GetField("_jsBundleFile", BindingFlags.NonPublic \| BindingFlags.Instance)`
`260`	`260`	`.SetValue(reactInstanceManager, latestJSBundleFile);`
Original file line number	Diff line number	Diff line change
`@@ -85,8 +85,8 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa`
`85`	`85`	`{`
`86`	`86`	`AssetsBundleFileName = assetsBundleFileName;`
`87`	`87`	`string binaryJsBundleUrl = CodePushConstants.AssetsBundlePrefix + assetsBundleFileName;`
`88`		`- var binaryResourcesModifiedTime = await GetBinaryResourcesModifiedTimeAsync();`
`89`		`- var packageFile = await UpdateManager.GetCurrentPackageBundleAsync(AssetsBundleFileName);`
	`88`	`+ var binaryResourcesModifiedTime = await GetBinaryResourcesModifiedTimeAsync().ConfigureAwait(false);`
	`89`	`+ var packageFile = await UpdateManager.GetCurrentPackageBundleAsync(AssetsBundleFileName).ConfigureAwait(false);`
`90`	`90`	`if (packageFile == null)`
`91`	`91`	`{`
`92`	`92`	`// There has not been any downloaded updates.`
`@@ -95,7 +95,7 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa`
`95`	`95`	`return binaryJsBundleUrl;`
`96`	`96`	`}`
`97`	`97`
`98`		`- var packageMetadata = await UpdateManager.GetCurrentPackageAsync();`
	`98`	`+ var packageMetadata = await UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);`
`99`	`99`	`long? binaryModifiedDateDuringPackageInstall = null;`
`100`	`100`	`var binaryModifiedDateDuringPackageInstallString = (string)packageMetadata[CodePushConstants.BinaryModifiedTimeKey];`
`101`	`101`	`if (binaryModifiedDateDuringPackageInstallString != null)`
`@@ -119,7 +119,7 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa`
`119`	`119`	`DidUpdate = false;`
`120`	`120`	`if (!MainPage.UseDeveloperSupport \|\| !AppVersion.Equals(packageAppVersion))`
`121`	`121`	`{`
`122`		`- await ClearUpdatesAsync();`
	`122`	`+ await ClearUpdatesAsync().ConfigureAwait(false);`
`123`	`123`	`}`
`124`	`124`
`125`	`125`	`CodePushUtils.LogBundleUrl(binaryJsBundleUrl);`
`@@ -134,8 +134,8 @@ public async Task<string> GetJavaScriptBundleFileAsync(string assetsBundleFileNa`
`134`	`134`
`135`	`135`	`internal async Task<long> GetBinaryResourcesModifiedTimeAsync()`
`136`	`136`	`{`
`137`		`- var assetJSBundleFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri(CodePushConstants.AssetsBundlePrefix + AssetsBundleFileName));`
`138`		`- var fileProperties = await assetJSBundleFile.GetBasicPropertiesAsync();`
	`137`	`+ var assetJSBundleFile = await StorageFile.GetFileFromApplicationUriAsync(new Uri(CodePushConstants.AssetsBundlePrefix + AssetsBundleFileName)).AsTask().ConfigureAwait(false);`
	`138`	`+ var fileProperties = await assetJSBundleFile.GetBasicPropertiesAsync().AsTask().ConfigureAwait(false);`
`139`	`139`	`return fileProperties.DateModified.ToUnixTimeMilliseconds();`
`140`	`140`	`}`
`141`	`141`
`@@ -170,7 +170,7 @@ internal void InitializeUpdateAfterRestart()`
`170`	`170`
`171`	`171`	`internal async Task ClearUpdatesAsync()`
`172`	`172`	`{`
`173`		`- await UpdateManager.ClearUpdatesAsync();`
	`173`	`+ await UpdateManager.ClearUpdatesAsync().ConfigureAwait(false);`
`174`	`174`	`SettingsManager.RemovePendingUpdate();`
`175`	`175`	`SettingsManager.RemoveFailedUpdates();`
`176`	`176`	`}`
`@@ -181,18 +181,18 @@ internal async Task ClearUpdatesAsync()`
`181`	`181`
`182`	`182`	`private async Task ClearReactDevBundleCacheAsync()`
`183`	`183`	`{`
`184`		`- var devBundleCacheFile = (StorageFile) await ApplicationData.Current.LocalFolder.TryGetItemAsync(CodePushConstants.ReactDevBundleCacheFileName);`
	`184`	`+ var devBundleCacheFile = (StorageFile)await ApplicationData.Current.LocalFolder.TryGetItemAsync(CodePushConstants.ReactDevBundleCacheFileName).AsTask().ConfigureAwait(false);`
`185`	`185`	`if (devBundleCacheFile != null)`
`186`	`186`	`{`
`187`		`- await devBundleCacheFile.DeleteAsync();`
	`187`	`+ await devBundleCacheFile.DeleteAsync().AsTask().ConfigureAwait(false);`
`188`	`188`	`}`
`189`	`189`	`}`
`190`	`190`
`191`	`191`	`private async Task RollbackPackageAsync()`
`192`	`192`	`{`
`193`		`- JObject failedPackage = await UpdateManager.GetCurrentPackageAsync();`
	`193`	`+ JObject failedPackage = await UpdateManager.GetCurrentPackageAsync().ConfigureAwait(false);`
`194`	`194`	`SettingsManager.SaveFailedUpdate(failedPackage);`
`195`		`- await UpdateManager.RollbackPackageAsync();`
	`195`	`+ await UpdateManager.RollbackPackageAsync().ConfigureAwait(false);`
`196`	`196`	`SettingsManager.RemovePendingUpdate();`
`197`	`197`	`}`
`198`	`198`
Original file line number	Diff line number	Diff line change
`@@ -12,7 +12,7 @@ internal class CodePushUtils`
`12`	`12`	`{`
`13`	`13`	`internal async static Task<JObject> GetJObjectFromFileAsync(StorageFile file)`
`14`	`14`	`{`
`15`		`- string jsonString = await FileIO.ReadTextAsync(file);`
	`15`	`+ string jsonString = await FileIO.ReadTextAsync(file).AsTask().ConfigureAwait(false);`
`16`	`16`	`if (jsonString.Length == 0)`
`17`	`17`	`{`
`18`	`18`	`return new JObject();`
Original file line number	Diff line number	Diff line change
`@@ -8,15 +8,15 @@ internal class FileUtils`
`8`	`8`	`{`
`9`	`9`	`internal async static Task MergeFoldersAsync(StorageFolder source, StorageFolder target)`
`10`	`10`	`{`
`11`		`- foreach (StorageFile sourceFile in await source.GetFilesAsync())`
	`11`	`+ foreach (StorageFile sourceFile in await source.GetFilesAsync().AsTask().ConfigureAwait(false))`
`12`	`12`	`{`
`13`		`- await sourceFile.CopyAndReplaceAsync(await target.CreateFileAsync(sourceFile.Name, CreationCollisionOption.OpenIfExists));`
	`13`	`+ await sourceFile.CopyAndReplaceAsync(await target.CreateFileAsync(sourceFile.Name, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false)).AsTask().ConfigureAwait(false);`
`14`	`14`	`}`
`15`	`15`
`16`		`- foreach (StorageFolder sourceDirectory in await source.GetFoldersAsync())`
	`16`	`+ foreach (StorageFolder sourceDirectory in await source.GetFoldersAsync().AsTask().ConfigureAwait(false))`
`17`	`17`	`{`
`18`		`- StorageFolder nextTargetSubDir = await target.CreateFolderAsync(sourceDirectory.Name, CreationCollisionOption.OpenIfExists);`
`19`		`- await MergeFoldersAsync(sourceDirectory, nextTargetSubDir);`
	`18`	`+ StorageFolder nextTargetSubDir = await target.CreateFolderAsync(sourceDirectory.Name, CreationCollisionOption.OpenIfExists).AsTask().ConfigureAwait(false);`
	`19`	`+ await MergeFoldersAsync(sourceDirectory, nextTargetSubDir).ConfigureAwait(false);`
`20`	`20`	`}`
`21`	`21`	`}`
`22`	`22`	`}`